name: PR Preview Package Comment

on:
  workflow_run:
    workflows: ["PR Preview Package"]
    types: [completed]

permissions:
  actions: read
  contents: read
  issues: write
  pull-requests: write

jobs:
  comment:
    if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event == 'pull_request'
    runs-on: ubuntu-latest

    steps:
      - name: Check comment payload artifact
        id: payload
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        with:
          script: |
            const runId = context.payload.workflow_run?.id;
            const { data } = await github.rest.actions.listWorkflowRunArtifacts({
              owner: context.repo.owner,
              repo: context.repo.repo,
              run_id: runId,
              per_page: 100,
            });
            const found = Boolean(
              data.artifacts?.some((artifact) => artifact.name === "pkg-pr-new-comment-payload")
            );
            core.setOutput("found", found ? "true" : "false");
            if (!found) {
              core.notice("No comment payload artifact found for this run; skipping comment.");
            }

      - name: Download comment payload
        if: steps.payload.outputs.found == 'true'
        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
        with:
          name: pkg-pr-new-comment-payload
          repository: ${{ github.repository }}
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ github.token }}

      - name: Comment install command
        if: steps.payload.outputs.found == 'true'
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        with:
          script: |
            const fs = require("fs");
            const payload = JSON.parse(fs.readFileSync("pkg-pr-new-comment-payload.json", "utf8"));
            const url = payload?.url;
            const payloadPr = payload?.pr;
            const sourceRepo = payload?.sourceRepo;
            const sourceBranch = payload?.sourceBranch;
            if (!Number.isInteger(payloadPr)) {
              throw new Error(`Invalid PR number in artifact payload: ${payloadPr}`);
            }
            if (payloadPr <= 0) {
              throw new Error(`Invalid PR number in artifact payload: ${payloadPr}`);
            }
            const issueNumber = payloadPr;
            const runPrNumber = context.payload.workflow_run?.pull_requests?.[0]?.number;
            if (Number.isInteger(runPrNumber) && runPrNumber !== issueNumber) {
              throw new Error(
                `PR number mismatch between workflow_run (${runPrNumber}) and artifact payload (${issueNumber})`,
              );
            }

            if (typeof url !== "string" || url.trim() !== url || /[\u0000-\u001F\u007F]/.test(url)) {
              throw new Error(`Invalid package URL in payload: ${url}`);
            }
            let parsedUrl;
            try {
              parsedUrl = new URL(url);
            } catch {
              throw new Error(`Invalid package URL in payload: ${url}`);
            }
            if (parsedUrl.protocol !== "https:" || parsedUrl.hostname !== "pkg.pr.new") {
              throw new Error(`Invalid package URL in payload: ${url}`);
            }

            const safeRepoPattern = /^[A-Za-z0-9_.-]+\/[A-Za-z0-9_.-]+$/;
            const safeBranchPattern = /^[A-Za-z0-9._\/-]+$/;
            const hasSkillSource =
              typeof sourceRepo === "string" &&
              typeof sourceBranch === "string" &&
              safeRepoPattern.test(sourceRepo) &&
              safeBranchPattern.test(sourceBranch);
            const skillSection = hasSkillSource
              ? [
                  "",
                  "### 🧩 Skill update",
                  "",
                  "```bash",
                  `npx skills add ${sourceRepo}#${sourceBranch} -y -g`,
                  "```",
                ]
              : [
                  "",
                  "### 🧩 Skill update",
                  "",
                  "_Unavailable for this PR because source repo/branch metadata is missing._",
                ];

            const body = [
              "<!-- pkg-pr-new-install-guide -->",
              "## 🚀 PR Preview Install Guide",
              "",
              "### 🧰 CLI update",
              "",
              "```bash",
              `npm i -g ${url}`,
              "```",
              ...skillSection,
            ].join("\n");

            const comments = await github.paginate(github.rest.issues.listComments, {
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueNumber,
              per_page: 100,
            });

            const existing = comments.find((comment) =>
              comment.user?.login === "github-actions[bot]" &&
              typeof comment.body === "string" &&
              comment.body.includes("<!-- pkg-pr-new-install-guide -->")
            );

            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: issueNumber,
                body,
              });
            }