name: Weekly Flake Update

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

jobs:
  check-updates:
    runs-on: nix
    outputs:
      changed: ${{ steps.changes.outputs.changed }}
      hosts: ${{ steps.hosts.outputs.hosts || '[]' }}
    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: |
          echo "DEBUG: GITHUB_OUTPUT='${GITHUB_OUTPUT:-<unset>}'"
          echo "DEBUG: Checking if GITHUB_OUTPUT var is set: $(if [ -z "${GITHUB_OUTPUT+x}" ]; then echo "NOT SET"; else echo "SET (value: '$GITHUB_OUTPUT')"; fi)"
          
          set_output() {
            echo "::set-output name=$1::$2"
            if [ -n "${GITHUB_OUTPUT:-}" ]; then
              echo "$1=$2" >> "$GITHUB_OUTPUT"
            fi
          }
          if git diff --quiet flake.lock; then
            set_output changed false
          else
            set_output changed true
          fi

      - name: Extract LXC hosts
        id: hosts
        if: steps.changes.outputs.changed == 'true'
        run: |
          set -euo pipefail
          
          set_output() {
            echo "::set-output name=$1::$2"
            if [ -n "${GITHUB_OUTPUT:-}" ]; then
              echo "$1=$2" >> "$GITHUB_OUTPUT"
            fi
          }
          
          HOSTS=$(nix eval --json .#colmena --apply 'x: builtins.filter (n: n != "meta" && builtins.elem "lxc" (x.${n}.deployment.tags or [])) (builtins.attrNames x)') || {
            echo "Failed to evaluate colmena hosts"
            exit 1
          }
          # 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"
            set_output hosts "[]"
            exit 0
          fi
          
          set_output hosts "$HOSTS"
          echo "Discovered hosts: $HOSTS"
          # Also write to file as backup (in case job outputs don't work)
          echo "$HOSTS" > hosts.json
          # Debug output
          echo "DEBUG: GITHUB_OUTPUT exists: ${GITHUB_OUTPUT:-NOT SET}"
          if [ -n "${GITHUB_OUTPUT:-}" ] && [ -f "$GITHUB_OUTPUT" ]; then
            echo "DEBUG: GITHUB_OUTPUT contents:"
            cat "$GITHUB_OUTPUT"
          fi

      - name: Debug job outputs
        if: steps.changes.outputs.changed == 'true'
        run: |
          echo "=== Step outputs ==="
          echo "steps.changes.outputs.changed = '${{ steps.changes.outputs.changed }}'"
          echo "steps.hosts.outputs.hosts = '${{ steps.hosts.outputs.hosts }}'"
          echo "Length of hosts output: ${#HOSTS_OUT}"
        env:
          HOSTS_OUT: ${{ steps.hosts.outputs.hosts }}

      - name: Upload flake.lock
        if: steps.changes.outputs.changed == 'true'
        uses: forgejo/upload-artifact@v4
        with:
          name: flake-lock
          path: flake.lock
          retention-days: 1

      - 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: check-updates
    if: needs.check-updates.outputs.changed == 'true' && needs.check-updates.outputs.hosts != '[]' && needs.check-updates.outputs.hosts != ''
    runs-on: nix
    strategy:
      fail-fast: false
      matrix:
        host: ${{ fromJson(needs.check-updates.outputs.hosts || '[]') }}
    steps:
      - name: Debug - show received values
        run: |
          echo "=== DEBUG: Values received from check-updates job ==="
          echo "needs.check-updates.outputs.changed = '${{ needs.check-updates.outputs.changed }}'"
          echo "needs.check-updates.outputs.hosts = '${{ needs.check-updates.outputs.hosts }}'"
          echo "matrix.host = '${{ matrix.host }}'"
          echo "=== END DEBUG ==="

      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Download updated flake.lock
        uses: forgejo/download-artifact@v4
        with:
          name: flake-lock

      - name: Build ${{ matrix.host }}
        id: build
        run: |
          HOST="${{ matrix.host }}"
          echo "DEBUG: matrix.host='$HOST'"
          echo "DEBUG: raw matrix.host='${{ matrix.host }}'"
          if [ -z "$HOST" ]; then
            echo "Error: Host name is empty"
            echo "This usually means the 'hosts' output from check-updates job was not received properly"
            exit 1
          fi
          echo "Building host: $HOST"
          nix build ".#nixosConfigurations.${HOST}.config.system.build.toplevel" --no-link 2>&1 | tee build-output.txt
        continue-on-error: true

      - name: Upload build log on failure
        if: failure() || steps.build.outcome == 'failure'
        uses: forgejo/upload-artifact@v4
        with:
          name: build-failure-${{ matrix.host }}
          path: build-output.txt
          retention-days: 7

      - name: Check build result
        run: |
          if [ "${{ steps.build.outcome }}" == "failure" ]; then
            echo "Build failed for ${{ matrix.host }}"
            exit 1
          fi

  report:
    needs: [check-updates, build]
    if: always() && needs.check-updates.outputs.changed == 'true'
    runs-on: nix
    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: Download updated flake.lock
        uses: forgejo/download-artifact@v4
        with:
          name: flake-lock

      - name: Download failure artifacts
        if: needs.build.result == 'failure'
        uses: forgejo/download-artifact@v4
        with:
          pattern: build-failure-*
          path: failures
          merge-multiple: false
        continue-on-error: true

      - name: Create branch and commit
        id: branch
        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" >> $GITHUB_OUTPUT

      - name: Create Pull Request
        if: needs.build.result == 'success'
        env:
          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
        run: |
          HOSTS='${{ needs.check-updates.outputs.hosts }}'
          HOST_LIST=$(echo "$HOSTS" | jq -r '.[] | "- " + .' | tr '\n' '\n')
          
          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: '"$(date -Iseconds)"'",
              "head": "'"${{ steps.branch.outputs.branch_name }}"'",
              "base": "master"
            }' \
            "${{ github.server_url }}/api/v1/repos/${{ github.repository }}/pulls"

      - name: Create Issue on failure
        if: needs.build.result == 'failure'
        env:
          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
        run: |
          # Collect failed hosts from artifact directories
          FAILED_HOSTS=""
          FAILURE_DETAILS=""
          
          if [ -d "failures" ]; then
            for dir in failures/build-failure-*; do
              if [ -d "$dir" ]; then
                HOST=$(basename "$dir" | sed 's/build-failure-//')
                FAILED_HOSTS="$FAILED_HOSTS\n- $HOST"
                
                if [ -f "$dir/build-output.txt" ]; then
                  # Get last 50 lines of build output
                  LOG_TAIL=$(tail -50 "$dir/build-output.txt" | sed 's/"/\\"/g' | sed ':a;N;$!ba;s/\n/\\n/g')
                  FAILURE_DETAILS="$FAILURE_DETAILS\n\n<details>\n<summary>$HOST build log (last 50 lines)</summary>\n\n\`\`\`\n$LOG_TAIL\n\`\`\`\n</details>"
                fi
              fi
            done
          fi
          
          # If no failure artifacts found, list from matrix
          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:** \`${{ steps.branch.outputs.branch_name }}\`\n**Run:** ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}\n\n**Failed hosts:**$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\"
            }" \
            "${{ github.server_url }}/api/v1/repos/${{ github.repository }}/issues"

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