"""Unit tests for TranslationRequest value object."""

import pytest
from src.domain.models.translation_request import TranslationRequest
from src.domain.models.text_content import TextContent


class TestTranslationRequest:
    """Test cases for TranslationRequest value object."""

    @pytest.fixture
    def sample_text_content(self):
        """Sample text content for testing."""
        return TextContent(
            text="Hello, world!",
            language="en"
        )

    def test_valid_translation_request_creation(self, sample_text_content):
        """Test creating valid TranslationRequest instance."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es",
            source_language="en"
        )

        assert request.source_text == sample_text_content
        assert request.target_language == "es"
        assert request.source_language == "en"
        assert request.effective_source_language == "en"
        assert request.is_auto_detect_source is False

    def test_translation_request_without_source_language(self, sample_text_content):
        """Test creating TranslationRequest without explicit source language."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es"
        )

        assert request.source_language is None
        assert request.effective_source_language == "en"  # From TextContent
        assert request.is_auto_detect_source is True

    def test_non_text_content_source_raises_error(self):
        """Test that non-TextContent source raises TypeError."""
        with pytest.raises(TypeError, match="Source text must be a TextContent instance"):
            TranslationRequest(
                source_text="not a TextContent",  # type: ignore
                target_language="es"
            )

    def test_non_string_target_language_raises_error(self, sample_text_content):
        """Test that non-string target language raises TypeError."""
        with pytest.raises(TypeError, match="Target language must be a string"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language=123  # type: ignore
            )

    def test_empty_target_language_raises_error(self, sample_text_content):
        """Test that empty target language raises ValueError."""
        with pytest.raises(ValueError, match="Target language cannot be empty"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language=""
            )

    def test_whitespace_target_language_raises_error(self, sample_text_content):
        """Test that whitespace-only target language raises ValueError."""
        with pytest.raises(ValueError, match="Target language cannot be empty"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language="   "
            )

    def test_invalid_target_language_format_raises_error(self, sample_text_content):
        """Test that invalid target language format raises ValueError."""
        invalid_codes = ["e", "ENG", "en-us", "en-USA", "123", "en_US"]

        for code in invalid_codes:
            with pytest.raises(ValueError, match="Invalid target language code format"):
                TranslationRequest(
                    source_text=sample_text_content,
                    target_language=code
                )

    def test_valid_target_language_codes(self, sample_text_content):
        """Test valid target language code formats."""
        valid_codes = ["es", "fr", "de", "zh", "ja", "en-US", "fr-FR", "zh-CN"]

        for code in valid_codes:
            request = TranslationRequest(
                source_text=sample_text_content,
                target_language=code
            )
            assert request.target_language == code

    def test_non_string_source_language_raises_error(self, sample_text_content):
        """Test that non-string source language raises TypeError."""
        with pytest.raises(TypeError, match="Source language must be a string"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language="es",
                source_language=123  # type: ignore
            )

    def test_empty_source_language_raises_error(self, sample_text_content):
        """Test that empty source language raises ValueError."""
        with pytest.raises(ValueError, match="Source language cannot be empty string"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language="es",
                source_language=""
            )

    def test_whitespace_source_language_raises_error(self, sample_text_content):
        """Test that whitespace-only source language raises ValueError."""
        with pytest.raises(ValueError, match="Source language cannot be empty string"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language="es",
                source_language="   "
            )

    def test_invalid_source_language_format_raises_error(self, sample_text_content):
        """Test that invalid source language format raises ValueError."""
        invalid_codes = ["e", "ENG", "en-us", "en-USA", "123", "en_US"]

        for code in invalid_codes:
            with pytest.raises(ValueError, match="Invalid source language code format"):
                TranslationRequest(
                    source_text=sample_text_content,
                    target_language="es",
                    source_language=code
                )

    def test_same_source_and_target_language_explicit_raises_error(self, sample_text_content):
        """Test that same explicit source and target language raises ValueError."""
        with pytest.raises(ValueError, match="Source and target languages cannot be the same"):
            TranslationRequest(
                source_text=sample_text_content,
                target_language="en",
                source_language="en"
            )

    def test_same_source_and_target_language_implicit_raises_error(self):
        """Test that same implicit source and target language raises ValueError."""
        text_content = TextContent(text="Hello", language="en")

        with pytest.raises(ValueError, match="Source and target languages cannot be the same"):
            TranslationRequest(
                source_text=text_content,
                target_language="en"  # Same as text_content.language
            )

    def test_text_length_property(self, sample_text_content):
        """Test text_length property."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es"
        )

        assert request.text_length == len(sample_text_content.text)

    def test_word_count_property(self, sample_text_content):
        """Test word_count property."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es"
        )

        assert request.word_count == sample_text_content.word_count

    def test_with_target_language_method(self, sample_text_content):
        """Test with_target_language method creates new instance."""
        original = TranslationRequest(
            source_text=sample_text_content,
            target_language="es",
            source_language="en"
        )

        new_request = original.with_target_language("fr")

        assert new_request.target_language == "fr"
        assert new_request.source_text == original.source_text
        assert new_request.source_language == original.source_language
        assert new_request is not original  # Different instances

    def test_with_source_language_method(self, sample_text_content):
        """Test with_source_language method creates new instance."""
        original = TranslationRequest(
            source_text=sample_text_content,
            target_language="es",
            source_language="en"
        )

        new_request = original.with_source_language("de")

        assert new_request.source_language == "de"
        assert new_request.target_language == original.target_language
        assert new_request.source_text == original.source_text
        assert new_request is not original  # Different instances

    def test_with_source_language_none(self, sample_text_content):
        """Test with_source_language method with None value."""
        original = TranslationRequest(
            source_text=sample_text_content,
            target_language="es",
            source_language="en"
        )

        new_request = original.with_source_language(None)
        assert new_request.source_language is None
        assert new_request.is_auto_detect_source is True

    def test_translation_request_is_immutable(self, sample_text_content):
        """Test that TranslationRequest is immutable (frozen dataclass)."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es"
        )

        with pytest.raises(AttributeError):
            request.target_language = "fr"  # type: ignore

    def test_effective_source_language_with_explicit_source(self, sample_text_content):
        """Test effective_source_language with explicit source language."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es",
            source_language="de"  # Different from text_content.language
        )

        assert request.effective_source_language == "de"

    def test_effective_source_language_with_implicit_source(self, sample_text_content):
        """Test effective_source_language with implicit source language."""
        request = TranslationRequest(
            source_text=sample_text_content,
            target_language="es"
        )

        assert request.effective_source_language == sample_text_content.language