"""Unit tests for ToolCallValidator and validate_agent_tools."""
import pytest
from agent_service.llm.tool_validator import (
    ToolCallValidator, AgentConfigError, ToolValidationError, validate_agent_tools,
)

SAMPLE_TOOLS = [
    {'name': 'get_invoices', 'parameters': {
        'state': {'type': 'string', 'optional': True},
        'limit': {'type': 'integer', 'optional': True},
        'partner_id': {'type': 'integer'},
    }},
    {'name': 'send_reminder', 'parameters': {
        'invoice_id': {'type': 'integer'},
        'message': {'type': 'string', 'optional': True},
    }},
]


def test_validator_init():
    v = ToolCallValidator(SAMPLE_TOOLS)
    assert 'get_invoices' in v._tools


def test_raises_on_too_many_tools():
    many_tools = [{'name': f'tool_{i}', 'parameters': {}} for i in range(9)]
    with pytest.raises(AgentConfigError, match='max is 8'):
        validate_agent_tools(many_tools, 'test_agent')


def test_validate_agent_tools_ok_for_8():
    tools_8 = [{'name': f'tool_{i}', 'parameters': {}} for i in range(8)]
    validate_agent_tools(tools_8, 'test_agent')  # should not raise


def test_valid_tool_call():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.validate({'name': 'get_invoices', 'arguments': {'partner_id': 42}})
    assert result['name'] == 'get_invoices'
    assert result['arguments']['partner_id'] == 42


def test_strips_hallucinated_params():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.validate({'name': 'get_invoices', 'arguments': {
        'partner_id': 1, 'nonexistent_param': 'bad',
    }})
    assert 'nonexistent_param' not in result['arguments']


def test_missing_required_param_raises():
    v = ToolCallValidator(SAMPLE_TOOLS)
    with pytest.raises(ToolValidationError, match='partner_id'):
        v.validate({'name': 'get_invoices', 'arguments': {}})


def test_type_coercion_int():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.validate({'name': 'get_invoices', 'arguments': {'partner_id': '42'}})
    assert result['arguments']['partner_id'] == 42


def test_unknown_tool_raises():
    v = ToolCallValidator(SAMPLE_TOOLS)
    with pytest.raises(ToolValidationError, match='Unknown tool'):
        v.validate({'name': 'nonexistent_tool', 'arguments': {}})


def test_parse_or_fallback_returns_none_on_unknown_tool():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.parse_or_fallback({'name': 'bad_tool', 'arguments': {}})
    assert result is None


def test_parse_or_fallback_returns_none_on_missing_required():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.parse_or_fallback({'name': 'get_invoices', 'arguments': {}})
    assert result is None


def test_parse_or_fallback_valid_call():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.parse_or_fallback({'name': 'send_reminder', 'arguments': {'invoice_id': 5}})
    assert result is not None
    assert result['name'] == 'send_reminder'


def test_parse_or_fallback_none_input():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.parse_or_fallback(None)
    assert result is None


def test_optional_param_not_required():
    v = ToolCallValidator(SAMPLE_TOOLS)
    result = v.validate({'name': 'get_invoices', 'arguments': {'partner_id': 1}})
    assert result['name'] == 'get_invoices'


def test_enum_validation_rejects_invalid_value():
    tools = [{'name': 'set_state', 'parameters': {
        'state': {'type': 'string', 'enum': ['draft', 'posted']},
    }}]
    v = ToolCallValidator(tools)
    with pytest.raises(ToolValidationError):
        v.validate({'name': 'set_state', 'arguments': {'state': 'invalid_state'}})


def test_enum_validation_accepts_valid_value():
    tools = [{'name': 'set_state', 'parameters': {
        'state': {'type': 'string', 'enum': ['draft', 'posted']},
    }}]
    v = ToolCallValidator(tools)
    result = v.validate({'name': 'set_state', 'arguments': {'state': 'posted'}})
    assert result['arguments']['state'] == 'posted'