package com.shaarit.presentation.dashboard

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.*
import androidx.compose.material3.*
import androidx.compose.runtime.*
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import androidx.hilt.navigation.compose.hiltViewModel
import com.shaarit.data.local.entity.ContentType
import java.text.NumberFormat
import java.util.concurrent.TimeUnit

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun DashboardScreen(
    onNavigateBack: () -> Unit,
    viewModel: DashboardViewModel = hiltViewModel()
) {
    val stats by viewModel.stats.collectAsState()
    val tagStats by viewModel.tagStats.collectAsState()
    val contentTypeStats by viewModel.contentTypeStats.collectAsState()
    val activityData by viewModel.activityData.collectAsState()

    Scaffold(
        topBar = {
            TopAppBar(
                title = { Text("Tableau de bord") },
                navigationIcon = {
                    IconButton(onClick = onNavigateBack) {
                        Icon(Icons.Default.ArrowBack, contentDescription = "Retour")
                    }
                },
                actions = {
                    IconButton(onClick = { viewModel.refreshStats() }) {
                        Icon(Icons.Default.Refresh, contentDescription = "Rafraîchir")
                    }
                }
            )
        }
    ) { padding ->
        LazyColumn(
            modifier = Modifier
                .fillMaxSize()
                .padding(padding),
            contentPadding = PaddingValues(16.dp),
            verticalArrangement = Arrangement.spacedBy(16.dp)
        ) {
            // Stats Cards Row
            item {
                Row(
                    modifier = Modifier.fillMaxWidth(),
                    horizontalArrangement = Arrangement.spacedBy(8.dp)
                ) {
                    StatCard(
                        title = "Total",
                        value = formatNumber(stats.totalLinks),
                        icon = Icons.Default.Bookmark,
                        color = MaterialTheme.colorScheme.primary,
                        modifier = Modifier.weight(1f)
                    )
                    StatCard(
                        title = "Cette semaine",
                        value = formatNumber(stats.linksThisWeek),
                        icon = Icons.Default.Today,
                        color = MaterialTheme.colorScheme.secondary,
                        modifier = Modifier.weight(1f)
                    )
                    StatCard(
                        title = "Ce mois",
                        value = formatNumber(stats.linksThisMonth),
                        icon = Icons.Default.DateRange,
                        color = MaterialTheme.colorScheme.tertiary,
                        modifier = Modifier.weight(1f)
                    )
                }
            }

            // Reading Time Stats
            item {
                ReadingTimeCard(
                    totalReadingTimeMinutes = stats.totalReadingTimeMinutes,
                    averageReadingTimeMinutes = stats.averageReadingTimeMinutes
                )
            }

            // Content Type Distribution
            item {
                ContentTypeCard(contentTypeStats)
            }

            // Top Tags
            item {
                TopTagsCard(tagStats)
            }

            // Activity Overview
            item {
                ActivityCard(activityData)
            }
        }
    }
}

@Composable
private fun StatCard(
    title: String,
    value: String,
    icon: ImageVector,
    color: Color,
    modifier: Modifier = Modifier
) {
    Card(
        modifier = modifier,
        colors = CardDefaults.cardColors(
            containerColor = color.copy(alpha = 0.1f)
        )
    ) {
        Column(
            modifier = Modifier
                .padding(12.dp)
                .fillMaxWidth(),
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Icon(
                imageVector = icon,
                contentDescription = null,
                tint = color,
                modifier = Modifier.size(24.dp)
            )
            Spacer(modifier = Modifier.height(4.dp))
            Text(
                text = value,
                style = MaterialTheme.typography.titleLarge,
                fontWeight = FontWeight.Bold,
                color = color
            )
            Text(
                text = title,
                style = MaterialTheme.typography.labelSmall,
                color = MaterialTheme.colorScheme.onSurfaceVariant
            )
        }
    }
}

@Composable
private fun ReadingTimeCard(
    totalReadingTimeMinutes: Int,
    averageReadingTimeMinutes: Int
) {
    Card {
        Column(
            modifier = Modifier
                .fillMaxWidth()
                .padding(16.dp)
        ) {
            Text(
                text = "Statistiques de lecture",
                style = MaterialTheme.typography.titleMedium,
                fontWeight = FontWeight.Bold
            )
            Spacer(modifier = Modifier.height(16.dp))
            
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.SpaceEvenly
            ) {
                ReadingTimeItem(
                    label = "Temps total",
                    minutes = totalReadingTimeMinutes,
                    icon = Icons.Default.Schedule
                )
                ReadingTimeItem(
                    label = "Moyenne/article",
                    minutes = averageReadingTimeMinutes,
                    icon = Icons.Default.Timer
                )
            }
        }
    }
}

@Composable
private fun ReadingTimeItem(
    label: String,
    minutes: Int,
    icon: ImageVector
) {
    Column(
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        Icon(
            imageVector = icon,
            contentDescription = null,
            tint = MaterialTheme.colorScheme.primary
        )
        Spacer(modifier = Modifier.height(4.dp))
        Text(
            text = formatDuration(minutes),
            style = MaterialTheme.typography.titleMedium,
            fontWeight = FontWeight.Bold
        )
        Text(
            text = label,
            style = MaterialTheme.typography.labelSmall,
            color = MaterialTheme.colorScheme.onSurfaceVariant
        )
    }
}

@Composable
private fun ContentTypeCard(
    contentTypeStats: Map<ContentType, Int>
) {
    Card {
        Column(
            modifier = Modifier
                .fillMaxWidth()
                .padding(16.dp)
        ) {
            Text(
                text = "Liens par type",
                style = MaterialTheme.typography.titleMedium,
                fontWeight = FontWeight.Bold
            )
            Spacer(modifier = Modifier.height(12.dp))
            
            val total = contentTypeStats.values.sum().coerceAtLeast(1)

            for ((type, count) in contentTypeStats.toList().sortedByDescending { it.second }) {
                val percentage = (count * 100) / total
                ContentTypeBar(
                    type = type,
                    count = count,
                    percentage = percentage
                )
                Spacer(modifier = Modifier.height(8.dp))
            }
        }
    }
}

@Composable
private fun ContentTypeBar(
    type: ContentType,
    count: Int,
    percentage: Int
) {
    val (icon, label, color) = when (type) {
        ContentType.ARTICLE -> Triple(Icons.Default.Article, "Article", Color(0xFF4CAF50))
        ContentType.VIDEO -> Triple(Icons.Default.PlayCircle, "Vidéo", Color(0xFFF44336))
        ContentType.IMAGE -> Triple(Icons.Default.Image, "Image", Color(0xFF9C27B0))
        ContentType.PODCAST -> Triple(Icons.Default.Audiotrack, "Podcast", Color(0xFFFF9800))
        ContentType.PDF -> Triple(Icons.Default.PictureAsPdf, "PDF", Color(0xFFE91E63))
        ContentType.REPOSITORY -> Triple(Icons.Default.Code, "Code", Color(0xFF607D8B))
        ContentType.DOCUMENT -> Triple(Icons.Default.Description, "Document", Color(0xFF795548))
        ContentType.SOCIAL -> Triple(Icons.Default.Share, "Social", Color(0xFF03A9F4))
        ContentType.SHOPPING -> Triple(Icons.Default.ShoppingCart, "Shopping", Color(0xFF2196F3))
        ContentType.NEWSLETTER -> Triple(Icons.Default.Email, "Newsletter", Color(0xFF9C27B0))
        ContentType.UNKNOWN -> Triple(Icons.Default.Link, "Autre", Color(0xFF9E9E9E))
    }

    Column {
        Row(
            verticalAlignment = Alignment.CenterVertically
        ) {
            Icon(
                imageVector = icon,
                contentDescription = null,
                tint = color,
                modifier = Modifier.size(20.dp)
            )
            Spacer(modifier = Modifier.width(8.dp))
            Text(
                text = label,
                style = MaterialTheme.typography.bodyMedium,
                modifier = Modifier.weight(1f)
            )
            Text(
                text = "$count ($percentage%)",
                style = MaterialTheme.typography.bodySmall,
                color = MaterialTheme.colorScheme.onSurfaceVariant
            )
        }
        Spacer(modifier = Modifier.height(4.dp))
        LinearProgressIndicator(
            progress = percentage / 100f,
            modifier = Modifier.fillMaxWidth(),
            color = color,
            trackColor = color.copy(alpha = 0.2f)
        )
    }
}

@Composable
private fun TopTagsCard(
    tagStats: List<TagStat>
) {
    Card {
        Column(
            modifier = Modifier
                .fillMaxWidth()
                .padding(16.dp)
        ) {
            Text(
                text = "Tags les plus utilisés",
                style = MaterialTheme.typography.titleMedium,
                fontWeight = FontWeight.Bold
            )
            Spacer(modifier = Modifier.height(12.dp))
            
            if (tagStats.isEmpty()) {
                Text(
                    text = "Aucun tag pour le moment",
                    style = MaterialTheme.typography.bodyMedium,
                    color = MaterialTheme.colorScheme.onSurfaceVariant
                )
            } else {
                tagStats.take(10).forEach { stat ->
                    TagStatRow(stat)
                    if (stat != tagStats.take(10).last()) {
                        Divider(modifier = Modifier.padding(vertical = 8.dp))
                    }
                }
            }
        }
    }
}

@Composable
private fun TagStatRow(stat: TagStat) {
    Row(
        modifier = Modifier.fillMaxWidth(),
        verticalAlignment = Alignment.CenterVertically
    ) {
        Surface(
            color = MaterialTheme.colorScheme.primaryContainer,
            shape = MaterialTheme.shapes.small
        ) {
            Text(
                text = stat.name,
                style = MaterialTheme.typography.labelMedium,
                modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp),
                color = MaterialTheme.colorScheme.onPrimaryContainer
            )
        }
        Spacer(modifier = Modifier.weight(1f))
        Text(
            text = "${stat.count} lien${if (stat.count > 1) "s" else ""}",
            style = MaterialTheme.typography.bodySmall,
            color = MaterialTheme.colorScheme.onSurfaceVariant
        )
    }
}

@Composable
private fun ActivityCard(
    activityData: List<ActivityPoint>
) {
    Card {
        Column(
            modifier = Modifier
                .fillMaxWidth()
                .padding(16.dp)
        ) {
            Text(
                text = "Activité (30 derniers jours)",
                style = MaterialTheme.typography.titleMedium,
                fontWeight = FontWeight.Bold
            )
            Spacer(modifier = Modifier.height(16.dp))
            
            if (activityData.isEmpty()) {
                Text(
                    text = "Pas d'activité récente",
                    style = MaterialTheme.typography.bodyMedium,
                    color = MaterialTheme.colorScheme.onSurfaceVariant
                )
            } else {
                ActivityChart(activityData)
            }
        }
    }
}

@Composable
private fun ActivityChart(
    data: List<ActivityPoint>
) {
    val maxValue = data.maxOfOrNull { it.count }?.coerceAtLeast(1) ?: 1
    
    Row(
        modifier = Modifier
            .fillMaxWidth()
            .height(100.dp),
        horizontalArrangement = Arrangement.SpaceBetween,
        verticalAlignment = Alignment.Bottom
    ) {
        data.takeLast(14).forEach { point ->
            val heightFraction = point.count.toFloat() / maxValue
            Column(
                horizontalAlignment = Alignment.CenterHorizontally,
                modifier = Modifier.weight(1f)
            ) {
                Box(
                    modifier = Modifier
                        .width(8.dp)
                        .fillMaxHeight(heightFraction.coerceAtLeast(0.05f))
                        .background(
                            color = MaterialTheme.colorScheme.primary,
                            shape = MaterialTheme.shapes.extraSmall
                        )
                )
                Spacer(modifier = Modifier.height(4.dp))
                Text(
                    text = point.day.substring(0, 1),
                    style = MaterialTheme.typography.labelSmall,
                    color = MaterialTheme.colorScheme.onSurfaceVariant
                )
            }
        }
    }
}

// Data classes
@Immutable
data class DashboardStats(
    val totalLinks: Int = 0,
    val linksThisWeek: Int = 0,
    val linksThisMonth: Int = 0,
    val totalReadingTimeMinutes: Int = 0,
    val averageReadingTimeMinutes: Int = 0
)

@Immutable
data class TagStat(
    val name: String,
    val count: Int
)

@Immutable
data class ActivityPoint(
    val day: String,
    val count: Int
)

// Helper functions
private fun formatNumber(number: Int): String {
    return NumberFormat.getInstance().format(number)
}

private fun formatDuration(minutes: Int): String {
    return when {
        minutes < 60 -> "${minutes}m"
        minutes < 1440 -> {
            val hours = minutes / 60
            val mins = minutes % 60
            if (mins > 0) "${hours}h ${mins}m" else "${hours}h"
        }
        else -> {
            val days = minutes / 1440
            "${days}j"
        }
    }
}