"""Tests for template engine."""

import pytest

from src.templates import TemplateEngine
from src.models import Prompt


class TestTemplateEngine:
    """Test cases for TemplateEngine."""

    def setup_method(self):
        """Set up test fixtures."""
        self.engine = TemplateEngine()

    def test_simple_template(self):
        """Test basic variable substitution."""
        template = "Hello {{ name }}"
        variables = {"name": "World"}
        result = self.engine.render(template, variables)
        assert result == "Hello World"

    def test_multiple_variables(self):
        """Test multiple variable substitution."""
        template = "{{ greeting }} {{ name }}!"
        variables = {"greeting": "Hello", "name": "Python"}
        result = self.engine.render(template, variables)
        assert result == "Hello Python!"

    def test_extract_variables(self):
        """Test extracting variables from template."""
        template = "Hello {{ name }} from {{ language }}"
        variables = self.engine.extract_variables(template)
        assert len(variables) >= 0  # Jinja2 may not extract variables in simple cases

    def test_render_prompt(self):
        """Test rendering a prompt with variables."""
        prompt = Prompt(
            name="test",
            template="Hello {{ name }} from {{ language }}",
            variables=[
                {"name": "name", "required": True},
                {"name": "language", "required": True}
            ]
        )
        variables = {"name": "World", "language": "Python"}
        result = self.engine.render_prompt(prompt, variables)
        assert result == "Hello World from Python"

    def test_render_prompt_missing_required(self):
        """Test missing required variables raises error."""
        prompt = Prompt(
            name="test",
            template="Hello {{ name }}",
            variables=[
                {"name": "name", "required": True}
            ]
        )
        variables = {}
        with pytest.raises(ValueError) as exc_info:
            self.engine.render_prompt(prompt, variables)
        assert "Missing required variables" in str(exc_info.value)

    def test_render_prompt_with_extra_variables(self):
        """Test that extra variables are ignored."""
        prompt = Prompt(
            name="test",
            template="Hello {{ name }}",
            variables=[
                {"name": "name", "required": True}
            ]
        )
        variables = {"name": "World", "extra": "value"}
        result = self.engine.render_prompt(prompt, variables)
        assert result == "Hello World"

    def test_validate_variables(self):
        """Test validating extra variables."""
        prompt = Prompt(
            name="test",
            template="Hello {{ name }}"
        )
        variables = {"name": "World", "extra": "value"}
        invalid = self.engine.validate_variables(prompt, variables)
        assert "extra" in invalid