name: Build and Cache Z3

on:
  # Allow manual trigger
  workflow_dispatch:
  # Run on schedule to keep cache fresh (daily at 2 AM UTC)
  schedule:
    - cron: '0 2 * * *'
  # Run on pushes to main to update cache with latest changes
  push:
    branches: [ "master", "main" ]
  # Make this callable as a reusable workflow
  workflow_call:
    outputs:
      cache-key:
        description: "The cache key for the built Z3 binary"
        value: ${{ jobs.build-z3.outputs.cache-key }}

permissions:
  contents: read

jobs:
  build-z3:
    name: "Build Z3 for caching"
    runs-on: ubuntu-latest
    timeout-minutes: 90
    outputs:
      cache-key: ${{ steps.cache-key.outputs.key }}
    
    steps:
      - name: Checkout code
        uses: actions/checkout@v6.0.2

      - name: Setup Python
        uses: actions/setup-python@v6
        with:
          python-version: '3.x'

      - name: Generate cache key
        id: cache-key
        run: |
          # Create a cache key based on git SHA and relevant source files
          echo "key=z3-build-${{ runner.os }}-${{ github.sha }}" >> $GITHUB_OUTPUT
          echo "fallback-key=z3-build-${{ runner.os }}-" >> $GITHUB_OUTPUT

      - name: Restore or create cache
        id: cache-z3
        uses: actions/cache@v5
        with:
          path: |
            build/z3
            build/libz3.so
            build/libz3.a
            build/*.so
            build/*.a
            build/python
          key: ${{ steps.cache-key.outputs.key }}
          restore-keys: |
            z3-build-${{ runner.os }}-

      - name: Configure Z3
        if: steps.cache-z3.outputs.cache-hit != 'true'
        run: python scripts/mk_make.py

      - name: Build Z3
        if: steps.cache-z3.outputs.cache-hit != 'true'
        run: |
          cd build
          make -j$(nproc)

      - name: Display build info
        run: |
          echo "Cache key: ${{ steps.cache-key.outputs.key }}"
          echo "Build directory contents:"
          ls -lh build/ || echo "Build directory not found"
          if [ -f build/z3 ]; then
            echo "Z3 version:"
            build/z3 --version
          fi