package com.craigvg.lichun_android.ui.screens.settings

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.*
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.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.hilt.navigation.compose.hiltViewModel
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
import androidx.lifecycle.compose.collectAsStateWithLifecycle

/**
 * Deletion state
 */
enum class DeletionState {
    CONFIRM,
    PROCESSING,
    SCHEDULED,
    ERROR
}

/**
 * Account deletion screen with confirmation
 */
@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AccountDeletionScreen(
    gameStateViewModel: GameStateViewModel = hiltViewModel(),
    onBack: () -> Unit = {},
    onConfirmDelete: () -> Unit = {}
) {
    val accountDeletionUpdate by gameStateViewModel.accountDeletionUpdate.collectAsStateWithLifecycle()
    val currentError by gameStateViewModel.currentError.collectAsStateWithLifecycle()
    var deletionState by remember { mutableStateOf(DeletionState.CONFIRM) }
    var statusMessage by remember { mutableStateOf<String?>(null) }
    var errorMessage by remember { mutableStateOf<String?>(null) }
    var confirmText by remember { mutableStateOf("") }
    val confirmWord = "DELETE"

    Scaffold(
        topBar = {
            TopAppBar(
                title = { Text("Delete Account", style = AppTypography.headline) },
                navigationIcon = {
                    IconButton(onClick = onBack) {
                        Icon(
                            imageVector = Icons.AutoMirrored.Filled.ArrowBack,
                            contentDescription = "Back",
                            tint = AppColors.primaryText
                        )
                    }
                },
                colors = TopAppBarDefaults.topAppBarColors(
                    containerColor = AppColors.surfaceElevated
                )
            )
        },
        containerColor = AppColors.background
    ) { paddingValues ->
        Column(
            modifier = Modifier
                .fillMaxSize()
                .padding(paddingValues)
                .verticalScroll(rememberScrollState())
                .padding(AppSpacing.lg),
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            when (deletionState) {
                DeletionState.CONFIRM -> {
                    ConfirmationContent(
                        confirmText = confirmText,
                        confirmWord = confirmWord,
                        onConfirmTextChange = { confirmText = it },
                        onDelete = {
                            deletionState = DeletionState.PROCESSING
                            statusMessage = null
                            errorMessage = null
                            gameStateViewModel.clearAccountDeletionUpdate()
                            gameStateViewModel.requestAccountDeletion()
                            onConfirmDelete()
                        },
                        canDelete = confirmText.equals(confirmWord, ignoreCase = true)
                    )
                }
                DeletionState.PROCESSING -> {
                    ProcessingContent()
                }
                DeletionState.SCHEDULED -> {
                    ScheduledContent(
                        message = statusMessage,
                        onDone = onBack
                    )
                }
                DeletionState.ERROR -> {
                    ErrorContent(
                        message = errorMessage,
                        onRetry = { deletionState = DeletionState.CONFIRM }
                    )
                }
            }
        }
    }

    LaunchedEffect(accountDeletionUpdate, deletionState) {
        if (deletionState == DeletionState.PROCESSING) {
            accountDeletionUpdate?.let { update ->
                if (update.scheduled) {
                    statusMessage = update.message
                    deletionState = DeletionState.SCHEDULED
                } else {
                    errorMessage = update.message
                    deletionState = DeletionState.ERROR
                }
            }
        }
    }

    LaunchedEffect(currentError, deletionState) {
        if (deletionState == DeletionState.PROCESSING) {
            currentError?.let {
                errorMessage = it.userMessage
                deletionState = DeletionState.ERROR
            }
        }
    }
}

@Composable
private fun ConfirmationContent(
    confirmText: String,
    confirmWord: String,
    onConfirmTextChange: (String) -> Unit,
    onDelete: () -> Unit,
    canDelete: Boolean
) {
    // Warning icon
    Box(
        modifier = Modifier
            .size(80.dp)
            .clip(CircleShape)
            .background(AppColors.error.copy(alpha = 0.15f)),
        contentAlignment = Alignment.Center
    ) {
        Icon(
            imageVector = Icons.Default.Warning,
            contentDescription = null,
            tint = AppColors.error,
            modifier = Modifier.size(40.dp)
        )
    }

    Spacer(modifier = Modifier.height(AppSpacing.lg))

    Text(
        text = "Are you sure?",
        style = AppTypography.title,
        color = AppColors.error
    )

    Spacer(modifier = Modifier.height(AppSpacing.sm))

    Text(
        text = "This action cannot be undone. All your data will be permanently deleted.",
        style = AppTypography.body,
        color = AppColors.secondaryText,
        textAlign = TextAlign.Center
    )

    Spacer(modifier = Modifier.height(AppSpacing.xl))

    // What will be deleted
    Card(
        modifier = Modifier.fillMaxWidth(),
        shape = RoundedCornerShape(AppSpacing.cornerRadius),
        colors = CardDefaults.cardColors(
            containerColor = AppColors.error.copy(alpha = 0.08f)
        )
    ) {
        Column(
            modifier = Modifier.padding(AppSpacing.md),
            verticalArrangement = Arrangement.spacedBy(AppSpacing.sm)
        ) {
            Text(
                text = "What will be deleted:",
                style = AppTypography.bodyBold,
                color = AppColors.primaryText
            )

            DeletionItem("Your character and progress")
            DeletionItem("All relationships and messages")
            DeletionItem("Achievements and rewards")
            DeletionItem("Purchase history (non-refundable)")
        }
    }

    Spacer(modifier = Modifier.height(AppSpacing.xl))

    // Confirmation input
    Text(
        text = "Type \"$confirmWord\" to confirm:",
        style = AppTypography.caption,
        color = AppColors.secondaryText
    )

    Spacer(modifier = Modifier.height(AppSpacing.xs))

    OutlinedTextField(
        value = confirmText,
        onValueChange = onConfirmTextChange,
        placeholder = { Text(confirmWord, color = AppColors.disabledText) },
        modifier = Modifier.fillMaxWidth(),
        shape = RoundedCornerShape(AppSpacing.cornerRadius),
        colors = OutlinedTextFieldDefaults.colors(
            focusedBorderColor = AppColors.error,
            unfocusedBorderColor = AppColors.surfaceSubtle
        ),
        singleLine = true
    )

    Spacer(modifier = Modifier.height(AppSpacing.xl))

    // Delete button
    Button(
        onClick = onDelete,
        modifier = Modifier
            .fillMaxWidth()
            .height(AppSpacing.buttonHeight),
        enabled = canDelete,
        shape = RoundedCornerShape(AppSpacing.pillCornerRadius),
        colors = ButtonDefaults.buttonColors(
            containerColor = AppColors.error,
            disabledContainerColor = AppColors.disabledText
        )
    ) {
        Icon(
            imageVector = Icons.Default.DeleteForever,
            contentDescription = null,
            modifier = Modifier.size(20.dp)
        )
        Spacer(modifier = Modifier.width(AppSpacing.sm))
        Text(
            text = "Delete My Account",
            style = AppTypography.bodyBold,
            color = Color.White
        )
    }
}

@Composable
private fun DeletionItem(text: String) {
    Row(verticalAlignment = Alignment.CenterVertically) {
        Icon(
            imageVector = Icons.Default.Close,
            contentDescription = null,
            tint = AppColors.error,
            modifier = Modifier.size(16.dp)
        )
        Spacer(modifier = Modifier.width(AppSpacing.sm))
        Text(
            text = text,
            style = AppTypography.body,
            color = AppColors.primaryText
        )
    }
}

@Composable
private fun ProcessingContent() {
    Spacer(modifier = Modifier.height(AppSpacing.xxl))

    CircularProgressIndicator(
        color = AppColors.error,
        modifier = Modifier.size(60.dp),
        strokeWidth = 4.dp
    )

    Spacer(modifier = Modifier.height(AppSpacing.lg))

    Text(
        text = "Processing Request...",
        style = AppTypography.headline,
        color = AppColors.primaryText
    )

    Spacer(modifier = Modifier.height(AppSpacing.sm))

    Text(
        text = "Please wait while we process your deletion request.",
        style = AppTypography.body,
        color = AppColors.secondaryText,
        textAlign = TextAlign.Center
    )
}

@Composable
private fun ScheduledContent(
    message: String?,
    onDone: () -> Unit
) {
    Spacer(modifier = Modifier.height(AppSpacing.xl))

    Box(
        modifier = Modifier
            .size(80.dp)
            .clip(CircleShape)
            .background(AppColors.success.copy(alpha = 0.15f)),
        contentAlignment = Alignment.Center
    ) {
        Icon(
            imageVector = Icons.Default.Schedule,
            contentDescription = null,
            tint = AppColors.success,
            modifier = Modifier.size(40.dp)
        )
    }

    Spacer(modifier = Modifier.height(AppSpacing.lg))

    Text(
        text = "Deletion Scheduled",
        style = AppTypography.title,
        color = AppColors.success
    )

    Spacer(modifier = Modifier.height(AppSpacing.sm))

    Text(
        text = message ?: "Your account will be permanently deleted in 30 days. You can cancel this by logging back in before then.",
        style = AppTypography.body,
        color = AppColors.secondaryText,
        textAlign = TextAlign.Center
    )

    Spacer(modifier = Modifier.height(AppSpacing.xl))

    // Grace period notice
    Card(
        modifier = Modifier.fillMaxWidth(),
        shape = RoundedCornerShape(AppSpacing.cornerRadius),
        colors = CardDefaults.cardColors(
            containerColor = AppColors.surfaceElevated
        )
    ) {
        Row(
            modifier = Modifier.padding(AppSpacing.md),
            verticalAlignment = Alignment.CenterVertically
        ) {
            Icon(
                imageVector = Icons.Default.Info,
                contentDescription = null,
                tint = AppColors.primary,
                modifier = Modifier.size(24.dp)
            )
            Spacer(modifier = Modifier.width(AppSpacing.sm))
            Text(
                text = "30-day grace period: Log back in anytime to cancel the deletion.",
                style = AppTypography.caption,
                color = AppColors.primaryText
            )
        }
    }

    Spacer(modifier = Modifier.height(AppSpacing.xl))

    Button(
        onClick = onDone,
        modifier = Modifier
            .fillMaxWidth()
            .height(AppSpacing.buttonHeight),
        shape = RoundedCornerShape(AppSpacing.pillCornerRadius),
        colors = ButtonDefaults.buttonColors(
            containerColor = AppColors.primary
        )
    ) {
        Text(
            text = "Done",
            style = AppTypography.bodyBold
        )
    }
}

@Composable
private fun ErrorContent(
    message: String?,
    onRetry: () -> Unit
) {
    Spacer(modifier = Modifier.height(AppSpacing.xl))

    Box(
        modifier = Modifier
            .size(80.dp)
            .clip(CircleShape)
            .background(AppColors.error.copy(alpha = 0.15f)),
        contentAlignment = Alignment.Center
    ) {
        Icon(
            imageVector = Icons.Default.Error,
            contentDescription = null,
            tint = AppColors.error,
            modifier = Modifier.size(40.dp)
        )
    }

    Spacer(modifier = Modifier.height(AppSpacing.lg))

    Text(
        text = "Something Went Wrong",
        style = AppTypography.title,
        color = AppColors.error
    )

    Spacer(modifier = Modifier.height(AppSpacing.sm))

    Text(
        text = message ?: "We couldn't process your request. Please try again later.",
        style = AppTypography.body,
        color = AppColors.secondaryText,
        textAlign = TextAlign.Center
    )

    Spacer(modifier = Modifier.height(AppSpacing.xl))

    Button(
        onClick = onRetry,
        modifier = Modifier
            .fillMaxWidth()
            .height(AppSpacing.buttonHeight),
        shape = RoundedCornerShape(AppSpacing.pillCornerRadius),
        colors = ButtonDefaults.buttonColors(
            containerColor = AppColors.primary
        )
    ) {
        Text(
            text = "Try Again",
            style = AppTypography.bodyBold
        )
    }
}