name: vociferate/decorate-pr
description: >
  Decorate pull requests with coverage badges, unreleased changelog entries,
  and other useful review information. Updates existing comment or creates a
  new one if it doesn't exist.

inputs:
  coverage-percentage:
    description: >
      Computed coverage percentage (0-100). Typically from coverage-badge
      action outputs.
    required: true
  badge-url:
    description: >
      Browser-facing URL for the coverage badge image (SVG). Typically from
      coverage-badge action outputs.
    required: true
  changelog:
    description: Path to changelog file relative to repository root.
    required: false
    default: CHANGELOG.md
  comment-title:
    description: >
      Title/identifier for the PR comment. Used to locate existing comment
      for updates. Defaults to 'Vociferate Review'.
    required: false
    default: 'Vociferate Review'
  token:
    description: >
      GitHub or Gitea token for posting PR comments. Defaults to the
      workflow token.
    required: false
    default: ''

outputs:
  comment-id:
    description: Numeric ID of the posted or updated PR comment.
    value: ${{ steps.post-comment.outputs.comment_id }}
  comment-url:
    description: URL to the posted or updated PR comment.
    value: ${{ steps.post-comment.outputs.comment_url }}

runs:
  using: composite
  steps:
    - name: Validate PR context
      id: validate
      shell: bash
      env:
        GITHUB_EVENT_NAME: ${{ github.event_name }}
        PR_NUMBER: ${{ github.event.pull_request.number }}
      run: |
        set -euo pipefail

        if [[ "$GITHUB_EVENT_NAME" != "pull_request" ]]; then
          echo "This action only works on pull_request events" >&2
          exit 1
        fi

        if [[ -z "$PR_NUMBER" ]]; then
          echo "Could not determine PR number from context" >&2
          exit 1
        fi

        printf 'pr_number=%s\n' "$PR_NUMBER" >> "$GITHUB_OUTPUT"

    - name: Extract changelog unreleased entries
      id: extract-changelog
      shell: bash
      env:
        CHANGELOG: ${{ inputs.changelog }}
      run: |
        set -euo pipefail

        if [[ ! -f "$CHANGELOG" ]]; then
          printf 'unreleased_entries=%s\n' "" >> "$GITHUB_OUTPUT"
          exit 0
        fi

        # Extract everything between [Unreleased] header and the next [X.Y.Z] header
        unreleased="$(awk '
          /^## \[Unreleased\]/ { in_unreleased=1; next }
          /^## \[[0-9]+\.[0-9]+\.[0-9]+\]/ { if (in_unreleased) exit }
          in_unreleased && NF { print }
        ' "$CHANGELOG")"

        # Use a temporary file to handle multiline content
        tmp_file=$(mktemp)
        printf '%s' "$unreleased" > "$tmp_file"
        
        # Read it back and set as output
        delimiter="EOF_CHANGELOG"
        printf '%s<<%s\n' "unreleased_entries<<$delimiter" "$delimiter" >> "$GITHUB_OUTPUT"
        cat "$tmp_file" >> "$GITHUB_OUTPUT"
        printf '%s\n' "$delimiter" >> "$GITHUB_OUTPUT"
        
        rm -f "$tmp_file"

    - name: Build PR comment markdown
      id: build-comment
      shell: bash
      env:
        COMMENT_TITLE: ${{ inputs.comment-title }}
        COVERAGE_PCT: ${{ inputs.coverage-percentage }}
        BADGE_URL: ${{ inputs.badge-url }}
        UNRELEASED: ${{ steps.extract-changelog.outputs.unreleased_entries }}
      run: |
        set -euo pipefail

        # Start building the comment
        tmp_file=$(mktemp)
        
        # Add title and coverage section
        cat > "$tmp_file" << 'EOF'
<!-- vociferate-pr-review -->
EOF
        
        printf '## %s\n\n' "$COMMENT_TITLE" >> "$tmp_file"
        
        # Coverage badge section
        cat >> "$tmp_file" << EOF
### Coverage
![Coverage Badge]($BADGE_URL)

**Coverage:** $COVERAGE_PCT%

EOF
        
        # Changelog section
        if [[ -n "$UNRELEASED" ]]; then
          cat >> "$tmp_file" << 'EOF'
### Unreleased Changes

EOF
          printf '%s\n' "$UNRELEASED" >> "$tmp_file"
          printf '\n' >> "$tmp_file"
        fi
        
        # Add footer
        cat >> "$tmp_file" << 'EOF'
---
*This comment was automatically generated by [vociferate/decorate-pr](https://git.hrafn.xyz/aether/vociferate).*
EOF
        
        # Store as output using delimiter
        delimiter="EOF_COMMENT"
        printf '%s<<%s\n' "comment_body<<$delimiter" "$delimiter" >> "$GITHUB_OUTPUT"
        cat "$tmp_file" >> "$GITHUB_OUTPUT"
        printf '%s\n' "$delimiter" >> "$GITHUB_OUTPUT"
        
        rm -f "$tmp_file"

    - name: Find and update/post PR comment
      id: post-comment
      shell: bash
      env:
        GITHUB_TOKEN: ${{ inputs.token != '' && inputs.token || github.token }}
        PR_NUMBER: ${{ steps.validate.outputs.pr_number }}
        COMMENT_BODY: ${{ steps.build-comment.outputs.comment_body }}
        SERVER_URL: ${{ github.server_url }}
        REPOSITORY: ${{ github.repository }}
      run: |
        set -euo pipefail

        API_URL="${SERVER_URL}/api/v1"
        if [[ "$SERVER_URL" == *"github.com"* ]]; then
          API_URL="https://api.github.com"
        fi

        # List existing comments to find vociferate comment
        comments_url="${API_URL}/repos/${REPOSITORY}/issues/${PR_NUMBER}/comments"
        
        response=$(curl -s -H "Authorization: Bearer ${GITHUB_TOKEN}" "$comments_url")
        
        # Find existing vociferate comment by checking for the marker
        existing_comment_id=$(printf '%s' "$response" | \
          jq -r '.[] | select(.body | contains("vociferate-pr-review")) | .id' 2>/dev/null | \
          head -1 || echo "")

        if [[ -n "$existing_comment_id" ]]; then
          # Update existing comment
          update_url="${API_URL}/repos/${REPOSITORY}/issues/comments/${existing_comment_id}"
          curl -s -X PATCH \
            -H "Authorization: Bearer ${GITHUB_TOKEN}" \
            -H "Content-Type: application/json" \
            -d "$(printf '{"body": %s}' "$(printf '%s' "$COMMENT_BODY" | jq -Rs .)")" \
            "$update_url" > /dev/null
          
          printf 'comment_id=%s\n' "$existing_comment_id" >> "$GITHUB_OUTPUT"
          printf 'comment_url=%s/repos/%s/issues/%s#issuecomment-%s\n' \
            "$SERVER_URL" "$REPOSITORY" "$PR_NUMBER" "$existing_comment_id" >> "$GITHUB_OUTPUT"
        else
          # Create new comment
          create_url="${API_URL}/repos/${REPOSITORY}/issues/${PR_NUMBER}/comments"
          response=$(curl -s -X POST \
            -H "Authorization: Bearer ${GITHUB_TOKEN}" \
            -H "Content-Type: application/json" \
            -d "$(printf '{"body": %s}' "$(printf '%s' "$COMMENT_BODY" | jq -Rs .)")" \
            "$create_url")
          
          comment_id=$(printf '%s' "$response" | jq -r '.id' 2>/dev/null)
          
          printf 'comment_id=%s\n' "$comment_id" >> "$GITHUB_OUTPUT"
          printf 'comment_url=%s/repos/%s/issues/%s#issuecomment-%s\n' \
            "$SERVER_URL" "$REPOSITORY" "$PR_NUMBER" "$comment_id" >> "$GITHUB_OUTPUT"
        fi