/*
 *  Copykitku. Copyright (C) 2020 selfisekai <laura@selfisekai.rocks> and other contributors.
 *
 *  This is free software, and you are welcome to redistribute it
 *  under the GNU General Public License 3.0 or later; see the LICENSE file for details,
 *  or, if the file is unavailable, visit <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
 */

import path from 'path';
import simpleGit from 'simple-git';
import addresses from 'email-addresses';
import fs from 'fs-extra';
import os from 'os';
import {
  VendorManager,
  CopykitkuConfig,
  CopykitkuProfile,
  Issue,
  RepoManager,
  VENDOR_TYPE,
  MergeRequest,
  Commit,
} from './types';
import { getConfig, DEFAULT_CONFIG } from './utils';

export default class Copykitku {
  vendorManagers: VendorManager[] = [];
  config: CopykitkuConfig = DEFAULT_CONFIG;

  public async initialize() {
    this.config = getConfig();
    this.vendorManagers = await Promise.all(
      this.config.vendorConfigs
        .map(
          (profile) =>
            [
              require(path.join(__dirname, 'vendor', profile.vendor.type, 'vendormgr')).default,
              profile,
            ] as [any, CopykitkuProfile],
        )
        .map(([VendorMgr, vendor]) => new VendorMgr(vendor.config) as VendorManager)
        .map((VendorMgr) => VendorMgr.initialize()),
    );
    return this;
  }

  public async replicateIssue(sourceIssue: Issue, destination: RepoManager) {
    // if markdown support on destination
    if ([VENDOR_TYPE.GITHUB, VENDOR_TYPE.GITLAB].includes(destination.repo.vendor.type)) {
      sourceIssue.content += `\n\nReplicated from ${sourceIssue.url} with [Copykitku](https://git.sakamoto.pl/laudompat/copykitku)`;
    } else {
      sourceIssue.content += `\n\nReplicated from ${sourceIssue.url} with https://git.sakamoto.pl/laudompat/copykitku`;
    }

    return destination.replicateIssue(sourceIssue);
  }

  public async replicateMergeRequest(
    sourceMR: MergeRequest,
    destination: RepoManager,
    opts: {
      destBranch?: string;
      doNotCommit?: boolean | null;
      doNotPush?: boolean | null;
      patchHook?: string | null;
      remote: string;
      targetBranch: string;
      includePaths?: string[];
      excludePaths?: string[];
    },
  ) {
    const destBranch =
      opts.destBranch || `${sourceMR.repo.owner.username}/${sourceMR.repo.name}/mr-${sourceMR.id}`;
    const {
      doNotCommit,
      doNotPush,
      remote,
      targetBranch,
      patchHook,
      includePaths,
      excludePaths,
    } = opts;

    await this.replicateCommits(sourceMR.commits, destination, {
      destBranch,
      doNotCommit,
      patchHook,
      includePaths,
      excludePaths,
    });

    if (doNotCommit !== true && doNotPush !== true) {
      const git = simpleGit({ baseDir: process.cwd() });
      git.push(remote, destBranch);

      // if markdown support on destination
      if ([VENDOR_TYPE.GITHUB, VENDOR_TYPE.GITLAB].includes(destination.repo.vendor.type)) {
        sourceMR.content += `\n\nReplicated from ${sourceMR.url} with [Copykitku](https://git.sakamoto.pl/laudompat/copykitku)`;
      } else {
        sourceMR.content += `\n\nReplicated from ${sourceMR.url} with https://git.sakamoto.pl/laudompat/copykitku`;
      }

      return destination.replicateMergeRequest(sourceMR, destBranch, targetBranch);
    }
    return true;
  }

  public async replicateCommits(
    sourceCommit: Commit | Commit[],
    destination: RepoManager,
    opts: {
      destBranch: string;
      doNotCommit?: boolean | null;
      patchHook?: string | null;
      includePaths?: string[];
      excludePaths?: string[];
    },
  ) {
    const { destBranch, doNotCommit, patchHook, includePaths, excludePaths } = opts;
    const commits = Array.isArray(sourceCommit) ? sourceCommit : [sourceCommit];

    const patchHookCall = patchHook
      ? (require(path.join(process.cwd(), ...patchHook.split('/'))) as (
          patchContent: string,
        ) => string | Promise<string>)
      : null;

    // saving patch files to /tmp or equivalent
    const tmpPath = fs.mkdtempSync(path.join(os.tmpdir(), 'copykitku-'));
    const patchFiles = await Promise.all(
      commits.map(async (c, index) => {
        const commit = c as Commit & {
          patchFile: string;
          from: string;
        };
        const filename = path.join(
          tmpPath,
          `${index.toString().padStart(4, '0')}-${commit.id}.patch`,
        );
        commit.patchFile = filename;
        let content = await commit.patchContent();

        if (patchHookCall) {
          content = await patchHookCall(content);
        }

        await fs.writeFile(filename, content);

        const [, from] = /^From: ([^\n]+)$/im.exec(content) || [, null];
        const [, date] = /^Date: ([^\n]+)$/im.exec(content) || [, null];
        if (!from || !date) {
          throw new Error(`Commit ${commit.id} could not be parsed`);
        }
        if (!addresses.parseOneAddress(from)) {
          throw new Error(`Commit ${commit.id} author could not be parsed`);
        }
        commit.from = from;
        return commit;
      }),
    );

    const git = simpleGit({ baseDir: process.cwd() });

    // assuming that the repository in cwd is the desired destination
    await git.checkoutLocalBranch(destBranch);

    for (let i = 0; i < patchFiles.length; i += 1) {
      const patch = patchFiles[i];
      await git.applyPatch(
        patch.patchFile,
        ['--index'].concat(
          ...(includePaths || []).map((inc) => ['--include', inc]),
          ...(excludePaths || []).map((inc) => ['--exclude', inc]),
        ),
      );
      if (doNotCommit !== true) {
        await git.commit(patch.title + (patch.content ? '\n\n' + patch.content : ''), {
          '--author': patch.from,
        });
      }
    }
  }
}