"""Tests for deterministic build configuration."""

from backend.app.services.deterministic import DeterministicBuildConfig


class TestDeterministicBuildConfig:
    """Test that same inputs produce same outputs."""

    def test_hash_deterministic(self) -> None:
        """Same config produces same hash."""
        config = {
            "packages": ["vim", "git", "base"],
            "overlays": [
                {
                    "name": "test",
                    "files": [{"path": "/etc/test", "content": "hello"}],
                }
            ],
        }

        hash1 = DeterministicBuildConfig.compute_config_hash(config)
        hash2 = DeterministicBuildConfig.compute_config_hash(config)

        assert hash1 == hash2

    def test_hash_order_independent(self) -> None:
        """Package order doesn't affect hash."""
        config1 = {"packages": ["vim", "git", "base"], "overlays": []}
        config2 = {"packages": ["base", "git", "vim"], "overlays": []}

        hash1 = DeterministicBuildConfig.compute_config_hash(config1)
        hash2 = DeterministicBuildConfig.compute_config_hash(config2)

        assert hash1 == hash2

    def test_hash_different_configs(self) -> None:
        """Different configs produce different hashes."""
        config1 = {"packages": ["vim"], "overlays": []}
        config2 = {"packages": ["emacs"], "overlays": []}

        hash1 = DeterministicBuildConfig.compute_config_hash(config1)
        hash2 = DeterministicBuildConfig.compute_config_hash(config2)

        assert hash1 != hash2

    def test_source_date_epoch_deterministic(self) -> None:
        """Same hash produces same timestamp."""
        config_hash = "abc123def456"

        epoch1 = DeterministicBuildConfig.get_source_date_epoch(config_hash)
        epoch2 = DeterministicBuildConfig.get_source_date_epoch(config_hash)

        assert epoch1 == epoch2

    def test_source_date_epoch_in_range(self) -> None:
        """Timestamp is within reasonable range."""
        config_hash = "abc123def456"

        epoch = DeterministicBuildConfig.get_source_date_epoch(config_hash)

        # Should be between 2020 and 2030
        assert 1577836800 <= epoch <= 1924991999