import Database from "bun:sqlite";
import { mkdirSync, rmSync } from "node:fs";
import { rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";

import type { MigrationRecord } from "../src/server/db/load-migrations";

import { createDatabase } from "../src/server/db/connection";
import { loadMigrationsFromDir } from "../src/server/db/load-migrations";
import { runMigrations } from "../src/server/db/migrate";
import { createMemoryLogger } from "../src/server/logger";

const RETRYABLE_RM_CODES = new Set(["EBUSY", "ENOTEMPTY", "EPERM"]);

export interface TestDatabaseHandle {
  cleanup: () => void;
  close: () => void;
  db: Database;
  dir: string;
  logger: ReturnType<typeof createMemoryLogger>;
}

export function closeSqliteForTest(db: Database): void {
  try {
    db.exec("PRAGMA wal_checkpoint(TRUNCATE)");
  } catch {
    // 关闭前的 checkpoint 是尽力操作；失败时仍继续 close，避免掩盖原测试断言。
  }

  try {
    db.exec("PRAGMA journal_mode = DELETE");
  } catch {
    // Windows 上 WAL/SHM 句柄释放可能延迟，切回 DELETE 失败时仍继续关闭连接。
  }

  db.close();
  forceBunGc();
  sleepSync(100);
}

export function configureSqliteForTest(db: Database): void {
  // 生产库使用 WAL；测试库切回 DELETE，避免 Windows 上 WAL/SHM 句柄延迟导致清理 EBUSY。
  db.exec("PRAGMA journal_mode = DELETE");
}

export function createMigratedMemoryTestDatabase(prefix: string): TestDatabaseHandle {
  const dir = makeTempDir(prefix);
  const logger = createMemoryLogger();
  const db = new Database(":memory:");
  configureSqliteForTest(db);
  let closed = false;

  runMigrations(db, loadMigrationsFromDir(), dir, logger);

  const close = () => {
    if (closed) return;
    closeSqliteForTest(db);
    closed = true;
  };

  return {
    cleanup: () => {
      close();
      rmRetrySync(dir);
    },
    close,
    db,
    dir,
    logger,
  };
}

export function createMigratedTestDatabase(prefix: string): TestDatabaseHandle {
  return createTestDatabase(prefix, loadMigrationsFromDir());
}

export function createTestDatabase(prefix: string, migrations: MigrationRecord[] = []): TestDatabaseHandle {
  const dir = makeTempDir(prefix);
  const logger = createMemoryLogger();
  const db = createDatabase(dir, logger);
  configureSqliteForTest(db);
  let closed = false;

  if (migrations.length > 0) {
    runMigrations(db, migrations, dir, logger);
  }

  const close = () => {
    if (closed) return;
    closeSqliteForTest(db);
    closed = true;
  };

  return {
    cleanup: () => {
      close();
      rmRetrySync(dir);
    },
    close,
    db,
    dir,
    logger,
  };
}

export function makeTempDir(prefix: string): string {
  const dir = join(tmpdir(), `${prefix}-${Date.now()}-${Math.random().toString(36).slice(2)}`);
  mkdirSync(dir, { recursive: true });
  return dir;
}

export function openTestDatabase(dir: string): Pick<TestDatabaseHandle, "close" | "db" | "logger"> {
  const logger = createMemoryLogger();
  const db = createDatabase(dir, logger);
  configureSqliteForTest(db);
  let closed = false;
  return {
    close: () => {
      if (closed) return;
      closeSqliteForTest(db);
      closed = true;
    },
    db,
    logger,
  };
}

export async function rmRetry(dir: string, retries = 10, delayMs = 500) {
  for (let i = 0; i < retries; i++) {
    try {
      await rm(dir, { force: true, recursive: true });
      return;
    } catch (e) {
      const code = getErrorCode(e);
      if (i === retries - 1 || (code && !RETRYABLE_RM_CODES.has(code))) {
        throw withCleanupMessage(e, dir, i + 1);
      }
      await new Promise((r) => setTimeout(r, delayMs));
    }
  }
}

export function rmRetrySync(dir: string, retries = 300, delayMs = 50): void {
  for (let i = 0; i < retries; i++) {
    try {
      forceBunGc();
      rmSync(dir, { force: true, recursive: true });
      return;
    } catch (e) {
      const code = getErrorCode(e);
      if (i === retries - 1 || (code && !RETRYABLE_RM_CODES.has(code))) {
        throw withCleanupMessage(e, dir, i + 1);
      }
      sleepSync(delayMs);
    }
  }
}

function forceBunGc(): void {
  const bun = (globalThis as typeof globalThis & { Bun?: { gc?: (force?: boolean) => void } }).Bun;
  bun?.gc?.(true);
}

function getErrorCode(error: unknown): string | undefined {
  return typeof error === "object" && error !== null && "code" in error
    ? String((error as { code?: unknown }).code)
    : undefined;
}

function sleepSync(ms: number): void {
  Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0, ms);
}

function withCleanupMessage(error: unknown, dir: string, attempts: number): Error {
  if (!(error instanceof Error)) {
    return new Error(`测试临时目录清理失败：${dir}，已重试 ${attempts} 次，原始错误：${String(error)}`);
  }

  error.message = `测试临时目录清理失败：${dir}，已重试 ${attempts} 次。${error.message}`;
  return error;
}