#!/usr/bin/env node

import { randomUUID } from 'node:crypto';
import { readFile } from 'node:fs/promises';
import path from 'node:path';
import {
  assertReadableFile,
  callSpacetimeProcedure,
  callSpacetimeProcedureViaCli,
  createSpacetimeWebIdentity,
  ensureProcedureOk,
  parseArgs,
} from './spacetime-migration-common.mjs';

const DEFAULT_MIGRATION_IMPORT_CHUNK_SIZE = 512 * 1024;

try {
  const options = parseArgs(process.argv.slice(2));
  if (!options.in) {
    throw new Error('必须传入 --in。');
  }
  if (options.incremental === true && options.replaceExisting === true) {
    throw new Error('--incremental 不能和 --replace-existing 同时使用。');
  }

  const inPath = path.resolve(options.in);
  await assertReadableFile(inPath);
  const migrationJson = await readFile(inPath, 'utf8');
  if (!migrationJson.trim()) {
    throw new Error(`迁移文件为空: ${inPath}`);
  }

  const webOptions = await prepareWebImportOptions(options);
  let result;
  try {
    result = await importMigrationJsonWithFallback(webOptions, migrationJson);
  } finally {
    await revokeTemporaryWebIdentity(webOptions);
  }
  ensureProcedureOk(result);

  console.log(
    `[spacetime:migration:import] ${options.dryRun ? 'dry-run 完成' : '导入完成'}: ${inPath}`,
  );
  printTableStats(result.table_stats);
  printMigrationWarnings(result.warnings);
} catch (error) {
  console.error(
    `[spacetime:migration:import] ${error instanceof Error ? error.message : String(error)}`,
  );
  process.exit(1);
}

async function prepareWebImportOptions(options) {
  if (options.token) {
    return { ...options, useHttp: true };
  }

  const identity = await createSpacetimeWebIdentity(options);
  console.log(
    `[spacetime:migration:import] 已通过 Web API 创建临时 identity: ${identity.identity}`,
  );

  try {
    const authorizeResult = await callSpacetimeProcedureViaCli(
      options,
      'authorize_database_migration_operator',
      {
        bootstrap_secret: options.bootstrapSecret || '',
        operator_identity_hex: identity.identity,
        note: options.note || 'temporary web api migration import',
      },
    );
    ensureProcedureOk(authorizeResult);
  } catch (error) {
    throw new Error(
      `授权临时 Web API identity 失败。当前 spacetime CLI identity 必须已经是迁移操作员；如果目标库迁移操作员表不为空，bootstrap secret 不会越权授权新的操作员。可先用已有迁移操作员授权当前部署机 identity，或为导入脚本提供已有迁移操作员的 --token。原始错误: ${
        error instanceof Error ? error.message : String(error)
      }`,
    );
  }
  console.log(`[spacetime:migration:import] 已授权临时 Web API identity`);

  return {
    ...options,
    token: identity.token,
    temporaryWebIdentity: identity.identity,
    useHttp: true,
  };
}

async function importMigrationJsonWithFallback(options, migrationJson) {
  const chunkSize = resolveChunkSize(options);
  if (Buffer.byteLength(migrationJson, 'utf8') > chunkSize) {
    return importMigrationJsonChunked(options, migrationJson, chunkSize);
  }

  try {
    return await importMigrationJsonDirect(options, migrationJson);
  } catch (error) {
    if (!isRequestBodyTooLargeError(error)) {
      throw error;
    }
    console.warn(
      `[spacetime:migration:import] 直接导入触发 HTTP 413，改用 ${chunkSize} bytes 分片上传。`,
    );
    return importMigrationJsonChunked(options, migrationJson, chunkSize);
  }
}

async function importMigrationJsonDirect(options, migrationJson) {
  const includeTables = resolveImportIncludeTables(options, migrationJson);
  const procedureName =
    options.incremental === true
      ? 'import_database_migration_incremental_from_file'
      : 'import_database_migration_from_file';
  const input = {
    migration_json: migrationJson,
    include_tables: includeTables,
    replace_existing: options.replaceExisting === true,
    dry_run: options.dryRun === true,
  };
  if (options.replaceExisting === true) {
    console.log(
      `[spacetime:migration:import] replace-existing 仅覆盖本次文件内的表: ${includeTables.join(', ') || '无'}`,
    );
  } else if (options.incremental === true) {
    console.log(`[spacetime:migration:import] 使用增量模式，已存在或冲突的行会跳过`);
  }
  return callSpacetimeProcedure(options, procedureName, input);
}

async function importMigrationJsonChunked(options, migrationJson, chunkSize) {
  const includeTables = resolveImportIncludeTables(options, migrationJson);
  const procedureName =
    options.incremental === true
      ? 'import_database_migration_incremental_from_chunks'
      : 'import_database_migration_from_chunks';
  const uploadId = `migration-${Date.now()}-${randomUUID()}`;
  const chunks = splitStringByUtf8Bytes(migrationJson, chunkSize);
  console.log(
    `[spacetime:migration:import] 使用分片导入: upload_id=${uploadId}, chunks=${chunks.length}, chunk_size=${chunkSize}`,
  );
  if (options.replaceExisting === true) {
    console.log(
      `[spacetime:migration:import] replace-existing 仅覆盖本次文件内的表: ${includeTables.join(', ') || '无'}`,
    );
  } else if (options.incremental === true) {
    console.log(`[spacetime:migration:import] 使用增量模式，已存在或冲突的行会跳过`);
  }

  let committed = false;
  try {
    for (let index = 0; index < chunks.length; index += 1) {
      const chunkResult = await callSpacetimeProcedure(
        options,
        'put_database_migration_import_chunk',
        {
          upload_id: uploadId,
          chunk_index: index,
          chunk_count: chunks.length,
          chunk: chunks[index],
        },
      );
      ensureProcedureOk(chunkResult);
      console.log(
        `[spacetime:migration:import] 已上传迁移分片 ${index + 1}/${chunks.length}`,
      );
    }

    const result = await callSpacetimeProcedure(options, procedureName, {
      upload_id: uploadId,
      include_tables: includeTables,
      replace_existing: options.replaceExisting === true,
      dry_run: options.dryRun === true,
    });
    ensureProcedureOk(result);
    committed = true;
    return result;
  } finally {
    if (!committed) {
      await clearMigrationChunksBestEffort(options, uploadId);
    }
  }
}

function resolveImportIncludeTables(options, migrationJson) {
  if (options.replaceExisting !== true) {
    return options.includeTables;
  }

  const migrationTables = readMigrationTableNames(migrationJson);
  if (options.includeTables.length === 0) {
    return migrationTables;
  }

  const requestedTables = new Set(options.includeTables);
  return migrationTables.filter((tableName) => requestedTables.has(tableName));
}

function readMigrationTableNames(migrationJson) {
  let payload;
  try {
    payload = JSON.parse(migrationJson);
  } catch (error) {
    throw new Error(
      `迁移文件 JSON 解析失败: ${error instanceof Error ? error.message : String(error)}`,
    );
  }

  if (!payload || !Array.isArray(payload.tables)) {
    throw new Error('迁移文件缺少 tables 数组。');
  }

  const tableNames = [];
  const seen = new Set();
  for (const table of payload.tables) {
    if (!table || typeof table.name !== 'string' || !table.name.trim()) {
      throw new Error('迁移文件 tables 内存在缺少 name 的表项。');
    }
    const tableName = table.name.trim();
    if (!seen.has(tableName)) {
      tableNames.push(tableName);
      seen.add(tableName);
    }
  }

  return tableNames;
}

function resolveChunkSize(options) {
  const chunkSize = options.chunkSize || DEFAULT_MIGRATION_IMPORT_CHUNK_SIZE;
  if (chunkSize > 1024 * 1024) {
    throw new Error('--chunk-size 不能超过 1048576，避免触发迁移分片 procedure 单片限制。');
  }
  return chunkSize;
}

function splitStringByUtf8Bytes(value, maxBytes) {
  const chunks = [];
  let current = '';
  let currentBytes = 0;
  for (const character of value) {
    const characterBytes = Buffer.byteLength(character, 'utf8');
    if (characterBytes > maxBytes) {
      throw new Error(`单个字符超过 chunk-size，当前 chunk-size: ${maxBytes}`);
    }
    if (currentBytes + characterBytes > maxBytes && current) {
      chunks.push(current);
      current = '';
      currentBytes = 0;
    }
    current += character;
    currentBytes += characterBytes;
  }
  if (current) {
    chunks.push(current);
  }
  return chunks;
}

function isRequestBodyTooLargeError(error) {
  const message = error instanceof Error ? error.message : String(error);
  return (
    message.includes('HTTP 413') ||
    message.toLowerCase().includes('length limit exceeded')
  );
}

async function clearMigrationChunksBestEffort(options, uploadId) {
  try {
    const result = await callSpacetimeProcedure(
      options,
      'clear_database_migration_import_chunks',
      { upload_id: uploadId },
    );
    ensureProcedureOk(result);
    console.warn(`[spacetime:migration:import] 已清理失败导入的临时分片: ${uploadId}`);
  } catch (error) {
    console.warn(
      `[spacetime:migration:import] 清理临时迁移分片失败: ${
        error instanceof Error ? error.message : String(error)
      }`,
    );
  }
}

async function revokeTemporaryWebIdentity(options) {
  if (!options.temporaryWebIdentity) {
    return;
  }

  try {
    const revokeResult = await callSpacetimeProcedure(
      options,
      'revoke_database_migration_operator',
      { operator_identity_hex: options.temporaryWebIdentity },
    );
    ensureProcedureOk(revokeResult);
    console.log(`[spacetime:migration:import] 已撤销临时 Web API identity`);
  } catch (error) {
    console.warn(
      `[spacetime:migration:import] 撤销临时 Web API identity 失败: ${
        error instanceof Error ? error.message : String(error)
      }`,
    );
  }
}

function printTableStats(tableStats) {
  if (!Array.isArray(tableStats) || tableStats.length === 0) {
    return;
  }

  const rows = tableStats.map((stat) => ({
    table: stat.table_name,
    imported: stat.imported_row_count,
    skipped: stat.skipped_row_count,
  }));
  console.table(rows);
}

function printMigrationWarnings(warnings) {
  if (!Array.isArray(warnings) || warnings.length === 0) {
    return;
  }

  console.warn('[spacetime:migration:import] 迁移告警汇总:');
  console.table(
    warnings.map((warning) => ({
      table: warning.table_name,
      kind: warning.warning_kind,
      message: warning.message,
    })),
  );
}