#!/usr/bin/env node
'use strict';

const fs = require('fs');
const path = require('path');

const ROOT_DIR = process.cwd();
const LOCALES_DIR = path.join(ROOT_DIR, 'locales');
const TEMPLATE_PATH = path.join(LOCALES_DIR, 'template.toml');
const LANG_FILES = ['ko.toml', 'en.toml'];
const FAIL_UNUSED = process.argv.includes('--fail-unused');

const SKIP_DIRS = new Set([
  '.git',
  'node_modules',
  'dist',
  'build',
  '.dart_tool',
  '.idea',
  '.vscode',
  'coverage',
  '.next',
  '.cache',
  'tmp',
  'logs',
]);

const CODE_EXTENSIONS = new Set(['.ts', '.tsx', '.dart']);

const CODE_PATTERNS = [
  /\b(?:i18n\.)?t\s*\(\s*['"]([^'"]+)['"]/g,
  /\btr\s*\(\s*['"]([^'"]+)['"]/g,
  /['"]([^'"]+)['"]\s*\.tr\s*\(/g,
];

function readFileRequired(filePath) {
  if (!fs.existsSync(filePath)) {
    return { ok: false, error: `파일이 없습니다: ${filePath}` };
  }
  return { ok: true, value: fs.readFileSync(filePath, 'utf8') };
}

function parseTomlKeys(filePath) {
  const result = readFileRequired(filePath);
  if (!result.ok) {
    return { ok: false, error: result.error, keys: new Set() };
  }

  const keys = new Set();
  const lines = result.value.split(/\r?\n/);
  let currentSection = [];

  for (const rawLine of lines) {
    const line = rawLine.trim();
    if (!line || line.startsWith('#')) {
      continue;
    }

    if (line.startsWith('[[') && line.endsWith(']]')) {
      const sectionName = line.slice(2, -2).trim();
      currentSection = sectionName ? sectionName.split('.').map((p) => p.trim()).filter(Boolean) : [];
      continue;
    }

    if (line.startsWith('[') && line.endsWith(']')) {
      const sectionName = line.slice(1, -1).trim();
      currentSection = sectionName ? sectionName.split('.').map((p) => p.trim()).filter(Boolean) : [];
      continue;
    }

    const eqIndex = line.indexOf('=');
    if (eqIndex === -1) {
      continue;
    }

    let key = line.slice(0, eqIndex).trim();
    if (!key) {
      continue;
    }

    // Strip quotes if present
    if (key.startsWith('"') && key.endsWith('"')) {
      key = key.slice(1, -1);
    }

    const fullKey = [...currentSection, key].join('.');
    keys.add(fullKey);
  }

  return { ok: true, keys };
}

function walkDir(dirPath, files) {
  const entries = fs.readdirSync(dirPath, { withFileTypes: true });
  for (const entry of entries) {
    if (entry.isDirectory()) {
      if (SKIP_DIRS.has(entry.name)) {
        continue;
      }
      walkDir(path.join(dirPath, entry.name), files);
      continue;
    }

    if (!entry.isFile()) {
      continue;
    }

    const ext = path.extname(entry.name).toLowerCase();
    if (!CODE_EXTENSIONS.has(ext)) {
      continue;
    }

    if (entry.name.includes('.test.') || entry.name.includes('.spec.')) {
      continue;
    }

    files.push(path.join(dirPath, entry.name));
  }
}

function collectCodeKeys() {
  const files = [];
  walkDir(ROOT_DIR, files);

  const keys = new Set();
  for (const filePath of files) {
    const content = fs.readFileSync(filePath, 'utf8');
    for (const pattern of CODE_PATTERNS) {
      let match;
      while ((match = pattern.exec(content)) !== null) {
        if (match[1]) {
          keys.add(match[1]);
        }
      }
    }
  }

  return keys;
}

function difference(aSet, bSet) {
  const result = [];
  for (const item of aSet) {
    if (!bSet.has(item)) {
      result.push(item);
    }
  }
  return result.sort();
}

function printList(title, items) {
  if (items.length === 0) {
    return;
  }
  console.log(`\n${title}`);
  for (const item of items) {
    console.log(`- ${item}`);
  }
}

function main() {
  const errors = [];
  const warnings = [];

  const templateResult = parseTomlKeys(TEMPLATE_PATH);
  if (!templateResult.ok) {
    errors.push(templateResult.error);
  }

  const langKeyMap = new Map();
  for (const fileName of LANG_FILES) {
    const langPath = path.join(LOCALES_DIR, fileName);
    const langResult = parseTomlKeys(langPath);
    if (!langResult.ok) {
      errors.push(langResult.error);
      continue;
    }
    langKeyMap.set(fileName, langResult.keys);
  }

  if (errors.length > 0) {
    console.error('i18n 검증 실패: 필수 리소스 파일을 찾지 못했습니다.');
    for (const error of errors) {
      console.error(`- ${error}`);
    }
    process.exit(1);
  }

  const templateKeys = templateResult.keys;
  const codeKeys = collectCodeKeys();

  for (const [fileName, langKeys] of langKeyMap.entries()) {
    const missingInLang = difference(templateKeys, langKeys);
    if (missingInLang.length > 0) {
      errors.push(`[Sync Error] ${fileName} 누락 키 ${missingInLang.length}개`);
      printList(`${fileName}에 없는 키`, missingInLang);
    }
  }

  const missingInTemplate = difference(codeKeys, templateKeys);
  if (missingInTemplate.length > 0) {
    errors.push(`[Missing Key] template.toml 누락 키 ${missingInTemplate.length}개`);
    printList('template.toml에 없는 코드 사용 키', missingInTemplate);
  }

  const unusedInTemplate = difference(templateKeys, codeKeys);
  if (unusedInTemplate.length > 0) {
    warnings.push(`[Unused Key] template.toml 미사용 키 ${unusedInTemplate.length}개`);
    printList('코드에서 사용되지 않는 키', unusedInTemplate);
  }

  if (errors.length > 0) {
    console.error('\n요약');
    for (const error of errors) {
      console.error(`- ${error}`);
    }
    process.exit(1);
  }

  if (warnings.length > 0) {
    console.warn('\n요약');
    for (const warning of warnings) {
      console.warn(`- ${warning}`);
    }
    if (FAIL_UNUSED) {
      process.exit(1);
    }
  }

  console.log('\n✅ i18n 검증 완료');
}

main();