name: Review Pull Request with AI

on:
  pull_request:
    types: [opened, synchronize, reopened]
    branches: ["main"]

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: true

jobs:
  ai-review:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip-ai-review') }}
    continue-on-error: true
    runs-on: ubuntu-latest
    name: AI Review
    permissions:
      pull-requests: write
      contents: read
    timeout-minutes: 30
    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4

      - name: Create temporary directory
        run: mkdir -p /tmp/pr_review

      - name: Process PR description
        id: process_pr
        run: |
          PR_BODY_ESCAPED=$(cat << 'EOF'
          ${{ github.event.pull_request.body }}
          EOF
          )
          PROCESSED_BODY=$(echo "$PR_BODY_ESCAPED" | sed -E 's/\[(.*?)\]\(.*?\)/\1/g')
          echo "$PROCESSED_BODY" > /tmp/pr_review/processed_body.txt

      - name: Fetch branches and output the diff
        run: |
          git fetch origin main:main
          git fetch origin pull/${{ github.event.pull_request.number }}/head:pr-branch
          git diff main..pr-branch > /tmp/pr_review/diff.txt

      - name: Prepare review request
        id: prepare_request
        run: |
          PR_TITLE=$(echo "${{ github.event.pull_request.title }}" | sed 's/[()]/\\&/g')
          DIFF_CONTENT=$(cat /tmp/pr_review/diff.txt)
          PROCESSED_BODY=$(cat /tmp/pr_review/processed_body.txt)

          jq -n \
            --arg model "${{ vars.OPENROUTER_MODEL }}" \
            --arg system "You are an experienced developer reviewing a Pull Request. You focus only on what matters and provide concise, actionable feedback.

          Review Context:
          Repository Name: \"${{ github.event.repository.name }}\"
          Repository Description: \"${{ github.event.repository.description }}\"
          Branch: \"${{ github.event.pull_request.head.ref }}\"
          PR Title: \"$PR_TITLE\"

          Guidelines:
          1. Only comment on issues that:
            - Could cause bugs or security issues
            - Significantly impact performance
            - Make the code harder to maintain
            - Violate critical best practices

          2. For each issue:
            - Point to the specific line/file
            - Explain why it's a problem
            - Suggest a concrete fix
            
          3. Praise exceptional solutions briefly, only if truly innovative

          4. Skip commenting on:
            - Minor style issues
            - Obvious changes
            - Working code that could be marginally improved
            - Things that are just personal preference

          Remember:
          Less is more. If the code is good and working, just say so, with a short message." \
            --arg user "This is the description of the pull request:
          \`\`\`markdown
          $PROCESSED_BODY
          \`\`\`

          And here is the diff of the changes, for you to review:
          \`\`\`diff
          $DIFF_CONTENT
          \`\`\`" \
            '{
              "model": $model,
              "messages": [
                {"role": "system", "content": $system},
                {"role": "user", "content": $user}
              ]
            }' > /tmp/pr_review/request.json

      - name: Get AI Review
        id: ai_review
        run: |
          RESPONSE=$(curl -s https://openrouter.ai/api/v1/chat/completions \
            -H "Content-Type: application/json" \
            -H "Authorization: Bearer ${{ secrets.OPENROUTER_API_KEY }}" \
            -d @/tmp/pr_review/request.json)

          echo "### Review" > /tmp/pr_review/response.txt
          echo "" >> /tmp/pr_review/response.txt
          echo "$RESPONSE" | jq -r '.choices[0].message.content' >> /tmp/pr_review/response.txt

      - name: Find Comment
        uses: peter-evans/find-comment@v3
        id: find_comment
        with:
          issue-number: ${{ github.event.pull_request.number }}
          comment-author: "github-actions[bot]"
          body-includes: "### Review"

      - name: Post or Update PR Review
        uses: peter-evans/create-or-update-comment@v4
        with:
          comment-id: ${{ steps.find_comment.outputs.comment-id }}
          issue-number: ${{ github.event.pull_request.number }}
          body-path: /tmp/pr_review/response.txt
          edit-mode: replace