from fastapi import APIRouter, HTTPException, Query
from uuid import uuid4
from datetime import datetime, date
from typing import Optional
from pydantic import BaseModel

from ..models.flight_models import (
    BookingRequest,
    RefundRequest,
    RescheduleRequest
)

from ..data.flight_dummy_data import (
    flight_db,
    booking_db,
    refund_db
)

router = APIRouter(prefix="/flights", tags=["Flights"])

book_id_counter = 1
refund_id_counter = 1

# ======================
# helper
# ======================
def find_flight(flight_id):
    for f in flight_db:
        if f["flight_id"] == flight_id:
            return f
    return None


def find_booking(booking_id):
    for b in booking_db:
        if b["booking_id"] == booking_id:
            return b
    return None


# ======================
# GET all flights
# ======================
@router.get("/")
def get_all_flights():
    return flight_db




@router.get("/search")
def search_flights(
    departure_date: Optional[str] = Query(None),
    origin: Optional[str] = Query(None),
    destination: Optional[str] = Query(None),
    seat_class: Optional[str] = Query(None),
    flight_id: Optional[str] = Query(None),
):
    results = []

    for flight in flight_db:

        if departure_date:
            departure_date_2 = datetime.strptime(departure_date, "%Y-%m-%d")
            if flight["departure_time"].date() != departure_date_2.date():
                continue

        if origin:
            if flight["origin"].upper() != origin.upper():
                continue

        if destination:
            if flight["destination"].upper() != destination.upper():
                continue

        if seat_class:
            if flight["seat_class"].upper() != destination.upper():
                continue
                
        if flight_id:
            if flight["flight_id"] != flight_id:
                continue

        results.append(flight)

        # stop at top 15
        if len(results) == 15:
            break

    return {
        "total": len(results),
        "limit": 15,
        "filters": {
            "departure_date": departure_date,
            "origin": origin,
            "destination": destination
        },
        "flights": results
    }


# ======================
# GET flight by id
# ======================
@router.get("/{flight_id}")
def get_flight(flight_id: str):
    flight = find_flight(flight_id)

    if not flight:
        return dict(status=404, messages="Flight not found")

    return flight


# ======================
# BOOKING
# ======================
@router.post("/booking")
def create_booking(data: BookingRequest):
    global book_id_counter

    flight = find_flight(data.flight_id)

    if not flight:
        return dict(status=404, messages="Flight not found")

    booking = {
        "booking_id": f"BK{book_id_counter:04d}",
        "customer_name": data.customer_name,
        "customer_id": data.customer_id,
        "flight_id": flight["flight_id"],
        "price_paid": flight["price"],
        "status": "pending",
        "booked_at": datetime.now()
    }

    booking_db.append(booking)

    book_id_counter += 1

    return booking


# ======================
# GET BOOKING
# ======================
@router.get("/booking/search")
def get_booking(booking_id: Optional[str] = Query(None)):
    booking = find_booking(booking_id)
    if not booking:
        return dict(status=404, messages="Booking not found")
    return booking


# ======================
# BOOKING PAYMENT
# ======================
class BookingPaymentRequest(BaseModel):
    booking_id: str
    payment_method: str
    payment_amount: float


# ======================
# REFUND PAYMENT
# ======================
class RefundPaymentRequest(BaseModel):
    refund_id: str
    bank_account: str
    

@router.post("/booking/payment")
def booking_payment(data: BookingPaymentRequest):

    booking = find_booking(data.booking_id)

    if not booking:
        raise HTTPException(404, "Booking not found")

    if booking["status"] == "complete":
        raise HTTPException(400, "Booking already paid at " + booking["paid_at"].strftime("%d-%m-%Y %H:%M"))

    if booking["price_paid"] != data.payment_amount:
        raise HTTPException(400, "Payment amount is incorrect")

    booking["status"] = "complete"
    booking["payment_method"] = data.payment_method
    booking["paid_at"] = datetime.now()

    return {
        "message": "Booking payment successful",
        "booking": booking
    }


@router.post("/refund/payment")
def refund_payment(data: RefundPaymentRequest):

    refund = find_refund(data.refund_id)

    if not refund:
        raise HTTPException(404, "Refund not found")

    if refund["status"] == "complete":
        raise HTTPException(400, "Refund already completed")

    refund["status"] = "complete"
    refund["bank_account"] = data.bank_account
    refund["processed_at"] = datetime.now()

    return {
        "message": "Refund completed",
        "refund": refund
    }

# ======================
# REFUND
# 80% refund
# ======================
@router.post("/refund")
def refund(data: RefundRequest):
    global refund_id_counter

    booking = find_booking(data.booking_id)

    if not booking:
        # return dict(404, "Booking not found")
        return {
            "status":404,
            "messages":"Booking not found!"
        }

    for r in refund_db:
        if str(r["booking_id"]) == data.booking_id:
            return {
                "status":401,
                "messages":"Refund On-Process"
            }    

    refund_amount = booking["price_paid"] #* 0.8

    item = {
        # "refund_id": str(uuid4()),
        "refund_id": f"RF{refund_id_counter:04d}",
        "booking_id": booking["booking_id"],
        "refund_amount": refund_amount,
        "status": "pending"
    }

    refund_db.append(item)

    refund_id_counter += 1

    return item



# ======================
# RESCHEDULE
# ======================
@router.post("/reschedule")
def reschedule(data: RescheduleRequest):

    booking = find_booking(data.booking_id)

    if not booking:
        return dict(status=404, messages="Booking not found")

    new_flight = find_flight(data.new_flight_id)

    if not new_flight:
        return dict(status=404, messages="New flight not found")

    old_price = booking["price_paid"]
    new_price = new_flight["price"]

    diff = new_price - old_price

    booking["flight_id"] = new_flight["flight_id"]
    booking["price_paid"] = new_price

    if diff > 0:
        booking["status"] = "pending"
    elif diff < 0:
        booking["status"] = "refund-on-process"
    else:
        booking["status"] = "complete"

    return {
        "message": "Rescheduled successfully",
        "old_price": old_price,
        "new_price": new_price,
        "price_difference": diff
    }