import sqlite3
import json
from http.server import HTTPServer, BaseHTTPRequestHandler
import urllib.parse

# --- 配置 ---
DATABASE_FILE = "workflows.sqlite"
PORT = 8000


# --- 数据库初始化 ---
def init_db():
    """初始化数据库，如果表不存在则创建它"""
    with sqlite3.connect(DATABASE_FILE) as conn:
        cursor = conn.cursor()
        cursor.execute("""
            CREATE TABLE IF NOT EXISTS workflows (
                name TEXT PRIMARY KEY,
                workflow_json TEXT NOT NULL
            )
        """)
        conn.commit()
    print(f"数据库 '{DATABASE_FILE}' 已准备就绪。")


# --- API 处理器 ---
class PersistentAPIHandler(BaseHTTPRequestHandler):

    def _send_cors_headers(self):
        """发送CORS头部"""
        self.send_header('Access-Control-Allow-Origin', '*')
        self.send_header('Access-Control-Allow-Methods', 'GET, POST, DELETE, OPTIONS')
        self.send_header("Access-Control-Allow-Headers", "X-Requested-With, Content-Type")

    def do_OPTIONS(self):
        """处理预检请求"""
        self.send_response(200, "ok")
        self._send_cors_headers()
        self.end_headers()

    def do_GET(self):
        """处理获取所有工作流的请求"""
        if self.path == '/api/workflow':
            try:
                with sqlite3.connect(DATABASE_FILE) as conn:
                    conn.row_factory = sqlite3.Row  # 让查询结果可以像字典一样访问
                    cursor = conn.cursor()
                    cursor.execute("SELECT name, workflow_json FROM workflows")
                    rows = cursor.fetchall()

                    # 将数据库行转换为前端期望的JSON格式
                    workflows_list = [
                        {"name": row["name"], "workflow": json.loads(row["workflow_json"])}
                        for row in rows
                    ]

                self.send_response(200)
                self.send_header('Content-type', 'application/json')
                self._send_cors_headers()
                self.end_headers()
                self.wfile.write(json.dumps(workflows_list).encode())

            except Exception as e:
                self._send_error(f"获取工作流时出错: {e}")
        else:
            self._send_error("路径未找到", 404)

    def do_POST(self):
        """处理发布/更新工作流的请求"""
        if self.path == '/api/workflow':
            try:
                content_length = int(self.headers['Content-Length'])
                post_data = self.rfile.read(content_length)
                data = json.loads(post_data)

                name = data.get('name')
                workflow_data = data.get('workflow')

                if not name or not workflow_data:
                    return self._send_error("请求体中缺少 'name' 或 'workflow'", 400)

                workflow_json_str = json.dumps(workflow_data)

                with sqlite3.connect(DATABASE_FILE) as conn:
                    cursor = conn.cursor()
                    # 使用 INSERT OR REPLACE 来处理创建和更新，非常方便
                    cursor.execute(
                        "INSERT OR REPLACE INTO workflows (name, workflow_json) VALUES (?, ?)",
                        (name, workflow_json_str)
                    )
                    conn.commit()

                print(f"--- 已保存/更新工作流: {name} ---")
                self.send_response(200)
                self.send_header('Content-type', 'application/json')
                self._send_cors_headers()
                self.end_headers()
                self.wfile.write(json.dumps({"status": "success", "name": name}).encode())

            except Exception as e:
                self._send_error(f"保存工作流时出错: {e}")
        else:
            self._send_error("路径未找到", 404)

    def do_DELETE(self):
        """处理删除指定工作流的请求"""
        parts = self.path.split('/api/workflow/')
        if len(parts) == 2 and parts[1]:
            workflow_name_to_delete = urllib.parse.unquote(parts[1])
            try:
                with sqlite3.connect(DATABASE_FILE) as conn:
                    cursor = conn.cursor()
                    cursor.execute("DELETE FROM workflows WHERE name = ?", (workflow_name_to_delete,))
                    conn.commit()

                    # 检查是否真的有行被删除了
                    if cursor.rowcount > 0:
                        print(f"--- 已删除工作流: {workflow_name_to_delete} ---")
                        self.send_response(200)
                        self.send_header('Content-type', 'application/json')
                        self._send_cors_headers()
                        self.end_headers()
                        self.wfile.write(json.dumps({"status": "deleted", "name": workflow_name_to_delete}).encode())
                    else:
                        self._send_error("工作流未找到，无法删除", 404)

            except Exception as e:
                self._send_error(f"删除工作流时出错: {e}")
        else:
            self._send_error("无效的删除路径", 400)

    def _send_error(self, message, code=500):
        self.send_response(code)
        self.send_header('Content-type', 'application/json')
        self._send_cors_headers()
        self.end_headers()
        self.wfile.write(json.dumps({"status": "error", "message": message}).encode())


# --- 主执行函数 ---
def run(server_class=HTTPServer, handler_class=PersistentAPIHandler, port=PORT):
    # 1. 初始化数据库
    init_db()

    # 2. 启动服务器
    server_address = ('', port)
    httpd = server_class(server_address, handler_class)
    print(f"\n持久化API服务器已在 http://localhost:{port} 上启动...")
    print(f"数据库文件: ./{DATABASE_FILE}")
    print("  - POST   /api/workflow       -> 发布/更新工作流")
    print("  - GET    /api/workflow       -> 获取所有工作流")
    print("  - DELETE /api/workflow/<name> -> 删除指定工作流")
    print("\n按 Ctrl+C 停止服务器。")
    httpd.serve_forever()


if __name__ == '__main__':
    run()