generate-changelog.yml

name: Generate AI Changelog

on:
  workflow_call:
    inputs:
      current_tag:
        description: 'Current release tag (e.g., v11.2.0)'
        required: true
        type: string
      previous_tag:
        description: 'Previous tag to compare against (optional, auto-detected if not provided)'
        required: false
        type: string
        default: ''
      product_name:
        description: 'Product name for the changelog'
        required: false
        type: string
        default: 'UTMStack'
      product_description:
        description: 'Product description for context'
        required: false
        type: string
        default: 'Unified Threat Management and SIEM Platform'
    secrets:
      OPENAI_API_KEY:
        required: true
    outputs:
      changelog:
        description: 'Generated changelog content'
        value: ${{ jobs.generate-changelog.outputs.changelog }}
      previous_tag:
        description: 'The previous tag used for comparison'
        value: ${{ jobs.generate-changelog.outputs.previous_tag }}

jobs:
  generate-changelog:
    name: Generate AI Changelog
    runs-on: ubuntu-latest
    outputs:
      changelog: ${{ steps.generate-changelog.outputs.changelog }}
      previous_tag: ${{ steps.get-tags.outputs.previous_tag }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Get previous tag
        id: get-tags
        run: |
          CURRENT_TAG="${{ inputs.current_tag }}"
          echo "Current release tag: $CURRENT_TAG"

          # Use provided previous_tag or auto-detect
          if [ -n "${{ inputs.previous_tag }}" ]; then
            PREVIOUS_TAG="${{ inputs.previous_tag }}"
            echo "Using provided previous tag: $PREVIOUS_TAG"
          else
            # Get all tags sorted by version (newest first)
            ALL_TAGS=$(git tag --sort=-v:refname)
            FOUND_CURRENT=false
            PREVIOUS_TAG=""

            for tag in $ALL_TAGS; do
              if [ "$FOUND_CURRENT" = true ]; then
                PREVIOUS_TAG="$tag"
                break
              fi
              if [ "$tag" = "$CURRENT_TAG" ]; then
                FOUND_CURRENT=true
              fi
            done

            if [ -z "$PREVIOUS_TAG" ]; then
              # No previous tag found, get first commit
              PREVIOUS_TAG=$(git rev-list --max-parents=0 HEAD | head -1)
              echo "No previous tag found, using first commit: $PREVIOUS_TAG"
            fi
          fi

          echo "Previous tag/commit: $PREVIOUS_TAG"
          echo "current_tag=$CURRENT_TAG" >> $GITHUB_OUTPUT
          echo "previous_tag=$PREVIOUS_TAG" >> $GITHUB_OUTPUT

      - name: Get commits between tags
        id: get-commits
        run: |
          CURRENT_TAG="${{ steps.get-tags.outputs.current_tag }}"
          PREVIOUS_TAG="${{ steps.get-tags.outputs.previous_tag }}"

          echo "Getting commits between $PREVIOUS_TAG and $CURRENT_TAG"

          # Get commit messages with hash, author, and message
          COMMITS=$(git log ${PREVIOUS_TAG}..${CURRENT_TAG} --pretty=format:"- %h %s (%an)" --no-merges)

          # Count commits
          COMMIT_COUNT=$(git rev-list --count ${PREVIOUS_TAG}..${CURRENT_TAG} --no-merges)

          echo "Found $COMMIT_COUNT commits"

          # Save commits to file (to handle multiline)
          echo "$COMMITS" > /tmp/commits.txt

          # Also get changed files summary
          CHANGED_FILES=$(git diff --stat ${PREVIOUS_TAG}..${CURRENT_TAG} | tail -1)
          echo "changed_files=$CHANGED_FILES" >> $GITHUB_OUTPUT
          echo "commit_count=$COMMIT_COUNT" >> $GITHUB_OUTPUT

      - name: Generate changelog with OpenAI
        id: generate-changelog
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
          PRODUCT_NAME: ${{ inputs.product_name }}
          PRODUCT_DESCRIPTION: ${{ inputs.product_description }}
        run: |
          COMMITS=$(cat /tmp/commits.txt)
          CURRENT_TAG="${{ steps.get-tags.outputs.current_tag }}"
          PREVIOUS_TAG="${{ steps.get-tags.outputs.previous_tag }}"
          COMMIT_COUNT="${{ steps.get-commits.outputs.commit_count }}"
          CHANGED_FILES="${{ steps.get-commits.outputs.changed_files }}"

          # Create the prompt
          PROMPT="You are a product marketing writer creating release notes for end users of a software product.

          Product: $PRODUCT_NAME - $PRODUCT_DESCRIPTION
          Release: $CURRENT_TAG

          Here are the commit messages from this release:
          $COMMITS

          Create user-friendly release notes in markdown format. This is for NON-TECHNICAL end users who want to know what's new and improved in the product.

          IMPORTANT RULES:
          1. ONLY include changes that DIRECTLY AFFECT END USERS - things they can see, use, or benefit from
          2. COMPLETELY IGNORE internal/technical changes like:
             - CI/CD, GitHub Actions, deployment pipelines
             - Code refactoring, component restructuring
             - Database migrations, backend infrastructure
             - Internal API changes, gRPC, service communication
             - Developer tooling, linting, formatting
             - README updates, internal documentation
          3. Write in simple, non-technical language
          4. Focus on BENEFITS to the user, not implementation details
          5. Group into these categories ONLY (skip empty categories):
             - **What's New** - New features users can now use
             - **Improved** - Enhancements to existing features
             - **Fixed** - Bugs that were affecting users
          6. Start with a brief 1-2 sentence summary of the release highlights
          7. Use bullet points, be concise (one line per item)
          8. Do NOT wrap output in markdown code blocks
          9. Do NOT include commit hashes or author names
          10. If most commits are internal/technical, just summarize with 'Minor improvements and bug fixes'

          Write the release notes directly in markdown format, ready to be used as-is."

          # Call OpenAI API
          RESPONSE=$(curl -s https://api.openai.com/v1/chat/completions \
            -H "Content-Type: application/json" \
            -H "Authorization: Bearer $OPENAI_API_KEY" \
            -d "$(jq -n \
              --arg prompt "$PROMPT" \
              '{
                model: "gpt-4o-mini",
                messages: [
                  {role: "system", content: "You are a technical writer specializing in software changelogs."},
                  {role: "user", content: $prompt}
                ],
                temperature: 0.3,
                max_tokens: 2000
              }')")

          # Extract the changelog from response
          CHANGELOG=$(echo "$RESPONSE" | jq -r '.choices[0].message.content // empty')

          if [ -z "$CHANGELOG" ]; then
            echo "Error: Failed to generate changelog"
            echo "Response: $RESPONSE"
            # Fallback to simple commit list
            CHANGELOG="## What's Changed

          $COMMITS

          **Full Changelog**: https://github.com/${{ github.repository }}/compare/${PREVIOUS_TAG}...${CURRENT_TAG}"
          fi

          # Add comparison link at the end
          CHANGELOG="${CHANGELOG}

          ---
          **Full Changelog**: https://github.com/${{ github.repository }}/compare/${PREVIOUS_TAG}...${CURRENT_TAG}"

          # Save changelog to file
          echo "$CHANGELOG" > /tmp/changelog.md

          # Output changelog using multiline format
          echo "changelog<<EOF" >> $GITHUB_OUTPUT
          cat /tmp/changelog.md >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

      - name: Output changelog preview
        run: |
          echo "## Generated Changelog Preview"
          echo ""
          cat /tmp/changelog.md