/**
 * Copyright 2017 Google Inc. All rights reserved.
 * Modifications copyright (c) Microsoft Corporation.
 *
 * 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 { EventEmitter } from 'events';
import { assert } from '../helper';
import { ConnectionTransport, ProtocolRequest, ProtocolResponse, protocolLog } from '../transport';
import { Protocol } from './protocol';
import { InnerLogger } from '../logger';
import { rewriteErrorMessage } from '../debug/stackTrace';

export const ConnectionEvents = {
  Disconnected: Symbol('Disconnected'),
};

// FFPlaywright uses this special id to issue Browser.close command which we
// should ignore.
export const kBrowserCloseMessageId = -9999;

export class FFConnection extends EventEmitter {
  private _lastId: number;
  private _callbacks: Map<number, {resolve: Function, reject: Function, error: Error, method: string}>;
  private _transport: ConnectionTransport;
  private _logger: InnerLogger;
  readonly _sessions: Map<string, FFSession>;
  _closed: boolean;

  on: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  addListener: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  off: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  removeListener: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  once: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;

  constructor(transport: ConnectionTransport, logger: InnerLogger) {
    super();
    this._transport = transport;
    this._logger = logger;
    this._lastId = 0;
    this._callbacks = new Map();

    this._transport.onmessage = this._onMessage.bind(this);
    this._transport.onclose = this._onClose.bind(this);
    this._sessions = new Map();
    this._closed = false;

    this.on = super.on;
    this.addListener = super.addListener;
    this.off = super.removeListener;
    this.removeListener = super.removeListener;
    this.once = super.once;
  }

  async send<T extends keyof Protocol.CommandParameters>(
    method: T,
    params?: Protocol.CommandParameters[T]
  ): Promise<Protocol.CommandReturnValues[T]> {
    const id = this.nextMessageId();
    this._rawSend({id, method, params});
    return new Promise((resolve, reject) => {
      this._callbacks.set(id, {resolve, reject, error: new Error(), method});
    });
  }

  nextMessageId(): number {
    return ++this._lastId;
  }

  _rawSend(message: ProtocolRequest) {
    if (this._logger._isLogEnabled(protocolLog))
      this._logger._log(protocolLog, 'SEND ► ' + rewriteInjectedScriptEvaluationLog(message));
    this._transport.send(message);
  }

  async _onMessage(message: ProtocolResponse) {
    if (this._logger._isLogEnabled(protocolLog))
      this._logger._log(protocolLog, '◀ RECV ' + JSON.stringify(message));
    if (message.id === kBrowserCloseMessageId)
      return;
    if (message.sessionId) {
      const session = this._sessions.get(message.sessionId);
      if (session)
        session.dispatchMessage(message);
    } else if (message.id) {
      const callback = this._callbacks.get(message.id);
      // Callbacks could be all rejected if someone has called `.dispose()`.
      if (callback) {
        this._callbacks.delete(message.id);
        if (message.error)
          callback.reject(createProtocolError(callback.error, callback.method, message.error));
        else
          callback.resolve(message.result);
      }
    } else {
      Promise.resolve().then(() => this.emit(message.method!, message.params));
    }
  }

  _onClose() {
    this._closed = true;
    this._transport.onmessage = undefined;
    this._transport.onclose = undefined;
    for (const callback of this._callbacks.values())
      callback.reject(rewriteErrorMessage(callback.error, `Protocol error (${callback.method}): Target closed.`));
    this._callbacks.clear();
    for (const session of this._sessions.values())
      session.dispose();
    this._sessions.clear();
    Promise.resolve().then(() => this.emit(ConnectionEvents.Disconnected));
  }

  close() {
    if (!this._closed)
      this._transport.close();
  }

  createSession(sessionId: string, type: string): FFSession {
    const session = new FFSession(this, type, sessionId, message => this._rawSend({...message, sessionId}));
    this._sessions.set(sessionId, session);
    return session;
  }
}

export const FFSessionEvents = {
  Disconnected: Symbol('Disconnected')
};

export class FFSession extends EventEmitter {
  _connection: FFConnection;
  _disposed = false;
  private _callbacks: Map<number, {resolve: Function, reject: Function, error: Error, method: string}>;
  private _targetType: string;
  private _sessionId: string;
  private _rawSend: (message: any) => void;
  private _crashed: boolean = false;
  on: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  addListener: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  off: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  removeListener: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;
  once: <T extends keyof Protocol.Events | symbol>(event: T, listener: (payload: T extends symbol ? any : Protocol.Events[T extends keyof Protocol.Events ? T : never]) => void) => this;

  constructor(connection: FFConnection, targetType: string, sessionId: string, rawSend: (message: any) => void) {
    super();
    this._callbacks = new Map();
    this._connection = connection;
    this._targetType = targetType;
    this._sessionId = sessionId;
    this._rawSend = rawSend;

    this.on = super.on;
    this.addListener = super.addListener;
    this.off = super.removeListener;
    this.removeListener = super.removeListener;
    this.once = super.once;
  }

  markAsCrashed() {
    this._crashed = true;
  }

  async send<T extends keyof Protocol.CommandParameters>(
    method: T,
    params?: Protocol.CommandParameters[T]
  ): Promise<Protocol.CommandReturnValues[T]> {
    if (this._crashed)
      throw new Error('Page crashed');
    if (this._disposed)
      throw new Error(`Protocol error (${method}): Session closed. Most likely the ${this._targetType} has been closed.`);
    const id = this._connection.nextMessageId();
    this._rawSend({method, params, id});
    return new Promise((resolve, reject) => {
      this._callbacks.set(id, {resolve, reject, error: new Error(), method});
    });
  }

  dispatchMessage(object: ProtocolResponse) {
    if (object.id && this._callbacks.has(object.id)) {
      const callback = this._callbacks.get(object.id)!;
      this._callbacks.delete(object.id);
      if (object.error)
        callback.reject(createProtocolError(callback.error, callback.method, object.error));
      else
        callback.resolve(object.result);
    } else {
      assert(!object.id);
      Promise.resolve().then(() => this.emit(object.method!, object.params));
    }
  }

  dispose() {
    for (const callback of this._callbacks.values())
      callback.reject(rewriteErrorMessage(callback.error, `Protocol error (${callback.method}): Target closed.`));
    this._callbacks.clear();
    this._disposed = true;
    this._connection._sessions.delete(this._sessionId);
    Promise.resolve().then(() => this.emit(FFSessionEvents.Disconnected));
  }
}

function createProtocolError(error: Error, method: string, protocolError: { message: string; data: any; }): Error {
  let message = `Protocol error (${method}): ${protocolError.message}`;
  if ('data' in protocolError)
    message += ` ${protocolError.data}`;
  return rewriteErrorMessage(error, message);
}

function rewriteInjectedScriptEvaluationLog(message: ProtocolRequest): string {
  // Injected script is very long and clutters protocol logs.
  // To increase development velocity, we skip replace it with short description in the log.
  if (message.method === 'Runtime.evaluate' && message.params && message.params.expression && message.params.expression.includes('src/injected/injected.ts'))
    return `{"id":${message.id} [evaluate injected script]}`;
  return JSON.stringify(message);
}