import { BadRequestException, Injectable } from "@nestjs/common";
import { InjectRepository } from "@nestjs/typeorm";
import { Repository } from "typeorm";
import { PullRequestReviewCommentHistogramDto } from "../histogram/dtos/pull_request_review_comment.dto";
import { GetPrevDateISOString } from "../common/util/datetimes";
import { OrderDirectionEnum } from "../common/constants/order-direction.constant";
import { DbPullRequestReviewCommentGitHubEventsHistogram } from "./entities/pull_request_review_comment_github_events_histogram.entity";
import { applyContribTypeEnumFilters } from "./common/counts";
import { ContributorStatsTypeEnum } from "./dtos/most-active-contrib.dto";
import { DbPullRequestReviewCommentGitHubEvents } from "./entities/pull_request_review_comment_github_events.entity";

/*
 * pull request review comment events, named "PullRequestReviewCommentEvent" in the GitHub API, are when
 * a GitHub actor creates/edits a pull request review comment. These are the threaded
 * comments you'll see in a pull request.
 *
 * for further details, refer to: https://docs.github.com/en/rest/using-the-rest-api/github-event-types?apiVersion=2022-11-28
 */

@Injectable()
export class PullRequestReviewCommentGithubEventsService {
  constructor(
    @InjectRepository(DbPullRequestReviewCommentGitHubEvents, "TimescaleConnection")
    private pullRequestReviewCommentGitHubEventsRepository: Repository<DbPullRequestReviewCommentGitHubEvents>
  ) {}

  baseQueryBuilder() {
    const builder = this.pullRequestReviewCommentGitHubEventsRepository.createQueryBuilder();

    return builder;
  }

  async getPrReviewCommentCountForAuthor(
    username: string,
    contribType: ContributorStatsTypeEnum,
    range: number,
    repos?: string[]
  ): Promise<number> {
    const queryBuilder = this.pullRequestReviewCommentGitHubEventsRepository.manager
      .createQueryBuilder()
      .select("COALESCE(COUNT(*), 0) AS pr_review_comments")
      .from("pull_request_review_comment_github_events", "pull_request_review_comment_github_events")
      .where("LOWER(actor_login) = :username", { username })
      .andWhere("now() - :range_interval::INTERVAL <= event_time", { range_interval: `${range} days` })
      .groupBy("LOWER(actor_login)");

    if (repos && repos.length > 0) {
      queryBuilder.andWhere(`LOWER(repo_name) IN (:...repos)`, { repos });
    }

    applyContribTypeEnumFilters(contribType, queryBuilder, range);

    const result = await queryBuilder.getRawOne<{ pr_review_comments: number }>();
    const parsedResult = parseFloat(`${result?.pr_review_comments ?? "0"}`);

    return parsedResult;
  }

  async getPullReqReviewCommentEventsForLogin(
    username: string,
    range: number,
    repos?: string[]
  ): Promise<DbPullRequestReviewCommentGitHubEvents[]> {
    const queryBuilder = this.baseQueryBuilder()
      .where("LOWER(actor_login) = :username", { username })
      .andWhere("event_time > NOW() - :range_interval::INTERVAL", { range_interval: `${range} days` });

    if (repos && repos.length > 0) {
      queryBuilder.andWhere(`LOWER(repo_name) IN (:...repos)`, { repos });
    }

    return queryBuilder.getMany();
  }

  async genPullRequestReviewCommentHistogram(
    options: PullRequestReviewCommentHistogramDto
  ): Promise<DbPullRequestReviewCommentGitHubEventsHistogram[]> {
    if (!options.contributor && !options.repo && !options.repoIds) {
      throw new BadRequestException("must provide contributor, repo, or repoIds");
    }

    const { range } = options;
    const order = options.orderDirection ?? OrderDirectionEnum.DESC;
    const startDate = GetPrevDateISOString(options.prev_days_start_date ?? 0);
    const width = options.width ?? 1;

    const queryBuilder = this.pullRequestReviewCommentGitHubEventsRepository.manager
      .createQueryBuilder()
      .select("time_bucket(:width_interval::INTERVAL, event_time)", "bucket")
      .addSelect("count(CASE WHEN LOWER(pr_review_comment_action) = 'created' THEN 1 END)", "all_review_comments")
      .addSelect(
        "count(CASE WHEN LOWER(review_comment_author_association) = 'collaborator' THEN 1 END)",
        "collaborator_associated_review_comments"
      )
      .addSelect(
        "count(CASE WHEN LOWER(review_comment_author_association) = 'contributor' THEN 1 END)",
        "contributor_associated_review_comments"
      )
      .addSelect(
        "count(CASE WHEN LOWER(review_comment_author_association) = 'member' THEN 1 END)",
        "member_associated_review_comments"
      )
      .addSelect(
        "count(CASE WHEN LOWER(review_comment_author_association) = 'none' THEN 1 END)",
        "non_associated_review_comments"
      )
      .addSelect(
        "count(CASE WHEN LOWER(review_comment_author_association) = 'owner' THEN 1 END)",
        "owner_associated_review_comments"
      )
      .from("pull_request_review_comment_github_events", "pull_request_review_comment_github_events")
      .where(`:start_date::TIMESTAMP >= "pull_request_review_comment_github_events"."event_time"`, {
        start_date: startDate,
      })
      .andWhere(
        `:start_date::TIMESTAMP - :range_interval::INTERVAL <= "pull_request_review_comment_github_events"."event_time"`,
        {
          start_date: startDate,
          range_interval: `${range} days`,
        }
      )
      .groupBy("bucket")
      .orderBy("bucket", order)
      .setParameter("width_interval", `${width} days`);

    /* filter on the provided pull request review author */
    if (options.contributor) {
      queryBuilder.andWhere(
        `LOWER("pull_request_review_comment_github_events"."review_comment_author_login") = LOWER(:author)`,
        {
          author: options.contributor,
        }
      );
    }

    /* filter on the provided repo names */
    if (options.repo) {
      queryBuilder.andWhere(`LOWER("pull_request_review_comment_github_events"."repo_name") IN (:...repoNames)`, {
        repoNames: options.repo.toLowerCase().split(","),
      });
    }

    /* filter on the provided repo ids */
    if (options.repoIds) {
      queryBuilder.andWhere(`"pull_request_review_comment_github_events"."repo_id" IN (:...repoIds)`, {
        repoIds: options.repoIds.split(","),
      });
    }

    const rawResults = await queryBuilder.getRawMany();

    return rawResults as DbPullRequestReviewCommentGitHubEventsHistogram[];
  }
}