name: Auto Update Build

on:
  pull_request:
    types: [opened, synchronize]
    branches:
      - master

jobs:
  build:
    # Only run for auto-update branches
    if: startsWith(github.head_ref, 'auto-update/')
    runs-on: nix
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Extract LXC hosts
        id: hosts
        run: |
          set -euo pipefail
          HOSTS=$(nix eval --json .#colmena --apply 'x: builtins.filter (n: n != "meta" && builtins.elem "lxc" (x.${n}.deployment.tags or [])) (builtins.attrNames x)')
          
          # Validate the output is a non-empty JSON array
          if ! echo "$HOSTS" | jq -e '. | if type == "array" and length > 0 then true else false end' > /dev/null 2>&1; then
            echo "Error: No LXC hosts found or invalid JSON output: $HOSTS"
            exit 1
          fi
          
          echo "$HOSTS" > hosts.json
          echo "Discovered hosts: $HOSTS"

      - name: Build all hosts
        id: build
        run: |
          set -euo pipefail
          
          if [ ! -f hosts.json ]; then
            echo "Error: hosts.json not found"
            exit 1
          fi
          
          HOSTS=$(cat hosts.json)
          echo "Building hosts: $HOSTS"
          
          FAILED_HOSTS=""
          SUCCESS_HOSTS=""
          
          declare -A BUILD_TIMES
          
          for HOST in $(echo "$HOSTS" | jq -r '.[]'); do
            echo ""
            echo "=========================================="
            echo "Building: $HOST"
            echo "=========================================="
            
            START_TIME=$(date +%s)
            
            if nix build ".#nixosConfigurations.${HOST}.config.system.build.toplevel" --no-link --quiet 2>&1 | tee "build-${HOST}.txt"; then
              END_TIME=$(date +%s)
              DURATION=$((END_TIME - START_TIME))
              DURATION_FMT=$(printf '%dm %ds' $((DURATION/60)) $((DURATION%60)))
              BUILD_TIMES[$HOST]="$DURATION_FMT"
              echo "✓ Build succeeded: $HOST (${DURATION_FMT})"
              SUCCESS_HOSTS="$SUCCESS_HOSTS $HOST"
            else
              END_TIME=$(date +%s)
              DURATION=$((END_TIME - START_TIME))
              DURATION_FMT=$(printf '%dm %ds' $((DURATION/60)) $((DURATION%60)))
              BUILD_TIMES[$HOST]="$DURATION_FMT"
              echo "✗ Build failed: $HOST (${DURATION_FMT})"
              FAILED_HOSTS="$FAILED_HOSTS $HOST"
            fi
          done
          
          echo ""
          echo "=========================================="
          echo "Build Summary"
          echo "=========================================="
          echo "Succeeded:$SUCCESS_HOSTS"
          echo "Failed:$FAILED_HOSTS"
          echo ""
          echo "Build times:"
          for HOST in "${!BUILD_TIMES[@]}"; do
            echo "  $HOST: ${BUILD_TIMES[$HOST]}"
          done
          
          # Save failed hosts for the comment step
          echo "$FAILED_HOSTS" > failed_hosts.txt
          
          if [ -n "$FAILED_HOSTS" ]; then
            echo "Some builds failed"
            exit 1
          fi
        continue-on-error: true

      - name: Upload build logs
        if: always()
        uses: forgejo/upload-artifact@v4
        with:
          name: build-logs
          path: build-*.txt
          retention-days: 7

      - name: Comment on PR with build failures
        if: steps.build.outcome == 'failure'
        env:
          PR_TOKEN: ${{ secrets.PR_TOKEN }}
        run: |
          set -euo pipefail
          
          if [ ! -f failed_hosts.txt ]; then
            echo "No failed hosts file found"
            exit 0
          fi
          
          FAILED_HOSTS=$(cat failed_hosts.txt)
          
          # Build comment body
          {
            echo "## ❌ Build Failed"
            echo ""
            echo "The following hosts failed to build:"
            echo ""
            
            for HOST in $FAILED_HOSTS; do
              LOG_FILE="build-${HOST}.txt"
              if [ -f "$LOG_FILE" ]; then
                echo "<details>"
                echo "<summary><b>${HOST}</b></summary>"
                echo ""
                echo '```'
                tail -n 150 "$LOG_FILE"
                echo '```'
                echo ""
                echo "</details>"
                echo ""
              fi
            done
          } > comment_body.md
          
          # Post comment to PR using jq for proper JSON escaping
          jq -Rs '{body: .}' comment_body.md > payload.json
          
          curl -sf -X POST \
            -H "Authorization: token $PR_TOKEN" \
            -H "Content-Type: application/json" \
            -d @payload.json \
            "${{ forgejo.api_url }}/repos/${{ forgejo.repository }}/issues/${{ forgejo.event.pull_request.number }}/comments"

      - name: Check build result
        run: |
          if [ "${{ steps.build.outcome }}" == "failure" ]; then
            echo "Some builds failed - check build-logs artifact"
            exit 1
          fi

      - name: Cleanup
        if: always()
        run: |
          nix-collect-garbage -d
          rm -rf result .direnv