package com.bitchat.android.ui

import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.ui.draw.clip
import androidx.compose.foundation.gestures.detectTapGestures
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.lazy.rememberLazyListState
 

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.input.pointer.pointerInput
import androidx.compose.ui.text.TextLayoutResult
import androidx.compose.ui.text.AnnotatedString
import androidx.compose.ui.text.SpanStyle
import androidx.compose.ui.text.buildAnnotatedString
import androidx.compose.ui.text.font.FontFamily
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.compose.ui.platform.LocalContext
import androidx.compose.ui.hapticfeedback.HapticFeedbackType
import androidx.compose.ui.platform.LocalHapticFeedback
import android.content.Intent
import android.net.Uri
import com.bitchat.android.model.BitchatMessage
import com.bitchat.android.model.DeliveryStatus
import com.bitchat.android.mesh.BluetoothMeshService
import java.text.SimpleDateFormat
import java.util.*
import com.bitchat.android.ui.media.VoiceNotePlayer
import androidx.compose.material3.Icon
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Close
import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.shape.CircleShape
import com.bitchat.android.ui.media.FileMessageItem
import com.bitchat.android.model.BitchatMessageType
import com.bitchat.android.R
import androidx.compose.ui.res.stringResource


// VoiceNotePlayer moved to com.bitchat.android.ui.media.VoiceNotePlayer

/**
 * Message display components for ChatScreen
 * Extracted from ChatScreen.kt for better organization
 */

@Composable
fun MessagesList(
    messages: List<BitchatMessage>,
    currentUserNickname: String,
    meshService: BluetoothMeshService,
    modifier: Modifier = Modifier,
    forceScrollToBottom: Boolean = false,
    onScrolledUpChanged: ((Boolean) -> Unit)? = null,
    onNicknameClick: ((String) -> Unit)? = null,
    onMessageLongPress: ((BitchatMessage) -> Unit)? = null,
    onCancelTransfer: ((BitchatMessage) -> Unit)? = null,
    onImageClick: ((String, List<String>, Int) -> Unit)? = null
) {
    val listState = rememberLazyListState()
    
    // Track if this is the first time messages are being loaded
    var hasScrolledToInitialPosition by remember { mutableStateOf(false) }
    
    // Smart scroll: auto-scroll to bottom for initial load, then only when user is at or near the bottom
    LaunchedEffect(messages.size) {
        if (messages.isNotEmpty()) {
            val layoutInfo = listState.layoutInfo
            val firstVisibleIndex = layoutInfo.visibleItemsInfo.firstOrNull()?.index ?: -1
            
            // With reverseLayout=true and reversed data, index 0 is the latest message at the bottom
            val isFirstLoad = !hasScrolledToInitialPosition
            val isNearLatest = firstVisibleIndex <= 2
            
            if (isFirstLoad || isNearLatest) {
                listState.animateScrollToItem(0)
                if (isFirstLoad) {
                    hasScrolledToInitialPosition = true
                }
            }
        }
    }
    
    // Track whether user has scrolled away from the latest messages
    val isAtLatest by remember {
        derivedStateOf {
            val firstVisibleIndex = listState.layoutInfo.visibleItemsInfo.firstOrNull()?.index ?: -1
            firstVisibleIndex <= 2
        }
    }
    LaunchedEffect(isAtLatest) {
        onScrolledUpChanged?.invoke(!isAtLatest)
    }
    
    // Force scroll to bottom when requested (e.g., when user sends a message)
    LaunchedEffect(forceScrollToBottom) {
        if (messages.isNotEmpty()) {
            // With reverseLayout=true and reversed data, latest is at index 0
            listState.animateScrollToItem(0)
        }
    }
    
    LazyColumn(
        state = listState,
        contentPadding = PaddingValues(horizontal = 12.dp, vertical = 8.dp),
        verticalArrangement = Arrangement.spacedBy(4.dp),
        modifier = modifier,
        reverseLayout = true
    ) {
        items(
            items = messages.asReversed(),
            key = { it.id }
        ) { message ->
                MessageItem(
                    message = message,
                    messages = messages,
                    currentUserNickname = currentUserNickname,
                    meshService = meshService,
                    onNicknameClick = onNicknameClick,
                    onMessageLongPress = onMessageLongPress,
                    onCancelTransfer = onCancelTransfer,
                    onImageClick = onImageClick
                )
        }
    }
}

@OptIn(ExperimentalFoundationApi::class)
@Composable
fun MessageItem(
    message: BitchatMessage,
    currentUserNickname: String,
    meshService: BluetoothMeshService,
    messages: List<BitchatMessage> = emptyList(),
    onNicknameClick: ((String) -> Unit)? = null,
    onMessageLongPress: ((BitchatMessage) -> Unit)? = null,
    onCancelTransfer: ((BitchatMessage) -> Unit)? = null,
    onImageClick: ((String, List<String>, Int) -> Unit)? = null
) {
    val colorScheme = MaterialTheme.colorScheme
    val timeFormatter = remember { SimpleDateFormat("HH:mm:ss", Locale.getDefault()) }
    
    Column(
        modifier = Modifier.fillMaxWidth(),
        verticalArrangement = Arrangement.spacedBy(0.dp)
    ) {
        Box(modifier = Modifier.fillMaxWidth()) {
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.Start,
                verticalAlignment = Alignment.Top
            ) {
                // Provide a small end padding for own private messages so overlay doesn't cover text
                val endPad = if (message.isPrivate && message.sender == currentUserNickname) 16.dp else 0.dp
                // Create a custom layout that combines selectable text with clickable nickname areas
                MessageTextWithClickableNicknames(
                    message = message,
                    messages = messages,
                    currentUserNickname = currentUserNickname,
                    meshService = meshService,
                    colorScheme = colorScheme,
                    timeFormatter = timeFormatter,
                    onNicknameClick = onNicknameClick,
                    onMessageLongPress = onMessageLongPress,
                    onCancelTransfer = onCancelTransfer,
                    onImageClick = onImageClick,
                    modifier = Modifier
                        .weight(1f)
                        .padding(end = endPad)
                )
            }

            // Delivery status for private messages (overlay, non-displacing)
            if (message.isPrivate && message.sender == currentUserNickname) {
                message.deliveryStatus?.let { status ->
                    Box(
                        modifier = Modifier
                            .align(Alignment.TopEnd)
                            .padding(top = 2.dp)
                    ) {
                        DeliveryStatusIcon(status = status)
                    }
                }
            }
        }
        
        // Link previews removed; links are now highlighted inline and clickable within the message text
    }
}

@OptIn(ExperimentalFoundationApi::class)
@Composable
    private fun MessageTextWithClickableNicknames(
        message: BitchatMessage,
        messages: List<BitchatMessage>,
        currentUserNickname: String,
        meshService: BluetoothMeshService,
        colorScheme: ColorScheme,
        timeFormatter: SimpleDateFormat,
        onNicknameClick: ((String) -> Unit)?,
        onMessageLongPress: ((BitchatMessage) -> Unit)?,
        onCancelTransfer: ((BitchatMessage) -> Unit)?,
        onImageClick: ((String, List<String>, Int) -> Unit)?,
        modifier: Modifier = Modifier
    ) {
    // Image special rendering
    if (message.type == BitchatMessageType.Image) {
        com.bitchat.android.ui.media.ImageMessageItem(
            message = message,
            messages = messages,
            currentUserNickname = currentUserNickname,
            meshService = meshService,
            colorScheme = colorScheme,
            timeFormatter = timeFormatter,
            onNicknameClick = onNicknameClick,
            onMessageLongPress = onMessageLongPress,
            onCancelTransfer = onCancelTransfer,
            onImageClick = onImageClick,
            modifier = modifier
        )
        return
    }

    // Voice note special rendering
    if (message.type == BitchatMessageType.Audio) {
        com.bitchat.android.ui.media.AudioMessageItem(
            message = message,
            currentUserNickname = currentUserNickname,
            meshService = meshService,
            colorScheme = colorScheme,
            timeFormatter = timeFormatter,
            onNicknameClick = onNicknameClick,
            onMessageLongPress = onMessageLongPress,
            onCancelTransfer = onCancelTransfer,
            modifier = modifier
        )
        return
    }

    // File special rendering
    if (message.type == BitchatMessageType.File) {
        val path = message.content.trim()
        // Derive sending progress if applicable
        val (overrideProgress, _) = when (val st = message.deliveryStatus) {
            is com.bitchat.android.model.DeliveryStatus.PartiallyDelivered -> {
                if (st.total > 0 && st.reached < st.total) {
                    (st.reached.toFloat() / st.total.toFloat()) to Color(0xFF1E88E5) // blue while sending
                } else null to null
            }
            else -> null to null
        }
        Column(modifier = modifier.fillMaxWidth()) {
            // Header: nickname + timestamp line above the file, identical styling to text messages
            val headerText = formatMessageHeaderAnnotatedString(
                message = message,
                currentUserNickname = currentUserNickname,
                meshService = meshService,
                colorScheme = colorScheme,
                timeFormatter = timeFormatter
            )
            val haptic = LocalHapticFeedback.current
            var headerLayout by remember { mutableStateOf<TextLayoutResult?>(null) }
            Text(
                text = headerText,
                fontFamily = FontFamily.Monospace,
                color = colorScheme.onSurface,
                modifier = Modifier.pointerInput(message.id) {
                    detectTapGestures(onTap = { pos ->
                        val layout = headerLayout ?: return@detectTapGestures
                        val offset = layout.getOffsetForPosition(pos)
                        val ann = headerText.getStringAnnotations("nickname_click", offset, offset)
                        if (ann.isNotEmpty() && onNicknameClick != null) {
                            haptic.performHapticFeedback(HapticFeedbackType.TextHandleMove)
                            onNicknameClick.invoke(ann.first().item)
                        }
                    }, onLongPress = { onMessageLongPress?.invoke(message) })
                },
                onTextLayout = { headerLayout = it }
            )

            // Try to load the file packet from the path
            val packet = try {
                val file = java.io.File(path)
                if (file.exists()) {
                    // Create a temporary BitchatFilePacket for display
                    // In a real implementation, this would be stored with the packet metadata
                    com.bitchat.android.model.BitchatFilePacket(
                        fileName = file.name,
                        fileSize = file.length(),
                        mimeType = com.bitchat.android.features.file.FileUtils.getMimeTypeFromExtension(file.name),
                        content = file.readBytes()
                    )
                } else null
            } catch (e: Exception) {
                null
            }

            Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.Start) {
                Box {
                    if (packet != null) {
                        if (overrideProgress != null) {
                            // Show sending animation while in-flight
                            com.bitchat.android.ui.media.FileSendingAnimation(
                                fileName = packet.fileName,
                                progress = overrideProgress,
                                modifier = Modifier.fillMaxWidth()
                            )
                        } else {
                            // Static file display with open/save dialog
                            FileMessageItem(
                                packet = packet,
                                onFileClick = {
                                    // handled inside FileMessageItem via dialog
                                }
                            )
                        }

                        // Cancel button overlay during sending
                        val showCancel = message.sender == currentUserNickname && (message.deliveryStatus is DeliveryStatus.PartiallyDelivered)
                        if (showCancel) {
                            Box(
                                modifier = Modifier
                                    .align(Alignment.TopEnd)
                                    .padding(4.dp)
                                    .size(22.dp)
                                    .background(Color.Gray.copy(alpha = 0.6f), CircleShape)
                                    .clickable { onCancelTransfer?.invoke(message) },
                                contentAlignment = Alignment.Center
                            ) {
                                Icon(imageVector = Icons.Filled.Close, contentDescription = stringResource(R.string.cd_cancel), tint = Color.White, modifier = Modifier.size(14.dp))
                            }
                        }
                    } else {
                        Text(text = stringResource(R.string.file_unavailable), fontFamily = FontFamily.Monospace, color = Color.Gray)
                    }
                }
            }
        }
        return
    }

    // Check if this message should be animated during PoW mining
    val shouldAnimate = shouldAnimateMessage(message.id)
    
    // If animation is needed, use the matrix animation component for content only
    if (shouldAnimate) {
        // Display message with matrix animation for content
        MessageWithMatrixAnimation(
            message = message,
            messages = messages,
            currentUserNickname = currentUserNickname,
            meshService = meshService,
            colorScheme = colorScheme,
            timeFormatter = timeFormatter,
            onNicknameClick = onNicknameClick,
            onMessageLongPress = onMessageLongPress,
            onImageClick = onImageClick,
            modifier = modifier
        )
    } else {
        // Normal message display
        val annotatedText = formatMessageAsAnnotatedString(
            message = message,
            currentUserNickname = currentUserNickname,
            meshService = meshService,
            colorScheme = colorScheme,
            timeFormatter = timeFormatter
        )
        
        // Check if this message was sent by self to avoid click interactions on own nickname
        val isSelf = message.senderPeerID == meshService.myPeerID || 
                     message.sender == currentUserNickname ||
                     message.sender.startsWith("$currentUserNickname#")
        
        val haptic = LocalHapticFeedback.current
        val context = LocalContext.current
        var textLayoutResult by remember { mutableStateOf<TextLayoutResult?>(null) }
        Text(
            text = annotatedText,
            modifier = modifier.pointerInput(message) {
                detectTapGestures(
                    onTap = { position ->
                        val layout = textLayoutResult ?: return@detectTapGestures
                        val offset = layout.getOffsetForPosition(position)
                        // Nickname click only when not self
                        if (!isSelf && onNicknameClick != null) {
                            val nicknameAnnotations = annotatedText.getStringAnnotations(
                                tag = "nickname_click",
                                start = offset,
                                end = offset
                            )
                            if (nicknameAnnotations.isNotEmpty()) {
                                val nickname = nicknameAnnotations.first().item
                                haptic.performHapticFeedback(HapticFeedbackType.TextHandleMove)
                                onNicknameClick.invoke(nickname)
                                return@detectTapGestures
                            }
                        }
                        // Geohash teleport (all messages)
                        val geohashAnnotations = annotatedText.getStringAnnotations(
                            tag = "geohash_click",
                            start = offset,
                            end = offset
                        )
                        if (geohashAnnotations.isNotEmpty()) {
                            val geohash = geohashAnnotations.first().item
                            try {
                                val locationManager = com.bitchat.android.geohash.LocationChannelManager.getInstance(
                                    context
                                )
                                val level = when (geohash.length) {
                                    in 0..2 -> com.bitchat.android.geohash.GeohashChannelLevel.REGION
                                    in 3..4 -> com.bitchat.android.geohash.GeohashChannelLevel.PROVINCE
                                    5 -> com.bitchat.android.geohash.GeohashChannelLevel.CITY
                                    6 -> com.bitchat.android.geohash.GeohashChannelLevel.NEIGHBORHOOD
                                    else -> com.bitchat.android.geohash.GeohashChannelLevel.BLOCK
                                }
                                val channel = com.bitchat.android.geohash.GeohashChannel(level, geohash.lowercase())
                                locationManager.setTeleported(true)
                                locationManager.select(com.bitchat.android.geohash.ChannelID.Location(channel))
                            } catch (_: Exception) { }
                            haptic.performHapticFeedback(HapticFeedbackType.TextHandleMove)
                            return@detectTapGestures
                        }
                        // URL open (all messages)
                        val urlAnnotations = annotatedText.getStringAnnotations(
                            tag = "url_click",
                            start = offset,
                            end = offset
                        )
                        if (urlAnnotations.isNotEmpty()) {
                            val raw = urlAnnotations.first().item
                            val resolved = if (raw.startsWith("http://", ignoreCase = true) || raw.startsWith("https://", ignoreCase = true)) raw else "https://$raw"
                            try {
                                val intent = Intent(Intent.ACTION_VIEW, Uri.parse(resolved))
                                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
                                context.startActivity(intent)
                            } catch (_: Exception) { }
                            haptic.performHapticFeedback(HapticFeedbackType.TextHandleMove)
                            return@detectTapGestures
                        }
                    },
                    onLongPress = {
                        haptic.performHapticFeedback(HapticFeedbackType.LongPress)
                        onMessageLongPress?.invoke(message)
                    }
                )
            },
            fontFamily = FontFamily.Monospace,
            softWrap = true,
            overflow = TextOverflow.Visible,
            style = androidx.compose.ui.text.TextStyle(
                color = colorScheme.onSurface
            ),
            onTextLayout = { result -> textLayoutResult = result }
        )
    }
}

@Composable
fun DeliveryStatusIcon(status: DeliveryStatus) {
    val colorScheme = MaterialTheme.colorScheme
    
    when (status) {
        is DeliveryStatus.Sending -> {
            Text(
                text = stringResource(R.string.status_sending),
                fontSize = 10.sp,
                color = colorScheme.primary.copy(alpha = 0.6f)
            )
        }
        is DeliveryStatus.Sent -> {
            // Use a subtle hollow marker for Sent; single check is reserved for Delivered (iOS parity)
            Text(
                text = stringResource(R.string.status_pending),
                fontSize = 10.sp,
                color = colorScheme.primary.copy(alpha = 0.6f)
            )
        }
        is DeliveryStatus.Delivered -> {
            // Single check for Delivered (matches iOS expectations)
            Text(
                text = stringResource(R.string.status_sent),
                fontSize = 10.sp,
                color = colorScheme.primary.copy(alpha = 0.8f)
            )
        }
        is DeliveryStatus.Read -> {
            Text(
                text = stringResource(R.string.status_delivered),
                fontSize = 10.sp,
                color = Color(0xFF007AFF), // Blue
                fontWeight = FontWeight.Bold
            )
        }
        is DeliveryStatus.Failed -> {
            Text(
                text = stringResource(R.string.status_failed),
                fontSize = 10.sp,
                color = Color.Red.copy(alpha = 0.8f)
            )
        }
        is DeliveryStatus.PartiallyDelivered -> {
            // Show a single subdued check without numeric label
            Text(
                text = stringResource(R.string.status_sent),
                fontSize = 10.sp,
                color = colorScheme.primary.copy(alpha = 0.6f)
            )
        }
    }
}