"""Tests for Phase 5.1 SubQuestions Pydantic model.

Validates the SubQuestions model used with LangChain with_structured_output().
Ensures proper validation of structured LLM responses.
"""

import pytest
from pydantic import ValidationError


class TestSubQuestionsModel:
    """Pydantic model tests for SubQuestions — no LLM calls needed."""

    def test_valid_subquestions(self):
        """SubQuestions should accept a valid list of 2-5 strings."""
        from app.models.decompose import SubQuestions

        sq = SubQuestions(questions=["What is A?", "What is B?"])
        assert sq.questions == ["What is A?", "What is B?"]
        assert len(sq.questions) == 2

    def test_min_length_one(self):
        """A single sub-question should be valid (min_length=1)."""
        from app.models.decompose import SubQuestions

        sq = SubQuestions(questions=["Single question"])
        assert len(sq.questions) == 1

    def test_max_length_five(self):
        """Up to 5 sub-questions should be valid (max_length=5)."""
        from app.models.decompose import SubQuestions

        sq = SubQuestions(questions=[f"Q{i}" for i in range(5)])
        assert len(sq.questions) == 5

    def test_empty_list_rejected(self):
        """Empty list should be rejected by min_length=1 constraint."""
        from app.models.decompose import SubQuestions

        with pytest.raises(ValidationError, match="questions"):
            SubQuestions(questions=[])

    def test_zero_questions_rejected(self):
        """Empty list should be rejected (same as above, explicit)."""
        from app.models.decompose import SubQuestions

        with pytest.raises(ValidationError, match="questions"):
            SubQuestions(questions=[])

    def test_too_many_questions_rejected(self):
        """More than 5 questions should be rejected by max_length=5."""
        from app.models.decompose import SubQuestions

        with pytest.raises(ValidationError, match="questions"):
            SubQuestions(questions=[f"Q{i}" for i in range(10)])

    def test_non_string_items_rejected(self):
        """Non-string items in the list should be rejected."""
        from app.models.decompose import SubQuestions

        with pytest.raises(ValidationError):
            SubQuestions(questions=[1, 2, 3])

    def test_missing_field_rejected(self):
        """Missing 'questions' field should be rejected."""
        from app.models.decompose import SubQuestions

        with pytest.raises(ValidationError):
            SubQuestions()  # type: ignore

    def test_wrong_type_rejected(self):
        """Passing a string instead of a list should be rejected."""
        from app.models.decompose import SubQuestions

        with pytest.raises(ValidationError):
            SubQuestions(questions="not a list")  # type: ignore

    def test_json_schema_generation(self):
        """JSON schema should be valid for structured output."""
        from app.models.decompose import SubQuestions

        schema = SubQuestions.model_json_schema()
        assert schema["type"] == "object"
        assert "questions" in schema["properties"]
        assert schema["properties"]["questions"]["type"] == "array"
        assert schema["properties"]["questions"]["items"]["type"] == "string"

    def test_cantonese_questions_accepted(self):
        """Cantonese/Chinese text should be accepted as valid strings."""
        from app.models.decompose import SubQuestions

        sq = SubQuestions(
            questions=[
                "立法會今日討論什麼議題？",
                "有咩重要決定？",
            ]
        )
        assert len(sq.questions) == 2
        assert all(isinstance(q, str) for q in sq.questions)