package com.aistudio.bonjuteri.jwlry.data

import android.content.Context
import com.aistudio.bonjuteri.jwlry.model.OrderStatus
import com.aistudio.bonjuteri.jwlry.model.PaymentStatus
import com.aistudio.bonjuteri.jwlry.model.Product
import com.google.firebase.firestore.FirebaseFirestore
import kotlinx.coroutines.tasks.await

data class AdminDashboardMetrics(
    val totalProducts: Long = 0L,
    val totalOrders: Long = 0L,
    val pendingOrders: Long = 0L,
    val totalUsers: Long = 0L,
    val lowStockCount: Long = 0L,
    val totalSalesAmount: Double = 0.0
)

class AdminDashboardRepository(
    private val firestore: FirebaseFirestore
) {
    companion object {
        @Volatile
        private var INSTANCE: AdminDashboardRepository? = null

        fun getInstance(context: Context): AdminDashboardRepository {
            return INSTANCE ?: synchronized(this) {
                INSTANCE ?: AdminDashboardRepository(
                    FirestoreHelper.getFirestore(context)
                ).also { INSTANCE = it }
            }
        }
    }

    suspend fun getMetrics(): AdminDashboardMetrics {
        return try {
            val productsSnapshot = firestore.collection(ProductRepository.PRODUCTS_COLLECTION).get().await()
            val totalProducts = productsSnapshot.size().toLong()
            var lowStockCount = 0L
            for (doc in productsSnapshot.documents) {
                val stock = doc.getLong("stock") ?: 0L
                if (stock in 1..4) {
                    lowStockCount++
                }
            }

            val ordersSnapshot = firestore.collection(OrderRepository.ORDERS_COLLECTION).get().await()
            val totalOrders = ordersSnapshot.size().toLong()
            var pendingOrders = 0L
            var totalSales = 0.0

            for (doc in ordersSnapshot.documents) {
                val orderStatus = doc.getString("orderStatus")
                val totalAmount = doc.getDouble("totalAmount") ?: 0.0
                val paymentStatus = doc.getString("paymentStatus")

                if (orderStatus == OrderStatus.PREPARING.name || paymentStatus == PaymentStatus.PENDING.name) {
                    pendingOrders++
                }
                if (orderStatus != OrderStatus.CANCELLED.name) {
                    totalSales += totalAmount
                }
            }

            val usersSnapshot = firestore.collection("users").get().await()
            val totalUsers = usersSnapshot.size().toLong()

            AdminDashboardMetrics(
                totalProducts = totalProducts,
                totalOrders = totalOrders,
                pendingOrders = pendingOrders,
                totalUsers = totalUsers,
                lowStockCount = lowStockCount,
                totalSalesAmount = totalSales
            )
        } catch (e: Exception) {
            AdminDashboardMetrics()
        }
    }
}