name: Release

on:
  push:
    tags:
      - "v*.*.*"

permissions:
  contents: write

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - name: Check out repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Build release notes from changelog
        env:
          TAG_NAME: ${{ github.ref_name }}
        run: |
          node --input-type=module <<'NODE'
          import { readFileSync, writeFileSync } from "node:fs";
          const tagName = process.env.TAG_NAME;
          const version = tagName?.replace(/^v/, "");
          if (!version) throw new Error("Missing release tag name.");
          const packageJson = JSON.parse(readFileSync("package.json", "utf8"));
          if (packageJson.version !== version) {
            throw new Error(`Tag ${tagName} does not match package.json version ${packageJson.version}.`);
          }
          const changelog = readFileSync("CHANGELOG.md", "utf8");
          const escapedVersion = version.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
          const pattern = new RegExp(`^##\\s+(${escapedVersion}(?:[^\\n]*)?)\\n([\\s\\S]*?)(?=^##\\s+|(?![\\s\\S]))`, "m");
          const match = changelog.match(pattern);
          if (!match) throw new Error(`CHANGELOG.md has no section for ${version}.`);
          const title = match[1].trim();
          const notes = match[2].trim();
          if (!notes) throw new Error(`CHANGELOG.md section for ${version} is empty.`);
          writeFileSync("release-title.txt", `${title}\n`);
          writeFileSync("release-notes.md", `${notes}\n`);
          NODE
      - name: Publish GitHub release
        env:
          GH_TOKEN: ${{ github.token }}
          TAG_NAME: ${{ github.ref_name }}
        run: |
          gh release create "$TAG_NAME" \
            --title "$(cat release-title.txt)" \
            --notes-file release-notes.md \
            --verify-tag