name: PR Title Checker

on:
  pull_request:
    types: [opened, edited, synchronize]

jobs:
  enforce-pr-title:
    name: Validate PR Title Format
    runs-on: ubuntu-latest
    steps:
      - name: Check PR Title and Manage Labels/Comments
        env:
          API_TOKEN: ${{ secrets.BOT_ACCESS_TOKEN }}
          API_BASE_URL: https://git.psmattas.com/api/v1
          REPO: ${{ gitea.repository }}
          PR_NUMBER: ${{ gitea.event.pull_request.number }}
          PR_TITLE: ${{ gitea.event.pull_request.title }}
          COMMENT_BODY_INVALID: |
            Hi @${{ gitea.actor }}, thanks for the contribution!

            The title of this pull request does not follow the required format. This PR is currently **blocked from merging**.

            To fix this, please update the title to match the following structure:
            **`EC-[ISSUE_NUMBER]: [TYPE]: [Your Description]`**

            - **Valid [TYPE] values are:** `FEAT`, `FIX`, `DOCS`, `REFACTOR`, `STYLE`, `PERF`, `TEST`, `CHORE`
            - **Example:** `EC-42: FEAT: Add new user login endpoint`

            Once you have updated the title, this check will re-run automatically and remove the blocking label.

            <!-- PR_TITLE_VALIDATOR_COMMENT -->
          COMMENT_BODY_WIP: |
            Hi @${{ gitea.actor }}, this pull request has been marked as a **Work in Progress**.

            While in this state, it is **blocked from merging**.

            When the PR is ready for review, please remove the `WIP:` prefix from the title. This check will re-run automatically and remove the blocking label.

            <!-- WIP_VALIDATOR_COMMENT -->
        run: |
          WIP_LABEL="status: work-in-progress"
          INVALID_LABEL="status: invalid-title"
          WIP_REGEX="^WIP:"
          FORMAT_REGEX="^EC-[0-9]+: (FEAT|FIX|DOCS|REFACTOR|STYLE|PERF|TEST|CHORE): .+$"
          ISSUES_API_URL="$API_BASE_URL/repos/$REPO/issues/$PR_NUMBER"

          if [ -z "$PR_NUMBER" ]; then
            echo "::error::Could not determine PR Number. Aborting."
            exit 1
          fi

          if [[ "$PR_TITLE" =~ $WIP_REGEX ]]; then
            echo "ℹ️ PR is marked as a Work in Progress."
            LABEL_JSON=$(echo "$WIP_LABEL" | jq -R '{"labels": [.]}')
            curl -s -f -X POST -H "Authorization: token $API_TOKEN" -H "Content-Type: application/json" -d "$LABEL_JSON" "$ISSUES_API_URL/labels"

            WIP_COMMENT_IDENTIFIER="<!-- WIP_VALIDATOR_COMMENT -->"
            EXISTING_COMMENTS=$(curl -s -H "Authorization: token $API_TOKEN" "$ISSUES_API_URL/comments")
            if ! echo "$EXISTING_COMMENTS" | grep -q "$WIP_COMMENT_IDENTIFIER"; then
              echo "Posting WIP comment."
              COMMENT_JSON=$(jq -n --arg body "$COMMENT_BODY_WIP" '{"body": $body}')
              curl -s -f -X POST -H "Authorization: token $API_TOKEN" -H "Content-Type: application/json" -d "$COMMENT_JSON" "$ISSUES_API_URL/comments"
            fi
            exit 1

          elif [[ "$PR_TITLE" =~ $FORMAT_REGEX ]]; then
            echo "✅ PR title format is correct and not a WIP."
            echo "Checking for labels to remove..."

            CURRENT_LABELS_JSON=$(curl -s -H "Authorization: token $API_TOKEN" "$ISSUES_API_URL/labels")

            INVALID_LABEL_ID=$(echo "$CURRENT_LABELS_JSON" | jq --arg name "$INVALID_LABEL" '.[] | select(.name == $name) | .id')
            if [ -n "$INVALID_LABEL_ID" ]; then
              echo "Found and removing '$INVALID_LABEL' (ID: $INVALID_LABEL_ID)..."
              curl -s -f -X DELETE -H "Authorization: token $API_TOKEN" "$ISSUES_API_URL/labels/$INVALID_LABEL_ID"
            fi

            WIP_LABEL_ID=$(echo "$CURRENT_LABELS_JSON" | jq --arg name "$WIP_LABEL" '.[] | select(.name == $name) | .id')
            if [ -n "$WIP_LABEL_ID" ]; then
              echo "Found and removing '$WIP_LABEL' (ID: $WIP_LABEL_ID)..."
              curl -s -f -X DELETE -H "Authorization: token $API_TOKEN" "$ISSUES_API_URL/labels/$WIP_LABEL_ID"
            fi

            exit 0

          else
            echo "❌ ERROR: PR title does not match the required format."
            echo "Adding '$INVALID_LABEL' label..."
            LABEL_JSON=$(echo "$INVALID_LABEL" | jq -R '{"labels": [.]}')
            curl -s -f -X POST -H "Authorization: token $API_TOKEN" -H "Content-Type: application/json" -d "$LABEL_JSON" "$ISSUES_API_URL/labels"

            # Remove WIP label just in case
            ENCODED_WIP_LABEL=$(python3 -c "import urllib.parse; print(urllib.parse.quote('$WIP_LABEL'))")
            curl -s -X DELETE -H "Authorization: token $API_TOKEN" "$ISSUES_API_URL/labels/$ENCODED_WIP_LABEL" || true

            INVALID_COMMENT_IDENTIFIER="<!-- PR_TITLE_VALIDATOR_COMMENT -->"
            EXISTING_COMMENTS=$(curl -s -H "Authorization: token $API_TOKEN" "$ISSUES_API_URL/comments")
            if ! echo "$EXISTING_COMMENTS" | grep -q "$INVALID_COMMENT_IDENTIFIER"; then
              echo "Posting invalid title comment."
              COMMENT_JSON=$(jq -n --arg body "$COMMENT_BODY_INVALID" '{"body": $body}')
              curl -s -f -X POST -H "Authorization: token $API_TOKEN" -H "Content-Type: application/json" -d "$COMMENT_JSON" "$ISSUES_API_URL/comments"
            fi
            exit 1
          fi
