from fastapi import APIRouter, Depends, HTTPException
from decimal import Decimal
from pydantic import BaseModel

from ..auth import get_current_user
from ..models import User
from ..billing.models import PricingConfig, Invoice, SubscriptionPlan
from ..billing.invoice_generator import InvoiceGenerator


def require_superuser(current_user: User = Depends(get_current_user)):
    if not current_user.is_superuser:
        raise HTTPException(status_code=403, detail="Superuser privileges required")
    return current_user


router = APIRouter(
    prefix="/api/admin/billing",
    tags=["admin", "billing"],
    dependencies=[Depends(require_superuser)],
)


class PricingConfigUpdate(BaseModel):
    config_key: str
    config_value: float


class PlanCreate(BaseModel):
    name: str
    display_name: str
    description: str
    storage_gb: int
    bandwidth_gb: int
    price_monthly: float
    price_yearly: float = None


@router.get("/pricing")
async def get_all_pricing(current_user: User = Depends(require_superuser)):
    configs = await PricingConfig.all()
    return [
        {
            "id": c.id,
            "config_key": c.config_key,
            "config_value": float(c.config_value),
            "description": c.description,
            "unit": c.unit,
            "updated_at": c.updated_at,
        }
        for c in configs
    ]


@router.put("/pricing/{config_id}")
async def update_pricing(
    config_id: int,
    update: PricingConfigUpdate,
    current_user: User = Depends(require_superuser),
):
    config = await PricingConfig.get_or_none(id=config_id)
    if not config:
        raise HTTPException(status_code=404, detail="Config not found")

    config.config_value = Decimal(str(update.config_value))
    config.updated_by = current_user
    await config.save()

    return {"message": "Pricing updated successfully"}


@router.post("/generate-invoices/{year}/{month}")
async def generate_all_invoices(
    year: int, month: int, current_user: User = Depends(require_superuser)
):
    users = await User.filter(is_active=True).all()
    generated = []
    skipped = []

    for user in users:
        invoice = await InvoiceGenerator.generate_monthly_invoice(user, year, month)
        if invoice:
            generated.append(
                {
                    "user_id": user.id,
                    "invoice_id": invoice.id,
                    "total": float(invoice.total),
                }
            )
        else:
            skipped.append(user.id)

    return {"generated": len(generated), "skipped": len(skipped), "invoices": generated}


@router.post("/plans")
async def create_plan(
    plan_data: PlanCreate, current_user: User = Depends(require_superuser)
):
    plan = await SubscriptionPlan.create(**plan_data.dict())
    return {"id": plan.id, "message": "Plan created successfully"}


@router.get("/stats")
async def get_billing_stats(current_user: User = Depends(require_superuser)):
    from tortoise.functions import Sum

    total_revenue = (
        await Invoice.filter(status="paid")
        .annotate(total_sum=Sum("total"))
        .values("total_sum")
    )

    invoice_count = await Invoice.all().count()
    pending_invoices = await Invoice.filter(status="open").count()

    return {
        "total_revenue": float(total_revenue[0]["total_sum"] or 0),
        "total_invoices": invoice_count,
        "pending_invoices": pending_invoices,
    }