name: Validate PR

on:
  pull_request:
    branches: [dev]
    types: [opened, edited, synchronize, reopened]

jobs:
  checkTitle:
    name: Check Title
    runs-on: ubuntu-latest
    if: github.event_name == 'pull_request'
    steps:
      - name: Validate Title
        id: validate-pr-title
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          echo "Creating label (if it does not exist)"
          LABEL="validation: invalid title"
          gh --repo "${{ github.repository }}" \
            label create "$LABEL" --description "Modifications to this pull request are requested" --color D93F0B || true

          PR_TITLE=$(\
            gh --repo "${{ github.repository }}" \
              pr view "${{ github.event.number }}" --json title --jq .title)
          echo "::set-output name=title::$PR_TITLE"
          echo "PR Title: $PR_TITLE"

          TITLE_REGEX="^[0-9A-Z\-]*: .*$"
          PR_TITLE_VALID=$(echo "$PR_TITLE" | grep -Eq "$TITLE_REGEX" && echo "true" || echo "false")

          if [ "$PR_TITLE_VALID" == "true" ]; then
            echo "Title is valid, removing label"
            gh --repo "${{ github.repository }}" \
              pr edit "${{ github.event.number }}" --remove-label "$LABEL" || true
          else
            echo "Invalid Title"
            ERROR_MSG="$PR_TITLE -> should match -> $TITLE_REGEX"
            echo "$ERROR_MSG"
            echo "::set-output name=invalid::true"
            echo "::set-output name=errorMessage::$ERROR_MSG"

            touch comment.txt
            echo "## The title \`$PR_TITLE\` should match \`$TITLE_REGEX\`" >> comment.txt
            echo "" >> comment.txt
            echo "SECTION: FIX #xzyw PLAYER DESCRIPTION" >> comment.txt
            echo "" >> comment.txt
            echo 'SECTION is something like "API", "UI", "MISC", "STANEK", "CORPORATION"' >> comment.txt
            echo 'FIX #xyzw is the issue number, if any' >> comment.txt
            echo "PLAYER DESCRIPTION is what you'd tell a non-contributor to convey what is changed." >> comment.txt

            echo "Add pr label"
            gh --repo "${{ github.repository }}" \
              pr edit "${{ github.event.number }}" --add-label "$LABEL"
            echo "And comment on the pr"
            gh --repo "${{ github.repository }}" \
              pr comment "${{ github.event.number }}" --body-file comment.txt
          fi
      - name: Flag workflow error
        if: steps.validate-pr-title.outputs.invalid == 'true'
        run: |
          echo "${{ steps.validate-pr-title.outputs.errorMessage }}"
          exit 1