/*
 * 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 axios from 'axios';
// eslint-disable-next-line @typescript-eslint/camelcase
import { cloudbuild_v1 } from 'googleapis';

import { keyManager } from './keymanager';

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

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

const GITHUB_API_BASE = 'https://api.github.com';

const GITHUB_URL_REPO_REGEX = /repos\/([^/]+\/[^/]+)\//;

function statusToState(status: string): string {
  switch (status) {
    case 'QUEUED':
    case 'WORKING':
      return 'pending';
    case 'SUCCESS':
      return 'success';
    case 'FAILURE':
      return 'failure';
    default:
      return 'error';
  }
}

function statusToDescription(status: string): string {
  switch (status) {
    case 'QUEUED':
      return 'Build queued.';
    case 'WORKING':
      return 'Build started.';
    case 'SUCCESS':
      return 'Build succeeded.';
    case 'FAILURE':
      return 'Build failed.';
    case 'INTERNAL_ERROR':
      return 'Build internal error.';
    case 'TIMEOUT':
      return 'Build timed out.';
    case 'CANCELLED':
      return 'Build cancelled.';
    default:
      return 'Build status unknown.';
  }
}

async function makeRequest(uri: string, body: any) {
  const repoMatch = GITHUB_URL_REPO_REGEX.exec(uri);
  if (!repoMatch) {
    throw new Error('Could not parse github url.');
  }
  const githubToken = await keyManager.getGithubToken(repoMatch[1]);
  return axios.post(uri, body, {
    headers: {
      'User-Agent': 'cloudbuild-github',
    },
    auth: {
      username: 'token',
      password: githubToken,
    },
  });
}

export default async function handleBuildEvent(data: string): Promise<void> {
  const build: Build = JSON.parse(Buffer.from(data, 'base64').toString('utf8'));

  let repoName: string | null = null;
  let revisionId: string | null = null;
  if (!build.substitutions) {
    // No substitutions for triggered builds, we'll post to the commit instead.
    const repoSource = build.sourceProvenance!.resolvedRepoSource;
    // eslint-disable-next-line prefer-destructuring
    const cloudbuildRepoName = repoSource!.repoName;
    if (!cloudbuildRepoName!.startsWith('github-')) {
      // Not a github repo.
      return;
    }
    repoName = cloudbuildRepoName!
      .substring('github-'.length)
      .replace('-', '/');
    revisionId = repoSource!.commitSha!;
  }

  const statusesUrl =
    repoName && revisionId
      ? `${GITHUB_API_BASE}/repos/${repoName}/statuses/${revisionId}`
      : build.substitutions![STATUSES_URL_KEY];
  if (!statusesUrl) {
    // A non-triggered build not from the webhook, nothing to do.
    return;
  }

  const status = {
    state: statusToState(build.status!),
    // eslint-disable-next-line @typescript-eslint/camelcase
    target_url: build.logUrl,
    description: statusToDescription(build.status!),
    context: 'ci/cloudbuild',
  };

  const statusResponse: any = await makeRequest(statusesUrl, status);
  if (!statusResponse.data.state) {
    throw new Error(
      `Failed to set status: ${JSON.stringify(statusResponse.data)}`,
    );
  }

  const commentsUrl =
    repoName && revisionId
      ? `${GITHUB_API_BASE}/repos/${repoName}/commits/${revisionId}/comments`
      : build.substitutions![COMMENTS_URL_KEY];
  if (!commentsUrl) {
    // A non-triggered build not from the webhook, nothing to do (we shouldn't
    // actually get here since we have a similar check for statuses).
    return;
  }

  let comment;
  switch (build.status) {
    case 'QUEUED':
    case 'WORKING':
    case 'CANCELLED':
    case 'STATUS_UNKNOWN':
      return;
    case 'SUCCESS': {
      if (repoName) {
        // Don't comment on success for triggered builds.
        return;
      }
      comment = `Build succeded. If you have approval, you're ready to merge!\n\nLogs:\n${
        build.logUrl
      }`;
      break;
    }
    case 'FAILURE':
      comment = `Build failed. Check the logs and try again.\n\nLogs:\n${
        build.logUrl
      }`;
      break;
    default:
      comment = `Build terminated with unknown error. You may want to retry.\n\nLogs:\n${
        build.logUrl
      }`;
      break;
  }
  const commentResponse: any = await makeRequest(commentsUrl, {
    body: comment,
  });
  if (!commentResponse.data.id) {
    throw new Error(
      `Failed to set comment: ${JSON.stringify(commentResponse.data)}`,
    );
  }
}