/*
 *  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 {
  RepoManager,
  Issue,
  Commit,
  Repo,
  ACTOR_TYPE,
  ISSUE_STATE,
  MergeRequest,
  MERGE_REQUEST_STATE,
  MERGE_REQUEST_MERGABILITY,
  ENTITY_TYPE,
} from '../../types';
import GitHubVendorManager from './vendormgr';
import assert from 'assert';
import {
  GHCommit,
  GHGitObject,
  GHMutation,
  GHMutationCreateIssueArgs,
  GHMutationCreatePullRequestArgs,
  GHPullRequest,
  GHPullRequestCommit,
} from './api-types';

export default class GitHubRepoManager implements RepoManager {
  vendorMgr: GitHubVendorManager;
  repo: Repo;
  repoId: string;

  constructor(vendorMgr: GitHubVendorManager, repoPath: string) {
    this.vendorMgr = vendorMgr;

    const mobj = /^([^/\s]+)\/([^/\s]+)$/.exec(repoPath);
    assert(mobj, 'invalid repo path');
    const [, owner, repoName] = mobj;

    this.repo = {
      vendor: this.vendorMgr.vendor,
      owner: {
        type: ACTOR_TYPE.UNKNOWN,
        username: owner,
        vendor: this.vendorMgr.vendor,
      },
      name: repoName,
      url: `https://${this.vendorMgr.vendor.domain}/${repoPath}`,
    };
    this.repoId = '';
  }

  public async initialize() {
    const meta = await this.vendorMgr._doRequest(
      `
        query Query($owner: String!, $name: String!) {
          repository(owner: $owner, name: $name) {
            id
            name
            owner {
              login
              __typename
            }
          }
        }
    `,
      {
        owner: this.repo.owner.username,
        name: this.repo.name,
      },
    );
    assert(meta.repository);
    assert(meta.repository.owner);
    this.repoId = meta.repository.id;
    this.repo.name = meta.repository.name;
    this.repo.owner.username = meta.repository.owner.login;
    // @ts-ignore graphql-codegen ignores built-in graphql values
    switch (meta.repository.owner.__typename) {
      case 'Organization':
        this.repo.owner.type = ACTOR_TYPE.ORG;
        break;
      case 'User':
        this.repo.owner.type = ACTOR_TYPE.USER;
        break;
    }
    return this;
  }

  public async getIssue(number: string): Promise<Issue> {
    const resp = await this.vendorMgr._doRequest(
      `
        query Query($owner: String!, $name: String!, $number: Int!) {
          repository(owner: $owner, name: $name) {
            issue(number: $number) {
              number
              title
              body
              closed
            }
          }
        }
    `,
      {
        owner: this.repo.owner.username,
        name: this.repo.name,
        number: parseInt(number, 10),
      },
    );
    assert(resp.repository, 'no repository');
    assert(resp.repository.issue, 'no issue');
    const { issue } = resp.repository;
    return {
      type: ENTITY_TYPE.ISSUE,
      id: number,
      content: issue.body,
      title: issue.title,
      repo: this.repo,
      state: issue.closed ? ISSUE_STATE.CLOSED : ISSUE_STATE.OPEN,
      url: `${this.repo.url}/issues/${issue.number}`,
    };
  }

  public async replicateIssue(issue: Issue) {
    const resp = await this.vendorMgr._doRequest<GHMutation, GHMutationCreateIssueArgs>(
      `
        mutation ($input: CreateIssueInput!) {
          createIssue(input: $input) {
            issue {
              number
              title
              body
              closed
            }
          }
        }
    `,
      {
        input: {
          repositoryId: this.repoId,
          title: issue.title,
          body: issue.content,
        },
      },
    );
    assert(resp.createIssue, 'creating issue failed');
    assert(resp.createIssue.issue, 'creating issue failed');
    const replicated = resp.createIssue.issue;
    return {
      type: ENTITY_TYPE.ISSUE as const,
      id: replicated.number.toString(),
      content: replicated.body,
      title: replicated.title,
      repo: this.repo,
      state: replicated.closed ? ISSUE_STATE.CLOSED : ISSUE_STATE.OPEN,
      url: `${this.repo.url}/issues/${replicated.number}`,
    };
  }

  protected async _parsePR(pullRequest: GHPullRequest): Promise<MergeRequest> {
    assert(pullRequest.commits.nodes, 'no commits in pull request (?)');
    assert(
      pullRequest.commits.nodes.length === pullRequest.commits.totalCount,
      "no replicating today, github is fucked up and the commit pagination doesn't fucking work",
    );
    return {
      type: ENTITY_TYPE.MERGE_REQUEST,
      id: pullRequest.number.toString(),
      content: pullRequest.body,
      title: pullRequest.title,
      repo: this.repo,
      state: {
        OPEN: MERGE_REQUEST_STATE.OPEN,
        CLOSED: MERGE_REQUEST_STATE.CLOSED,
        MERGED: MERGE_REQUEST_STATE.MERGED,
      }[pullRequest.state],
      mergability: {
        MERGEABLE: MERGE_REQUEST_MERGABILITY.MERGEABLE,
        CONFLICTING: MERGE_REQUEST_MERGABILITY.CONFLICTING,
        UNKNOWN: null,
      }[pullRequest.mergeable],
      // for some fucking reason GitHub declared that the array of commits could contain null values
      commits: (pullRequest.commits.nodes.filter((n) => !!n) as GHPullRequestCommit[])
        .map((n) => n.commit)
        .map((c) => this._parseCommit(c)),
      isDraft: pullRequest.isDraft,
      url: `${this.repo.url}/pull/${pullRequest.number}`,
    };
  }

  public async getMergeRequest(number: string): Promise<MergeRequest> {
    const resp = await this.vendorMgr._doRequest(
      `
        query Query($owner: String!, $name: String!, $number: Int!) {
          repository(owner: $owner, name: $name) {
            pullRequest(number: $number) {
              number
              title
              body
              isDraft
              mergeable
              state
              commits(first: 250) {
                nodes {
                  commit {
                    messageHeadline
                    messageBody
                    oid
                  }
                }
                totalCount
              }
            }
          }
        }
      `,
      {
        owner: this.repo.owner.username,
        name: this.repo.name,
        number: parseInt(number, 10),
      },
    );
    assert(resp.repository, 'no repository');
    assert(resp.repository.pullRequest, 'no pull request');
    return this._parsePR(resp.repository.pullRequest);
  }

  public async replicateMergeRequest(
    mergeRequest: MergeRequest,
    destBranch: string,
    targetBranch: string,
  ) {
    const resp = await this.vendorMgr._doRequest<GHMutation, GHMutationCreatePullRequestArgs>(
      `
        mutation ($input: CreatePullRequestInput!) {
          createPullRequest(input: $input) {
            pullRequest {
              number
              title
              body
              isDraft
              mergeable
              state
              commits(first: 250) {
                nodes {
                  commit {
                    messageHeadline
                    messageBody
                    oid
                  }
                }
                totalCount
              }
            }
          }
        }      
      `,
      {
        input: {
          repositoryId: this.repoId,
          title: mergeRequest.title,
          body: mergeRequest.content,
          baseRefName: targetBranch,
          headRefName: destBranch,
        },
      },
    );
    assert(resp.createPullRequest, 'no pull request creation object');
    assert(resp.createPullRequest.pullRequest, 'no pull request');
    return this._parsePR(resp.createPullRequest.pullRequest);
  }

  protected _parseCommit(commit: GHCommit): Commit {
    return {
      type: ENTITY_TYPE.COMMIT,
      id: commit.oid,
      title: commit.messageHeadline,
      content: commit.messageBody,
      repo: this.repo,
      url: `${this.repo.url}/commit/${commit.oid}`,
      patchURL: `${this.repo.url}/commit/${commit.oid}.patch`,
      patchContent: () => this.vendorMgr._http_get(`${this.repo.url}/commit/${commit.oid}.patch`),
      diffURL: `${this.repo.url}/commit/${commit.oid}.diff`,
      diffContent: () => this.vendorMgr._http_get(`${this.repo.url}/commit/${commit.oid}.diff`),
    };
  }

  public async getCommit(oid: string) {
    const resp = await this.vendorMgr._doRequest(
      `
        query Query($owner: String!, $name: String!, $oid: GitObjectID!) {
          repository(owner: $owner, name: $name) {
            object(oid: $oid) {
              __typename
              ... on Commit {
                messageHeadline
                messageBody
                oid
              }
            }
          }
        }
      `,
      {
        owner: this.repo.owner.username,
        name: this.repo.name,
        oid: oid,
      },
    );
    assert(resp.repository, 'no repository');
    assert(resp.repository.object, 'no repository object');
    const object = resp.repository.object as GHGitObject | GHCommit;
    assert('__typename' in object && object.__typename === 'Commit', 'object is not a commit (?)');
    return this._parseCommit(object);
  }
}