name: PR Checks

on:
  pull_request:
    types: [opened, reopened, edited, ready_for_review]

env:
  PR_URL: ${{github.event.pull_request.html_url}}

jobs:
  fix-pr-title:
    name: Fix PR Title
    runs-on: ubuntu-latest
    steps:
      - name: Check title format
        env:
          GITHUB_TOKEN: ${{secrets.SUPPLYCART_BOT_TOKEN}}
          PR_BRANCH: ${{ github.head_ref }}
        run: |
          echo "PR URL: $PR_URL"
          TITLE=$(gh pr view --json 'title' --jq '.title' "$PR_URL")
          echo "Current title: $TITLE"

          ALLOWED_OPERATIONS=("FIX" "FEAT" "UPDATE" "PATCH" "DEPLOYMENT" "CHERRY-PICK")

          # Convert the ticket and operation to uppercase while keeping the rest intact
          format_title() {
              local title="$1"
              local ticket="${title%% *}"
              local operation="${title#* }"
              local rest="${title#* * }"
              ticket=$(echo "$ticket" | tr '[:lower:]' '[:upper:]') # ticket="${ticket^^}"

              if [[ $ticket == "ST" ]]; then
                  local ticket_code="${title#* *}"
                  ticket="$ticket-${ticket_code%% *}"
                  ticket=$(echo "$ticket" | tr '[:lower:]' '[:upper:]')
                  operation="${operation#* *}"
                  rest="${rest#* *}"
              fi

              operation="${operation%% *}"
              operation=$(echo "$operation" | tr '[:lower:]' '[:upper:]') # operation=${operation^^}

              echo "$ticket $operation $rest"
          }

          validate_ticket_format() {
              local ticket="$1"
              [[ "$ticket" =~ ^ST-[0-9]+$ ]]
          }

          validate_operation() {
              local operation="$1"
              for op in "${ALLOWED_OPERATIONS[@]}"; do
                  [[ "$op" == "$operation" ]] && return 0
              done
              return 1
          }

          extract_ticket_from_branch() {
              local branch="$1"
              local ticket_pattern="^(ST-[0-9]+)"

              if [[ $branch =~ $ticket_pattern ]]; then
                  echo "${BASH_REMATCH[1]}" | tr '[:lower:]' '[:upper:]'
                  return 0
              fi

              echo "ERROR: Unable to extract a valid ticket from branch '$branch'." >&2
              return 1
          }

          extract_operation_from_branch() {
              local branch=$(echo "$1" | tr '[:lower:]' '[:upper:]')
              local operation_pattern="[/-]($(IFS=\|; echo "${ALLOWED_OPERATIONS[*]}"))[/-]"

              if [[ $branch =~ $operation_pattern ]]; then
                  echo "${BASH_REMATCH[1]}" | tr '[:lower:]' '[:upper:]' #echo "${BASH_REMATCH[1]^^}"  # Convert to uppercase
                  return 0
              fi

              echo "ERROR: Unable to extract a valid operation from branch '$branch'." >&2
              return 1
          }

          post_error_and_exit() {
              local error_message='ERROR: TITLE format is incorrect. Must be `<jira-ticket> <operation> <rest>`.'
              gh pr comment --body "$error_message" "$PR_URL"
              exit 1
          }

          # Get PR Title and format it
          FORMATTED_TITLE=$(format_title "$TITLE")
          JIRA_TICKET="${FORMATTED_TITLE%% *}"
          OPS="${FORMATTED_TITLE#* }"
          OPS="${OPS%% *}"
          REST="${FORMATTED_TITLE#* * }"

          # Validate ticket format
          if validate_ticket_format "$JIRA_TICKET"; then
              echo "INFO: Jira Ticket => $JIRA_TICKET"
          else
              echo "INFO: Invalid ticket format in PR title. Extracting from branch..."
              JIRA_TICKET=$(extract_ticket_from_branch "$PR_BRANCH") || post_error_and_exit
          fi

          # Validate operations
          if validate_operation "$OPS"; then
              echo "INFO: Operations => $OPS"
          else
              echo "INFO: Invalid operation in PR title. Extracting from branch..."
              OPS=$(extract_operation_from_branch "$PR_BRANCH") || post_error_and_exit
          fi

          # Final validation
          if ! validate_ticket_format "$JIRA_TICKET" || ! validate_operation "$OPS"; then
              post_error_and_exit
          fi

          # Success case
          NEW_TITLE="$JIRA_TICKET $OPS $REST"
          echo "New title: $NEW_TITLE"
          gh pr edit --title="$NEW_TITLE" "$PR_URL"
          echo "SUCCESS: PR title fixed"
          exit 0

      - name: Enable auto-merge
        run: gh pr merge --auto --squash "$PR_URL"
        env:
          GITHUB_TOKEN: ${{secrets.SUPPLYCART_BOT_TOKEN}}