/*
 * MIT License
 *
 * Copyright (c) 2017 Choko (choko@curioswitch.org)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import WebhooksApi from '@octokit/webhooks';
// eslint-disable-next-line @typescript-eslint/camelcase
import { cloudbuild_v1 } from 'googleapis';
import { Response } from 'express-serve-static-core';
import { PullRequest } from 'github-webhook-event-types';
import HttpStatus from 'http-status-codes';
import parseDuration from 'parse-duration';

import getGoogleApis from './gcloud';
import { keyManager } from './keymanager';

import config from './config';
import { COMMENTS_URL_KEY, STATUSES_URL_KEY } from './constants';
import { CloudFunctionsRequest } from './index';

// eslint-disable-next-line @typescript-eslint/camelcase
import Build = cloudbuild_v1.Schema$Build;

const MILLIS_IN_SECOND = 1000;

async function handlePullRequest(event: PullRequest) {
  if (event.action !== 'opened' && event.action !== 'synchronize') {
    console.log('Unhandled event action: ', event.action);
    return;
  }

  const pull = event.pull_request;
  const otherBranchRemoteRef = `refs/pull/${pull.number}/head`;
  const otherBranchLocalRef = `refs/remotes/origin/PR-${pull.number}`;
  const baseBranchRemoteRef = `refs/heads/${pull.base.ref}`;
  const baseBranchLocalRef = `refs/remotes/origin/${pull.base.ref}`;
  const repo = event.repository.full_name;

  const substitutions = {
    _REPOSITORY_URL: pull.base.repo.clone_url,
    _OTHER_BRANCH_REMOTE_REF: otherBranchRemoteRef,
    _OTHER_BRANCH_LOCAL_REF: otherBranchLocalRef,
    _BASE_BRANCH_REMOTE_REF: baseBranchRemoteRef,
    _BASE_BRANCH_LOCAL_REF: baseBranchLocalRef,
    [STATUSES_URL_KEY]: pull.statuses_url,
    [COMMENTS_URL_KEY]: pull.comments_url,
  };

  const prTag = `pr.${pull.number}`;
  const tags = [
    `repo.${event.repository.name.replace('_', '-')}`,
    `sender.${event.sender.login}`,
    prTag,
  ];

  const google = await getGoogleApis();

  const projectId = await google.auth.getProjectId();

  const cloudbuild = google.cloudbuild({ version: 'v1' });
  try {
    const existingBuilds = await cloudbuild.projects.builds.list({
      projectId,
      filter: `tags="${prTag}"`,
    });

    if (existingBuilds.data && existingBuilds.data.builds) {
      existingBuilds.data.builds
        .filter(
          (build) => build.status === 'QUEUED' || build.status === 'WORKING',
        )
        .forEach((build) => {
          console.log(`Found existing build ${build.id}. Cancelling.`);
          cloudbuild.projects.builds.cancel({ projectId, id: build.id });
        });
    }
  } catch (e) {
    console.log(
      'Error fetching existing builds, not cancelling existing builds.',
    );
  }
  console.log(`Starting cloud build for pull request ${pull.number}.`);

  const cloudbuildConfig: Build = config.repos[repo].cloudbuild;
  const sanitizedConfig: Build = cloudbuildConfig.timeout
    ? {
        ...cloudbuildConfig,
        timeout: `${parseDuration(cloudbuildConfig.timeout) /
          MILLIS_IN_SECOND}s`,
      }
    : cloudbuildConfig;

  await cloudbuild.projects.builds.create({
    projectId,
    requestBody: {
      ...sanitizedConfig,
      options: {
        ...sanitizedConfig.options,
        substitutionOption: 'ALLOW_LOOSE',
      },
      substitutions,
      tags,
    },
  });
}

export default async function handleWebhook(
  req: CloudFunctionsRequest,
  res: Response,
) {
  const secret = await keyManager.getWebhookSecret();

  const webhooks = new WebhooksApi({
    secret,
  });

  if (!webhooks.verify(req.rawBody.toString(), req.get('X-Hub-Signature'))) {
    console.error('Invalid signature.');
    res.status(HttpStatus.BAD_REQUEST).end();
    return;
  }

  const event = req.body;
  const eventType = req.get('X-GitHub-Event');
  switch (eventType) {
    case 'pull_request':
      await handlePullRequest(event as PullRequest);
      break;
    default:
      console.log('Unhandled event type: ', eventType);
      break;
  }
  res.status(HttpStatus.OK).end();
}