name: Nightly with Manual

on:
    push:
        tags:
            - "nightly-testing-*"
    workflow_dispatch:
    workflow_call:
    schedule:
        - cron: "0 14 * * *" # 2PM UTC
        - cron: "0 22 * * *" # 10PM UTC

jobs:
    build:
        runs-on: ubuntu-latest
        if: github.repository == 'leanprover/reference-manual'
        steps:
            - name: Checkout repository
              uses: actions/checkout@v4
              with:
                  fetch-depth: 0 # Fetch all history and tags

            - name: Find most recent nightly-testing tag
              id: find_tag
              run: |
                  # Fetch all tags
                  git fetch --tags

                  # Find all tags matching nightly-testing-YYYY-MM-DD pattern
                  # Sort them in reverse order (most recent first) and get the first one
                  LATEST_TAG=$(git tag -l 'nightly-testing-*' | sort -r | head -n 1)

                  # Extract just the YYYY-MM-DD portion
                  NIGHTLY=$(echo "$LATEST_TAG" | sed 's/^nightly-testing-//')

                  echo "Latest nightly-testing tag: $LATEST_TAG"
                  echo "Nightly date: $NIGHTLY"
                  echo "nightly=$NIGHTLY" >> $GITHUB_OUTPUT

            # Next, we'll update the `nightly-with-manual` branch at Lean.
            - name: Cleanup workspace
              run: |
                  sudo rm -rf -- *
            # Check out the Lean repository on 'nightly-with-manual'
            - name: Check out Lean repository
              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
              with:
                  repository: leanprover/lean4
                  token: ${{ secrets.LEAN_PR_TESTING }}
                  ref: nightly-with-manual

            # Merge the relevant nightly.
            - name:
                  Fetch tags from 'lean4-nightly', and merge relevant nightly into
                  'nightly-with-manual'
              env:
                  NIGHTLY: ${{ steps.find_tag.outputs.nightly }}
              run: |
                  git remote add nightly https://github.com/leanprover/lean4-nightly.git
                  git fetch nightly --tags
                  # Note: old jobs may run out of order, but it is safe to merge an older `nightly-YYYY-MM-DD`.
                  git merge "nightly-${NIGHTLY}" --strategy-option ours --allow-unrelated-histories || true
                  git push origin