name: Close Discussion on PR Merge

on:
  push:
    branches:
      - main

permissions:
  contents: read
  discussions: write

jobs:
  close-discussion:
    runs-on: runner-cluster-htl-set

    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4

      - name: Set Up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: "20"

      - name: Install Dependencies
        run: npm install zx @octokit/graphql

      - name: Close Discussion
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          GITHUB_SHA: ${{ github.sha }}
          GITHUB_REPOSITORY: ${{ github.repository }}
        run: |
          npx zx << 'EOF'
          import { graphql } from "@octokit/graphql";

          (async function () {
            try {
              const token = process.env.GITHUB_TOKEN;
              const commitSha = process.env.GITHUB_SHA;
              const [owner, repo] = process.env.GITHUB_REPOSITORY.split("/");

              if (!token || !commitSha || !owner || !repo) {
                console.log("Missing required environment variables.");
                process.exit(1);
              }

              const graphqlWithAuth = graphql.defaults({
                headers: { authorization: `Bearer ${token}` },
              });

              // Find PR from commit SHA
              const searchQuery = `
                query($owner: String!, $repo: String!, $sha: GitObjectID!) {
                  repository(owner: $owner, name: $repo) {
                    object(oid: $sha) {
                      ... on Commit {
                        associatedPullRequests(first: 1) {
                          nodes {
                            number
                            body
                          }
                        }
                      }
                    }
                  }
                }
              `;

              const prResult = await graphqlWithAuth(searchQuery, {
                owner,
                repo,
                sha: commitSha,
              });

              const pr = prResult.repository.object.associatedPullRequests.nodes[0];
              if (!pr) {
                console.log("No PR found for this commit.");
                return;
              }

              const prNumber = pr.number;
              const prBody = pr.body;

              const match = prBody.match(/#(\d+)/);
              if (!match) {
                console.log("No discussion ID found in PR body.");
                return;
              }

              const discussionNumber = match[1];
              console.log(`Extracted Discussion Number: ${discussionNumber}`);

              // Fetch GraphQL discussion ID
              const discussionQuery = `
                query($owner: String!, $repo: String!, $number: Int!) {
                  repository(owner: $owner, name: $repo) {
                    discussion(number: $number) {
                      id
                    }
                  }
                }
              `;

              //
              try {
                const discussionResponse = await graphqlWithAuth(discussionQuery, {
                  owner,
                  repo,
                  number: parseInt(discussionNumber, 10),
                });

                const discussionQLId = discussionResponse.repository.discussion.id;
                if (!discussionQLId) {
                  console.log("Failed to fetch discussion GraphQL ID.");
                  return;
                }
              } catch (error) {
                console.error("Discussion not found or error occurred while fetching discussion:", error);
                return;
              }

              // Post comment
              const commentMutation = `
                mutation($discussionId: ID!, $body: String!) {
                  addDiscussionComment(input: { discussionId: $discussionId, body: $body }) {
                    comment { id body }
                  }
                }
              `;

              const commentResponse = await graphqlWithAuth(commentMutation, {
                discussionId: discussionQLId,
                body: `Merged with PR #${prNumber}`,
              });

              const commentId = commentResponse.addDiscussionComment.comment.id;
              if (!commentId) {
                console.log("Failed to post the comment.");
                return;
              }

              console.log(`Comment Posted Successfully! Comment ID: ${commentId}`);

              // Mark comment as answer
              const markAnswerMutation = `
                mutation($id: ID!) {
                  markDiscussionCommentAsAnswer(input: { id: $id }) {
                    discussion { id title }
                  }
                }
              `;

              await graphqlWithAuth(markAnswerMutation, { id: commentId });

              console.log("Comment marked as answer successfully!");

            } catch (error) {
              console.error("Error:", error);
              process.exit(1);
            }
          })();
          EOF