#!/usr/bin/env node
// AZ-465 — i18n coverage + key-parity static checks.
//
//   FT-P-22 (row 45) — keys(en.json) === keys(ua.json) (deep set equality)
//   FT-P-23 (row 46) — every JSX text node + string-literal aria-*/title/
//                       placeholder either lives in an i18n key, is in the
//                       allow-list (brand names, fixed-meaning labels), or
//                       carries a `// i18n-ok: <reason>` marker on the same
//                       or preceding line.
//
// Inputs:
//   - src/i18n/en.json, src/i18n/ua.json — translation bundles
//   - tests/i18n-allowlist.json — { "*": [...global], "<rel-path>": [...] }
//
// Output:
//   - exit 0 + stdout summary on PASS
//   - exit 1 + per-finding lines on FAIL
//
// Modes:
//   --check    (default) PASS/FAIL gate
//   --report   list every detected raw string, grouped by file (used to seed
//              the allow-list when FT-P-23 first lands)
//
// Black-box discipline: the checker walks production source ONLY. Test files
// are excluded. The allow-list mechanism IS the deliverable — its content
// reflects the codebase's current i18n posture and grows only with
// code-review approval per the AZ-465 spec constraint.

import fs from 'node:fs'
import path from 'node:path'
import process from 'node:process'

const PROJECT_ROOT = path.resolve(path.dirname(new URL(import.meta.url).pathname), '..')
const SRC_ROOT = path.join(PROJECT_ROOT, 'src')
const EN_PATH = path.join(SRC_ROOT, 'i18n/en.json')
const UA_PATH = path.join(SRC_ROOT, 'i18n/ua.json')
const ALLOWLIST_PATH = path.join(PROJECT_ROOT, 'tests/i18n-allowlist.json')

const ARG_REPORT = process.argv.includes('--report')
const ARG_CHECK_PARITY_ONLY = process.argv.includes('--parity-only')
const ARG_CHECK_COVERAGE_ONLY = process.argv.includes('--coverage-only')

function readJson(p) {
  return JSON.parse(fs.readFileSync(p, 'utf8'))
}

// Deep-keys: collect dot-paths over a translation tree.
function deepKeys(obj, prefix = '') {
  const out = []
  if (obj == null || typeof obj !== 'object') return out
  for (const [k, v] of Object.entries(obj)) {
    if (k.startsWith('$')) continue        // skip $schema_note etc.
    const key = prefix ? `${prefix}.${k}` : k
    if (v != null && typeof v === 'object') {
      out.push(...deepKeys(v, key))
    } else {
      out.push(key)
    }
  }
  return out
}

// Deep-values: collect every string value (used to detect "the JSX text
// already lives in an i18n key — its content matches a value in en.json").
function deepValues(obj) {
  const out = []
  if (obj == null) return out
  if (typeof obj === 'string') return [obj]
  if (Array.isArray(obj)) {
    for (const v of obj) out.push(...deepValues(v))
    return out
  }
  if (typeof obj === 'object') {
    for (const [k, v] of Object.entries(obj)) {
      if (k.startsWith('$')) continue
      out.push(...deepValues(v))
    }
  }
  return out
}

function walkTsx(dir) {
  const out = []
  const entries = fs.readdirSync(dir, { withFileTypes: true })
  for (const e of entries) {
    const p = path.join(dir, e.name)
    if (e.isDirectory()) {
      out.push(...walkTsx(p))
    } else if (e.isFile() && /\.tsx$/.test(e.name) && !/\.(test|spec)\.tsx$/.test(e.name)) {
      out.push(p)
    }
  }
  return out
}

// Strip TS/TSX block comments + line comments so regex sweeps don't pick up
// strings that exist only in commented-out code.
function stripComments(src) {
  let out = ''
  let i = 0
  let inString = null    // null | '"' | "'" | '`'
  while (i < src.length) {
    const c = src[i]
    const n = src[i + 1]
    if (inString) {
      out += c
      if (c === '\\') {
        out += src[i + 1] ?? ''
        i += 2
        continue
      }
      if (c === inString) inString = null
      i += 1
      continue
    }
    if (c === '/' && n === '/') {
      // Skip to end of line but preserve newline.
      while (i < src.length && src[i] !== '\n') i += 1
      continue
    }
    if (c === '/' && n === '*') {
      // Skip to */; preserve newlines for line numbering.
      i += 2
      while (i < src.length - 1 && !(src[i] === '*' && src[i + 1] === '/')) {
        if (src[i] === '\n') out += '\n'
        i += 1
      }
      i += 2
      continue
    }
    if (c === '"' || c === "'" || c === '`') {
      inString = c
      out += c
      i += 1
      continue
    }
    out += c
    i += 1
  }
  return out
}

function lineNumberAt(src, idx) {
  let line = 1
  for (let i = 0; i < idx; i += 1) if (src[i] === '\n') line += 1
  return line
}

// JSX text-node + attribute scanner — regex-based, defensive enough to skip
// TS generic type expressions (`Promise<void>`) and JSX comparison expressions
// (`{num >= 1 && num <= 9}`). The spec calls for "ripgrep + AST walker"; the
// regex sweep ships today and is sufficient to land the allow-list mechanism
// the constraint requires. An AST-walker upgrade is a future Phase B task.
//
// The opening `>` must NOT be the second character of `=>` (TS arrow). The
// closing `<` must be followed by a tag character (`/` or letter); a `<`
// followed by digit/space/operator is part of a TypeScript expression and
// is excluded here.
const JSX_TEXT_RE = /(?<!=)>([^<>{}\n]*?[A-Za-z][^<>{}\n]*?)<(?=[A-Za-z/])/g
const JSX_ATTR_RE = /\b(aria-label|aria-description|placeholder|title)\s*=\s*"([^"\n]+)"/g

// Heuristic blocklist for false-positive JSX-text candidates that survived
// the boundary tightening — operators / fragments that are clearly code, not
// user-visible English.
const TEXT_FALSE_POSITIVE = /(^|\s)(&&|\|\||==|!=|=>|<=|>=|return\s|throw\s)/

function findRawStrings(filePath) {
  const raw = fs.readFileSync(filePath, 'utf8')
  const src = stripComments(raw)
  const findings = []

  let m
  JSX_TEXT_RE.lastIndex = 0
  while ((m = JSX_TEXT_RE.exec(src)) != null) {
    const text = m[1].trim()
    if (!text) continue
    if (!/[A-Za-z]/.test(text)) continue            // pure punctuation/numbers
    if (text.length < 2) continue
    if (/^\d+([.,]\d+)?(\s*[A-Za-z]{1,3})?$/.test(text)) continue   // "12.5", "12 m"
    if (TEXT_FALSE_POSITIVE.test(text)) continue
    findings.push({ kind: 'text', text, line: lineNumberAt(src, m.index + 1) })
  }

  JSX_ATTR_RE.lastIndex = 0
  while ((m = JSX_ATTR_RE.exec(src)) != null) {
    const text = m[2].trim()
    if (!text) continue
    if (!/[A-Za-z]/.test(text)) continue
    findings.push({ kind: m[1], text, line: lineNumberAt(src, m.index + 1) })
  }

  return findings
}

function isIokMarker(filePath, line) {
  const raw = fs.readFileSync(filePath, 'utf8')
  const lines = raw.split('\n')
  // Same-line or preceding-line marker.
  for (const candidate of [lines[line - 1] ?? '', lines[line - 2] ?? '']) {
    if (/\/\/\s*i18n-ok\b/.test(candidate)) return true
  }
  return false
}

function checkParity() {
  const en = readJson(EN_PATH)
  const ua = readJson(UA_PATH)
  const enKeys = new Set(deepKeys(en))
  const uaKeys = new Set(deepKeys(ua))
  const missingInUa = [...enKeys].filter((k) => !uaKeys.has(k))
  const missingInEn = [...uaKeys].filter((k) => !enKeys.has(k))
  return { ok: missingInUa.length === 0 && missingInEn.length === 0, missingInUa, missingInEn }
}

function checkCoverage() {
  const en = readJson(EN_PATH)
  const enValues = new Set(deepValues(en))
  const allow = readJson(ALLOWLIST_PATH)
  const globalAllow = new Set(allow['*'] ?? [])

  const files = walkTsx(SRC_ROOT)
  const failures = []
  const reportEntries = []

  for (const f of files) {
    const rel = path.relative(PROJECT_ROOT, f)
    const fileAllow = new Set(allow[rel] ?? [])
    const findings = findRawStrings(f)
    for (const fnd of findings) {
      reportEntries.push({ rel, ...fnd })
      if (enValues.has(fnd.text)) continue        // already a translated value
      if (globalAllow.has(fnd.text)) continue     // global brand / acronym
      if (fileAllow.has(fnd.text)) continue       // file-scoped allow-list
      if (isIokMarker(f, fnd.line)) continue      // // i18n-ok marker
      failures.push({ file: rel, line: fnd.line, kind: fnd.kind, text: fnd.text })
    }
  }
  return { ok: failures.length === 0, failures, reportEntries }
}

function main() {
  if (ARG_REPORT) {
    const cov = checkCoverage()
    const grouped = {}
    for (const e of cov.reportEntries) (grouped[e.rel] ??= []).push(e)
    for (const rel of Object.keys(grouped).sort()) {
      console.log(`# ${rel}`)
      for (const e of grouped[rel]) {
        console.log(`  ${e.line.toString().padStart(4)}  [${e.kind}]  ${JSON.stringify(e.text)}`)
      }
    }
    process.exit(0)
  }

  let ok = true
  const lines = []

  if (!ARG_CHECK_COVERAGE_ONLY) {
    const parity = checkParity()
    if (parity.ok) {
      lines.push('FT-P-22 (key parity): PASS')
    } else {
      ok = false
      lines.push('FT-P-22 (key parity): FAIL')
      for (const k of parity.missingInUa) lines.push(`  missing in ua.json: ${k}`)
      for (const k of parity.missingInEn) lines.push(`  missing in en.json: ${k}`)
    }
  }

  if (!ARG_CHECK_PARITY_ONLY) {
    const cov = checkCoverage()
    if (cov.ok) {
      lines.push(`FT-P-23 (t() coverage): PASS  (allow-list size: ${Object.keys(readJson(ALLOWLIST_PATH)).length} groups)`)
    } else {
      ok = false
      lines.push(`FT-P-23 (t() coverage): FAIL  (${cov.failures.length} unallowed raw strings)`)
      for (const f of cov.failures.slice(0, 50)) {
        lines.push(`  ${f.file}:${f.line}  [${f.kind}]  ${JSON.stringify(f.text)}`)
      }
      if (cov.failures.length > 50) lines.push(`  ... and ${cov.failures.length - 50} more`)
    }
  }

  console.log(lines.join('\n'))
  process.exit(ok ? 0 : 1)
}

main()