import pytest
from datetime import datetime, timedelta
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
import app.models.db_base  # Ensures all tables registered in metadata
from app.core.database.db_session import Base
from app.models.CustomerDeviceModel import CustomerDevice
from app.models.ServiceModel import ServiceCatalog, ServiceJob, ServiceAppointment, ServiceJobAssignment
from app.models.TechnicianModel import TechnicianProfile, TechnicianSkill, TechnicianWorkingHours
from app.services.SlotAllocationService import SlotAllocationService

# Setup in-memory SQLite database for testing
DATABASE_URL = "sqlite:///:memory:"
engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

@pytest.fixture(scope="function")
def db_session():
    Base.metadata.create_all(bind=engine)
    db = TestingSessionLocal()
    try:
        yield db
    finally:
        db.close()
        Base.metadata.drop_all(bind=engine)

def test_dynamic_slot_allocation_success(db_session):
    # 1. Setup seed catalog services
    service = ServiceCatalog(
        service_id="serv_1",
        name="Screen Replacement",
        base_price=5000.00,
        estimated_duration_minutes=60,
        workflow_type="REPAIR_QUOTE",
        active=True
    )
    db_session.add(service)

    # 2. Setup technician profile
    tech = TechnicianProfile(
        technician_id="tech_1",
        user_id="user_tech_1",
        active=True
    )
    db_session.add(tech)

    # 3. Setup technician skill
    skill = TechnicianSkill(
        technician_id="tech_1",
        service_type_id="serv_1",
        skill_level=3
    )
    db_session.add(skill)

    # 4. Setup working hours (Monday is weekday 0)
    wh = TechnicianWorkingHours(
        working_hour_id="wh_1",
        technician_id="tech_1",
        day_of_week=0,
        start_time="09:00",
        end_time="11:00"
    )
    db_session.add(wh)
    db_session.commit()

    # Calculate slots for next Monday (e.g. 2026-08-31)
    target_date = datetime(2026, 8, 31).date()
    allocation_service = SlotAllocationService()
    slots = allocation_service.get_available_slots(db_session, target_date, "serv_1")

    # Since duration is 60 mins and working hours are 09:00 - 11:00:
    # 09:00 - 10:00 -> Slot 1
    # 09:30 - 10:30 -> Slot 2
    # 10:00 - 11:00 -> Slot 3
    assert len(slots) == 3
    assert slots[0]["start_time"] == "2026-08-31T09:00:00"
    assert slots[2]["start_time"] == "2026-08-31T10:00:00"

def test_dynamic_slot_allocation_overlap(db_session):
    # 1. Setup seed catalog services & technician
    service = ServiceCatalog(
        service_id="serv_1",
        name="Screen Replacement",
        base_price=5000.00,
        estimated_duration_minutes=60,
        active=True
    )
    db_session.add(service)

    tech = TechnicianProfile(
        technician_id="tech_1",
        user_id="user_tech_1",
        active=True
    )
    db_session.add(tech)

    skill = TechnicianSkill(
        technician_id="tech_1",
        service_type_id="serv_1",
        skill_level=3
    )
    db_session.add(skill)

    wh = TechnicianWorkingHours(
        working_hour_id="wh_1",
        technician_id="tech_1",
        day_of_week=0,
        start_time="09:00",
        end_time="11:00"
    )
    db_session.add(wh)

    # 2. Book an overlapping slot (09:30 - 10:30)
    device = CustomerDevice(
        device_id="dev_1",
        customer_id="cust_1",
        brand="Apple",
        model="iPhone 14"
    )
    db_session.add(device)

    job = ServiceJob(
        job_id="job_1",
        job_no="SRV-12345",
        customer_id="cust_1",
        device_id="dev_1",
        service_id="serv_1",
        status="BOOKED"
    )
    db_session.add(job)

    appt = ServiceAppointment(
        appointment_id="appt_1",
        service_job_id="job_1",
        scheduled_start=datetime(2026, 8, 31, 9, 30),
        scheduled_end=datetime(2026, 8, 31, 10, 30),
        status="CONFIRMED"
    )
    db_session.add(appt)

    assignment = ServiceJobAssignment(
        assignment_id="assign_1",
        service_job_id="job_1",
        appointment_id="appt_1",
        technician_id="tech_1"
    )
    db_session.add(assignment)
    db_session.commit()

    # Re-calculate availability
    target_date = datetime(2026, 8, 31).date()
    allocation_service = SlotAllocationService()
    slots = allocation_service.get_available_slots(db_session, target_date, "serv_1")

    # Overlapping appt is 09:30 - 10:30.
    # Slot 09:00 - 10:00 overlaps (ends after 09:30) -> overlap!
    # Slot 09:30 - 10:30 overlaps -> overlap!
    # Slot 10:00 - 11:00 overlaps (starts before 10:30) -> overlap!
    # So there should be 0 available slots!
    assert len(slots) == 0