#!/usr/bin/env node

import { readFile, writeFile } from 'node:fs/promises';
import path from 'node:path';

if (isCliEntry()) {
  runCli(process.argv.slice(2)).catch((error) => {
    console.error(
      `[repair-auth-public-user-codes] ${error instanceof Error ? error.message : String(error)}`,
    );
    process.exit(1);
  });
}

export function repairAuthPublicUserCodesInMigration(migration) {
  if (!migration || !Array.isArray(migration.tables)) {
    throw new Error('迁移 JSON 必须包含 tables 数组。');
  }

  const userTable = migration.tables.find(
    (table) => table?.name === 'user_account',
  );
  if (!userTable || !Array.isArray(userTable.rows)) {
    throw new Error('迁移 JSON 缺少 user_account 表。');
  }

  const usedCodes = new Set();
  const usedUsernames = new Set();
  let maxPublicSequence = 0;
  let maxPhoneUsernameSequence = 0;

  for (const row of userTable.rows) {
    const sequence = parsePublicUserCode(row?.public_user_code);
    if (sequence !== null) {
      maxPublicSequence = Math.max(maxPublicSequence, sequence);
    }
    const phoneUsernameSequence = parsePhoneUsername(row?.username);
    if (phoneUsernameSequence !== null) {
      maxPhoneUsernameSequence = Math.max(
        maxPhoneUsernameSequence,
        phoneUsernameSequence,
      );
    }
  }

  const repairedRows = [];
  for (const row of userTable.rows) {
    if (!row || typeof row !== 'object') {
      continue;
    }

    const originalCode =
      typeof row.public_user_code === 'string' ? row.public_user_code : '';
    const publicSequence = parsePublicUserCode(originalCode);
    const normalizedCode =
      publicSequence === null ? '' : formatPublicUserCode(publicSequence);
    if (publicSequence === null || usedCodes.has(normalizedCode)) {
      const nextSequence = allocatePublicSequence();
      row.public_user_code = formatPublicUserCode(nextSequence);
      repairedRows.push({
        userId: readUserId(row),
        field: 'public_user_code',
        from: originalCode,
        to: row.public_user_code,
      });
    } else {
      row.public_user_code = normalizedCode;
      usedCodes.add(normalizedCode);
    }

    const originalUsername =
      typeof row.username === 'string' ? row.username.trim() : '';
    if (!originalUsername || usedUsernames.has(originalUsername)) {
      const nextUsername = allocateUsername(row, originalUsername);
      row.username = nextUsername;
      repairedRows.push({
        userId: readUserId(row),
        field: 'username',
        from: originalUsername,
        to: nextUsername,
      });
    } else {
      row.username = originalUsername;
      usedUsernames.add(originalUsername);
    }
  }

  return {
    migration: {
      schema_version: migration.schema_version,
      exported_at_micros: migration.exported_at_micros,
      tables: [
        {
          name: 'user_account',
          rows: userTable.rows,
        },
      ],
    },
    repairedRows,
    nextPublicSequence: maxPublicSequence + 1,
  };

  function allocatePublicSequence() {
    let sequence = maxPublicSequence + 1;
    while (usedCodes.has(formatPublicUserCode(sequence))) {
      sequence += 1;
    }
    maxPublicSequence = sequence;
    usedCodes.add(formatPublicUserCode(sequence));
    return sequence;
  }

  function allocateUsername(row, originalUsername) {
    let username;
    if (shouldUsePhoneUsername(row, originalUsername)) {
      do {
        maxPhoneUsernameSequence += 1;
        username = `phone_${String(maxPhoneUsernameSequence).padStart(8, '0')}`;
      } while (usedUsernames.has(username));
    } else {
      const base = sanitizeUsernameBase(
        originalUsername || row.display_name || 'user',
      );
      let suffix =
        parsePublicUserCode(row.public_user_code) ?? maxPublicSequence;
      do {
        username = `${base}_${String(suffix).padStart(8, '0')}`;
        suffix += 1;
      } while (usedUsernames.has(username));
    }
    usedUsernames.add(username);
    return username;
  }
}

function parsePublicUserCode(value) {
  if (typeof value !== 'string') {
    return null;
  }
  const match = value
    .trim()
    .toUpperCase()
    .match(/^SY-?([0-9]{1,8})$/u);
  if (!match) {
    return null;
  }
  const sequence = Number.parseInt(match[1], 10);
  return Number.isSafeInteger(sequence) && sequence > 0 ? sequence : null;
}

function formatPublicUserCode(sequence) {
  return `SY-${String(sequence).padStart(8, '0')}`;
}

function parsePhoneUsername(value) {
  if (typeof value !== 'string') {
    return null;
  }
  const match = value.trim().match(/^phone_([0-9]{1,8})$/u);
  if (!match) {
    return null;
  }
  const sequence = Number.parseInt(match[1], 10);
  return Number.isSafeInteger(sequence) && sequence > 0 ? sequence : null;
}

function shouldUsePhoneUsername(row, originalUsername) {
  const loginMethod =
    typeof row.login_method === 'string' ? row.login_method.trim() : '';
  return (
    /^phone_[0-9]{1,8}$/u.test(originalUsername) ||
    loginMethod === 'phone' ||
    loginMethod === 'password'
  );
}

function sanitizeUsernameBase(value) {
  const sanitized = String(value)
    .trim()
    .replace(/[^A-Za-z0-9_]+/gu, '_')
    .replace(/^_+|_+$/gu, '');
  return sanitized || 'user';
}

function readUserId(row) {
  return typeof row.user_id === 'string' && row.user_id.trim()
    ? row.user_id
    : '<unknown>';
}

async function runCli(argv) {
  const options = parseCliArgs(argv);
  const inputPath = path.resolve(options.in);
  const outputPath = path.resolve(options.out);
  const migration = JSON.parse(await readFile(inputPath, 'utf8'));
  const result = repairAuthPublicUserCodesInMigration(migration);

  if (!options.dryRun) {
    await writeFile(
      outputPath,
      `${JSON.stringify(result.migration, null, 2)}\n`,
      'utf8',
    );
  }

  console.log(
    `[repair-auth-public-user-codes] ${options.dryRun ? 'dry-run' : `已写入 ${outputPath}`}，修复 ${result.repairedRows.length} 项`,
  );
  if (result.repairedRows.length > 0) {
    console.table(result.repairedRows.slice(0, 50));
    if (result.repairedRows.length > 50) {
      console.log(
        `[repair-auth-public-user-codes] 仅展示前 50 项，共 ${result.repairedRows.length} 项。`,
      );
    }
  }
}

function parseCliArgs(argv) {
  const options = {
    in: '',
    out: '',
    dryRun: false,
  };

  for (let index = 0; index < argv.length; index += 1) {
    const arg = argv[index];
    const readValue = (name) => {
      const value = argv[index + 1];
      if (!value || value.startsWith('--')) {
        throw new Error(`${name} 缺少参数值。`);
      }
      index += 1;
      return value;
    };

    if (arg === '--in') {
      options.in = readValue(arg);
    } else if (arg === '--out') {
      options.out = readValue(arg);
    } else if (arg === '--dry-run') {
      options.dryRun = true;
    } else {
      throw new Error(`未知参数: ${arg}`);
    }
  }

  if (!options.in) {
    throw new Error('必须传入 --in。');
  }
  if (!options.out && !options.dryRun) {
    throw new Error('非 dry-run 必须传入 --out。');
  }
  return options;
}

function isCliEntry() {
  const entry = process.argv[1];
  return entry
    ? import.meta.url === `file://${entry.replace(/\\/gu, '/')}`
    : false;
}