package com.aistudio.bonjuteri.jwlry.ui.components

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.pager.HorizontalPager
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.outlined.Diamond
import androidx.compose.material3.Card
import androidx.compose.material3.CardDefaults
import androidx.compose.material3.Icon
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
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.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.platform.LocalContext
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.theme.GoldPrimary
import com.aistudio.bonjuteri.jwlry.ui.theme.PrimaryBlack
import com.aistudio.bonjuteri.jwlry.ui.theme.PureWhite

@Composable
fun BannerCarousel(
    banners: List<Banner>,
    onBannerClick: (Banner) -> Unit,
    modifier: Modifier = Modifier
) {
    if (banners.isEmpty()) {
        // Fallback welcoming hero card
        Card(
            modifier = modifier
                .fillMaxWidth()
                .padding(horizontal = 16.dp, vertical = 8.dp)
                .height(140.dp),
            shape = RoundedCornerShape(16.dp),
            colors = CardDefaults.cardColors(containerColor = PrimaryBlack)
        ) {
            Box(
                modifier = Modifier
                    .fillMaxSize()
                    .background(
                        Brush.linearGradient(
                            listOf(Color(0xFF1F1C18), Color(0xFF0F0E0C))
                        )
                    )
                    .padding(20.dp),
                contentAlignment = Alignment.CenterStart
            ) {
                Column(modifier = Modifier.fillMaxWidth(0.7f)) {
                    Text(
                        text = "BONJUTERİ BUTİK",
                        color = GoldPrimary,
                        fontSize = 11.sp,
                        fontWeight = FontWeight.Bold,
                        letterSpacing = 1.2.sp
                    )
                    Spacer(modifier = Modifier.height(4.dp))
                    Text(
                        text = "Işıltınızı Tamamlayan Özel Tasarımlar",
                        color = PureWhite,
                        fontSize = 17.sp,
                        fontWeight = FontWeight.Bold,
                        lineHeight = 22.sp
                    )
                }
                Icon(
                    imageVector = Icons.Outlined.Diamond,
                    contentDescription = null,
                    tint = GoldPrimary.copy(alpha = 0.25f),
                    modifier = Modifier
                        .size(80.dp)
                        .align(Alignment.CenterEnd)
                )
            }
        }
        return
    }

    val pagerState = rememberPagerState(pageCount = { banners.size })

    Column(modifier = modifier.fillMaxWidth()) {
        HorizontalPager(
            state = pagerState,
            modifier = Modifier
                .fillMaxWidth()
                .padding(horizontal = 16.dp, vertical = 6.dp)
                .height(150.dp)
        ) { page ->
            val banner = banners[page]
            Card(
                modifier = Modifier
                    .fillMaxSize()
                    .clip(RoundedCornerShape(16.dp))
                    .clickable { onBannerClick(banner) },
                shape = RoundedCornerShape(16.dp),
                elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
            ) {
                Box(modifier = Modifier.fillMaxSize()) {
                    if (banner.imageUrl.isNotBlank()) {
                        AsyncImage(
                            model = ImageRequest.Builder(LocalContext.current)
                                .data(banner.imageUrl)
                                .crossfade(true)
                                .build(),
                            contentDescription = banner.title,
                            modifier = Modifier.fillMaxSize(),
                            contentScale = ContentScale.Crop
                        )
                    } else {
                        Box(
                            modifier = Modifier
                                .fillMaxSize()
                                .background(
                                    Brush.linearGradient(
                                        listOf(Color(0xFF23201C), Color(0xFF141210))
                                    )
                                )
                        )
                    }

                    // Elegant gradient scrim for text readability
                    Box(
                        modifier = Modifier
                            .fillMaxSize()
                            .background(
                                Brush.verticalGradient(
                                    listOf(Color.Transparent, Color(0xCC000000))
                                )
                            )
                            .padding(16.dp),
                        contentAlignment = Alignment.BottomStart
                    ) {
                        Column {
                            if (banner.subtitle.isNotBlank()) {
                                Text(
                                    text = banner.subtitle.uppercase(),
                                    color = GoldPrimary,
                                    fontSize = 10.sp,
                                    fontWeight = FontWeight.Bold,
                                    letterSpacing = 1.sp
                                )
                            }
                            Text(
                                text = banner.title,
                                color = PureWhite,
                                fontSize = 16.sp,
                                fontWeight = FontWeight.Bold
                            )
                        }
                    }
                }
            }
        }

        // Indicator dots
        if (banners.size > 1) {
            Row(
                modifier = Modifier
                    .fillMaxWidth()
                    .padding(top = 4.dp),
                horizontalArrangement = Arrangement.Center,
                verticalAlignment = Alignment.CenterVertically
            ) {
                repeat(banners.size) { index ->
                    val isSelected = pagerState.currentPage == index
                    Box(
                        modifier = Modifier
                            .padding(horizontal = 3.dp)
                            .size(if (isSelected) 8.dp else 5.dp)
                            .background(
                                color = if (isSelected) GoldPrimary else Color.LightGray,
                                shape = CircleShape
                            )
                    )
                }
            }
        }
    }
}