/**
 * Copyright (c) Microsoft Corporation. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import type { BrowserContext } from './browserContext';
import type { APIRequestContext } from './fetch';
import type { StackFrame } from '@protocol/channels';

// Instrumentation can mutate the data, for example change apiName or stepId.
export interface ApiCallData {
  apiName: string;
  title?: string;
  frames: StackFrame[];
  userData: any;
  stepId?: string;
  error?: Error;
}

export interface ClientInstrumentation {
  addListener(listener: ClientInstrumentationListener): void;
  removeListener(listener: ClientInstrumentationListener): void;
  removeAllListeners(): void;
  onApiCallBegin(apiCall: ApiCallData, channel: { type: string, method: string, params?: Record<string, any> }): void;
  onApiCallEnd(apiCall: ApiCallData): void;
  onWillPause(options: { keepTestTimeout: boolean }): void;

  runAfterCreateBrowserContext(context: BrowserContext): Promise<void>;
  runAfterCreateRequestContext(context: APIRequestContext): Promise<void>;
  runBeforeCloseBrowserContext(context: BrowserContext): Promise<void>;
  runBeforeCloseRequestContext(context: APIRequestContext): Promise<void>;
}

export interface ClientInstrumentationListener {
  onApiCallBegin?(apiCall: ApiCallData, channel: { type: string, method: string, params?: Record<string, any>  }): void;
  onApiCallEnd?(apiCall: ApiCallData): void;
  onWillPause?(options: { keepTestTimeout: boolean }): void;

  runAfterCreateBrowserContext?(context: BrowserContext): Promise<void>;
  runAfterCreateRequestContext?(context: APIRequestContext): Promise<void>;
  runBeforeCloseBrowserContext?(context: BrowserContext): Promise<void>;
  runBeforeCloseRequestContext?(context: APIRequestContext): Promise<void>;
}

export function createInstrumentation(): ClientInstrumentation {
  const listeners: ClientInstrumentationListener[] = [];
  return new Proxy({}, {
    get: (obj: any, prop: string | symbol) => {
      if (typeof prop !== 'string')
        return obj[prop];
      if (prop === 'addListener')
        return (listener: ClientInstrumentationListener) => listeners.push(listener);
      if (prop === 'removeListener')
        return (listener: ClientInstrumentationListener) => listeners.splice(listeners.indexOf(listener), 1);
      if (prop === 'removeAllListeners')
        return () => listeners.splice(0, listeners.length);
      if (prop.startsWith('run')) {
        return async (...params: any[]) => {
          for (const listener of listeners)
            await (listener as any)[prop]?.(...params);
        };
      }
      if (prop.startsWith('on')) {
        return (...params: any[]) => {
          for (const listener of listeners)
            (listener as any)[prop]?.(...params);
        };
      }
      return obj[prop];
    },
  });
}
