package com.socialapp.presentation.ui.screens

import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.PaddingValues
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.LazyColumn
import androidx.compose.foundation.lazy.LazyRow
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.FavoriteBorder
import androidx.compose.material.icons.filled.Favorite
import androidx.compose.material.icons.filled.ChatBubbleOutline
import androidx.compose.material.icons.filled.Share
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
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.layout.ContentScale
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.hilt.navigation.compose.hiltViewModel
import coil.compose.AsyncImage
import com.socialapp.data.api.Post
import com.socialapp.data.api.Story
import com.socialapp.presentation.ui.theme.AccentMagenta
import com.socialapp.presentation.ui.theme.PrimaryBlue
import com.socialapp.presentation.viewmodel.PostViewModel

@Composable
fun HomeScreen(
    viewModel: PostViewModel = hiltViewModel(),
    onPostClick: (Int) -> Unit = {},
    onProfileClick: (Int) -> Unit = {}
) {
    val posts = viewModel.posts.value
    val isLoading = viewModel.isLoading.value

    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(MaterialTheme.colorScheme.background)
    ) {
        // Header with Logo and Icons
        Row(
            modifier = Modifier
                .fillMaxWidth()
                .padding(16.dp),
            horizontalArrangement = androidx.compose.foundation.layout.Arrangement.SpaceBetween,
            verticalAlignment = Alignment.CenterVertically
        ) {
            Text(
                text = "Hopenity",
                fontSize = 28.sp,
                fontWeight = FontWeight.Bold,
                color = AccentMagenta
            )
            Row(
                horizontalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(12.dp)
            ) {
                IconButton(onClick = { /* Location */ }, modifier = Modifier.size(36.dp)) {
                    Icon(
                        imageVector = Icons.Default.FavoriteBorder,
                        contentDescription = "Location",
                        tint = MaterialTheme.colorScheme.onBackground,
                        modifier = Modifier.size(20.dp)
                    )
                }
                IconButton(onClick = { /* Search */ }, modifier = Modifier.size(36.dp)) {
                    Icon(
                        imageVector = Icons.Default.ChatBubbleOutline,
                        contentDescription = "Search",
                        tint = MaterialTheme.colorScheme.onBackground,
                        modifier = Modifier.size(20.dp)
                    )
                }
            }
        }

        // Category Pills
        LazyRow(
            modifier = Modifier
                .fillMaxWidth()
                .padding(horizontal = 8.dp),
            contentPadding = PaddingValues(horizontal = 8.dp),
            horizontalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(8.dp)
        ) {
            items(listOf("Feed", "Nearby", "Art & Creativity", "Astrology & Spirituality")) { category ->
                CategoryPill(
                    text = category,
                    isSelected = category == "Feed"
                )
            }
        }

        Spacer(modifier = Modifier.height(12.dp))

        LazyColumn(
            modifier = Modifier.fillMaxSize(),
            contentPadding = PaddingValues(vertical = 8.dp)
        ) {
            // What's on your mind input
            item {
                WhatsOnYourMindRow(onPostClick = { onPostClick(-1) })
                Spacer(modifier = Modifier.height(16.dp))
            }

            // Story Ring
            item {
                StoryRingRow(onStoryClick = { /* Handle story click */ })
                Spacer(modifier = Modifier.height(16.dp))
            }

            // Posts Feed
            items(posts) { post ->
                PostCard(
                    post = post,
                    onLikeClick = {
                        if (post.isLiked) {
                            viewModel.unlikePost(post.id)
                        } else {
                            viewModel.likePost(post.id)
                        }
                    },
                    onCommentClick = { onPostClick(post.id) },
                    onProfileClick = { onProfileClick(post.userId) }
                )
                Spacer(modifier = Modifier.height(12.dp))
            }

            // Load More Button
            if (!isLoading && posts.isNotEmpty()) {
                item {
                    Box(
                        modifier = Modifier
                            .fillMaxWidth()
                            .padding(16.dp)
                            .clickable { viewModel.loadMorePosts() },
                        contentAlignment = Alignment.Center
                    ) {
                        Text("Load More Posts", color = PrimaryBlue)
                    }
                }
            }
        }
    }
}

@Composable
private fun CategoryPill(text: String, isSelected: Boolean) {
    Box(
        modifier = Modifier
            .clip(RoundedCornerShape(20.dp))
            .background(
                if (isSelected) MaterialTheme.colorScheme.onBackground.copy(alpha = 0.2f)
                else MaterialTheme.colorScheme.surface
            )
            .padding(horizontal = 16.dp, vertical = 8.dp),
        contentAlignment = Alignment.Center
    ) {
        Text(
            text = text,
            fontSize = 13.sp,
            color = if (isSelected) MaterialTheme.colorScheme.onBackground else MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f),
            fontWeight = if (isSelected) FontWeight.SemiBold else FontWeight.Normal
        )
    }
}

@Composable
private fun WhatsOnYourMindRow(onPostClick: () -> Unit) {
    Row(
        modifier = Modifier
            .fillMaxWidth()
            .padding(horizontal = 12.dp),
        verticalAlignment = Alignment.CenterVertically,
        horizontalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(8.dp)
    ) {
        // Profile Avatar
        Box(
            modifier = Modifier
                .size(40.dp)
                .clip(CircleShape)
                .background(AccentMagenta.copy(alpha = 0.3f)),
            contentAlignment = Alignment.Center
        ) {
            Text(
                text = "U",
                fontSize = 18.sp,
                fontWeight = FontWeight.Bold,
                color = AccentMagenta
            )
        }

        // Input Field
        Box(
            modifier = Modifier
                .weight(1f)
                .height(40.dp)
                .clip(RoundedCornerShape(20.dp))
                .background(MaterialTheme.colorScheme.surface)
                .clickable { onPostClick() }
                .padding(horizontal = 12.dp),
            contentAlignment = Alignment.CenterStart
        ) {
            Text(
                text = "What's on your mind?",
                fontSize = 13.sp,
                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.5f)
            )
        }

        // Image Icon
        IconButton(onClick = { /* Pick image */ }, modifier = Modifier.size(40.dp)) {
            Icon(
                imageVector = Icons.Default.FavoriteBorder,
                contentDescription = "Add Image",
                tint = PrimaryBlue,
                modifier = Modifier.size(20.dp)
            )
        }
    }
}

@Composable
private fun StoryRingRow(onStoryClick: (Int) -> Unit) {
    // Mock stories for now
    val mockStories = listOf(
        Story(1, 1, "User1", null, "", "", ""),
        Story(2, 2, "User2", null, "", "", ""),
        Story(3, 3, "User3", null, "", "", ""),
        Story(4, 4, "User4", null, "", "", ""),
    )

    LazyRow(
        modifier = Modifier
            .fillMaxWidth()
            .padding(horizontal = 8.dp),
        contentPadding = PaddingValues(horizontal = 8.dp),
        horizontalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(8.dp)
    ) {
        items(mockStories) { story ->
            StoryAvatar(
                name = story.username,
                onStoryClick = { onStoryClick(story.id) }
            )
        }
    }
}

@Composable
private fun StoryAvatar(name: String, onStoryClick: () -> Unit) {
    Column(
        modifier = Modifier
            .width(80.dp)
            .clickable { onStoryClick() },
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        Box(
            modifier = Modifier
                .size(64.dp)
                .clip(CircleShape)
                .background(AccentMagenta)
                .padding(2.dp)
                .clip(CircleShape)
                .background(MaterialTheme.colorScheme.background),
            contentAlignment = Alignment.Center
        ) {
            Box(
                modifier = Modifier
                    .size(60.dp)
                    .clip(CircleShape)
                    .background(AccentMagenta.copy(alpha = 0.3f))
            )
        }
        Spacer(modifier = Modifier.height(4.dp))
        Text(
            text = name,
            fontSize = 10.sp,
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
            modifier = Modifier.width(64.dp)
        )
    }
}

@Composable
fun PostCard(
    post: Post,
    onLikeClick: () -> Unit,
    onCommentClick: () -> Unit,
    onProfileClick: () -> Unit
) {
    Column(
        modifier = Modifier
            .fillMaxWidth()
            .padding(horizontal = 8.dp)
            .clip(RoundedCornerShape(20.dp))
            .background(MaterialTheme.colorScheme.surface)
    ) {
        // Post Header
        Row(
            modifier = Modifier
                .fillMaxWidth()
                .padding(12.dp),
            verticalAlignment = Alignment.CenterVertically
        ) {
            Box(
                modifier = Modifier
                    .size(40.dp)
                    .clip(CircleShape)
                    .background(PrimaryBlue)
                    .clickable { onProfileClick() }
            )
            Spacer(modifier = Modifier.width(12.dp))
            Column(modifier = Modifier.weight(1f)) {
                Text(
                    text = post.username,
                    fontWeight = FontWeight.SemiBold,
                    fontSize = 14.sp
                )
                Text(
                    text = "Just now",
                    fontSize = 12.sp,
                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
                )
            }
        }

        // Post Content
        if (post.content.isNotEmpty()) {
            Text(
                text = post.content,
                modifier = Modifier.padding(horizontal = 12.dp),
                fontSize = 14.sp
            )
        }

        // Post Media
        if (!post.mediaUrl.isNullOrEmpty()) {
            Spacer(modifier = Modifier.height(8.dp))
            Box(
                modifier = Modifier
                    .fillMaxWidth()
                    .height(300.dp)
                    .background(MaterialTheme.colorScheme.onBackground.copy(alpha = 0.1f)),
                contentAlignment = Alignment.Center
            ) {
                AsyncImage(
                    model = post.mediaUrl.firstOrNull(),
                    contentDescription = null,
                    modifier = Modifier.fillMaxSize(),
                    contentScale = ContentScale.Crop
                )
            }
        }

        // Engagement Metrics
        Row(
            modifier = Modifier
                .fillMaxWidth()
                .padding(12.dp),
            horizontalArrangement = androidx.compose.foundation.layout.Arrangement.SpaceBetween
        ) {
            Text(
                text = "${post.likesCount} Likes",
                fontSize = 12.sp,
                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
            )
            Text(
                text = "${post.commentsCount} Comments",
                fontSize = 12.sp,
                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
            )
        }

        // Action Buttons
        Row(
            modifier = Modifier
                .fillMaxWidth()
                .padding(horizontal = 4.dp),
            horizontalArrangement = androidx.compose.foundation.layout.Arrangement.SpaceEvenly
        ) {
            IconButton(onClick = onLikeClick) {
                Icon(
                    imageVector = if (post.isLiked) Icons.Filled.Favorite else Icons.Default.FavoriteBorder,
                    contentDescription = "Like",
                    tint = if (post.isLiked) AccentMagenta else MaterialTheme.colorScheme.onSurface,
                    modifier = Modifier.size(20.dp)
                )
            }
            IconButton(onClick = onCommentClick) {
                Icon(
                    imageVector = Icons.Default.ChatBubbleOutline,
                    contentDescription = "Comment",
                    tint = MaterialTheme.colorScheme.onSurface,
                    modifier = Modifier.size(20.dp)
                )
            }
            IconButton(onClick = { /* Share */ }) {
                Icon(
                    imageVector = Icons.Default.Share,
                    contentDescription = "Share",
                    tint = MaterialTheme.colorScheme.onSurface,
                    modifier = Modifier.size(20.dp)
                )
            }
        }
    }
}