import json
import os

import pytest

from pr.core.usage_tracker import UsageTracker


@pytest.fixture
def temp_usage_file(tmp_path, monkeypatch):
    from pr.core import usage_tracker

    original_file = usage_tracker.USAGE_DB_FILE
    temp_file = str(tmp_path / "usage.json")
    monkeypatch.setattr(usage_tracker, "USAGE_DB_FILE", temp_file)
    yield temp_file
    if os.path.exists(temp_file):
        os.remove(temp_file)
    monkeypatch.setattr(usage_tracker, "USAGE_DB_FILE", original_file)


def test_usage_tracker_init():
    tracker = UsageTracker()
    summary = tracker.get_session_summary()
    assert summary["requests"] == 0
    assert summary["total_tokens"] == 0
    assert summary["estimated_cost"] == 0.0


def test_track_request_known_model():
    tracker = UsageTracker()
    tracker.track_request("gpt-3.5-turbo", 100, 50)

    summary = tracker.get_session_summary()
    assert summary["requests"] == 1
    assert summary["input_tokens"] == 100
    assert summary["output_tokens"] == 50
    assert summary["total_tokens"] == 150
    assert "gpt-3.5-turbo" in summary["models_used"]
    # Cost: (100/1000)*0.0005 + (50/1000)*0.0015 = 0.00005 + 0.000075 = 0.000125
    assert abs(summary["estimated_cost"] - 0.000125) < 1e-6


def test_track_request_unknown_model():
    tracker = UsageTracker()
    tracker.track_request("unknown-model", 100, 50)

    summary = tracker.get_session_summary()
    assert summary["requests"] == 1
    assert summary["estimated_cost"] == 0.0  # Unknown model, cost 0


def test_track_request_multiple():
    tracker = UsageTracker()
    tracker.track_request("gpt-3.5-turbo", 100, 50)
    tracker.track_request("gpt-4", 200, 100)

    summary = tracker.get_session_summary()
    assert summary["requests"] == 2
    assert summary["input_tokens"] == 300
    assert summary["output_tokens"] == 150
    assert summary["total_tokens"] == 450
    assert len(summary["models_used"]) == 2


def test_get_formatted_summary():
    tracker = UsageTracker()
    tracker.track_request("gpt-3.5-turbo", 100, 50)

    formatted = tracker.get_formatted_summary()
    assert "Total Requests: 1" in formatted
    assert "Total Tokens: 150" in formatted
    assert "Estimated Cost: $0.0001" in formatted
    assert "gpt-3.5-turbo" in formatted


def test_get_total_usage_no_file(temp_usage_file):
    total = UsageTracker.get_total_usage()
    assert total["total_requests"] == 0
    assert total["total_tokens"] == 0
    assert total["total_cost"] == 0.0


def test_get_total_usage_with_data(temp_usage_file):
    # Manually create history file
    history = [
        {
            "timestamp": "2023-01-01",
            "model": "gpt-3.5-turbo",
            "input_tokens": 100,
            "output_tokens": 50,
            "total_tokens": 150,
            "cost": 0.000125,
        },
        {
            "timestamp": "2023-01-02",
            "model": "gpt-4",
            "input_tokens": 200,
            "output_tokens": 100,
            "total_tokens": 300,
            "cost": 0.008,
        },
    ]
    with open(temp_usage_file, "w") as f:
        json.dump(history, f)

    total = UsageTracker.get_total_usage()
    assert total["total_requests"] == 2
    assert total["total_tokens"] == 450
    assert abs(total["total_cost"] - 0.008125) < 1e-6