name: Update maintainers list

on:
  push:
    branches:
      - main
    paths:
      - lib/maintainers.nix
  schedule:
    # Update every Monday at 9 AM UTC
    - cron: "0 9 * * 1"
  workflow_dispatch:
    inputs:
      create_pr:
        description: "Create PR even if no changes"
        required: false
        default: false
        type: boolean

jobs:
  update-maintainers:
    runs-on: ubuntu-latest
    if: github.repository_owner == 'nix-community' || github.event_name == 'workflow_dispatch'
    # Permissions required for workflow
    # `contents`: to update maintainers file
    # `pull-requests`: to create pr
    # `issues`: to label pr
    permissions:
      contents: write
      pull-requests: write
      issues: write
    env:
      pr_branch: update/maintainers-${{ github.ref_name }}
    steps:
      - name: Create GitHub App token
        uses: actions/create-github-app-token@v2
        if: vars.CI_APP_ID
        id: app-token
        with:
          app-id: ${{ vars.CI_APP_ID }}
          private-key: ${{ secrets.CI_APP_PRIVATE_KEY }}
          permission-contents: write
          permission-pull-requests: write
          permission-issues: write

      - name: Get GitHub App user info
        id: user-info
        if: vars.CI_APP_ID
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
          slug: ${{ steps.app-token.outputs.app-slug }}
        run: |
          name="$slug[bot]"
          id=$(gh api "/users/$name" --jq .id)
          {
            echo "id=$id"
            echo "name=$name"
            echo "email=$id+$name@users.noreply.github.com"
          } >> "$GITHUB_OUTPUT"

      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          token: ${{ steps.app-token.outputs.token || github.token }}

      - name: Install Nix
        uses: cachix/install-nix-action@v31
        with:
          github_access_token: ${{ steps.app-token.outputs.token || github.token }}
          extra_nix_config: |
            allow-import-from-derivation = false

      - name: Setup Git
        env:
          name: ${{ steps.user-info.outputs.name || 'github-actions[bot]' }}
          email: ${{ steps.user-info.outputs.email || '41898282+github-actions[bot]@users.noreply.github.com' }}
        run: |
          git config user.name "$name"
          git config user.email "$email"

      - name: Generate updated maintainers list
        run: |
          echo "::group::📋 Generating updated generated/all-maintainers.nix..."
          nix run .#generate-all-maintainers -- --root . --output generated/all-maintainers.nix
          echo "::endgroup::"
          echo "::group::🎨 Formatting with nixfmt..."
          nix fmt generated/all-maintainers.nix
          echo "::endgroup::"

      - name: Check for changes
        id: check-changes
        run: |
          if git diff --quiet generated/all-maintainers.nix; then
            echo "No changes to generated/all-maintainers.nix"
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          else
            echo "Changes detected in generated/all-maintainers.nix"
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
            added=$(git diff --numstat generated/all-maintainers.nix | cut -f1)
            removed=$(git diff --numstat generated/all-maintainers.nix | cut -f2)
            echo "changes_summary=+$added -$removed lines" >> "$GITHUB_OUTPUT"
          fi

      - name: Validate generated file
        if: steps.check-changes.outputs.has_changes == 'true'
        run: |
          echo "🔍 Validating generated generated/all-maintainers.nix..."
          if nix-instantiate --eval  generated/all-maintainers.nix --strict > /dev/null; then
            echo "✅ Generated file has valid Nix syntax"
          else
            echo "❌ Generated file has invalid Nix syntax"
            exit 1
          fi

      - name: Create update branch
        run: |
          git branch -D "$pr_branch" || echo "Nothing to delete"
          git switch -c "$pr_branch"

      - name: Get info on the current PR
        id: open_pr_info
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token || github.token }}
        run: |
          # Query for info about the already open update PR
          info=$(
            gh api graphql -F owner='{owner}' -F repo='{repo}' -F branch="$pr_branch" -f query='
              query($owner:String!, $repo:String!, $branch:String!) {
                repository(owner: $owner, name: $repo) {
                  pullRequests(first: 1, states: OPEN, headRefName: $branch) {
                    nodes {
                      number
                      url
                    }
                  }
                }
              }
            ' | jq --raw-output '
              .data.repository.pullRequests.nodes[]
              | to_entries[]
              | "\(.key)=\(.value)"
            '
          )
          if [[ -n "$info" ]]; then
            echo "PR info:"
            echo "$info"
            echo "$info" >> $GITHUB_OUTPUT
          else
            echo "No PR is currently open"
          fi

      - name: Fetch current PR's branch
        if: steps.open_pr_info.outputs.number
        run: |
          git fetch origin "$pr_branch"
          git branch --set-upstream-to "origin/$pr_branch"

      - name: Create Pull Request
        id: create-pr
        if: steps.check-changes.outputs.has_changes == 'true' || github.event.inputs.create_pr == 'true'
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token || github.token }}
          title: "maintainers: update generated/all-maintainers.nix"
          commit_body: |
            Automated update of the master maintainers list combining:
            - Nixvim specific maintainers from lib/maintainers.nix
            - Nixpkgs maintainers referenced in Nixvim modules

            Changes: ${{ steps.check-changes.outputs.changes_summary || 'No content changes' }}

            Generated by: flake/dev/generate-all-maintainers/generate-all-maintainers.py
          pr_url: ${{ steps.open_pr_info.outputs.url }}
          pr_num: ${{ steps.open_pr_info.outputs.number }}
          pr_body: |
            ## 📋 Summary

            This PR updates the master maintainers list (`generated/all-maintainers.nix`) which combines:
            - **Nixvim specific maintainers** from `lib/maintainers.nix`
            - **Nixpkgs maintainers** referenced in Nixvim modules

            ## 🔄 Changes

            **Statistics:** ${{ steps.check-changes.outputs.changes_summary || 'No content changes (format/comment updates only)' }}

            The updated list includes all maintainers needed for review assignments across the Nixvim project.

            ## 🤖 Automation

            - **Generated by:** `flake/dev/generate-all-maintainers/generate-all-maintainers.py`
            - **Trigger:** ${{ github.event_name == 'schedule' && 'Scheduled weekly update' || 'Manual workflow dispatch' }}
            - **Validation:** File syntax verified with `nix-instantiate --eval`

            ## 📚 Usage

            This file can be imported and used for maintainer lookups:
            ```nix
            let allMaintainers = import ./generated/all-maintainers.nix; in
            # Access any maintainer by name: allMaintainers.username
            ```

            ---
            🤖 *This PR was automatically created by the [update-maintainers workflow](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})*
        run: |
          git add generated/all-maintainers.nix
          git commit -m "$title" -m "$commit_body"

          echo "Pushing to remote branch $pr_branch"
          git push --force --set-upstream origin "$pr_branch"

          if [ -z "$pr_num" ]; then
            echo "Creating new pull request."
            PR_URL=$(
              gh pr create \
                --title "$title" \
                --body "$pr_body"
            )
          else
            PR_URL=$pr_url
            echo "Pull request already exists: $PR_URL"
            gh pr edit "$pr_num" --body "$pr_body"
          fi

          echo "pr_url=$PR_URL" >> "$GITHUB_OUTPUT"

      - name: Summary
        env:
          has_changes: ${{ steps.check-changes.outputs.has_changes }}
          changes: ${{ steps.check-changes.outputs.changes_summary }}
          pr_url: ${{ steps.create-pr.outputs.pr_url}}
          pr_num: ${{ steps.open_pr_info.outputs.number }}
        run: |
          if [[ "$has_changes" == "true" ]]; then
              if [[ -n "$pr_num" ]]; then
                echo "✅ Successfully updated PR with new changes."
                echo "$changes"
                echo "🔗 PR URL: $pr_url"
                echo "### ✅ PR Updated" >> $GITHUB_STEP_SUMMARY
                echo "[$pr_url]($pr_url)" >> $GITHUB_STEP_SUMMARY
              elif [[ -n "$pr_url" ]]; then
                echo "✅ Successfully created PR with maintainer updates."
                echo "$changes"
                echo "🔗 PR URL: $pr_url"
                echo "### ✅ PR Created" >> $GITHUB_STEP_SUMMARY
                echo "[$pr_url]($pr_url)" >> $GITHUB_STEP_SUMMARY
              else
                echo "❌ Failed to create or update pull request."
                echo "### ❌ PR Operation Failed" >> $GITHUB_STEP_SUMMARY
                echo "A pull request was intended but the URL was not captured. Please check the logs." >> $GITHUB_STEP_SUMMARY
              fi
          else
            echo "ℹ️ No changes detected - maintainers list is up to date."
            echo "### ℹ️ No Changes" >> $GITHUB_STEP_SUMMARY
            echo "The maintainers list is up-to-date. No PR was created." >> $GITHUB_STEP_SUMMARY
          fi