name: Update Flake and Validate Build

on:
  schedule:
    - cron: "30 00 * * 1"
  workflow_dispatch: # Allow manual triggering

# Set default permissions as read only
permissions: read-all

jobs:
  update-flake:
    runs-on: ubuntu-latest
    permissions:
      # Only need contents write to update the flake lock file
      contents: write
    outputs:
      update_available: ${{ steps.check_updates.outputs.update_available }}
    
    steps:
      - name: Repository Checkout
        uses: actions/checkout@v4

      - name: Install Nix
        uses: DeterminateSystems/nix-installer-action@v18

      - name: Check for Updates
        id: check_updates
        run: |
          # Create a temporary copy of flake.lock
          cp flake.lock flake.lock.backup
          
          # Try to update flake.lock
          nix flake update
          
          # Check if there are differences
          if ! cmp -s flake.lock flake.lock.backup; then
            echo "update_available=true" >> "$GITHUB_OUTPUT"
            # Restore original flake.lock
            mv flake.lock.backup flake.lock
          else
            echo "update_available=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Update flake.lock
        if: steps.check_updates.outputs.update_available == 'true'
        uses: DeterminateSystems/update-flake-lock@v26
        with:
          nix-options: --debug --log-format raw
          token: ${{ secrets.FLAKE_TOKEN }}
          pr-title: "deps: update flake.lock"
          pr-labels: |
            dependencies
            automated

  build-and-check:
    needs: update-flake
    permissions:
      # Needed for checking out code
      contents: read
      # Needed for creating issues
      issues: write
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest]
      fail-fast: false # Continue with other jobs even if one fails
    
    runs-on: ${{ matrix.os }}
    
    steps:
      - name: Repository Checkout
        uses: actions/checkout@v4
        with:
          ref: update_flake_lock_action

      - name: Install Nix
        uses: DeterminateSystems/nix-installer-action@v18

      - name: Build and Test Configuration
        id: build
        continue-on-error: true # Continue to next steps even if build fails
        run: |
          set +e  # Don't exit immediately on error
          # Run the build and capture output
          OUTPUT=$(nix build .# 2>&1)
          BUILD_EXIT_CODE=$?
          echo "build_output<<EOF" >> $GITHUB_ENV
          echo "$OUTPUT" >> $GITHUB_ENV
          echo "EOF" >> $GITHUB_ENV
          
          # Check if build succeeded
          if [ $BUILD_EXIT_CODE -eq 0 ]; then
            echo "build_status=success" >> $GITHUB_ENV
          else
            echo "build_status=failure" >> $GITHUB_ENV
            # Ensure the error is visible in the logs
            echo "::error::Build failed with exit code $BUILD_EXIT_CODE"
            echo "$OUTPUT"
          fi

      - name: Create Issue on Build Failure
        if: env.build_status == 'failure'
        uses: actions/github-script@v7
        with:
          script: |
            const os = '${{ matrix.os }}';
            const buildOutput = process.env.build_output;
            const isUpdate = '${{ needs.update-flake.outputs.update_available }}' === 'true';
            
            // Extract warnings and errors from build output
            const warnings = buildOutput.match(/evaluation warning:[^\n]+/g) || [];
            const errors = buildOutput.match(/error:[^\n]+/g) || [];
            
            // Create a summary section
            const summary = [
              warnings.length > 0 ? `${warnings.length} evaluation warnings` : '',
              errors.length > 0 ? `${errors.length} errors` : ''
            ].filter(Boolean).join(' and ');
            
            // Get repository information from context
            const [owner, repo] = process.env.GITHUB_REPOSITORY.split('/');
            
            await github.rest.issues.create({
              owner,
              repo,
              title: `🔨 Build Failed on ${os}: ${summary}${isUpdate ? ' (Dependency Update)' : ''}`,
              body: `Build failed during automated validation on ${os}${isUpdate ? ' while testing dependency updates.' : '.'}\n
              ${isUpdate ? 'This failure occurred on the dependency update branch `deps/update-flake-lock`.' : 'This failure occurred on the main branch.'}\n
              
              ### Summary
              ${summary}\n
              
              ${warnings.length > 0 ? `### Warnings\n\`\`\`\n${warnings.join('\n')}\n\`\`\`\n` : ''}
              ${errors.length > 0 ? `### Errors\n\`\`\`\n${errors.join('\n')}\n\`\`\`\n` : ''}
              
              <details>
              <summary>Build Output</summary>
              
              \`\`\`
              ${buildOutput}
              \`\`\`
              </details>
              
              Please review the build output and fix any issues.`,
              labels: [
                'build-failure',
                'bug',
                ...(warnings.length > 0 ? ['has-warnings'] : []),
                ...(errors.length > 0 ? ['has-errors'] : [])
              ]
            });