AutoSync Seller Financial OS -- Apps Script source bundle
https://guides.desklark.com/autosync/

This is the exact, unmodified contents of the 5 files under
ventures/niche-financial-spreadsheets/build/apps-script/etsy-csv-import/AppsScript/
concatenated for a one-file download. Full install steps (with the same
code shown inline, if you'd rather copy from a web page instead of this
file) are at https://guides.desklark.com/autosync/install/

How to use this file: open it in any plain-text editor, then for each
of the 5 sections below, copy everything between the ===== markers
(not the marker lines themselves) into a same-named file in your
Google Sheet's Extensions > Apps Script editor. Exact steps at the URL
above.

==============================================================================
FILE: Errors.gs
==============================================================================
// errors.js -- shared error types for the Etsy CSV importer.
// Pure JS, zero dependencies. Safe to paste verbatim into an Apps Script
// project (Apps Script's V8 runtime supports `class extends Error`).
//
// Design principle (see README.md "Fail-loud semantics"): every error thrown
// by src/parser.js or src/aggregate.js is one of these two types, always
// carries a human-readable `message` that names the row/column/value at
// fault, and is never swallowed -- the Apps Script wrapper's job is only to
// surface `.message` (and `.rowErrors` when present) to the seller via
// SpreadsheetApp.getUi().alert(), never to catch-and-continue.

/**
 * Thrown when the CSV's HEADER doesn't satisfy the contract: a required
 * logical field has no matching column present anywhere in the header row.
 * This must never be thrown for a merely reordered or additional column --
 * only for a genuinely missing required field.
 */
class CsvContractError extends Error {
  constructor(message, details) {
    super(message);
    this.name = 'CsvContractError';
    this.details = details || {};
  }
}

/**
 * Thrown when one or more DATA ROWS fail to parse/coerce cleanly (bad
 * currency, ambiguous date, unrecognized status, wrong column count, etc).
 * `rowErrors` is an array of { row, field, rawValue, message } so the caller
 * can show every problem at once instead of stopping at the first row.
 */
class CsvParseError extends Error {
  constructor(message, rowErrors) {
    super(message);
    this.name = 'CsvParseError';
    this.rowErrors = rowErrors || [];
  }
}

/**
 * Thrown by applyMapping.js's buildApplyPlan()/parseStagingRows() when
 * applying an already-staged import to the Master Dashboard / Monthly
 * Bookkeeping Ledger tabs must be refused -- e.g. the staging sheet has no
 * readable TOTAL row, or the staged data spans more than one calendar year
 * (see applyMapping.js for why that specific case is refused rather than
 * guessed). Same fail-loud contract as the two error types above: always a
 * human-readable `message`, never caught-and-continued by the caller except
 * to display it and abort with nothing written.
 */
class ApplyMappingError extends Error {
  constructor(message) {
    super(message);
    this.name = 'ApplyMappingError';
  }
}

/**
 * _CsvContractError(...)/_CsvParseError(...) -- the single source for
 * constructing CsvContractError/CsvParseError instances. Defined ONCE here,
 * not duplicated in Parser.gs and Aggregate.gs (both used to declare their
 * own byte-identical copies of `function _CsvContractError(...)`, and
 * Parser.gs also declared `function _CsvParseError(...)`).
 *
 * Why that duplication was a real (if latent) risk: Apps Script merges every
 * .gs file in a project into ONE shared global scope. Two files each
 * declaring `function _CsvContractError(...)` at top level is legal JS --
 * function/function redeclaration of the same name in the same scope does
 * not throw, unlike the var/class collision described below -- but it means
 * whichever file Apps Script happens to concatenate LAST silently wins, and
 * Apps Script does not guarantee file load order by filename. That was
 * harmless only because both copies had byte-identical bodies; editing just
 * one of them would have made behavior depend on undocumented load order.
 * Parser.gs and Aggregate.gs now call `_CsvContractError(...)` /
 * `_CsvParseError(...)` directly and resolve them via the normal JS scope
 * chain to THESE declarations, instead of declaring their own.
 *
 * Because these factories live in the SAME file as the `class
 * CsvContractError`/`class CsvParseError` declarations, they can reference
 * those class names directly -- no `require('./errors.js')` indirection is
 * needed here (that indirection exists in Parser.gs/Aggregate.gs precisely
 * because, under Node, each file is its own module with no shared scope; see
 * those files' header comments).
 */
function _CsvContractError(message, details) {
  return new CsvContractError(message, details);
}
function _CsvParseError(message, rowErrors) {
  return new CsvParseError(message, rowErrors);
}

if (typeof module !== 'undefined' && module.exports) {
  module.exports = {
    CsvContractError,
    CsvParseError,
    ApplyMappingError,
    _CsvContractError,
    _CsvParseError,
  };
}

==============================================================================
FILE: Parser.gs
==============================================================================
// parser.js -- pure, Google-free CSV parsing for Etsy's "Orders" CSV export.
//
// Zero dependencies, zero Google/SpreadsheetApp calls. Every function here
// takes plain strings/arrays in and returns plain objects/throws -- that is
// what lets tests/run-tests.mjs exercise it under plain node with fixture
// files, and it is what AppsScript/Parser.gs is (a verbatim copy of this
// file, ready to paste into an Apps Script project's global scope).
//
// See CSV-CONTRACT.md for the header contract this file implements and,
// importantly, for which parts of that contract are VERIFIED vs UNVERIFIED
// against Etsy's own documentation. Where the contract is unverified, this
// file is deliberately conservative: it fails loudly on anything it cannot
// confidently interpret rather than guessing.
//
// Error factories: `_CsvContractError(...)`/`_CsvParseError(...)` are the
// single source of truth, declared ONCE in errors.js (mirrored verbatim into
// AppsScript/Errors.gs) -- see that file for the full rationale. This file
// used to declare its own byte-identical copies of both factories (as did
// aggregate.js for `_CsvContractError`), which was harmless ONLY because the
// bodies were identical; the moment Apps Script's shared global scope
// concatenated two files each declaring the same function name, behavior
// depended on undocumented load order. This file now simply CALLS
// `_CsvContractError(...)`/`_CsvParseError(...)` below and resolves them via
// the normal JS scope chain to errors.js's declarations.
//
// Under Apps Script that resolution is automatic (Errors.gs is another file
// in the same merged project). Under Node, where each file is its own
// module with no shared scope, the `if` block below re-exports the same two
// functions from './errors.js'. This is a `var` declaration -- but note it
// sits inside a branch (`typeof module !== 'undefined'`) that NEVER executes
// under Apps Script (Apps Script has no `module` global), so per the
// hoisting rule that matters here: `var` declarations are hoisted at PARSE
// time regardless of which branch executes, but a hoisted-but-never-ASSIGNED
// `var` sharing a name with a `function` declaration in the same scope is
// legal JS (unlike `var` colliding with a `class`, which throws a
// SyntaxError at parse time -- see tests/verify-appsscript-loads.mjs, which
// exists specifically to catch that class of mutation). Errors.gs's
// `function _CsvContractError`/`function _CsvParseError` declarations are
// therefore never overwritten by this file's hoisted-but-unassigned `var`s.
if (typeof module !== 'undefined' && module.exports) {
  var _errors = require('./errors.js');
  var _CsvContractError = _errors._CsvContractError;
  var _CsvParseError = _errors._CsvParseError;
}

// ---------------------------------------------------------------------------
// 1. Header contract
// ---------------------------------------------------------------------------

// Logical field -> the exact column header string(s) that count as that
// field. Matching is case-insensitive and trims whitespace, and is tolerant
// of the column appearing in ANY position (order-independent) and of columns
// this map doesn't know about being present anywhere (added/renamed-elsewhere
// columns are simply ignored, never an error).
//
// NOTE ON PROVENANCE: this alias list is built from CSV-CONTRACT.md, which
// is UNVERIFIED against Etsy's own official docs (help.etsy.com returned
// HTTP 403 to automated fetch every time it was tried). It is the best
// available synthesis of third-party sources. Treat every string below as
// "our best guess of Etsy's real header," not a confirmed fact.
const FIELD_ALIASES = {
  orderId: ['Order ID'],
  saleDate: ['Sale Date', 'Order Date'],
  currency: ['Currency'],
  orderTotal: ['Order Total'],
  status: ['Status'],
  // Optional / not required for a successful parse, but recognized and
  // coerced when present.
  orderValue: ['Order Value'],
  fees: ['Card Processing Fees'],
  orderNet: ['Order Net'],
  shipping: ['Shipping'],
  salesTax: ['Sales Tax'],
  couponCode: ['Coupon Code'],
  discountAmount: ['Discount Amount'],
  buyer: ['Buyer', 'Full Name'],
  sku: ['SKU'],
  numberOfItems: ['Number of Items'],
};

// A parse is refused outright if any of these logical fields has zero
// matching columns in the header row. This is intentionally a SMALL set --
// every additional required field is one more way a real (slightly
// different) Etsy export gets rejected instead of imported. See
// CSV-CONTRACT.md "Required vs optional" for the reasoning.
const REQUIRED_FIELDS = ['orderId', 'saleDate', 'currency', 'orderTotal', 'status'];

function normalizeHeaderCell(cell) {
  return String(cell == null ? '' : cell).trim().toLowerCase();
}

/**
 * detectHeader(headerRow: string[]) -> { columnMap, unknownColumns }
 * columnMap: { logicalField: columnIndex }
 * Throws CsvContractError if a required field's aliases are all absent.
 * Order-independent, case/whitespace-insensitive. Never errors on unknown
 * (extra) columns -- they're reported in `unknownColumns` for visibility
 * only.
 */
function detectHeader(headerRow) {
  if (!Array.isArray(headerRow) || headerRow.length === 0) {
    throw _CsvContractError(
      'The CSV has no header row at all (file is empty or blank). Cannot import.'
    );
  }
  const normalized = headerRow.map(normalizeHeaderCell);
  const columnMap = {};
  const claimedIndexes = new Set();

  for (const [field, aliases] of Object.entries(FIELD_ALIASES)) {
    for (const alias of aliases) {
      const idx = normalized.indexOf(alias.toLowerCase());
      if (idx !== -1) {
        columnMap[field] = idx;
        claimedIndexes.add(idx);
        break;
      }
    }
  }

  const missingRequired = REQUIRED_FIELDS.filter((f) => !(f in columnMap));
  if (missingRequired.length > 0) {
    const missingDetail = missingRequired
      .map((f) => `"${f}" (looked for column named: ${FIELD_ALIASES[f].map((a) => `"${a}"`).join(' or ')})`)
      .join('; ');
    throw _CsvContractError(
      `This CSV is missing ${missingRequired.length} required column(s): ${missingDetail}. ` +
        `Found header columns: [${headerRow.map((c) => `"${String(c).trim()}"`).join(', ')}]. ` +
        `Refusing to import -- a partial or wrong-file import must never silently produce numbers.`,
      { missingRequired, headerRow }
    );
  }

  const unknownColumns = headerRow
    .map((c, i) => ({ c, i }))
    .filter(({ i }) => !claimedIndexes.has(i))
    .map(({ c, i }) => ({ name: String(c).trim(), index: i }));

  return { columnMap, unknownColumns };
}

// ---------------------------------------------------------------------------
// 2. RFC-4180-ish CSV tokenizer (handles quoted fields with embedded commas,
//    embedded newlines, and doubled "" escaped quotes). Etsy's real export
//    quoting style is unconfirmed, so this implements the CSV standard
//    rather than a naive String.split(',').
// ---------------------------------------------------------------------------

/**
 * parseCsvText(text: string) -> string[][]
 * Returns an array of rows, each row an array of raw (untrimmed-of-nothing,
 * but unquoted) string cells. Does not interpret types -- purely tokenizes.
 */
function parseCsvText(text) {
  const rows = [];
  let row = [];
  let field = '';
  let inQuotes = false;
  // Normalize CRLF/CR to LF up front with a blind global replace, so the state
  // machine below only ever deals with \n. KNOWN CONSEQUENCE: a CRLF embedded
  // INSIDE a quoted field is also normalized, so such a field comes back with a
  // bare \n rather than the verbatim \r\n it had on disk. That is accepted --
  // Etsy's export does not put CRLFs inside quoted cells, and every downstream
  // consumer here treats the cell as text. Do not "fix" this by reverting to a
  // char-by-char normalizer without a fixture proving a real CRLF-in-quotes
  // case; the blind replace is what the code actually does and this comment now
  // says so (the previous comment claimed char-by-char handling that was never
  // implemented).
  const s = text.replace(/\r\n/g, '\n').replace(/\r/g, '\n');

  for (let i = 0; i < s.length; i++) {
    const ch = s[i];
    if (inQuotes) {
      if (ch === '"') {
        if (s[i + 1] === '"') {
          field += '"';
          i++;
        } else {
          inQuotes = false;
        }
      } else {
        field += ch;
      }
    } else if (ch === '"' && field.trim().length === 0) {
      // A quote opens quote-mode only when everything accumulated in
      // `field` so far is pure whitespace (usually nothing at all, but
      // sometimes a single leading space) -- NOT merely field.length === 0.
      // Real-world CSV writers commonly pad a quoted field with a space
      // after the delimiter, e.g. `foo, "bar, baz",qux`; strict RFC 4180
      // (a quoted field's opening " must be the FIRST character of the
      // field) would treat that leading space as literal data, which
      // breaks the quoting and silently mis-splits the embedded comma into
      // an extra field -- a field-count corruption, not a cosmetic
      // rendering issue. Trimming before the check absorbs that padding
      // while still refusing to open quote-mode on a quote that follows
      // REAL (non-whitespace) content already in the field (e.g. a bare
      // inches mark in `12" TAPER`, or a nickname quote in `Chris "Bud"
      // Lee`) -- those are literal data, not a quoting directive, and fall
      // through to the plain-char branch below, which appends them to
      // `field` unchanged. See fixtures/leading-whitespace-quoted.csv for
      // the regression case this guards against.
      inQuotes = true;
    } else if (ch === ',') {
      row.push(field);
      field = '';
    } else if (ch === '\n') {
      row.push(field);
      rows.push(row);
      row = [];
      field = '';
    } else {
      field += ch;
    }
  }
  // Unterminated-quote guard. Reaching EOF while still inQuotes means a quote
  // opened a field that never closed -- everything after it was swallowed into
  // one giant cell. Without this check that failure is SILENT: the swallowed
  // rows simply vanish, `errors` stays 0, and the caller reconciles against a
  // truncated file. The trigger is real, not theoretical: `a,   ",b` (a
  // whitespace-only field followed by a bare quote) opens quote-mode under the
  // `field.trim().length === 0` rule above and never closes.
  //
  // Why the guard is here and not in the opening condition: tightening that
  // condition to `field.length === 0 || field === ' '` was measured to break
  // two-space and tab padding (`a,  "x,y",b` tokenizes to 4 fields instead of
  // 3), reintroducing the column-shift corruption the trim() rule exists to
  // prevent. Neither opening rule dominates, so we keep the permissive one and
  // convert its failure mode from silent truncation into a loud refusal.
  //
  // RESIDUAL (known, not fixed): a stray quote later in the file can still
  // "close" a runaway field, in which case EOF is reached with inQuotes false
  // and this throw does not fire. The guard narrows the class; it does not
  // eliminate it.
  if (inQuotes) {
    throw _CsvParseError(
      'Unterminated quoted field: reached end of file while inside a quoted ' +
        'value (row ' +
        (rows.length + 1) +
        '). The file is likely truncated or contains a stray double-quote ' +
        'character. Re-download the CSV export and try again.',
      [
        {
          row: rows.length + 1,
          field: 'n/a',
          message: 'unterminated quoted field at end of file',
        },
      ]
    );
  }
  // Flush trailing field/row (handles files with no trailing newline).
  if (field.length > 0 || row.length > 0) {
    row.push(field);
    rows.push(row);
  }
  // Drop fully-blank trailing rows produced by a trailing newline.
  while (rows.length > 0 && rows[rows.length - 1].every((c) => c === '')) {
    rows.pop();
  }
  return rows;
}

// ---------------------------------------------------------------------------
// 3. Type coercion primitives
// ---------------------------------------------------------------------------

// Matches "45", "45.00", "1,234.56", "-45.00", "$45.00", "$1,234.56" style
// US/thousands-comma-decimal-dot amounts, optionally wrapped in parens for
// negative ("(12.34)"), optionally prefixed/suffixed with a currency symbol
// or code. Deliberately does NOT attempt to support the EU "1.234,56"
// (dot-thousands, comma-decimal) convention -- we cannot safely
// disambiguate "1.234,56" from a malformed US number without a confirmed
// locale signal, so such values are rejected rather than guessed.
const CURRENCY_SYMBOLS = /[$€£¥]/g;
const CURRENCY_CODE_PREFIX = /^[A-Z]{3}\s?/;
const AMOUNT_RE = /^-?\d{1,3}(,\d{3})*(\.\d{1,2})?$|^-?\d+(\.\d{1,2})?$/;

/**
 * parseCurrency(raw: string, ctx: {row, field}) -> number (in the export's
 * stated currency unit, e.g. dollars not cents)
 * Throws CsvParseError with row/field context on anything it can't
 * confidently parse -- never returns 0/NaN for bad input.
 */
function parseCurrency(raw, ctx) {
  const original = raw;
  let s = String(raw == null ? '' : raw).trim();
  if (s === '') {
    throw fieldError(ctx, 'empty amount value', original);
  }
  let negative = false;
  if (/^\(.*\)$/.test(s)) {
    negative = true;
    s = s.slice(1, -1).trim();
  }
  if (s.startsWith('-')) {
    negative = true;
    s = s.slice(1).trim();
  }
  s = s.replace(CURRENCY_SYMBOLS, '').trim();
  s = s.replace(CURRENCY_CODE_PREFIX, '').trim();
  s = s.replace(/\s/g, '');

  if (!AMOUNT_RE.test(s)) {
    throw fieldError(
      ctx,
      `amount "${original}" is not a recognized currency format (expected e.g. "45.00", "$1,234.56", "(12.00)")`,
      original
    );
  }
  const numeric = parseFloat(s.replace(/,/g, ''));
  if (!isFinite(numeric)) {
    throw fieldError(ctx, `amount "${original}" did not parse to a finite number`, original);
  }
  return negative ? -numeric : numeric;
}

const MONTH_NAMES = {
  jan: 1, january: 1, feb: 2, february: 2, mar: 3, march: 3, apr: 4, april: 4,
  may: 5, jun: 6, june: 6, jul: 7, july: 7, aug: 8, august: 8, sep: 9, sept: 9,
  september: 9, oct: 10, october: 10, nov: 11, november: 11, dec: 12, december: 12,
};

/**
 * parseDate(raw: string, ctx) -> { iso: 'YYYY-MM-DD', year, month, monthKey: 'YYYY-MM' }
 *
 * Accepts ONLY unambiguous formats:
 *   - ISO 8601 date, optionally with a time/offset: "2026-08-01", "2026-08-01T10:00:00Z"
 *   - "Mon D, YYYY" / "Month D, YYYY": "Aug 1, 2026", "August 1, 2026"
 *
 * Deliberately REJECTS slash-separated numeric dates ("08/01/2026") outright
 * -- whether Etsy's export uses US (MM/DD/YYYY) or localized (DD/MM/YYYY)
 * ordering for international sellers is UNCONFIRMED (see CSV-CONTRACT.md),
 * so any such value is ambiguous by construction and this function refuses
 * to guess which digit is the month.
 */
function parseDate(raw, ctx) {
  const original = raw;
  const s = String(raw == null ? '' : raw).trim();
  if (s === '') {
    throw fieldError(ctx, 'empty date value', original);
  }

  if (/^\d{1,2}\/\d{1,2}\/\d{2,4}$/.test(s)) {
    throw fieldError(
      ctx,
      `date "${original}" uses ambiguous slash-separated format (could be MM/DD/YYYY or DD/MM/YYYY -- ` +
        `Etsy's exact convention for this export is unconfirmed). Refusing to guess; re-export with an ` +
        `unambiguous date format or resolve this in code with a confirmed convention before importing.`,
      original
    );
  }

  const isoMatch = /^(\d{4})-(\d{2})-(\d{2})(?:[T\s].*)?$/.exec(s);
  if (isoMatch) {
    const year = parseInt(isoMatch[1], 10);
    const month = parseInt(isoMatch[2], 10);
    const day = parseInt(isoMatch[3], 10);
    if (month < 1 || month > 12 || day < 1 || day > 31) {
      throw fieldError(ctx, `date "${original}" has an out-of-range month/day`, original);
    }
    return isoResult(year, month, day);
  }

  const monthNameMatch = /^([A-Za-z]+)\.?\s+(\d{1,2}),?\s+(\d{4})$/.exec(s);
  if (monthNameMatch) {
    const monthName = monthNameMatch[1].toLowerCase();
    const month = MONTH_NAMES[monthName];
    if (!month) {
      throw fieldError(ctx, `date "${original}" has an unrecognized month name "${monthNameMatch[1]}"`, original);
    }
    const day = parseInt(monthNameMatch[2], 10);
    const year = parseInt(monthNameMatch[3], 10);
    if (day < 1 || day > 31) {
      throw fieldError(ctx, `date "${original}" has an out-of-range day`, original);
    }
    return isoResult(year, month, day);
  }

  throw fieldError(
    ctx,
    `date "${original}" is not in a recognized unambiguous format (expected "YYYY-MM-DD" or "Mon D, YYYY")`,
    original
  );
}

function isoResult(year, month, day) {
  const mm = String(month).padStart(2, '0');
  const dd = String(day).padStart(2, '0');
  return { iso: `${year}-${mm}-${dd}`, year, month, monthKey: `${year}-${mm}` };
}

// UNVERIFIED vocabulary (see CSV-CONTRACT.md "Status field") -- these are
// our best guess at Etsy's real Status column values, not a confirmed list.
// Anything outside these three buckets is refused rather than guessed.
const REVENUE_STATUSES = new Set(['completed', 'paid', 'shipped']);
const EXCLUDED_STATUSES = new Set(['canceled', 'cancelled']);
const REFUND_STATUSES = new Set(['refunded', 'partially refunded']);

/**
 * classifyStatus(raw, ctx) -> 'revenue' | 'excluded' | 'refund'
 * Throws on any status string not in the known (unverified) vocabulary.
 */
function classifyStatus(raw, ctx) {
  const s = String(raw == null ? '' : raw).trim().toLowerCase();
  if (REVENUE_STATUSES.has(s)) return 'revenue';
  if (EXCLUDED_STATUSES.has(s)) return 'excluded';
  if (REFUND_STATUSES.has(s)) return 'refund';
  throw fieldError(
    ctx,
    `unrecognized order Status "${raw}" -- this importer only knows how to classify ` +
      `[${[...REVENUE_STATUSES, ...EXCLUDED_STATUSES, ...REFUND_STATUSES].join(', ')}] ` +
      `(an UNVERIFIED guessed vocabulary, see CSV-CONTRACT.md). Refusing to guess whether this status ` +
      `counts as revenue -- extend the vocabulary in src/parser.js once you've confirmed the real value ` +
      `against an actual Etsy export.`,
    raw
  );
}

function fieldError(ctx, message, rawValue) {
  return _CsvParseError(`Row ${ctx.row}, column "${ctx.field}": ${message}`, [
    { row: ctx.row, field: ctx.field, rawValue, message },
  ]);
}

// ---------------------------------------------------------------------------
// 4. Row coercion + full-file parse
// ---------------------------------------------------------------------------

/**
 * coerceRow(rawRow, columnMap, rowNumber) -> normalized record
 * rowNumber is 1-based and counts data rows only (header is row 0), matching
 * what a seller would count if opening the CSV in a spreadsheet minus the
 * header -- i.e. rowNumber 1 is the first DATA row.
 * Throws CsvParseError (with a single rowErrors entry) on the first
 * uncoercible required field in this row; parseOrdersCsv() below collects
 * these across all rows before deciding whether to abort.
 */
function coerceRow(rawRow, columnMap, rowNumber) {
  const get = (field) => (columnMap[field] != null ? rawRow[columnMap[field]] : undefined);

  const orderId = String(get('orderId') || '').trim();
  if (!orderId) {
    throw fieldError({ row: rowNumber, field: 'Order ID' }, 'empty Order ID', get('orderId'));
  }

  const date = parseDate(get('saleDate'), { row: rowNumber, field: 'Sale Date' });
  const currency = String(get('currency') || '').trim().toUpperCase();
  if (!currency) {
    throw fieldError({ row: rowNumber, field: 'Currency' }, 'empty Currency', get('currency'));
  }
  const orderTotal = parseCurrency(get('orderTotal'), { row: rowNumber, field: 'Order Total' });
  const statusClass = classifyStatus(get('status'), { row: rowNumber, field: 'Status' });

  const record = {
    row: rowNumber,
    orderId,
    date,
    currency,
    orderTotal,
    statusRaw: String(get('status') || '').trim(),
    statusClass,
  };

  // Optional fields: coerce only if the column exists AND the cell is
  // non-empty; a missing optional column, or a blank cell in a present
  // optional column, is not an error.
  if (columnMap.fees != null && String(get('fees') || '').trim() !== '') {
    record.fees = parseCurrency(get('fees'), { row: rowNumber, field: 'Card Processing Fees' });
  }
  if (columnMap.shipping != null && String(get('shipping') || '').trim() !== '') {
    record.shipping = parseCurrency(get('shipping'), { row: rowNumber, field: 'Shipping' });
  }
  if (columnMap.salesTax != null && String(get('salesTax') || '').trim() !== '') {
    record.salesTax = parseCurrency(get('salesTax'), { row: rowNumber, field: 'Sales Tax' });
  }
  if (columnMap.orderNet != null && String(get('orderNet') || '').trim() !== '') {
    record.orderNet = parseCurrency(get('orderNet'), { row: rowNumber, field: 'Order Net' });
  }
  if (columnMap.sku != null) {
    const sku = String(get('sku') || '').trim();
    if (sku) record.sku = sku;
  }
  if (columnMap.buyer != null) {
    const buyer = String(get('buyer') || '').trim();
    if (buyer) record.buyer = buyer;
  }
  if (columnMap.couponCode != null) {
    const coupon = String(get('couponCode') || '').trim();
    if (coupon) record.couponCode = coupon;
  }

  return record;
}

/**
 * parseOrdersCsv(csvText: string) -> { records, unknownColumns, columnMap }
 *
 * Full pipeline: tokenize -> detect header -> coerce every data row.
 * - Throws CsvContractError immediately if the header is missing a required
 *   field (never even looks at data rows).
 * - Otherwise coerces EVERY row and collects ALL row-level failures, then
 *   throws ONE CsvParseError listing every failing row (not just the
 *   first) if there were any -- so a seller sees the whole problem at once.
 * - An all-header, zero-data-row file is valid and returns records: [].
 */
function parseOrdersCsv(csvText) {
  const rows = parseCsvText(csvText);
  if (rows.length === 0) {
    throw _CsvContractError('The CSV file is completely empty (no header row found).');
  }
  const [headerRow, ...dataRows] = rows;
  const { columnMap, unknownColumns } = detectHeader(headerRow);

  const records = [];
  const rowErrors = [];
  dataRows.forEach((raw, i) => {
    const rowNumber = i + 1;
    // Skip fully-blank rows (common trailing-blank-line artifact) without
    // treating them as a parse failure.
    if (raw.every((c) => String(c).trim() === '')) return;
    try {
      records.push(coerceRow(raw, columnMap, rowNumber));
    } catch (err) {
      if (err && err.name === 'CsvParseError' && err.rowErrors) {
        rowErrors.push(...err.rowErrors);
      } else {
        rowErrors.push({ row: rowNumber, field: '(unknown)', rawValue: raw, message: String(err && err.message) });
      }
    }
  });

  if (rowErrors.length > 0) {
    const summary = rowErrors
      .slice(0, 20)
      .map((e) => `  - Row ${e.row}, ${e.field}: ${e.message}`)
      .join('\n');
    const more = rowErrors.length > 20 ? `\n  ...and ${rowErrors.length - 20} more.` : '';
    throw _CsvParseError(
      `Import refused: ${rowErrors.length} of ${dataRows.length} data row(s) failed to parse. ` +
        `NO data was written anywhere. Fix the file (or the parser's understanding of it) and re-import.\n${summary}${more}`,
      rowErrors
    );
  }

  return { records, unknownColumns, columnMap };
}

// ---------------------------------------------------------------------------
// module exports (Node only; Apps Script has no `module` so this is skipped
// and every function above is simply available in the project's global
// scope for Code.gs to call).
// ---------------------------------------------------------------------------
if (typeof module !== 'undefined' && module.exports) {
  module.exports = {
    FIELD_ALIASES,
    REQUIRED_FIELDS,
    detectHeader,
    parseCsvText,
    parseCurrency,
    parseDate,
    classifyStatus,
    coerceRow,
    parseOrdersCsv,
  };
}

==============================================================================
FILE: Aggregate.gs
==============================================================================
// aggregate.js -- pure aggregation of parsed Etsy order records into the
// shape the bundle's Master Dashboard / Monthly Bookkeeping Ledger tabs
// need. Zero Google dependency, same Node/Apps-Script dual-use pattern as
// parser.js (see that file's header comment for the `require` guard
// explanation).
//
// IMPORTANT SCOPE NOTE: this module produces a normalized aggregate object.
// It does NOT write to any spreadsheet -- that is Code.gs's job, and only
// via the non-destructive staging-tab flow documented in README.md. Keeping
// this pure and Google-free is what lets tests/run-tests.mjs exercise it
// under plain node with zero mocking.

// Error factory: `_CsvContractError(...)` is the single source of truth,
// declared ONCE in errors.js (mirrored verbatim into AppsScript/Errors.gs).
// See src/parser.js's header comment (above its own identical-purpose guard)
// for the full rationale, including why this file's own `var` re-export
// below cannot collide with Errors.gs's `function _CsvContractError`
// declaration once every .gs file is concatenated into Apps Script's shared
// global scope (proven by tests/verify-appsscript-loads.mjs). This file used
// to declare its own byte-identical copy of this factory (as did
// parser.js), which risked exactly the load-order-dependent duplicate
// identifier that dedupe fixed.
if (typeof module !== 'undefined' && module.exports) {
  var _errors = require('./errors.js');
  var _CsvContractError = _errors._CsvContractError;
}

/**
 * aggregateOrders(records: NormalizedRecord[]) -> {
 *   currency: string | null,      // null only when records is empty
 *   byMonth: { [monthKey: 'YYYY-MM']: {
 *     revenue: number,            // sum of orderTotal for 'revenue' + 'refund' class rows
 *     orderCount: number,         // all rows this month, any status
 *     revenueOrderCount: number,
 *     refundedOrderCount: number,
 *     canceledOrderCount: number,
 *     fees: number,               // sum of optional `fees` field, 0 if absent
 *     salesTax: number,
 *   }},
 *   totals: { revenue, orderCount, revenueOrderCount, refundedOrderCount,
 *             canceledOrderCount, fees, salesTax },
 * }
 *
 * Policy (see CSV-CONTRACT.md "Status field" -- UNVERIFIED vocabulary,
 * classified upstream by parser.js's classifyStatus):
 *   - statusClass 'revenue' -> orderTotal counts fully toward revenue.
 *   - statusClass 'refund'  -> orderTotal counts toward revenue AS-IS, under
 *     the assumption (UNVERIFIED, documented in CSV-CONTRACT.md) that
 *     Etsy's Order Total for a refunded row already reflects the refund
 *     adjustment. Tallied separately in refundedOrderCount so a seller can
 *     see refund volume at a glance.
 *   - statusClass 'excluded' (canceled) -> contributes $0 to revenue,
 *     tallied in canceledOrderCount.
 *
 * Throws CsvContractError if records span more than one currency -- this
 * function refuses to sum unlike currencies rather than silently producing
 * a meaningless blended total. The caller (or the seller) must split a
 * multi-currency export by currency and import each slice separately.
 */
function aggregateOrders(records) {
  if (!Array.isArray(records)) {
    throw new TypeError('aggregateOrders() expects an array of normalized records');
  }
  if (records.length === 0) {
    return { currency: null, byMonth: {}, totals: emptyTotals() };
  }

  const currencies = new Set(records.map((r) => r.currency));
  if (currencies.size > 1) {
    throw _CsvContractError(
      `Cannot aggregate: this export mixes ${currencies.size} currencies (${[...currencies].sort().join(', ')}). ` +
        `Summing different currencies into one total would produce a meaningless number. ` +
        `Filter/split the CSV to a single currency and import each slice separately.`,
      { currencies: [...currencies] }
    );
  }
  const currency = [...currencies][0];

  const byMonth = {};
  const totals = emptyTotals();

  for (const r of records) {
    const key = r.date.monthKey;
    if (!byMonth[key]) byMonth[key] = emptyTotals();
    const bucket = byMonth[key];

    bucket.orderCount += 1;
    totals.orderCount += 1;

    if (r.statusClass === 'revenue' || r.statusClass === 'refund') {
      bucket.revenue += r.orderTotal;
      totals.revenue += r.orderTotal;
      bucket.revenueOrderCount += r.statusClass === 'revenue' ? 1 : 0;
      totals.revenueOrderCount += r.statusClass === 'revenue' ? 1 : 0;
      if (r.statusClass === 'refund') {
        bucket.refundedOrderCount += 1;
        totals.refundedOrderCount += 1;
      }
    } else if (r.statusClass === 'excluded') {
      bucket.canceledOrderCount += 1;
      totals.canceledOrderCount += 1;
    }

    if (typeof r.fees === 'number') {
      bucket.fees += r.fees;
      totals.fees += r.fees;
    }
    if (typeof r.salesTax === 'number') {
      bucket.salesTax += r.salesTax;
      totals.salesTax += r.salesTax;
    }
  }

  // Round every monetary figure to 2dp to avoid float-noise like
  // 1234.5600000000002 leaking into the sheet.
  round2InPlace(totals);
  for (const key of Object.keys(byMonth)) round2InPlace(byMonth[key]);

  return { currency, byMonth, totals };
}

function emptyTotals() {
  return {
    revenue: 0,
    orderCount: 0,
    revenueOrderCount: 0,
    refundedOrderCount: 0,
    canceledOrderCount: 0,
    fees: 0,
    salesTax: 0,
  };
}

function round2InPlace(bucket) {
  bucket.revenue = Math.round(bucket.revenue * 100) / 100;
  bucket.fees = Math.round(bucket.fees * 100) / 100;
  bucket.salesTax = Math.round(bucket.salesTax * 100) / 100;
}

if (typeof module !== 'undefined' && module.exports) {
  module.exports = { aggregateOrders };
}

==============================================================================
FILE: ApplyMapping.gs
==============================================================================
// applyMapping.js -- pure logic for mapping an already-staged Etsy CSV
// import onto the shipping bundle's "Master Dashboard" / "Monthly
// Bookkeeping Ledger" tabs. Zero SpreadsheetApp dependency -- everything
// here takes plain values in and returns plain values or throws, exactly
// like parser.js/aggregate.js, so it's testable under plain node (see
// tests/apply-mapping.mjs) with no fake-Sheets harness needed. Code.gs is
// the only file that actually reads/writes a live sheet or shows UI; it
// calls the functions below to decide WHAT to write and what to tell the
// seller, never decides that inline.
//
// ---------------------------------------------------------------------------
// DERIVED CELL COORDINATES -- confirmed against the ACTUAL generated
// Seller-OS-Command-Center.xlsx (built by
// ventures/niche-financial-spreadsheets/build/etsy/bundle-99/build_bundle_workbooks.py),
// by loading that exact file with openpyxl and reading real cell values --
// not just by reading the generator source, and not trusted from Code.gs's
// old stub comment:
//   Master Dashboard!D7  = "Total Revenue (YTD)"   (the row's label)
//   Master Dashboard!E7  = 214800                  (its manual-entry value cell)
//   Monthly Bookkeeping Ledger!B7     = "Etsy Income"        (the row's label)
//   Monthly Bookkeeping Ledger!D7:O7  = the 12 Jan-Dec monthly figures
//   Monthly Bookkeeping Ledger!P7     = "=SUM(D7:O7)"        (YTD formula --
//     never written directly; it recomputes itself from D:O)
// Loudly noting: this matches Code.gs's PRE-EXISTING stub guess (E7 / row 7
// D:O) exactly. That guess turned out to be CORRECT once actually checked
// against the shipped file, not wrong -- there is no coordinate correction
// to make. They are used here only as a FALLBACK, though: the primary
// lookup is by scanning for the row's own text LABEL at runtime (see
// findRowByLabel below), so a future regeneration of the workbook that
// inserts or removes a row above these does not silently drift the target
// out from under a hardcoded number.
// ---------------------------------------------------------------------------

// See src/parser.js's header comment (above its own identical-purpose
// guard) for why this must NOT declare a bare `var ApplyMappingError = ...;`
// -- that would collide, at Apps Script's PARSE time, with Errors.gs's
// top-level `class ApplyMappingError` once every .gs file is concatenated
// into one shared global scope (proven by tests/verify-appsscript-loads.mjs).
// The `_ApplyMappingError(...)` factory function introduces only a new,
// non-colliding name; the bare `ApplyMappingError` reference inside its body
// is a lookup, not a declaration, resolved via `_errors` under Node or via
// the normal scope chain to Errors.gs's class under Apps Script.
if (typeof module !== 'undefined' && module.exports) {
  var _errors = require('./errors.js');
}
function _ApplyMappingError(message) {
  var Ctor = (typeof _errors !== 'undefined' && _errors) ? _errors.ApplyMappingError : ApplyMappingError;
  return new Ctor(message);
}

var MASTER_DASHBOARD_SHEET_NAME = 'Master Dashboard';
var LEDGER_SHEET_NAME = 'Monthly Bookkeeping Ledger';

var REVENUE_ROW_LABEL = 'Total Revenue (YTD)';
var REVENUE_LABEL_COL = 4; // column D ("Metric")
var REVENUE_VALUE_COL = 5; // column E ("Value")
var REVENUE_FALLBACK_ROW = 7;

var LEDGER_ROW_LABEL = 'Etsy Income';
var LEDGER_LABEL_COL = 2; // column B ("Category")
var LEDGER_MONTH_COL_START = 4; // column D (Jan)
var LEDGER_MONTH_COUNT = 12; // through column O (Dec)
var LEDGER_FALLBACK_ROW = 7;

var MONTH_KEY_RE = /^(\d{4})-(\d{2})$/;

/**
 * findRowByLabel(columnValues, label) -> 1-indexed row number, or null.
 * columnValues[0] is row 1's value, columnValues[1] is row 2's, etc, i.e.
 * exactly what Range(1, col, lastRow, 1).getValues().map(function(r){return
 * r[0];}) returns. Exact match after trimming whitespace; case-sensitive
 * (these are this template's own literal strings, not free-form user
 * input, so a loose/fuzzy match would only risk matching the wrong row).
 */
function findRowByLabel(columnValues, label) {
  for (var i = 0; i < columnValues.length; i++) {
    var v = columnValues[i];
    if (typeof v === 'string' && v.trim() === label) return i + 1;
  }
  return null;
}

/**
 * parseStagingRows(rows) -> { byMonth: { 'YYYY-MM': { revenue } }, totals: { revenue } }
 *
 * `rows` is the full 2D getValues() array of the staging sheet ("Import
 * Staging (Etsy CSV)", written by Code.gs's writeStagingSheet_()), row 1
 * through the sheet's last row, column 1 through its last column. Month
 * rows and the TOTAL row are found by their OWN label in column A ('YYYY-MM'
 * or literal 'TOTAL') rather than by the fixed row offsets writeStagingSheet_
 * happens to use today -- this function does not need to know or assume
 * exactly which row number the header, month rows, or TOTAL row landed on.
 *
 * Why this re-parses the staging sheet instead of receiving the in-memory
 * aggregate object from the import step: applyStagedImportToDashboard() is
 * a separate, independently-invoked menu action (see Code.gs), and Apps
 * Script has no in-memory state carried between two separate menu-click
 * executions -- the staging SHEET is the only durable record of what was
 * imported. Re-parsing it (rather than, say, caching JSON in
 * PropertiesService) also means what gets applied is always exactly what
 * the seller can see and review on the staging tab, which is the whole
 * point of the two-step stage-then-apply design.
 *
 * Throws ApplyMappingError if no TOTAL row with a numeric revenue value is
 * found -- that would mean the staging sheet is empty, malformed, or from an
 * incompatible version of this tool, and silently treating that as "$0
 * revenue" would be a wrong-number risk, not a safe default.
 */
function parseStagingRows(rows) {
  var byMonth = {};
  var totalsRevenue = null;
  for (var i = 0; i < rows.length; i++) {
    var row = rows[i];
    var col1 = row[0];
    if (typeof col1 !== 'string') continue;
    var trimmed = col1.trim();
    var m = MONTH_KEY_RE.exec(trimmed);
    if (m) {
      var revenue = Number(row[1]);
      if (!isNaN(revenue)) byMonth[trimmed] = { revenue: revenue };
    } else if (trimmed === 'TOTAL') {
      var totalRevenue = Number(row[1]);
      if (!isNaN(totalRevenue)) totalsRevenue = totalRevenue;
    }
  }
  if (totalsRevenue === null) {
    throw _ApplyMappingError(
      'Could not find a "TOTAL" row with a numeric revenue value on the staging sheet -- it may be empty, ' +
        'malformed, or from an incompatible version of this tool. Nothing was changed. Re-run ' +
        '"1. Import Orders CSV..." to regenerate the staging sheet, then try applying again.'
    );
  }
  return { byMonth: byMonth, totals: { revenue: totalsRevenue } };
}

/**
 * buildApplyPlan(staged, revenueRow, ledgerRow, opts) -> {
 *   warnings: string[],
 *   masterDashboard: { row, col, value },
 *   ledger: { row, writes: [{ col, value }] },
 *   year: string | null,
 * }
 *
 * Pure decision logic: given the ALREADY-RESOLVED target rows (label match
 * or fallback -- the label lookup itself has to happen in Code.gs, since
 * only it can read a live sheet) and the staged totals from
 * parseStagingRows(), decides exactly which cells to write, what value goes
 * in each, and what warnings (if any) to surface in the confirm dialog.
 *
 * Refuses (throws ApplyMappingError, decides nothing) if the staged import
 * spans more than one calendar year: the Ledger has exactly one column per
 * calendar month for a single year, so folding two different years'
 * Januaries into the same "Jan" column would silently misattribute revenue
 * to the wrong year. This mirrors aggregateOrders()'s existing policy of
 * refusing to sum mixed currencies rather than guessing (see aggregate.js).
 *
 * Only months actually PRESENT in the staged data get a write entry -- a
 * month the seller's CSV export didn't cover is left OUT of
 * `ledger.writes` entirely, so applying a 3-month import can never zero out
 * the other 9 months' pre-existing ledger figures that this import simply
 * has no data for.
 */
function buildApplyPlan(staged, revenueRow, ledgerRow, opts) {
  opts = opts || {};
  var warnings = [];
  if (opts.revenueLabelFound === false) {
    warnings.push(
      'Could not find a row labeled "' + REVENUE_ROW_LABEL + '" in column D of "' + MASTER_DASHBOARD_SHEET_NAME +
        '" -- using fallback row ' + REVENUE_FALLBACK_ROW + '. Double-check that is still the right row before confirming.'
    );
  }
  if (opts.ledgerLabelFound === false) {
    warnings.push(
      'Could not find a row labeled "' + LEDGER_ROW_LABEL + '" in column B of "' + LEDGER_SHEET_NAME +
        '" -- using fallback row ' + LEDGER_FALLBACK_ROW + '. Double-check that is still the right row before confirming.'
    );
  }

  var monthKeys = Object.keys(staged.byMonth).sort();
  var years = [];
  for (var i = 0; i < monthKeys.length; i++) {
    var y = monthKeys[i].slice(0, 4);
    if (years.indexOf(y) === -1) years.push(y);
  }
  if (years.length > 1) {
    throw _ApplyMappingError(
      'Staged import spans ' + years.length + ' different years (' + years.join(', ') + '). The Monthly ' +
        'Bookkeeping Ledger has one set of Jan-Dec columns for a single year, so applying a multi-year import ' +
        'would silently mix different years into the same 12 columns. Import and apply one year at a time.'
    );
  }

  var ledgerWrites = monthKeys.map(function (key) {
    var month = parseInt(key.slice(5, 7), 10);
    return { col: LEDGER_MONTH_COL_START + (month - 1), value: round2(staged.byMonth[key].revenue) };
  });

  return {
    warnings: warnings,
    masterDashboard: { row: revenueRow, col: REVENUE_VALUE_COL, value: round2(staged.totals.revenue) },
    ledger: { row: ledgerRow, writes: ledgerWrites },
    year: years.length === 1 ? years[0] : null,
  };
}

function round2(n) {
  return Math.round(n * 100) / 100;
}

/**
 * buildConfirmMessage(plan) -> string shown in the YES/NO confirm dialog
 * before anything is written. Pure string formatting so its exact wording
 * is testable without a UI, and so the seller always sees precisely which
 * cells are about to change (and any warnings) before they can say YES.
 */
function buildConfirmMessage(plan) {
  var lines = [];
  lines.push('This will write:');
  lines.push(
    '  - "' + MASTER_DASHBOARD_SHEET_NAME + '" row ' + plan.masterDashboard.row + ', column ' +
      colLetter(plan.masterDashboard.col) + ' ("' + REVENUE_ROW_LABEL + '") -> ' + plan.masterDashboard.value
  );
  if (plan.ledger.writes.length === 0) {
    lines.push(
      '  - "' + LEDGER_SHEET_NAME + '" row ' + plan.ledger.row + ' ("' + LEDGER_ROW_LABEL +
        '"): the staged import has no months, so nothing will be written there.'
    );
  } else {
    lines.push(
      '  - "' + LEDGER_SHEET_NAME + '" row ' + plan.ledger.row + ' ("' + LEDGER_ROW_LABEL + '"), ' +
        plan.ledger.writes.length + ' month column(s) for ' + plan.year + ':'
    );
    plan.ledger.writes.forEach(function (w) {
      lines.push('      column ' + colLetter(w.col) + ' -> ' + w.value);
    });
  }
  lines.push('');
  lines.push('Only these specific cells change. Every other cell on both tabs is left exactly as it is.');
  if (plan.warnings.length > 0) {
    lines.push('');
    lines.push('WARNING:');
    plan.warnings.forEach(function (w) {
      lines.push('  - ' + w);
    });
  }
  return lines.join('\n');
}

/** colLetter(col) -> 1 -> 'A', 5 -> 'E', 15 -> 'O', etc. */
function colLetter(col) {
  var s = '';
  while (col > 0) {
    var rem = (col - 1) % 26;
    s = String.fromCharCode(65 + rem) + s;
    col = Math.floor((col - 1) / 26);
  }
  return s;
}

if (typeof module !== 'undefined' && module.exports) {
  module.exports = {
    MASTER_DASHBOARD_SHEET_NAME: MASTER_DASHBOARD_SHEET_NAME,
    LEDGER_SHEET_NAME: LEDGER_SHEET_NAME,
    REVENUE_ROW_LABEL: REVENUE_ROW_LABEL,
    REVENUE_LABEL_COL: REVENUE_LABEL_COL,
    REVENUE_VALUE_COL: REVENUE_VALUE_COL,
    REVENUE_FALLBACK_ROW: REVENUE_FALLBACK_ROW,
    LEDGER_ROW_LABEL: LEDGER_ROW_LABEL,
    LEDGER_LABEL_COL: LEDGER_LABEL_COL,
    LEDGER_MONTH_COL_START: LEDGER_MONTH_COL_START,
    LEDGER_MONTH_COUNT: LEDGER_MONTH_COUNT,
    LEDGER_FALLBACK_ROW: LEDGER_FALLBACK_ROW,
    findRowByLabel: findRowByLabel,
    parseStagingRows: parseStagingRows,
    buildApplyPlan: buildApplyPlan,
    buildConfirmMessage: buildConfirmMessage,
    colLetter: colLetter,
  };
}

==============================================================================
FILE: Code.gs
==============================================================================
/**
 * Code.gs -- THIN Apps Script wrapper over the pure functions in
 * Parser.gs / Aggregate.gs / Errors.gs / ApplyMapping.gs (byte-identical
 * copies of src/parser.js / src/aggregate.js / src/errors.js /
 * src/applyMapping.js -- verified by tests/verify-appsscript-sync.mjs).
 * This file is the ONLY one that touches SpreadsheetApp/Ui -- everything
 * else is Google-free and covered by the node test harness in tests/
 * (including this file's own orchestration, via the fake SpreadsheetApp in
 * tests/fake-spreadsheet-app.mjs -- see tests/apply-staged-import.mjs).
 *
 * ============================================================================
 * STATUS: WRITTEN, NOT YET DEPLOYED OR RUN AGAINST A REAL GOOGLE SHEET.
 * This phase built the harness and parser per the task brief's explicit
 * scope ("Phase 1 is the harness and the parser, not the polished
 * product"). Deploying this file into an actual Apps Script project bound
 * to the bundle's .xlsx (as a Google Sheet) requires opening the file in
 * Google Sheets, which needs the owner's Google account -- out of scope for
 * this phase and not something this agent can or should do (no accounts,
 * no logins, per the hard rules). Treat every SpreadsheetApp/Ui call below
 * as UNTESTED until a human (or a future phase with sanctioned Sheets
 * access) runs it inside a real Sheet and confirms the menu, the staging
 * write, and the confirm-before-apply flow all behave as designed.
 * ============================================================================
 *
 * NON-DESTRUCTIVE IMPORT DESIGN (this is the load-bearing decision):
 *   1. importEtsyOrdersCsv() takes pasted CSV text, calls the pure
 *      importOrdersCsv() logic, and -- ONLY if it does not throw -- writes
 *      the result to a sheet named "Import Staging (Etsy CSV)", which it
 *      creates fresh (clearing any prior staging content) each run. It
 *      NEVER touches "Master Dashboard" or "Monthly Bookkeeping Ledger".
 *   2. If importOrdersCsv() throws (CsvContractError or CsvParseError),
 *      NOTHING is written anywhere -- not even to the staging sheet. The
 *      seller sees the error message via a UI alert and their existing
 *      dashboard numbers are completely untouched.
 *   3. applyStagedImportToDashboard() is a SEPARATE, explicitly-invoked
 *      function (its own menu item) that copies staging values into the
 *      real tabs -- and ONLY after SpreadsheetApp.getUi().alert() with a
 *      YES_NO prompt the seller must actively confirm. There is no
 *      one-click "import and overwrite" path by design: a CSV mis-parse
 *      corrupting a seller's own revenue tracker is a trust/refund-class
 *      failure (see the task brief this was built against), so the two
 *      steps (stage, then explicitly apply) are kept structurally separate
 *      rather than a single convenient button.
 *
 * WHERE staged data maps (NOT a live formula link -- the bundle's own
 * Master Dashboard tab already explains, in cell B4, why cross-file live
 * formulas were deliberately rejected; applyStagedImportToDashboard() below
 * follows the same "copy values, not formulas" philosophy, just from a
 * staging tab within the SAME file instead of a manual re-type):
 *   - Master Dashboard!E7 "Total Revenue (YTD)"    <- staging totals.revenue
 *   - Monthly Bookkeeping Ledger row 7 "Etsy Income", columns D:O (Jan-Dec)
 *     <- staging byMonth[...].revenue per month
 * These coordinates were DERIVED, not guessed: confirmed by loading the
 * actual generated Seller-OS-Command-Center.xlsx (built by
 * ventures/niche-financial-spreadsheets/build/etsy/bundle-99/build_bundle_workbooks.py)
 * with openpyxl and reading real cell values (see applyMapping.js's header
 * comment for the exact evidence). They match what an earlier draft of this
 * file guessed, which is a coincidence worth stating loudly rather than
 * quietly relying on -- that is why applyStagedImportToDashboard() below
 * does NOT hardcode row 7 as the only source of truth: it looks up each
 * target row by scanning for its own text label at runtime (see
 * findRowByLabel() in ApplyMapping.gs) and only falls back to the derived
 * row number if that label can't be found, so a future regeneration of the
 * workbook that inserts a row above these does not silently write to the
 * wrong place. applyStagedImportToDashboard() is implemented below (see its
 * own comment) but, like every SpreadsheetApp/Ui call in this file, has
 * NEVER been executed against a real Google Sheet -- see STATUS above.
 */

var STAGING_SHEET_NAME = 'Import Staging (Etsy CSV)';

function onOpen() {
  SpreadsheetApp.getUi()
    .createMenu('Etsy CSV Import')
    .addItem('1. Import Orders CSV (paste text)...', 'importEtsyOrdersCsv_promptFlow')
    .addItem('2. Apply staged import to dashboard...', 'applyStagedImportToDashboard')
    .addToUi();
}

/**
 * Menu entry point: prompts the seller to paste their Etsy Orders CSV
 * (downloaded from Shop Manager > Settings > Options > Download Data, per
 * CSV-CONTRACT.md) into a dialog, then runs the non-destructive import.
 * UNTESTED (see file header) -- SpreadsheetApp.getUi().prompt() with a
 * large pasted CSV may need a proper HtmlService dialog instead of the
 * built-in prompt (which has a practical input-length ceiling); that is a
 * concrete open question for whoever runs this against a real Sheet first.
 */
function importEtsyOrdersCsv_promptFlow() {
  var ui = SpreadsheetApp.getUi();
  var response = ui.prompt(
    'Import Etsy Orders CSV',
    'Paste the full contents of your Etsy Orders CSV export below, then click OK.\n\n' +
      '(Shop Manager > Settings > Options > Download Data > Orders > CSV Type: Orders)',
    ui.ButtonSet.OK_CANCEL
  );
  if (response.getSelectedButton() !== ui.Button.OK) return;
  var csvText = response.getResponseText();
  try {
    importEtsyOrdersCsv(csvText);
    ui.alert(
      'Import staged successfully.',
      'Your CSV parsed cleanly and was written to the "' +
        STAGING_SHEET_NAME +
        '" tab. Nothing on Master Dashboard or Monthly Bookkeeping Ledger has been changed yet -- ' +
        'review the staged numbers, then use "2. Apply staged import to dashboard..." when ready.',
      ui.ButtonSet.OK
    );
  } catch (err) {
    // Fail-loud: surface the FULL error message (which names every bad row
    // / missing column / ambiguous value) and write NOTHING anywhere.
    ui.alert('Import refused -- nothing was changed.', String(err && err.message ? err.message : err), ui.ButtonSet.OK);
  }
}

/**
 * importEtsyOrdersCsv(csvText) -- the actual non-destructive import logic,
 * separated from the UI prompt above so it's callable directly (e.g. from
 * a custom HtmlService dialog in a future revision) without duplicating
 * the staging-write logic.
 *
 * Calls the pure importOrdersCsv() (global function from the composed
 * Parser.gs + Aggregate.gs -- Apps Script has no per-file imports needed
 * since all .gs files share one global scope) via the small inline
 * composition below (mirrors src/index.js, which Node uses instead).
 * Throws straight through on any CsvContractError/CsvParseError -- this
 * function must NEVER catch-and-continue; only the caller's UI layer
 * catches, to display the message.
 */
function importEtsyOrdersCsv(csvText) {
  var parsed = parseOrdersCsv(csvText); // from Parser.gs
  var aggregate = aggregateOrders(parsed.records); // from Aggregate.gs
  writeStagingSheet_(parsed, aggregate);
  return { records: parsed.records, unknownColumns: parsed.unknownColumns, aggregate: aggregate };
}

/**
 * writeStagingSheet_(parsed, aggregate) -- the ONLY function in this file
 * that writes to the spreadsheet, and it only ever writes to the staging
 * sheet (never Master Dashboard / Monthly Bookkeeping Ledger). Recreates
 * the staging sheet fresh every run so a prior staged (but never applied)
 * import can never be partially overwritten by a new one.
 */
function writeStagingSheet_(parsed, aggregate) {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var existing = ss.getSheetByName(STAGING_SHEET_NAME);
  if (existing) ss.deleteSheet(existing);
  var sheet = ss.insertSheet(STAGING_SHEET_NAME);

  sheet.getRange(1, 1).setValue('Etsy CSV Import -- Staging (not yet applied to Dashboard/Ledger)');
  sheet.getRange(2, 1).setValue('Imported ' + new Date().toISOString() + ' -- ' + parsed.records.length + ' order(s), currency ' + aggregate.currency);
  if (parsed.unknownColumns.length > 0) {
    sheet.getRange(3, 1).setValue(
      'Ignored ' + parsed.unknownColumns.length + ' unrecognized column(s): ' +
        parsed.unknownColumns.map(function (c) { return c.name; }).join(', ')
    );
  }

  var headerRow = 5;
  sheet.getRange(headerRow, 1, 1, 8).setValues([[
    'Month', 'Revenue', 'Order Count', 'Revenue Orders', 'Refunded Orders', 'Canceled Orders', 'Fees', 'Sales Tax',
  ]]);
  var months = Object.keys(aggregate.byMonth).sort();
  var rows = months.map(function (m) {
    var b = aggregate.byMonth[m];
    return [m, b.revenue, b.orderCount, b.revenueOrderCount, b.refundedOrderCount, b.canceledOrderCount, b.fees, b.salesTax];
  });
  if (rows.length > 0) {
    sheet.getRange(headerRow + 1, 1, rows.length, 8).setValues(rows);
  }

  var totalsRow = headerRow + rows.length + 2;
  sheet.getRange(totalsRow, 1).setValue('TOTAL');
  sheet.getRange(totalsRow, 2, 1, 7).setValues([[
    aggregate.totals.revenue, aggregate.totals.orderCount, aggregate.totals.revenueOrderCount,
    aggregate.totals.refundedOrderCount, aggregate.totals.canceledOrderCount, aggregate.totals.fees, aggregate.totals.salesTax,
  ]]);
}

/**
 * applyStagedImportToDashboard() -- copies the already-staged import's
 * totals into Master Dashboard!<Total Revenue row>,E and Monthly Bookkeeping
 * Ledger!<Etsy Income row>,D:O, and ONLY after the seller explicitly
 * confirms a YES/NO dialog that shows exactly which cells are about to
 * change. UNTESTED against a real Google Sheet -- see file header STATUS;
 * everything below is proven by the fake-SpreadsheetApp harness in
 * tests/apply-staged-import.mjs under plain node, never by actually running
 * this file inside Apps Script.
 *
 * Sequence (every step fails safe -- see each inline comment for exactly
 * what "fails safe" means at that step):
 *   1. No staging sheet -> alert and return. Nothing read, nothing written.
 *   2. Re-parse the staging sheet's own TOTAL/month rows via
 *      parseStagingRows() (ApplyMapping.gs) -- NOT any in-memory value from
 *      the import step, because Apps Script menu clicks are independent
 *      executions with no shared state. If the staging sheet doesn't look
 *      like one this tool wrote, parseStagingRows() throws and nothing is
 *      read further.
 *   3. Look up "Master Dashboard" and "Monthly Bookkeeping Ledger" BY NAME.
 *      Either missing -> alert naming which tab and abort. This function
 *      never creates a tab or guesses a differently-named one.
 *   4. Look up each target ROW by scanning for its known text label
 *      (findRowByLabel()); only fall back to the derived row 7 if the label
 *      isn't found, and say so as a warning in the confirm dialog either way.
 *   5. buildApplyPlan() (pure, ApplyMapping.gs) decides exactly which cells
 *      to write. It throws (nothing written) if the staged data spans more
 *      than one calendar year -- see its comment for why that's refused
 *      rather than guessed.
 *   6. Show the seller the exact plan (buildConfirmMessage()) in a YES/NO
 *      dialog. Anything but YES -> alert "not applied" and return; both
 *      target tabs are untouched.
 *   7. On YES, executeApplyPlan_() writes VALUES ONLY (never formulas) to
 *      ONLY the planned cells -- ledger month columns actually present in
 *      the staged data first, then the single Master Dashboard total cell.
 *      Months the staged CSV has no data for are left alone, not zeroed.
 *      RESIDUAL RISK: Sheets has no cross-cell transaction -- if a write
 *      throws partway through the ledger's per-month loop, the cells
 *      already written stay written and the rest (including the Master
 *      Dashboard cell, written last) do not. This is a documented partial-
 *      write window, not an eliminated one; the alert on that path tells
 *      the seller to check both tabs by hand.
 */
function applyStagedImportToDashboard() {
  var ui = SpreadsheetApp.getUi();
  var ss = SpreadsheetApp.getActiveSpreadsheet();

  var staging = ss.getSheetByName(STAGING_SHEET_NAME);
  if (!staging) {
    ui.alert('Nothing to apply -- run "1. Import Orders CSV..." first.');
    return;
  }

  var staged;
  try {
    staged = readStagedAggregate_(staging);
  } catch (err) {
    ui.alert('Apply refused -- nothing was changed.', String(err && err.message ? err.message : err), ui.ButtonSet.OK);
    return;
  }

  var dashboard = ss.getSheetByName(MASTER_DASHBOARD_SHEET_NAME);
  if (!dashboard) {
    ui.alert(
      'Apply refused -- nothing was changed.',
      'Could not find a tab named "' + MASTER_DASHBOARD_SHEET_NAME + '" in this spreadsheet. This tool never ' +
        'creates or guesses a differently-named tab -- rename/restore the tab (or check you\'re in the right ' +
        'file) and try again.',
      ui.ButtonSet.OK
    );
    return;
  }
  var ledger = ss.getSheetByName(LEDGER_SHEET_NAME);
  if (!ledger) {
    ui.alert(
      'Apply refused -- nothing was changed.',
      'Could not find a tab named "' + LEDGER_SHEET_NAME + '" in this spreadsheet. This tool never creates or ' +
        'guesses a differently-named tab -- rename/restore the tab (or check you\'re in the right file) and try again.',
      ui.ButtonSet.OK
    );
    return;
  }

  var revenueLookup = resolveTargetRow_(dashboard, REVENUE_LABEL_COL, REVENUE_ROW_LABEL, REVENUE_FALLBACK_ROW);
  var ledgerLookup = resolveTargetRow_(ledger, LEDGER_LABEL_COL, LEDGER_ROW_LABEL, LEDGER_FALLBACK_ROW);

  var plan;
  try {
    plan = buildApplyPlan(staged, revenueLookup.row, ledgerLookup.row, {
      revenueLabelFound: revenueLookup.found,
      ledgerLabelFound: ledgerLookup.found,
    });
  } catch (err) {
    ui.alert('Apply refused -- nothing was changed.', String(err && err.message ? err.message : err), ui.ButtonSet.OK);
    return;
  }

  var response = ui.alert('Apply staged import to dashboard?', buildConfirmMessage(plan), ui.ButtonSet.YES_NO);
  if (response !== ui.Button.YES) {
    ui.alert('Not applied.', 'No answer other than YES writes anything -- Master Dashboard and Monthly Bookkeeping Ledger are unchanged.', ui.ButtonSet.OK);
    return;
  }

  try {
    executeApplyPlan_(dashboard, ledger, plan);
  } catch (err) {
    ui.alert(
      'Apply failed partway through -- please check both tabs by hand.',
      String(err && err.message ? err.message : err) +
        '\n\nSome of the planned cells may already be written while others are not (see this function\'s ' +
        'comment in Code.gs for why Sheets writes can\'t be made atomic across cells).',
      ui.ButtonSet.OK
    );
    return;
  }

  ui.alert(
    'Applied.',
    'Master Dashboard!' + colLetter(plan.masterDashboard.col) + plan.masterDashboard.row + ' and ' +
      plan.ledger.writes.length + ' month cell(s) on "' + LEDGER_SHEET_NAME + '" row ' + plan.ledger.row +
      ' were updated. The staging tab is left as-is for reference.',
    ui.ButtonSet.OK
  );
}

/**
 * readStagedAggregate_(stagingSheet) -- reads the staging sheet's full used
 * range and hands it to parseStagingRows() (ApplyMapping.gs, pure) to pull
 * out the TOTAL and per-month revenue figures by their own labels. The only
 * SpreadsheetApp call in this function is the single getRange().getValues()
 * -- everything else is the pure, node-tested parser.
 */
function readStagedAggregate_(stagingSheet) {
  var lastRow = Math.max(stagingSheet.getLastRow(), 1);
  var lastCol = Math.max(stagingSheet.getLastColumn(), 2);
  var rows = stagingSheet.getRange(1, 1, lastRow, lastCol).getValues();
  return parseStagingRows(rows);
}

/**
 * resolveTargetRow_(sheet, labelCol, label, fallbackRow) -> { row, found }
 * Reads column `labelCol` (row 1..lastRow) and hands it to findRowByLabel()
 * (ApplyMapping.gs, pure) to find the row whose text matches `label`
 * exactly. Falls back to `fallbackRow` (the coordinate derived from the
 * shipping workbook -- see file header) only if the label can't be found,
 * and reports which happened so the caller can warn the seller.
 */
function resolveTargetRow_(sheet, labelCol, label, fallbackRow) {
  var lastRow = Math.max(sheet.getLastRow(), 1);
  var columnValues = sheet.getRange(1, labelCol, lastRow, 1).getValues().map(function (r) {
    return r[0];
  });
  var found = findRowByLabel(columnValues, label);
  return { row: found || fallbackRow, found: found !== null };
}

/**
 * executeApplyPlan_(dashboardSheet, ledgerSheet, plan) -- the ONLY function
 * that writes to Master Dashboard / Monthly Bookkeeping Ledger, and only
 * ever the exact cells `plan` names (see buildApplyPlan() in
 * ApplyMapping.gs). Writes ledger month cells first (one setValue() per
 * planned month -- never a full D:O setValues() call, so months absent from
 * `plan.ledger.writes` are never touched, not even with a blank), then the
 * single Master Dashboard total cell last. Every setValue() call sets a
 * plain number, never a formula, matching the workbook's own stated
 * anti-live-link philosophy (see Master Dashboard!B4).
 */
function executeApplyPlan_(dashboardSheet, ledgerSheet, plan) {
  plan.ledger.writes.forEach(function (w) {
    ledgerSheet.getRange(plan.ledger.row, w.col).setValue(w.value);
  });
  dashboardSheet.getRange(plan.masterDashboard.row, plan.masterDashboard.col).setValue(plan.masterDashboard.value);
}