issue-auto-respond.yml

name: Auto-Reply to Issue Comments

on:
  issue_comment:
    types: [created]
  issues:
    types: [assigned]

permissions:
  issues: write
  contents: read

jobs:
  auto-respond:
    if: ${{ !github.event.issue.pull_request && (contains(github.event.issue.labels.*.name, 'community') || contains(github.event.issue.labels.*.name, 'good first issue') || contains(github.event.issue.labels.*.name, 'beginner-friendly') || contains(github.event.issue.labels.*.name, 'first-timers-only') || contains(github.event.issue.labels.*.name, 'up-for-grabs') || contains(github.event.issue.labels.*.name, 'help wanted')) && (github.event_name != 'issue_comment' || (github.event.comment.user.login != 'github-actions[bot]' && github.event.comment.user.login != github.repository_owner)) }}

    runs-on: ubuntu-latest
    timeout-minutes: 5

    steps:
      - name: Check and respond to commenter
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.AUTOMATION_PR_TOKEN || secrets.GITHUB_TOKEN }}
          script: |
            const path = '.github/templates/messages.cjs';
            const ref = context.sha;

            const { data: file } = await github.rest.repos.getContent({
              owner: context.repo.owner,
              repo: context.repo.repo,
              path,
              ref
            });

            if (!file || !file.content) {
              throw new Error('Could not load templates from repository content.');
            }

            const content = Buffer.from(file.content, 'base64').toString('utf8');
            const module = { exports: {} };
            const vm = require('vm');
            vm.runInNewContext(content, { module, exports: module.exports });
            const templates = module.exports;
            const t = templates.issueAutoRespond;

            const issue = context.payload.issue;
            const commenter = context.payload.comment?.user?.login;
            const repoUrl = `https://github.com/${context.repo.owner}/${context.repo.repo}`;
            const excludedUsers = new Set(['github-actions[bot]', context.repo.owner, 'tentoumushii']);

            function fillTemplate(str, vars) {
              return Object.entries(vars).reduce((acc, [key, value]) => {
                return acc
                  .replaceAll(`{${key}}`, String(value))
                  .replaceAll(`@{${key}}`, `@${value}`)
                  .replaceAll(`#{${key}}`, `#${value}`);
              }, str);
            }

            const reactionPool = ['+1', 'laugh', 'hooray', 'heart', 'rocket', 'eyes'];
            function pickRandomReactions(count) {
              const shuffled = [...reactionPool].sort(() => Math.random() - 0.5);
              return shuffled.slice(0, Math.min(count, reactionPool.length));
            }
            async function reactToComment(commentId, reactions) {
              for (const content of reactions) {
                try {
                  await github.rest.reactions.createForIssueComment({
                    owner: context.repo.owner,
                    repo: context.repo.repo,
                    comment_id: commentId,
                    content
                  });
                } catch (e) {
                  console.log(`Reaction ${content} failed: ${e.message}`);
                }
              }
            }
            async function hasAlreadyAssignedNoticePostedForUser(username) {
              const marker = `<!-- already-assigned-notice:${username} -->`;
              const comments = await github.paginate(github.rest.issues.listComments, {
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: issue.number,
                per_page: 100
              });
              return comments.some((comment) => {
                return comment.user?.login === 'github-actions[bot]' && typeof comment.body === 'string' && comment.body.includes(marker);
              });
            }

            if (context.eventName === 'issues') {
              const assignee = context.payload.assignee?.login;

              if (!assignee) {
                console.log('No assignee found in payload; skipping.');
                return;
              }

              const msg = t.assigned;
              const nextSteps = msg.nextSteps.items.map(function(item, i) {
                return `${i + 1}. ${fillTemplate(item, { commenter: assignee, issueNumber: issue.number, repoUrl })}`;
              }).join('\n');

              const resources = msg.resources.items.map(function(item) {
                return '- ' + fillTemplate(item, { commenter: assignee, issueNumber: issue.number, repoUrl });
              }).join('\n');

              const reply = await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: issue.number,
                body: `${fillTemplate(msg.greeting, { commenter: assignee, issueNumber: issue.number, repoUrl })}\n\n${fillTemplate(msg.body, { commenter: assignee, issueNumber: issue.number, repoUrl })}\n\n${fillTemplate(msg.nextSteps.title, { commenter: assignee, issueNumber: issue.number, repoUrl })}\n${nextSteps}\n\n${fillTemplate(msg.resources.title, { commenter: assignee, issueNumber: issue.number, repoUrl })}\n${resources}\n\n${fillTemplate(msg.footer, { commenter: assignee, issueNumber: issue.number, repoUrl })}\n\n${fillTemplate(msg.encouragement, { commenter: assignee, issueNumber: issue.number, repoUrl })}`
              });
              await reactToComment(reply.data.id, pickRandomReactions(3));

              console.log(`Posted assignment instructions for issue #${issue.number} to @${assignee}`);
              return;
            }

            if (!commenter) {
              console.log('No commenter found in payload; skipping.');
              return;
            }

            if (excludedUsers.has(commenter)) {
              console.log(`Skipping @${commenter} — excluded user.`);
              return;
            }

            // Skip repo collaborators (write/admin) — they should never be auto-assigned
            const { data: perm } = await github.rest.repos.getCollaboratorPermissionLevel({
              owner: context.repo.owner,
              repo: context.repo.repo,
              username: commenter
            }).catch(() => ({ data: { permission: 'none' } }));
            if (['admin', 'write'].includes(perm.permission)) {
              console.log(`Skipping @${commenter} — has ${perm.permission} access.`);
              return;
            }

            if (issue.assignees && issue.assignees.length > 0) {
              const assignee = issue.assignees[0].login;
              
              if (assignee !== commenter) {
                if (await hasAlreadyAssignedNoticePostedForUser(commenter)) {
                  console.log(`Skipping duplicate already-assigned reply for @${commenter} on issue #${issue.number}.`);
                  return;
                }
                const msg = t.alreadyAssigned;
                await github.rest.issues.createComment({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  issue_number: issue.number,
                  body: `<!-- already-assigned-notice:${commenter} -->\n${fillTemplate(msg.greeting, { commenter, assignee, issueNumber: issue.number, repoUrl })}\n\n${fillTemplate(msg.body, { commenter, assignee, issueNumber: issue.number, repoUrl })}\n\n${fillTemplate(msg.suggestion, { commenter, assignee, issueNumber: issue.number, repoUrl })}\n\n${fillTemplate(msg.encouragement, { commenter, assignee, issueNumber: issue.number, repoUrl })}`
                });
              }
              return;
            }

            await github.rest.issues.addAssignees({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issue.number,
              assignees: [commenter]
            });
            await reactToComment(context.payload.comment.id, pickRandomReactions(3));

            console.log(`Assigned issue #${issue.number} to @${commenter} — assignment reply will be posted by the issues:assigned event.`);