/**
 * 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 fs from 'fs';
import type EventEmitter from 'events';
import type { ClientSideCallMetadata, StackFrame } from '@protocol/channels';
import type { SerializedClientSideCallMetadata, SerializedStack, SerializedStackFrame } from '@trace/traceUtils';
import { yazl, yauzl } from '../zipBundle';
import { ManualPromise } from './manualPromise';
import type { ActionTraceEvent } from '@trace/trace';
import { calculateSha1 } from './crypto';
import { monotonicTime } from './time';

export function serializeClientSideCallMetadata(metadatas: ClientSideCallMetadata[]): SerializedClientSideCallMetadata {
  const fileNames = new Map<string, number>();
  const stacks: SerializedStack[] = [];
  for (const m of metadatas) {
    if (!m.stack || !m.stack.length)
      continue;
    const stack: SerializedStackFrame[] = [];
    for (const frame of m.stack) {
      let ordinal = fileNames.get(frame.file);
      if (typeof ordinal !== 'number') {
        ordinal = fileNames.size;
        fileNames.set(frame.file, ordinal);
      }
      const stackFrame: SerializedStackFrame = [ordinal, frame.line || 0, frame.column || 0, frame.function || ''];
      stack.push(stackFrame);
    }
    stacks.push([m.id, stack]);
  }
  return { files: [...fileNames.keys()], stacks };
}

export async function mergeTraceFiles(fileName: string, temporaryTraceFiles: string[]) {
  if (temporaryTraceFiles.length === 1) {
    await fs.promises.rename(temporaryTraceFiles[0], fileName);
    return;
  }

  const mergePromise = new ManualPromise();
  const zipFile = new yazl.ZipFile();
  const entryNames = new Set<string>();
  (zipFile as any as EventEmitter).on('error', error => mergePromise.reject(error));

  for (let i = 0; i < temporaryTraceFiles.length; ++i) {
    const tempFile = temporaryTraceFiles[i];
    const promise = new ManualPromise<void>();
    yauzl.open(tempFile, (err, inZipFile) => {
      if (err) {
        promise.reject(err);
        return;
      }
      let pendingEntries = inZipFile.entryCount;
      inZipFile.on('entry', entry => {
        let entryName = entry.fileName;
        if (entry.fileName.startsWith('trace.'))
          entryName = i + '-' + entry.fileName;
        inZipFile.openReadStream(entry, (err, readStream) => {
          if (err) {
            promise.reject(err);
            return;
          }
          if (!entryNames.has(entryName)) {
            entryNames.add(entryName);
            zipFile.addReadStream(readStream!, entryName);
          }
          if (--pendingEntries === 0)
            promise.resolve();
        });
      });
    });
    await promise;
  }

  zipFile.end(undefined, () => {
    zipFile.outputStream.pipe(fs.createWriteStream(fileName)).on('close', () => {
      Promise.all(temporaryTraceFiles.map(tempFile => fs.promises.unlink(tempFile))).then(() => {
        mergePromise.resolve();
      });
    });
  });
  await mergePromise;
}

export async function saveTraceFile(fileName: string, traceEvents: ActionTraceEvent[], saveSources: boolean) {
  const lines: string[] = traceEvents.map(e => JSON.stringify(e));
  const zipFile = new yazl.ZipFile();
  zipFile.addBuffer(Buffer.from(lines.join('\n')), 'trace.trace');

  if (saveSources) {
    const sourceFiles = new Set<string>();
    for (const event of traceEvents) {
      for (const frame of event.stack || [])
        sourceFiles.add(frame.file);
    }
    for (const sourceFile of sourceFiles) {
      await fs.promises.readFile(sourceFile, 'utf8').then(source => {
        zipFile.addBuffer(Buffer.from(source), 'resources/src@' + calculateSha1(sourceFile) + '.txt');
      }).catch(() => {});
    }
  }
  await new Promise(f => {
    zipFile.end(undefined, () => {
      zipFile.outputStream.pipe(fs.createWriteStream(fileName)).on('close', f);
    });
  });
}

export function createTraceEventForExpect(apiName: string, expected: any, stack: StackFrame[], wallTime: number): ActionTraceEvent {
  return {
    type: 'action',
    callId: 'expect@' + wallTime,
    wallTime,
    startTime: monotonicTime(),
    endTime: 0,
    class: 'Test',
    method: 'step',
    apiName,
    params: { expected: generatePreview(expected) },
    snapshots: [],
    log: [],
    stack,
  };
}

function generatePreview(value: any, visited = new Set<any>()): string {
  if (visited.has(value))
    return '';
  visited.add(value);
  if (typeof value === 'string')
    return value;
  if (typeof value === 'number')
    return value.toString();
  if (typeof value === 'boolean')
    return value.toString();
  if (value === null)
    return 'null';
  if (value === undefined)
    return 'undefined';
  if (Array.isArray(value))
    return '[' + value.map(v => generatePreview(v, visited)).join(', ') + ']';
  if (typeof value === 'object')
    return 'Object';
  return String(value);
}