assign-docs-pr.yml

name: Assign Docs PR

on:
  pull_request:
    types: [opened, reopened, edited, ready_for_review, synchronize]

permissions:
  issues: write
  pull-requests: write

jobs:
  assign-docs-pr:
    name: Assign docs PR to source PR author
    runs-on: ubuntu-latest

    steps:
      - name: Assign source PR author
        uses: actions/github-script@v7
        with:
          script: |
            const docsPr = context.payload.pull_request;
            const body = docsPr.body || '';
            const handleAliases = new Map([
              ['tatiana', 'tatianainama'],
              ['tatiana-inama', 'tatianainama'],
            ]);
            const normalizeHandle = (handle) => handleAliases.get(handle.toLowerCase()) || handle;
            const sourceMatch = body.match(/lightdash\/lightdash(?:#|\/pull\/)(\d+)/i);
            const contextualSourceMatch = body.match(/(?:upstream PR|source PR|triggered by|follows|follow-up to)[^#]{0,120}#(\d{5,})/is);
            let sourcePrNumber = sourceMatch ? Number(sourceMatch[1]) : undefined;
            let sourceReason = sourceMatch ? 'body source reference' : undefined;

            if (!sourcePrNumber && contextualSourceMatch) {
              sourcePrNumber = Number(contextualSourceMatch[1]);
              sourceReason = 'body contextual source reference';
            }

            if (!sourcePrNumber) {
              const events = await github.paginate(github.rest.issues.listEventsForTimeline, {
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: docsPr.number,
                per_page: 100,
              });

              const sourceEvent = [...events].reverse().find((event) => (
                event.event === 'cross-referenced' &&
                event.source?.issue?.repository?.full_name === 'lightdash/lightdash' &&
                event.source?.issue?.pull_request
              ));

              if (sourceEvent) {
                sourcePrNumber = sourceEvent.source.issue.number;
                sourceReason = 'timeline cross-reference';
              }
            }

            // Resolve the author to assign: prefer the source PR author, then fall
            // back to an explicit `cc @author` mention in the docs PR body.
            let author;
            let reason;

            if (sourcePrNumber) {
              let sourcePr;
              try {
                ({ data: sourcePr } = await github.rest.pulls.get({
                  owner: 'lightdash',
                  repo: 'lightdash',
                  pull_number: sourcePrNumber,
                }));
              } catch (error) {
                core.info(`Could not load lightdash/lightdash#${sourcePrNumber} (${error.status || error.message}). Falling back to cc mention.`);
              }

              const sourceAuthor = sourcePr?.user?.login ? normalizeHandle(sourcePr.user.login) : undefined;
              if (sourcePr && !sourceAuthor) {
                core.info(`Source PR #${sourcePrNumber} has no author.`);
              } else if (sourceAuthor?.endsWith('[bot]')) {
                core.info(`Source PR #${sourcePrNumber} author is ${sourceAuthor}. Skipping bot assignment.`);
                return;
              } else if (sourceAuthor) {
                author = sourceAuthor;
                reason = sourceReason;
              }
            }

            if (!author) {
              const ccMatch = body.match(/(?:^|\n)\s*cc\s+@([A-Za-z0-9-]+)/i);
              if (ccMatch) {
                const ccAuthor = normalizeHandle(ccMatch[1]);
                if (ccAuthor.endsWith('[bot]')) {
                  core.info(`cc mention is bot @${ccAuthor}. Skipping.`);
                } else {
                  author = ccAuthor;
                  reason = 'cc mention';
                }
              }
            }

            if (!author && docsPr.user?.login && !docsPr.user.login.endsWith('[bot]')) {
              author = normalizeHandle(docsPr.user.login);
              reason = 'docs PR author';
            }

            if (!author) {
              core.info('No lightdash/lightdash source PR author or cc mention found.');
              return;
            }

            try {
              const { data: issue } = await github.rest.issues.addAssignees({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: docsPr.number,
                assignees: [author],
              });

              const wasAssigned = issue.assignees?.some((assignee) => assignee.login === author);
              if (wasAssigned) {
                core.info(`Assigned docs PR #${docsPr.number} to ${author} via ${reason}.`);
                return;
              }
            } catch (error) {
              core.info(`Could not assign docs PR #${docsPr.number} to ${author} (${error.status || error.message}). Falling back to cc comment.`);
            }

            const fallbackBody = `cc @${author}`;
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: docsPr.number,
              per_page: 100,
            });

            const hasFallback = comments.some((comment) => comment.body?.trim() === fallbackBody);
            if (hasFallback) {
              core.info(`Assignment did not land, but fallback comment already exists for ${author}.`);
              return;
            }

            try {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: docsPr.number,
                body: fallbackBody,
              });

              core.info(`Assignment did not land for ${author}. Posted fallback cc comment.`);
            } catch (error) {
              core.info(`Assignment and fallback comment both failed for ${author} (${error.status || error.message}).`);
            }