name: Weekly Flake Update

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

jobs:
  update:
    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: Update flake inputs
        run: nix flake update

      - name: Check for changes
        id: changes
        run: |
          if git diff --quiet flake.lock; then
            echo "changed=false" >> $GITHUB_OUTPUT
          else
            echo "changed=true" >> $GITHUB_OUTPUT
          fi

      - name: Build all hosts
        if: steps.changes.outputs.changed == 'true'
        run: |
          nix develop -c colmena build

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

      - name: Create Pull Request
        if: steps.changes.outputs.changed == 'true'
        env:
          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
        run: |
          curl -X POST \
            -H "Authorization: token $FORGEJO_TOKEN" \
            -H "Content-Type: application/json" \
            -d '{
              "title": "chore: weekly flake update",
              "body": "Automated flake update from CI.\n\nThis PR updates all flake inputs and has been verified to build successfully.\n\nGenerated on: '"$(date -Iseconds)"'",
              "head": "'"${{ steps.branch.outputs.branch_name }}"'",
              "base": "master"
            }' \
            "${{ github.server_url }}/api/v1/repos/${{ github.repository }}/pulls"

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