package com.aistudio.bonjuteri.jwlry.ui.screens.admin

import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.lazy.grid.GridCells
import androidx.compose.foundation.lazy.grid.GridItemSpan
import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.automirrored.filled.ArrowBack
import androidx.compose.material.icons.automirrored.filled.ArrowForwardIos
import androidx.compose.material.icons.filled.Category
import androidx.compose.material.icons.filled.Diamond
import androidx.compose.material.icons.filled.Group
import androidx.compose.material.icons.filled.Image
import androidx.compose.material.icons.filled.Inventory
import androidx.compose.material.icons.filled.MonetizationOn
import androidx.compose.material.icons.filled.PendingActions
import androidx.compose.material.icons.filled.ShoppingBag
import androidx.compose.material.icons.filled.Warning
import androidx.compose.material3.Card
import androidx.compose.material3.CardDefaults
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.material3.TopAppBar
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.platform.testTag
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import com.aistudio.bonjuteri.jwlry.data.AdminDashboardMetrics
import com.aistudio.bonjuteri.jwlry.model.Product
import com.aistudio.bonjuteri.jwlry.ui.theme.ErrorRed
import com.aistudio.bonjuteri.jwlry.ui.theme.GoldDark
import com.aistudio.bonjuteri.jwlry.ui.theme.GoldPrimary
import com.aistudio.bonjuteri.jwlry.ui.theme.GoldSubtle
import com.aistudio.bonjuteri.jwlry.ui.theme.InfoBlue
import com.aistudio.bonjuteri.jwlry.ui.theme.MutedGrey
import com.aistudio.bonjuteri.jwlry.ui.theme.OffWhite
import com.aistudio.bonjuteri.jwlry.ui.theme.PrimaryBlack
import com.aistudio.bonjuteri.jwlry.ui.theme.PureWhite
import com.aistudio.bonjuteri.jwlry.ui.theme.SuccessGreen
import com.aistudio.bonjuteri.jwlry.ui.theme.WarningAmber

enum class AdminSection {
    DASHBOARD,
    PRODUCTS,
    CATEGORIES,
    ORDERS,
    BANNERS
}

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AdminDashboardScreen(
    metrics: AdminDashboardMetrics,
    onNavigateSection: (AdminSection) -> Unit,
    onBackClick: () -> Unit,
    modifier: Modifier = Modifier
) {
    Scaffold(
        topBar = {
            TopAppBar(
                title = {
                    Column {
                        Text("Yönetim Paneli", fontWeight = FontWeight.Bold)
                        Text("BONJUTERİ Yönetim & Operasyon", style = MaterialTheme.typography.labelSmall.copy(color = GoldDark))
                    }
                },
                navigationIcon = {
                    IconButton(onClick = onBackClick) {
                        Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Mağazaya Dön")
                    }
                },
                colors = TopAppBarDefaults.topAppBarColors(containerColor = PureWhite)
            )
        }
    ) { padding ->
        LazyVerticalGrid(
            columns = GridCells.Fixed(2),
            modifier = modifier
                .fillMaxSize()
                .padding(padding)
                .background(OffWhite)
                .padding(14.dp),
            horizontalArrangement = Arrangement.spacedBy(10.dp),
            verticalArrangement = Arrangement.spacedBy(10.dp)
        ) {
            // Metrics Header
            item(span = { GridItemSpan(2) }) {
                Text(
                    text = "Performans Göstergeleri",
                    style = MaterialTheme.typography.titleMedium.copy(fontWeight = FontWeight.Bold, color = PrimaryBlack),
                    modifier = Modifier.padding(vertical = 4.dp)
                )
            }

            // Metric: Toplam Satış
            item(span = { GridItemSpan(2) }) {
                Card(
                    modifier = Modifier.fillMaxWidth(),
                    colors = CardDefaults.cardColors(containerColor = PrimaryBlack),
                    shape = RoundedCornerShape(14.dp)
                ) {
                    Row(
                        modifier = Modifier.padding(16.dp),
                        verticalAlignment = Alignment.CenterVertically
                    ) {
                        Box(
                            modifier = Modifier
                                .size(48.dp)
                                .background(GoldPrimary, CircleShape),
                            contentAlignment = Alignment.Center
                        ) {
                            Icon(Icons.Filled.MonetizationOn, contentDescription = null, tint = PureWhite, modifier = Modifier.size(26.dp))
                        }
                        Spacer(modifier = Modifier.width(14.dp))
                        Column {
                            Text("Gerçekleşen Satış Toplamı", color = GoldSubtle, fontSize = 12.sp, fontWeight = FontWeight.Medium)
                            Text(
                                text = Product.formatCurrency(metrics.totalSalesAmount),
                                color = PureWhite,
                                fontSize = 22.sp,
                                fontWeight = FontWeight.Black
                            )
                        }
                    }
                }
            }

            // Metric 1: Toplam Ürün
            item {
                MetricCard(
                    title = "Toplam Ürün",
                    value = metrics.totalProducts.toString(),
                    icon = Icons.Filled.Inventory,
                    iconTint = InfoBlue
                )
            }

            // Metric 2: Toplam Sipariş
            item {
                MetricCard(
                    title = "Toplam Sipariş",
                    value = metrics.totalOrders.toString(),
                    icon = Icons.Filled.ShoppingBag,
                    iconTint = GoldPrimary
                )
            }

            // Metric 3: Bekleyen Sipariş
            item {
                MetricCard(
                    title = "Bekleyen Sipariş",
                    value = metrics.pendingOrders.toString(),
                    icon = Icons.Filled.PendingActions,
                    iconTint = WarningAmber
                )
            }

            // Metric 4: Toplam Kullanıcı
            item {
                MetricCard(
                    title = "Kayıtlı Kullanıcı",
                    value = metrics.totalUsers.toString(),
                    icon = Icons.Filled.Group,
                    iconTint = SuccessGreen
                )
            }

            // Metric 5: Düşük Stok Uyarısı
            item(span = { GridItemSpan(2) }) {
                Card(
                    modifier = Modifier.fillMaxWidth(),
                    colors = CardDefaults.cardColors(
                        containerColor = if (metrics.lowStockCount > 0) Color(0xFFFFF4E5) else PureWhite
                    ),
                    shape = RoundedCornerShape(12.dp)
                ) {
                    Row(
                        modifier = Modifier.padding(14.dp),
                        verticalAlignment = Alignment.CenterVertically
                    ) {
                        Icon(
                            imageVector = Icons.Filled.Warning,
                            contentDescription = null,
                            tint = if (metrics.lowStockCount > 0) WarningAmber else SuccessGreen,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(12.dp))
                        Column(modifier = Modifier.weight(1f)) {
                            Text(
                                text = "Düşük Stoklu Ürünler",
                                fontWeight = FontWeight.Bold,
                                fontSize = 14.sp
                            )
                            Text(
                                text = if (metrics.lowStockCount > 0)
                                    "${metrics.lowStockCount} ürün kritik stok seviyesinde (< 5 adet)"
                                else
                                    "Tüm ürünlerin stok durumu yeterli seviyede",
                                color = MutedGrey,
                                fontSize = 12.sp
                            )
                        }
                    }
                }
            }

            // Management Navigation Section
            item(span = { GridItemSpan(2) }) {
                Spacer(modifier = Modifier.height(8.dp))
                Text(
                    text = "Yönetim Modülleri",
                    style = MaterialTheme.typography.titleMedium.copy(fontWeight = FontWeight.Bold, color = PrimaryBlack),
                    modifier = Modifier.padding(vertical = 4.dp)
                )
            }

            // Module: Ürün Yönetimi
            item(span = { GridItemSpan(2) }) {
                AdminModuleCard(
                    title = "Ürün Yönetimi",
                    subtitle = "Ürün ekle, düzenle, sil, fiyat & stok güncelle",
                    icon = Icons.Filled.Diamond,
                    onClick = { onNavigateSection(AdminSection.PRODUCTS) },
                    testTag = "admin_nav_products"
                )
            }

            // Module: Sipariş Yönetimi
            item(span = { GridItemSpan(2) }) {
                AdminModuleCard(
                    title = "Sipariş Yönetimi",
                    subtitle = "Siparişleri incele, kargo & durum güncelle",
                    icon = Icons.Filled.ShoppingBag,
                    onClick = { onNavigateSection(AdminSection.ORDERS) },
                    testTag = "admin_nav_orders"
                )
            }

            // Module: Kategori Yönetimi
            item(span = { GridItemSpan(2) }) {
                AdminModuleCard(
                    title = "Kategori Yönetimi",
                    subtitle = "Kategori ekle, sırala ve düzenle",
                    icon = Icons.Filled.Category,
                    onClick = { onNavigateSection(AdminSection.CATEGORIES) },
                    testTag = "admin_nav_categories"
                )
            }

            // Module: Banner & Kampanya
            item(span = { GridItemSpan(2) }) {
                AdminModuleCard(
                    title = "Banner & Kampanya Yönetimi",
                    subtitle = "Ana sayfa vitrin bannerlarını yönet",
                    icon = Icons.Filled.Image,
                    onClick = { onNavigateSection(AdminSection.BANNERS) },
                    testTag = "admin_nav_banners"
                )
            }
        }
    }
}

@Composable
private fun MetricCard(
    title: String,
    value: String,
    icon: ImageVector,
    iconTint: Color
) {
    Card(
        colors = CardDefaults.cardColors(containerColor = PureWhite),
        shape = RoundedCornerShape(12.dp),
        elevation = CardDefaults.cardElevation(defaultElevation = 1.dp)
    ) {
        Column(modifier = Modifier.padding(14.dp)) {
            Icon(imageVector = icon, contentDescription = title, tint = iconTint, modifier = Modifier.size(24.dp))
            Spacer(modifier = Modifier.height(10.dp))
            Text(text = value, style = MaterialTheme.typography.headlineSmall.copy(fontWeight = FontWeight.Black))
            Text(text = title, style = MaterialTheme.typography.bodySmall.copy(color = MutedGrey))
        }
    }
}

@Composable
private fun AdminModuleCard(
    title: String,
    subtitle: String,
    icon: ImageVector,
    onClick: () -> Unit,
    testTag: String
) {
    Card(
        modifier = Modifier
            .fillMaxWidth()
            .clip(RoundedCornerShape(12.dp))
            .clickable { onClick() }
            .testTag(testTag),
        colors = CardDefaults.cardColors(containerColor = PureWhite),
        elevation = CardDefaults.cardElevation(defaultElevation = 1.dp)
    ) {
        Row(
            modifier = Modifier.padding(16.dp),
            verticalAlignment = Alignment.CenterVertically
        ) {
            Box(
                modifier = Modifier
                    .size(42.dp)
                    .background(GoldSubtle, CircleShape),
                contentAlignment = Alignment.Center
            ) {
                Icon(imageVector = icon, contentDescription = null, tint = GoldPrimary, modifier = Modifier.size(22.dp))
            }
            Spacer(modifier = Modifier.width(14.dp))
            Column(modifier = Modifier.weight(1f)) {
                Text(text = title, fontWeight = FontWeight.Bold, fontSize = 14.sp)
                Text(text = subtitle, color = MutedGrey, fontSize = 11.sp)
            }
            Icon(
                imageVector = Icons.AutoMirrored.Filled.ArrowForwardIos,
                contentDescription = null,
                tint = MutedGrey,
                modifier = Modifier.size(14.dp)
            )
        }
    }
}