name: Weekly Flake Update

on:
  schedule:
    # Every Friday at 22:00 UTC
    - cron: '0 22 * * 5'
  workflow_dispatch: {}

jobs:
  prepare:
    runs-on: nix
    outputs:
      changed: ${{ steps.changes.outputs.changed }}
      branch_name: ${{ steps.commit.outputs.branch_name }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Configure Git
        run: |
          git config user.name "Flake Update Bot"
          git config user.email "bot@noreply.local"

      - name: Update flake inputs
        run: nix flake update

      - name: Check for changes
        id: changes
        run: |
          if git diff --quiet flake.lock; then
            echo "changed=false" >> $FORGEJO_OUTPUT
            echo "No changes to flake.lock"
          else
            echo "changed=true" >> $FORGEJO_OUTPUT
            echo "flake.lock has been updated"
          fi

      - name: Create branch and commit
        id: commit
        if: steps.changes.outputs.changed == 'true'
        run: |
          BRANCH_NAME="auto-update/$(date +%Y-%m-%d)"
          git checkout -b "$BRANCH_NAME"
          git add flake.lock
          git commit -m "chore: update flake inputs $(date +%Y-%m-%d)"
          git push origin "$BRANCH_NAME"
          echo "branch_name=$BRANCH_NAME" >> $FORGEJO_OUTPUT
          echo "Created and pushed branch: $BRANCH_NAME"

      - name: Extract LXC hosts
        if: steps.changes.outputs.changed == 'true'
        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: Upload hosts list
        if: steps.changes.outputs.changed == 'true'
        uses: forgejo/upload-artifact@v4
        with:
          name: hosts-list
          path: hosts.json
          retention-days: 1

  build:
    needs: prepare
    if: needs.prepare.outputs.changed == 'true'
    runs-on: nix
    steps:
      - name: Checkout update branch
        uses: actions/checkout@v4
        with:
          ref: ${{ needs.prepare.outputs.branch_name }}

      - name: Download hosts list
        uses: forgejo/download-artifact@v4
        with:
          name: hosts-list

      - 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 results for report job
          echo "$FAILED_HOSTS" > failed-hosts.txt
          echo "$SUCCESS_HOSTS" > success-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: Upload build results
        if: always()
        uses: forgejo/upload-artifact@v4
        with:
          name: build-results
          path: |
            failed-hosts.txt
            success-hosts.txt
          retention-days: 1

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

  report:
    needs: [prepare, build]
    if: always() && needs.prepare.outputs.changed == 'true'
    runs-on: nix
    steps:
      - name: Download hosts list
        uses: forgejo/download-artifact@v4
        with:
          name: hosts-list

      - name: Download build results
        uses: forgejo/download-artifact@v4
        with:
          name: build-results
        continue-on-error: true

      - name: Download build logs
        if: needs.build.result == 'failure'
        uses: forgejo/download-artifact@v4
        with:
          name: build-logs
          path: logs
        continue-on-error: true

      - name: Create Pull Request
        if: needs.build.result == 'success'
        env:
          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
        run: |
          HOSTS=$(cat hosts.json)
          HOST_LIST=$(echo "$HOSTS" | jq -r '.[] | "- " + .')
          
          curl -X POST \
            -H "Authorization: token $FORGEJO_TOKEN" \
            -H "Content-Type: application/json" \
            -d '{
              "title": "chore: weekly flake update",
              "body": "Automated flake update from CI.\n\nThis PR updates all flake inputs and has been verified to build successfully.\n\n**Hosts built:**\n'"$(echo "$HOST_LIST" | sed 's/$/\\n/g' | tr -d '\n')"'\n\nGenerated on: '"$(date -Iseconds)"'",
              "head": "'"${{ needs.prepare.outputs.branch_name }}"'",
              "base": "master"
            }' \
            "${{ forgejo.api_url }}/repos/${{ forgejo.repository }}/pulls"

      - name: Create Issue on failure
        if: needs.build.result == 'failure'
        env:
          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
        run: |
          FAILED_HOSTS=""
          FAILURE_DETAILS=""
          
          # Read failed hosts from build results
          if [ -f "failed-hosts.txt" ]; then
            for HOST in $(cat failed-hosts.txt); do
              FAILED_HOSTS="$FAILED_HOSTS\n- $HOST"
              
              # Get build log if available
              if [ -f "logs/build-${HOST}.txt" ]; then
                LOG_TAIL=$(tail -150 "logs/build-${HOST}.txt" | sed 's/"/\\"/g' | sed ':a;N;$!ba;s/\n/\\n/g')
                FAILURE_DETAILS="$FAILURE_DETAILS\n\n<details>\n<summary>$HOST build log (last 150 lines)</summary>\n\n\`\`\`\n$LOG_TAIL\n\`\`\`\n</details>"
              fi
            done
          fi
          
          if [ -z "$FAILED_HOSTS" ]; then
            FAILED_HOSTS="\n- (Unable to determine failed hosts - check workflow logs)"
          fi
          
          ISSUE_BODY="Weekly flake update failed to build some hosts.\n\n**Branch:** \`${{ needs.prepare.outputs.branch_name }}\`\n**Run:** ${{ forgejo.api_url }}/${{ forgejo.repository }}/actions/runs/${{ forgejo.run_id }}\n\n**Failed hosts:**$FAILED_HOSTS\n$FAILURE_DETAILS\n\nGenerated on: $(date -Iseconds)"
          
          curl -X POST \
            -H "Authorization: token $FORGEJO_TOKEN" \
            -H "Content-Type: application/json" \
            -d "{
              \"title\": \"Build failure: weekly flake update $(date +%Y-%m-%d)\",
              \"body\": \"$ISSUE_BODY\"
            }" \
            "${{ forgejo.api_url }}/repos/${{ forgejo.repository }}/issues"

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