/*
 * @Date: 2025-06-12 16:48:44
 * @LastEditors: 陈子健
 * @LastEditTime: 2025-06-13 14:23:03
 * @FilePath: /my-score/honoback/db/index.ts
 */
import postgres from "postgres";

// 从环境变量获取数据库连接信息
const DATABASE_URL =
  process.env.DATABASE_URL ||
  `postgresql://${process.env.DB_USER || "postgres"}:${
    process.env.DB_PASSWORD || "postgres"
  }@${process.env.DB_HOST || "localhost"}:${process.env.DB_PORT || "5432"}/${
    process.env.DB_NAME || "media"
  }`;

// 初始化 PostgreSQL 连接
const sql = postgres(DATABASE_URL);

// 将 SQLite 的 ? 占位符转换为 PostgreSQL 的 $1, $2, $3...
function convertQuery(query: string, params: any[]): [string, any[]] {
  let pgQuery = query;
  let paramIndex = 1;
  const pgParams: any[] = [];

  // 替换 ? 为 $1, $2, $3...
  pgQuery = pgQuery.replace(/\?/g, () => {
    if (paramIndex <= params.length) {
      pgParams.push(params[paramIndex - 1]);
    }
    return `$${paramIndex++}`;
  });

  return [pgQuery, pgParams];
}

// 创建一个兼容的数据库接口，模拟 SQLite 的 prepare 方法
class DatabaseAdapter {
  private sql: ReturnType<typeof postgres>;

  constructor(sql: ReturnType<typeof postgres>) {
    this.sql = sql;
  }

  prepare(query: string) {
    return {
      // all() 方法用于查询多条记录
      all: async (...params: any[]) => {
        const [pgQuery, pgParams] = convertQuery(query, params);
        const result = await this.sql.unsafe(pgQuery, pgParams);
        return result;
      },
      // get() 方法用于查询单条记录
      get: async (...params: any[]) => {
        const [pgQuery, pgParams] = convertQuery(query, params);
        const result = await this.sql.unsafe(pgQuery, pgParams);
        return result[0] || null;
      },
      // run() 方法用于执行 INSERT/UPDATE/DELETE
      run: async (...params: any[]) => {
        const [pgQuery, pgParams] = convertQuery(query, params);
        const result = await this.sql.unsafe(pgQuery, pgParams);

        // 如果是 INSERT 语句，返回类似 SQLite 的 lastInsertRowid
        if (query.trim().toUpperCase().startsWith("INSERT")) {
          // PostgreSQL 使用 RETURNING 子句获取插入的 ID
          if (query.includes("RETURNING")) {
            return {
              lastInsertRowid: result[0]?.id || null,
              changes: result.length,
            };
          } else {
            // 如果没有 RETURNING，需要查询最后插入的 ID
            // 注意：这需要表有 id 列且是 SERIAL 类型
            const lastIdResult = await this.sql.unsafe(
              "SELECT lastval() as id"
            );
            return {
              lastInsertRowid: lastIdResult[0]?.id || null,
              changes: result.length || 1,
            };
          }
        }

        return {
          changes: result.length || 0,
        };
      },
    };
  }
}

const db = new DatabaseAdapter(sql);

export { db, sql };