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

import androidx.compose.foundation.background
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.aspectRatio
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.LazyColumn
import androidx.compose.foundation.lazy.items
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.filled.Add
import androidx.compose.material.icons.filled.Delete
import androidx.compose.material.icons.filled.Edit
import androidx.compose.material.icons.filled.Image
import androidx.compose.material3.AlertDialog
import androidx.compose.material3.Button
import androidx.compose.material3.ButtonDefaults
import androidx.compose.material3.Card
import androidx.compose.material3.CardDefaults
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.FloatingActionButton
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedButton
import androidx.compose.material3.OutlinedTextField
import androidx.compose.material3.Scaffold
import androidx.compose.material3.SnackbarHostState
import androidx.compose.material3.Switch
import androidx.compose.material3.SwitchDefaults
import androidx.compose.material3.Text
import androidx.compose.material3.TopAppBar
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.platform.LocalContext
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 coil.compose.AsyncImage
import coil.request.ImageRequest
import com.aistudio.bonjuteri.jwlry.model.Banner
import com.aistudio.bonjuteri.jwlry.ui.components.EmptyStateView
import com.aistudio.bonjuteri.jwlry.ui.theme.ErrorRed
import com.aistudio.bonjuteri.jwlry.ui.theme.GoldPrimary
import com.aistudio.bonjuteri.jwlry.ui.theme.LightSurface
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 kotlinx.coroutines.launch

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AdminBannerScreen(
    banners: List<Banner>,
    onAddBanner: suspend (String, String, String, String, Long) -> Result<Banner>,
    onUpdateBanner: suspend (Banner) -> Result<Banner>,
    onDeleteBanner: suspend (String) -> Result<Unit>,
    onBackClick: () -> Unit,
    snackbarHostState: SnackbarHostState,
    modifier: Modifier = Modifier
) {
    var showDialog by remember { mutableStateOf(false) }
    var editingBanner by remember { mutableStateOf<Banner?>(null) }
    val scope = rememberCoroutineScope()

    Scaffold(
        topBar = {
            TopAppBar(
                title = { Text("Banner & Kampanyalar (${banners.size})", fontWeight = FontWeight.Bold) },
                navigationIcon = {
                    IconButton(onClick = onBackClick) {
                        Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Geri")
                    }
                },
                colors = TopAppBarDefaults.topAppBarColors(containerColor = PureWhite)
            )
        },
        floatingActionButton = {
            FloatingActionButton(
                onClick = {
                    editingBanner = null
                    showDialog = true
                },
                containerColor = PrimaryBlack,
                contentColor = PureWhite,
                modifier = Modifier.testTag("admin_add_banner_fab")
            ) {
                Icon(Icons.Filled.Add, contentDescription = "Banner Ekle")
            }
        }
    ) { padding ->
        if (banners.isEmpty()) {
            EmptyStateView(
                icon = Icons.Filled.Image,
                title = "Banner Bulunmuyor",
                description = "Ana sayfa için promosyon veya kampanya afişleri ekleyebilirsiniz.",
                actionButtonText = "+ Yeni Banner Ekle",
                onActionClick = {
                    editingBanner = null
                    showDialog = true
                },
                modifier = Modifier.padding(padding).fillMaxSize()
            )
        } else {
            LazyColumn(
                modifier = modifier
                    .fillMaxSize()
                    .padding(padding)
                    .background(OffWhite)
                    .padding(14.dp),
                verticalArrangement = Arrangement.spacedBy(10.dp)
            ) {
                items(banners, key = { it.id }) { banner ->
                    Card(
                        modifier = Modifier.fillMaxWidth(),
                        colors = CardDefaults.cardColors(containerColor = PureWhite),
                        shape = RoundedCornerShape(12.dp),
                        elevation = CardDefaults.cardElevation(defaultElevation = 1.dp)
                    ) {
                        Column {
                            if (banner.imageUrl.isNotBlank()) {
                                AsyncImage(
                                    model = ImageRequest.Builder(LocalContext.current)
                                        .data(banner.imageUrl)
                                        .crossfade(true)
                                        .build(),
                                    contentDescription = banner.title,
                                    modifier = Modifier
                                        .fillMaxWidth()
                                        .height(110.dp)
                                        .clip(RoundedCornerShape(topStart = 12.dp, topEnd = 12.dp)),
                                    contentScale = ContentScale.Crop
                                )
                            }
                            Row(
                                modifier = Modifier
                                    .fillMaxWidth()
                                    .padding(12.dp),
                                verticalAlignment = Alignment.CenterVertically
                            ) {
                                Column(modifier = Modifier.weight(1f)) {
                                    if (banner.subtitle.isNotBlank()) {
                                        Text(banner.subtitle, color = GoldPrimary, fontSize = 10.sp, fontWeight = FontWeight.Bold)
                                    }
                                    Text(banner.title, fontWeight = FontWeight.Bold, fontSize = 14.sp)
                                }
                                IconButton(onClick = { editingBanner = banner; showDialog = true }) {
                                    Icon(Icons.Filled.Edit, contentDescription = "Düzenle", tint = PrimaryBlack)
                                }
                                IconButton(onClick = {
                                    scope.launch {
                                        val res = onDeleteBanner(banner.id)
                                        if (res.isSuccess) snackbarHostState.showSnackbar("Banner silindi.")
                                    }
                                }) {
                                    Icon(Icons.Filled.Delete, contentDescription = "Sil", tint = ErrorRed)
                                }
                            }
                        }
                    }
                }
            }
        }

        if (showDialog) {
            var title by remember { mutableStateOf(editingBanner?.title ?: "") }
            var subtitle by remember { mutableStateOf(editingBanner?.subtitle ?: "") }
            var imageUrl by remember { mutableStateOf(editingBanner?.imageUrl ?: "") }
            var linkTarget by remember { mutableStateOf(editingBanner?.linkTarget ?: "") }
            var orderStr by remember { mutableStateOf((editingBanner?.order ?: (banners.size + 1)).toString()) }

            AlertDialog(
                onDismissRequest = { showDialog = false },
                title = { Text(if (editingBanner == null) "Yeni Banner Ekle" else "Bannerı Düzenle", fontWeight = FontWeight.Bold) },
                text = {
                    Column(verticalArrangement = Arrangement.spacedBy(10.dp)) {
                        OutlinedTextField(value = title, onValueChange = { title = it }, label = { Text("Başlık *") }, modifier = Modifier.fillMaxWidth().testTag("admin_banner_title_input"), singleLine = true)
                        OutlinedTextField(value = subtitle, onValueChange = { subtitle = it }, label = { Text("Alt Başlık") }, modifier = Modifier.fillMaxWidth(), singleLine = true)
                        OutlinedTextField(value = imageUrl, onValueChange = { imageUrl = it }, label = { Text("Görsel URL *") }, modifier = Modifier.fillMaxWidth().testTag("admin_banner_image_input"), singleLine = true)
                        OutlinedTextField(value = linkTarget, onValueChange = { linkTarget = it }, label = { Text("Yönlendirme Linki / Kategori") }, modifier = Modifier.fillMaxWidth(), singleLine = true)
                        OutlinedTextField(value = orderStr, onValueChange = { orderStr = it }, label = { Text("Sıralama") }, modifier = Modifier.fillMaxWidth(), singleLine = true)
                    }
                },
                confirmButton = {
                    Button(
                        onClick = {
                            val trimmedT = title.trim()
                            val trimmedImg = imageUrl.trim()
                            if (trimmedT.isBlank() || trimmedImg.isBlank()) return@Button
                            val ord = orderStr.toLongOrNull() ?: 1L

                            scope.launch {
                                val res = if (editingBanner == null) {
                                    onAddBanner(trimmedT, subtitle.trim(), trimmedImg, linkTarget.trim(), ord)
                                } else {
                                    onUpdateBanner(editingBanner!!.copy(title = trimmedT, subtitle = subtitle.trim(), imageUrl = trimmedImg, linkTarget = linkTarget.trim(), order = ord))
                                }
                                if (res.isSuccess) {
                                    showDialog = false
                                    snackbarHostState.showSnackbar("Banner kaydedildi.")
                                } else {
                                    snackbarHostState.showSnackbar(res.exceptionOrNull()?.message ?: "Hata oluştu.")
                                }
                            }
                        },
                        colors = ButtonDefaults.buttonColors(containerColor = PrimaryBlack),
                        modifier = Modifier.testTag("admin_save_banner_btn")
                    ) {
                        Text("Kaydet")
                    }
                },
                dismissButton = {
                    OutlinedButton(onClick = { showDialog = false }) {
                        Text("İptal")
                    }
                }
            )
        }
    }
}