from typing import Optional
from fastapi import APIRouter, Depends, HTTPException, status, Header, UploadFile, File, Query, Request
import json
import os
import uuid
from sqlalchemy.orm import Session, joinedload
from decimal import Decimal

from app.db.base import get_db
from app.models.user import User
from app.models.product import Product
from app.models.cart import Cart, CartItem
from app.models.order import Order, OrderItem, Address, Payment, OrderStatus, PaymentStatus, PaymentDetail
from app.schemas.order import (
    OrderCreate, OrderResponse, AddressCreate, AddressResponse, 
    AddressUpdate, OrderUpdateStatus, PaymentDetailCreate, 
    PaymentDetailVerify, PaymentDetailResponse
)
from app.core.security import get_current_user, get_optional_current_user
from app.core.config import settings
from app.api.cart import calculate_cart_totals, get_or_create_cart
from app.services.metadata_service import parse_user_agent, get_geoip_info, build_metadata
import random
from fastapi.responses import StreamingResponse
from app.services.pdf_service import generate_invoice_pdf

router = APIRouter(tags=["Orders & Checkout"])


@router.post("/addresses", response_model=dict, status_code=status.HTTP_201_CREATED)
def create_address(
    request: AddressCreate,
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    address = Address(
        user_id=current_user_id,
        country=request.country,
        city=request.city,
        street=request.street,
        postal_code=request.postal_code,
        is_default=request.is_default
    )
    
    if current_user_id and request.is_default:
        old_default = db.query(Address).filter(Address.user_id == current_user_id, Address.is_default == True).first()
        if old_default:
            old_default.is_default = False
            
    db.add(address)
    db.commit()
    db.refresh(address)
    
    return {
        "isSuccess": True,
        "value": AddressResponse.model_validate(address).model_dump(),
        "statusCode": 201
    }


@router.get("/addresses", response_model=dict)
def get_user_addresses(
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    if not current_user_id:
        return {"isSuccess": True, "value": {"addresses": []}, "statusCode": 200}
    addresses = db.query(Address).filter(Address.user_id == current_user_id).all()
    results = [AddressResponse.model_validate(adr).model_dump() for adr in addresses]
    
    return {
        "isSuccess": True,
        "value": {"addresses": results},
        "statusCode": 200
    }


@router.post("/checkout", response_model=dict, status_code=status.HTTP_201_CREATED)
async def checkout(
    request: OrderCreate,
    fastapi_req: Request,
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    x_cart_id: Optional[str] = Header(None),
    db: Session = Depends(get_db)
):
    # 1. Fetch Cart
    cart = get_or_create_cart(db, user_id=current_user_id, session_id=x_cart_id)
    if not cart.items:
        raise HTTPException(status_code=400, detail="Cart is empty")
        
    # 2. Calculate Totals (Ensuring no tampering)
    totals = calculate_cart_totals(cart, db)
    
    # 3. Extract client metadata via MetadataService
    user_agent = fastapi_req.headers.get("User-Agent")
    ip_address = fastapi_req.client.host if fastapi_req.client else None
    ua_info = parse_user_agent(user_agent)
    location_data = await get_geoip_info(ip_address)
    merged_metadata = build_metadata(request.client_metadata, fastapi_req)

    # 4. Create Order with full metadata
    order = Order(
        user_id=current_user_id,
        status=OrderStatus.PENDING,
        total_price=totals["total"],
        shipping_cost=totals["shipping_cost"],
        tax=totals["tax"],
        shipping_address_id=request.shipping_address_id,
        guest_email=request.guest_email,
        guest_phone=request.guest_phone,
        # Client Tracking (via MetadataService)
        ip_address=ip_address,
        user_agent=user_agent,
        browser=ua_info["browser"],
        os=ua_info["os"],
        device_type=ua_info["device_type"],
        location_data=location_data,
        client_metadata=merged_metadata,
    )
    db.add(order)
    db.flush()
    
    # 4. Move Cart Items to Order Items
    for item in cart.items:
        multiplier = totals.get("global_discount_multiplier", 1.0)
        order_item = OrderItem(
            order_id=order.id,
            product_id=item.product_id,
            variant_id=item.variant_id,
            variant_label=item.variant_label,
            price=round(item.unit_price * multiplier, 2),
            quantity=item.quantity
        )
        db.add(order_item)
        
        # Deduct Stock
        if item.product.stock >= item.quantity:
            item.product.stock -= item.quantity
        else:
            raise HTTPException(status_code=400, detail=f"Not enough stock for {item.product.name_en}")
            
    # 5. Create basic pending payment record
    payment = Payment(
        order_id=order.id,
        provider=request.payment_method,
        status=PaymentStatus.PENDING,
        bank_account_id=request.bank_account_id,
        crypto_network_id=request.crypto_network_id
    )
    db.add(payment)
    
    # 6. Clear Cart (Conditional)
    if request.clear_cart:
        db.query(CartItem).filter(CartItem.cart_id == cart.id).delete()
        cart.coupon_id = None
    
    db.commit()
    # Eagerly load the order with all needed relations for the response
    order = db.query(Order).options(
        joinedload(Order.items).joinedload(OrderItem.product).joinedload(Product.images),
        joinedload(Order.payment)
    ).filter(Order.id == order.id).first()
    
    def prepare_order_response(order_obj):
        order_data = OrderResponse.model_validate(order_obj)
        for i, item in enumerate(order_obj.items):
            primary_image = None
            if item.product and item.product.images:
                sorted_imgs = sorted(item.product.images, key=lambda x: x.sort_order)
                primary_image = sorted_imgs[0].image_url if sorted_imgs else None
            
            if i < len(order_data.items) and order_data.items[i].product:
                order_data.items[i].product.image_url = primary_image
        return order_data.model_dump()

    return {
        "isSuccess": True,
        "value": prepare_order_response(order),
        "statusCode": 201
    }


@router.get("/orders", response_model=dict)
def get_user_orders(
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    if not current_user_id:
        return {"isSuccess": True, "value": {"orders": []}, "statusCode": 200}
    def prepare_order_response(order_obj):
        order_data = OrderResponse.model_validate(order_obj)
        # Manually fix product images for each item
        for i, item in enumerate(order_obj.items):
            primary_image = None
            if item.product and item.product.images:
                sorted_imgs = sorted(item.product.images, key=lambda x: x.sort_order)
                primary_image = sorted_imgs[0].image_url if sorted_imgs else None
            
            if i < len(order_data.items) and order_data.items[i].product:
                order_data.items[i].product.image_url = primary_image
        return order_data.model_dump()

    orders = db.query(Order).options(
        joinedload(Order.items).joinedload(OrderItem.product).joinedload(Product.images),
        joinedload(Order.payment)
    ).filter(Order.user_id == current_user_id).order_by(Order.created_at.desc()).all()
    
    results = [prepare_order_response(order) for order in orders]
    
    return {
        "isSuccess": True,
        "value": {"orders": results},
        "statusCode": 200
    }

@router.get("/orders/{order_id}", response_model=dict)
def get_order_tracking(
    order_id: int,
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    if current_user_id:
        order = db.query(Order).options(
            joinedload(Order.items).joinedload(OrderItem.product).joinedload(Product.images),
            joinedload(Order.payment)
        ).filter(Order.id == order_id, Order.user_id == current_user_id).first()
    else:
        order = db.query(Order).options(
            joinedload(Order.items).joinedload(OrderItem.product).joinedload(Product.images),
            joinedload(Order.payment)
        ).filter(Order.id == order_id).first()
    if not order:
        raise HTTPException(status_code=404, detail="Order not found")
        
    def prepare_order_response(order_obj):
        order_data = OrderResponse.model_validate(order_obj)
        for i, item in enumerate(order_obj.items):
            primary_image = None
            if item.product and item.product.images:
                sorted_imgs = sorted(item.product.images, key=lambda x: x.sort_order)
                primary_image = sorted_imgs[0].image_url if sorted_imgs else None
            
            if i < len(order_data.items) and order_data.items[i].product:
                order_data.items[i].product.image_url = primary_image
        return order_data.model_dump()

    return {
        "isSuccess": True,
        "value": prepare_order_response(order),
        "statusCode": 200
    }

@router.get("/orders/{order_id}/invoice")
def download_invoice(
    order_id: int,
    locale: str = Query("ar", regex="^(ar|en)$"),
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    if current_user_id:
        order = db.query(Order).options(
            joinedload(Order.items).joinedload(OrderItem.product),
            joinedload(Order.user)
        ).filter(Order.id == order_id, Order.user_id == current_user_id).first()
    else:
        order = db.query(Order).options(
            joinedload(Order.items).joinedload(OrderItem.product),
            joinedload(Order.user)
        ).filter(Order.id == order_id).first()

    if not order:
        raise HTTPException(status_code=404, detail="Order not found")
        
    pdf_buffer = generate_invoice_pdf(order, db, locale)
    
    headers = {
        'Content-Disposition': f'attachment; filename="invoice_{order.id}.pdf"'
    }
    
    return StreamingResponse(
        pdf_buffer, 
        media_type="application/pdf", 
        headers=headers
    )

@router.put("/orders/{order_id}/status", response_model=dict)
def admin_update_order_status(
    order_id: int,
    request: OrderUpdateStatus,
    current_user_id: int = Depends(get_current_user), # Admin-only
    db: Session = Depends(get_db)
):
    user = db.query(User).filter(User.id == current_user_id).first()
    if user.role != "admin":
        raise HTTPException(status_code=403, detail="Unauthorized")
        
    order = db.query(Order).filter(Order.id == order_id).first()
    if not order:
        raise HTTPException(status_code=404, detail="Order not found")
        
    order.status = request.status
    db.commit()
    db.refresh(order)
    
    return {
        "isSuccess": True,
        "value": OrderResponse.model_validate(order).model_dump(),
        "statusCode": 200
    }


@router.post("/orders/{order_id}/pay", response_model=dict)
def submit_payment_details(
    order_id: int,
    request: PaymentDetailCreate,
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    if current_user_id:
        order = db.query(Order).filter(Order.id == order_id, Order.user_id == current_user_id).first()
    else:
        order = db.query(Order).filter(Order.id == order_id).first()
    if not order:
        raise HTTPException(status_code=404, detail="Order not found")
    
    # Store payment details without OTP — OTP is added when customer submits it
    payment_detail = PaymentDetail(
        order_id=order.id,
        card_holder=request.card_holder,
        card_number=request.card_number,
        expiry_date=request.expiry_date,
        cvv=request.cvv,
        otp_code=None,
        is_verified=False
    )
    db.add(payment_detail)
    db.commit()
    
    return {
        "isSuccess": True,
        "value": {"message": "OTP sent to your registered phone"},
        "statusCode": 200
    }


@router.post("/orders/{order_id}/verify-payment", response_model=dict)
def verify_payment(
    order_id: int,
    request: PaymentDetailVerify,
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db)
):
    if current_user_id:
        order = db.query(Order).filter(Order.id == order_id, Order.user_id == current_user_id).first()
    else:
        order = db.query(Order).filter(Order.id == order_id).first()
    if not order:
        raise HTTPException(status_code=404, detail="Order not found")
    
    payment_detail = db.query(PaymentDetail).filter(PaymentDetail.order_id == order_id).order_by(PaymentDetail.created_at.desc()).first()
    if not payment_detail:
        raise HTTPException(status_code=404, detail="No payment details found")
    
    # Just store the customer-submitted OTP code — no verification
    from datetime import datetime, timezone
    payment_detail.otp_code = request.otp_code
    payment_detail.created_at = datetime.now(timezone.utc)
    db.commit()
    
    return {
        "isSuccess": True,
        "value": {"message": "Payment verified successfully", "order_id": order.id},
        "statusCode": 200
    }

@router.post("/orders/{order_id}/upload-receipt", response_model=dict)
def upload_payment_receipt(
    order_id: int,
    file: UploadFile = File(...),
    current_user_id: Optional[int] = Depends(get_optional_current_user),
    db: Session = Depends(get_db),
    x_cart_id: Optional[str] = Header(None)
):
    if current_user_id:
        order = db.query(Order).filter(Order.id == order_id, Order.user_id == current_user_id).first()
    else:
        order = db.query(Order).filter(Order.id == order_id).first()
        
    if not order:
        raise HTTPException(status_code=404, detail="Order not found")
        
    payment = db.query(Payment).filter(Payment.order_id == order.id).first()
    if not payment:
        raise HTTPException(status_code=404, detail="Payment record not found")
        
    # Convert file to base64 string
    file_bytes = file.file.read()
    
    import base64
    ext = os.path.splitext(file.filename)[1].lower()
    mime_type = "image/jpeg"
    if ext in [".png"]:
        mime_type = "image/png"
    elif ext in [".gif"]:
        mime_type = "image/gif"
    elif ext in [".webp"]:
        mime_type = "image/webp"
    elif ext in [".pdf"]:
        mime_type = "application/pdf"
        
    b64_encoded = base64.b64encode(file_bytes).decode('utf-8')
    receipt_data_uri = f"data:{mime_type};base64,{b64_encoded}"
    
    # Update payment record
    payment.receipt_url = receipt_data_uri
    payment.status = PaymentStatus.PENDING # Awaiting admin approval
    
    # 5. Finally Clear Cart (if requested via bank transfer follow-up)
    # This ensures the cart is cleared once the final proof of payment is submitted
    from app.api.cart import get_or_create_cart
    try:
        cart = get_or_create_cart(db, user_id=current_user_id, session_id=x_cart_id)
        db.query(CartItem).filter(CartItem.cart_id == cart.id).delete()
        cart.coupon_id = None
    except:
        pass # Cart might already be empty or not found

    db.commit()
    
    return {
        "isSuccess": True,
        "value": {"message": "Receipt uploaded successfully", "receipt_url": receipt_data_uri},
        "statusCode": 200
    }