name: Build physicslib4

on:
  push:
    branches:
      - main
    paths:
      - '**/*.lean'
      - 'lean-toolchain'
      - 'lakefile.toml'
      - 'lake-manifest.json'
  pull_request:
    branches:
      - main
    paths:
      - '**/*.lean'
      - 'lean-toolchain'
      - 'lakefile.toml'
      - 'lake-manifest.json'
  workflow_dispatch: # Allow manual triggering of the workflow from the GitHub Actions interface

# Cancel previous runs if a new commit is pushed to the same PR or branch
concurrency:
  group: ${{ github.ref }}  # Group runs by the ref (branch or PR)
  cancel-in-progress: true  # Cancel any ongoing runs in the same group

# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages and modify PR labels
permissions:
  contents: read          # Read access to repository contents
  pages: write            # Write access to GitHub Pages
  id-token: write         # Write access to ID tokens

jobs:
  build_project:
    runs-on: ubuntu-latest
    name: Build project
    steps:
      - name: Checkout project
        uses: actions/checkout@v5
        with:
          fetch-depth: 0 # Fetch all history for all branches and tags

      - name: Install and configure Lean, and get mathlib cache
        uses: leanprover/lean-action@434f25c2f80ded67bba02502ad3a86f25db50709 # v1.3.0
        with:
          auto-config: false
          use-github-cache: false
          use-mathlib-cache: true

      - name: "Check that physicslib4.lean is up to date"
        run: |
          ~/.elan/bin/lake exe mk_all --check || echo "ERROR: please ensure that physicslib4.lean is up to date, for instance by running lake exe mk_all"

      - name: Cache build artifacts
        uses: actions/cache@v4
        with:
          path: .lake/build
          key: LakeBuild-${{ runner.os }}-${{ hashFiles('lean-toolchain') }}-${{ hashFiles('lake-manifest.json') }}
          restore-keys: LakeBuild-

      - name: Build project
        run: ~/.elan/bin/lake build physicslib4