import pytest
from unittest.mock import MagicMock
from sqlalchemy.orm import Session
from src.services.bike_matching import match_activity_to_bike, calculate_observed_ratio
from src.models import Activity, BikeSetup

@pytest.fixture
def mock_db():
    db = MagicMock(spec=Session)
    
    # Mock bike setups
    # 1. 50/15 => 3.33
    # 2. 48/16 => 3.00
    # 3. 52/11 => 4.72
    
    setup1 = BikeSetup(id=1, frame="Fixie", chainring=50, rear_cog=15, name="Fixie A")
    setup2 = BikeSetup(id=2, frame="Commuter", chainring=48, rear_cog=16, name="City")
    setup3 = BikeSetup(id=3, frame="Road", chainring=52, rear_cog=11, name="Race")
    
    db.query.return_value.all.return_value = [setup1, setup2, setup3]
    return db

def test_calculate_observed_ratio():
    # Ratio = (Speed * 60) / (Cadence * 2.1)
    # Speed 10m/s (36kmh), Cadence 90
    # Ratio = 600 / (90 * 2.1) = 600 / 189 = 3.17
    ratio = calculate_observed_ratio(10, 90)
    assert abs(ratio - 3.17) < 0.01

def test_match_activity_success(mock_db):
    # Setup 2 is 48/16 = 3.0
    # Target: Speed for Ratio 3.0 at 90 RPM
    # Speed = (3.0 * 90 * 2.1) / 60 = 567 / 60 = 9.45 m/s
    
    activity = Activity(
        id=101, 
        activity_type='cycling', 
        avg_speed=9.45, 
        avg_cadence=90,
        streams=None # valid attribute
    )
    
    match, confidence = match_activity_to_bike(mock_db, activity)
    assert match is not None
    assert match.id == 2 # Commuter (Ratio 3.0)

def test_match_activity_indoor_ignored(mock_db):
    activity = Activity(
        id=102, 
        activity_type='Indoor Cycling', 
        avg_speed=9.45, 
        avg_cadence=90,
        streams=None
    )
    match, confidence = match_activity_to_bike(mock_db, activity)
    assert match is None

def test_match_activity_no_match(mock_db):
    # Ratio 1.0 (Very low gear)
    # Speed = 3.15 m/s at 90 RPM
    activity = Activity(
        id=103, 
        activity_type='cycling', 
        avg_speed=3.15, 
        avg_cadence=90,
        streams=None
    )
    match, confidence = match_activity_to_bike(mock_db, activity)
    assert match is None