"""Tests for cost tracking module."""

from agenteval.evaluation.cost_tracking import (
    DEFAULT_PRICING,
    CostBreakdown,
    ModelPricing,
    build_eval_cost_section,
    calculate_cost,
    get_pricing,
    reload_pricing_overrides,
    usage_breakdown,
)


def test_model_pricing_model():
    pricing = ModelPricing(
        model_id="gpt-4o",
        prompt_cost_per_1m=5.0,
        completion_cost_per_1m=15.0,
    )
    assert pricing.model_id == "gpt-4o"
    assert pricing.prompt_cost_per_1m == 5.0


def test_calculate_cost_gpt4o_mini():
    pricing = ModelPricing(model_id="gpt-4o-mini", prompt_cost_per_1m=0.15, completion_cost_per_1m=0.60)
    # (1000/1M * 0.15) + (500/1M * 0.60) = 0.00015 + 0.0003 = 0.00045
    cost = calculate_cost(1000, 500, pricing)
    assert abs(cost - 0.00045) < 0.00001


def test_calculate_cost_zero_tokens():
    pricing = ModelPricing(model_id="gpt-4o", prompt_cost_per_1m=5.0, completion_cost_per_1m=15.0)
    assert calculate_cost(0, 0, pricing) == 0.0


def test_get_pricing_known_model():
    pricing = get_pricing("gpt-4o-mini")
    assert pricing is not None
    assert pricing.prompt_cost_per_1m == DEFAULT_PRICING["gpt-4o-mini"].prompt_cost_per_1m


def test_get_pricing_unknown_or_empty():
    assert get_pricing("no-such-model") is None
    assert get_pricing(None) is None
    assert get_pricing("") is None


def test_get_pricing_override_file(tmp_path, monkeypatch):
    override_file = tmp_path / "model_pricing.json"
    override_file.write_text(
        '{"custom-judge": {"prompt_cost_per_1m": 1.0, "completion_cost_per_1m": 2.0},'
        ' "broken": "not-a-dict"}',
        encoding="utf-8",
    )
    monkeypatch.setattr("agenteval.evaluation.cost_tracking._PRICING_FILE", override_file)
    reload_pricing_overrides()
    try:
        pricing = get_pricing("custom-judge")
        assert pricing is not None
        assert pricing.completion_cost_per_1m == 2.0
        # 覆盖优先于默认表
        override_file.write_text(
            '{"gpt-4o-mini": {"prompt_cost_per_1m": 9.9, "completion_cost_per_1m": 9.9}}',
            encoding="utf-8",
        )
        reload_pricing_overrides()
        assert get_pricing("gpt-4o-mini").prompt_cost_per_1m == 9.9
        # 坏条目被跳过，不抛异常
        assert get_pricing("broken") is None
    finally:
        reload_pricing_overrides()


def test_get_pricing_missing_file_is_noop(tmp_path, monkeypatch):
    monkeypatch.setattr("agenteval.evaluation.cost_tracking._PRICING_FILE", tmp_path / "missing.json")
    reload_pricing_overrides()
    try:
        assert get_pricing("gpt-4o") is DEFAULT_PRICING["gpt-4o"]
    finally:
        reload_pricing_overrides()


def test_usage_breakdown():
    pricing = DEFAULT_PRICING["gpt-4o-mini"]
    breakdown = usage_breakdown({"prompt_tokens": 1000, "completion_tokens": 500}, pricing)
    assert isinstance(breakdown, CostBreakdown)
    assert breakdown.total_tokens == 1500
    assert abs(breakdown.cost_usd - 0.00045) < 0.00001


def test_usage_breakdown_missing_fields():
    pricing = DEFAULT_PRICING["gpt-4o-mini"]
    breakdown = usage_breakdown({}, pricing)
    assert breakdown.total_tokens == 0
    assert breakdown.cost_usd == 0.0


def test_build_eval_cost_section_by_purpose():
    usage = {
        "judge": {"prompt_tokens": 1000, "completion_tokens": 500, "total_tokens": 1500},
        "generator": {"prompt_tokens": 2000, "completion_tokens": 1000, "total_tokens": 3000},
    }
    model_configs = {
        "judge": {"model_name": "gpt-4o-mini"},
        "generator": {"model_name": "unknown-model"},
    }
    section = build_eval_cost_section(usage, model_configs)
    assert section is not None
    by_purpose = {i["purpose"]: i for i in section["by_purpose"]}
    assert abs(by_purpose["judge"]["cost_usd"] - 0.00045) < 0.00001
    # 未知定价：token 数仍展示，成本为空
    assert by_purpose["generator"]["cost_usd"] is None
    assert by_purpose["generator"]["total_tokens"] == 3000
    assert section["total_tokens"] == 4500
    assert abs(section["total_cost_usd"] - 0.00045) < 0.00001


def test_build_eval_cost_section_empty():
    assert build_eval_cost_section(None, None) is None
    assert build_eval_cost_section({}, {}) is None