package com.craigvg.lichun_android.ui.screens.character

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.automirrored.filled.ArrowBack
import androidx.compose.material.icons.filled.CheckCircle
import androidx.compose.material.icons.filled.Diamond
import androidx.compose.material.icons.filled.Lock
import androidx.compose.material.icons.filled.Star
import androidx.compose.material.icons.filled.Work
import androidx.compose.material.icons.filled.WorkspacePremium
import androidx.compose.material3.*
import androidx.compose.runtime.*
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.unit.dp
import androidx.hilt.navigation.compose.hiltViewModel
import androidx.lifecycle.compose.collectAsStateWithLifecycle
import com.craigvg.lichun_android.ui.theme.AppColors
import com.craigvg.lichun_android.ui.theme.AppSpacing
import com.craigvg.lichun_android.ui.theme.AppTypography
import com.craigvg.lichun_android.viewmodel.GameStateViewModel

/**
 * Prestige screen (Wave 2) — surfaces the player's current prestige and the
 * compounding family (generational) prestige, plus what prestige unlocks:
 * senior/top job tiers and prestige-gated shop items. Each threshold is shown as
 * a milestone: unlocked once current prestige meets it, otherwise locked with
 * the gap remaining.
 *
 * Thresholds mirror the server: jobs (senior 100 / top 300) and shop items
 * (100 / 250 / 500).
 */
@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun PrestigeScreen(
    gameStateViewModel: GameStateViewModel = hiltViewModel(),
    onBack: () -> Unit = {}
) {
    val prestige by gameStateViewModel.prestige.collectAsStateWithLifecycle()
    val familyPrestige by gameStateViewModel.familyPrestige.collectAsStateWithLifecycle()

    Scaffold(
        topBar = {
            TopAppBar(
                title = { Text("Prestige", style = AppTypography.headline) },
                navigationIcon = {
                    IconButton(onClick = onBack) {
                        Icon(Icons.AutoMirrored.Filled.ArrowBack, "Back", tint = AppColors.primaryText)
                    }
                },
                colors = TopAppBarDefaults.topAppBarColors(containerColor = AppColors.surfaceElevated)
            )
        },
        containerColor = AppColors.background
    ) { padding ->
        Column(
            modifier = Modifier
                .fillMaxSize()
                .padding(padding)
                .verticalScroll(rememberScrollState())
                .padding(horizontal = AppSpacing.md)
        ) {
            Spacer(Modifier.height(AppSpacing.md))

            PrestigeHeader(prestige = prestige, familyPrestige = familyPrestige)

            Spacer(Modifier.height(AppSpacing.lg))

            Text("Career Tiers", style = AppTypography.headline, color = AppColors.primaryText)
            Spacer(Modifier.height(AppSpacing.sm))
            MilestoneRow(Icons.Default.Work, "Senior roles", "Unlock senior-level jobs", 100, prestige)
            Spacer(Modifier.height(AppSpacing.sm))
            MilestoneRow(Icons.Default.WorkspacePremium, "Top-tier roles", "Unlock the most prestigious jobs", 300, prestige)

            Spacer(Modifier.height(AppSpacing.lg))

            Text("Prestige Shop", style = AppTypography.headline, color = AppColors.primaryText)
            Spacer(Modifier.height(AppSpacing.sm))
            MilestoneRow(Icons.Default.Diamond, "Tier 1 items", "Exclusive items unlock", 100, prestige)
            Spacer(Modifier.height(AppSpacing.sm))
            MilestoneRow(Icons.Default.Diamond, "Tier 2 items", "Premium prestige items", 250, prestige)
            Spacer(Modifier.height(AppSpacing.sm))
            MilestoneRow(Icons.Default.Diamond, "Tier 3 items", "The rarest items in the game", 500, prestige)

            Spacer(Modifier.height(AppSpacing.lg))
            Text(
                "Family prestige compounds across generations and survives each new life. " +
                    "Personal prestige resets, so keep building your legacy.",
                style = AppTypography.caption,
                color = AppColors.secondaryText
            )
            Spacer(Modifier.height(AppSpacing.xl))
        }
    }
}

@Composable
private fun PrestigeHeader(prestige: Int, familyPrestige: Double) {
    Card(
        modifier = Modifier.fillMaxWidth(),
        shape = RoundedCornerShape(AppSpacing.cornerRadius),
        colors = CardDefaults.cardColors(containerColor = AppColors.surfaceElevated)
    ) {
        Row(
            modifier = Modifier
                .fillMaxWidth()
                .padding(AppSpacing.md),
            horizontalArrangement = Arrangement.SpaceEvenly,
            verticalAlignment = Alignment.CenterVertically
        ) {
            PrestigeStat("$prestige", "Prestige", AppColors.prestige)
            Box(
                modifier = Modifier
                    .width(1.dp)
                    .height(48.dp)
                    .background(AppColors.disabledText.copy(alpha = 0.3f))
            )
            PrestigeStat("${familyPrestige.toInt()}", "Family Prestige", AppColors.secondary)
        }
    }
}

@Composable
private fun PrestigeStat(value: String, label: String, color: Color) {
    Column(horizontalAlignment = Alignment.CenterHorizontally) {
        Box(
            modifier = Modifier
                .size(48.dp)
                .background(color.copy(alpha = 0.18f), CircleShape),
            contentAlignment = Alignment.Center
        ) {
            Icon(Icons.Default.Star, null, tint = color, modifier = Modifier.size(24.dp))
        }
        Spacer(Modifier.height(AppSpacing.xs))
        Text(value, style = AppTypography.title2, color = AppColors.primaryText)
        Text(label, style = AppTypography.caption, color = AppColors.secondaryText)
    }
}

@Composable
private fun MilestoneRow(
    icon: ImageVector,
    title: String,
    subtitle: String,
    threshold: Int,
    currentPrestige: Int
) {
    val unlocked = currentPrestige >= threshold
    val fraction = (currentPrestige.toFloat() / threshold.toFloat()).coerceIn(0f, 1f)
    Card(
        modifier = Modifier.fillMaxWidth(),
        shape = RoundedCornerShape(AppSpacing.cornerRadius),
        colors = CardDefaults.cardColors(
            containerColor = if (unlocked) AppColors.success.copy(alpha = 0.1f) else AppColors.surfaceElevated
        ),
        elevation = CardDefaults.cardElevation(defaultElevation = 1.dp)
    ) {
        Column(modifier = Modifier.padding(AppSpacing.md)) {
            Row(verticalAlignment = Alignment.CenterVertically) {
                Box(
                    modifier = Modifier
                        .size(44.dp)
                        .background(
                            (if (unlocked) AppColors.success else AppColors.prestige).copy(alpha = 0.15f),
                            CircleShape
                        ),
                    contentAlignment = Alignment.Center
                ) {
                    Icon(
                        if (unlocked) Icons.Default.CheckCircle else icon,
                        null,
                        tint = if (unlocked) AppColors.success else AppColors.prestige,
                        modifier = Modifier.size(20.dp)
                    )
                }
                Spacer(Modifier.width(AppSpacing.sm))
                Column(modifier = Modifier.weight(1f)) {
                    Text(title, style = AppTypography.bodyBold, color = AppColors.primaryText)
                    Text(subtitle, style = AppTypography.caption, color = AppColors.secondaryText)
                }
                if (!unlocked) {
                    Icon(Icons.Default.Lock, null, tint = AppColors.disabledText, modifier = Modifier.size(18.dp))
                }
            }
            if (!unlocked) {
                Spacer(Modifier.height(AppSpacing.sm))
                Box(
                    modifier = Modifier
                        .fillMaxWidth()
                        .height(6.dp)
                        .clip(RoundedCornerShape(3.dp))
                        .background(AppColors.prestige.copy(alpha = 0.2f))
                ) {
                    Box(
                        modifier = Modifier
                            .fillMaxWidth(fraction)
                            .fillMaxHeight()
                            .clip(RoundedCornerShape(3.dp))
                            .background(AppColors.prestige)
                    )
                }
                Spacer(Modifier.height(AppSpacing.xxs))
                Text(
                    "$currentPrestige / $threshold prestige (${(threshold - currentPrestige).coerceAtLeast(0)} to go)",
                    style = AppTypography.caption,
                    color = AppColors.secondaryText
                )
            }
        }
    }
}