name: Build

on:
  pull_request:
    branches: [ "main" ]
  push:
    branches: [ "main" ]
  workflow_call:
    inputs:
      env_file:
        description: "Which env file to use (.env.stable or .env.latest)"
        required: false
        type: string

permissions:
  contents: read
  packages: read

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      # Pick the env file:
      # - Default to .env.stable for PR/push
      # - If invoked via workflow_call and an env_file was provided, use it
      - name: Select env file
        shell: bash
        run: |
          if [[ "${{ github.event_name }}" == "workflow_call" && -n "${{ inputs.env_file }}" ]]; then
            echo "ENV_FILE=${{ inputs.env_file }}" >> "$GITHUB_ENV"
          else
            echo "ENV_FILE=.env.stable" >> "$GITHUB_ENV"
          fi
          echo "Using env file: $ENV_FILE"

      - name: Reset compose state
        run: |
          docker compose down --volumes --remove-orphans || true
          rm -rf build && mkdir -p build

      - name: Build (to named volume)
        run: docker compose --env-file "$ENV_FILE" run --rm l2-build

      - name: Export to ./build (host-owned files)
        run: docker compose --env-file "$ENV_FILE" run --rm l2-export | tar -C build -xf -

      - name: List build output
        run: ls -la build | head -n 200

      - name: Upload build artifacts
        uses: actions/upload-artifact@v4
        with:
          name: build-artifacts
          path: build
          if-no-files-found: error