package com.suno.android.ui.bottom_sheets.comments

import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
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.heightIn
import androidx.compose.foundation.layout.offset
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.LazyListState
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicTextField
import androidx.compose.foundation.text.KeyboardActions
import androidx.compose.foundation.text.KeyboardOptions
import androidx.compose.material3.Icon
import androidx.compose.material3.SheetState
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.focus.FocusManager
import androidx.compose.ui.focus.FocusRequester
import androidx.compose.ui.focus.focusRequester
import androidx.compose.ui.focus.onFocusChanged
import androidx.compose.ui.graphics.SolidColor
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.res.pluralStringResource
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.res.vectorResource
import androidx.compose.ui.text.SpanStyle
import androidx.compose.ui.text.buildAnnotatedString
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.input.ImeAction
import androidx.compose.ui.text.input.OffsetMapping
import androidx.compose.ui.text.input.TextFieldValue
import androidx.compose.ui.text.input.TransformedText
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.dp
import com.suno.android.common_core_utils.Id
import com.suno.android.common_core_utils.extensions.xAsMinutesSecondsTimecode
import com.suno.android.common_core_utils.extensions.xAsTimecodeStringToDuration
import com.suno.android.common_core_utils.model.Url
import com.suno.android.common_core_utils.model.UserHandle
import com.suno.android.common_data.comments.Comment
import com.suno.android.common_data.comments.MediaEntity
import com.suno.android.common_data.user.UserProfile
import com.suno.android.common_networking.remote.entities.SimpleProfileInfoSchema
import com.suno.android.common_ui.components.images.ProfileAvatarImage
import com.suno.android.common_ui.components.list_items.comments.CommentListItem
import com.suno.android.common_ui.components.list_items.comments.CommentListItemType
import com.suno.android.common_ui.components.list_items.comments.MentionState
import com.suno.android.common_ui.components.loading.SunoSpinner
import com.suno.android.common_ui.components.omni.CircleIconButton
import com.suno.android.common_ui.theme.ExtendedTheme
import kotlinx.coroutines.launch
import com.suno.android.common_res.R as CommonResR
import com.suno.android.common_ui.R as CommonUIR

@Composable
fun CommentsBottomSheetContent(
    viewState: CommentsBottomSheetState,
    vm: CommentsBottomSheetVM,
    mediaEntity: MediaEntity,
    authorId: Id<UserProfile>?,
    authorHandle: UserHandle?,
    onDismiss: () -> Unit,
    onProfileClicked: (UserHandle) -> Unit,
    onBeginWriting: () -> Unit,
    focusRequester: FocusRequester,
    focusManager: FocusManager,
    lazyListState: LazyListState,
    sheetState: SheetState,
    isTextFieldFocused: Boolean,
    hasBegunTyping: Boolean,
    onFocusChanged: (Boolean) -> Unit,
    onTypingStateChanged: (Boolean) -> Unit,
    onShowReportSheet: () -> Unit,
    modifier: Modifier = Modifier,
) {
    val scope = rememberCoroutineScope()

    Column(
        modifier = modifier,
        verticalArrangement = Arrangement.SpaceBetween,
    ) {
        CommentsHeader(
            loading = viewState.loading,
            totalCount = viewState.totalCount,
            onDismiss = onDismiss,
            modifier = Modifier
                .fillMaxWidth()
                .height(96.dp),
        )

        if (viewState.loading) {
            Box(
                modifier = Modifier
                    .fillMaxWidth()
                    .weight(1f)
                    .padding(top = 32.dp),
                contentAlignment = Alignment.TopCenter,
            ) {
                SunoSpinner()
            }
        } else {
            LazyColumn(
                modifier = Modifier
                    .padding(horizontal = 16.dp)
                    .weight(1f),
                state = lazyListState,
            ) {
                if (viewState.comments?.isEmpty() == true) {
                    item {
                        EmptyCommentsState(
                            modifier = Modifier
                                .fillMaxWidth()
                                .padding(top = 48.dp),
                        )
                    }
                }

                items(viewState.comments ?: emptyList()) { comment ->
                    val repliesLoading = viewState.commentRepliesLoadingMap[comment.id] ?: false
                    CommentListItem(
                        comment = comment,
                        onProfileClicked = { userHandle ->
                            onProfileClicked(userHandle)
                        },
                        onTimecodeClicked = { timecode ->
                            vm.sendEvent(
                                CommentsBottomSheetEvent.OnTimecodeClicked(
                                    timecode = timecode.xAsTimecodeStringToDuration(),
                                ),
                            )
                        },
                        authorId = authorId?.value,
                        onReactClicked = { commentId, reaction, parentCommentId ->
                            vm.sendEvent(
                                CommentsBottomSheetEvent.OnReactToComment(
                                    commentId = Id(commentId),
                                    // All replies will have entityType (clip or hook) of parent comment
                                    commentType = comment.entityType.toCommentType(),
                                    reaction = reaction,
                                    parentCommentId = parentCommentId?.let(::Id),
                                ),
                            )
                        },
                        fetchedReplies = viewState.commentRepliesMap[comment.id],
                        fetchReplies = {
                            vm.sendEvent(
                                CommentsBottomSheetEvent.OnGetCommentReplies(
                                    commentId = Id(comment.id),
                                    commentType = comment.entityType.toCommentType(),
                                ),
                            )
                        },
                        repliesLoading = repliesLoading,
                        reactLoadingMap = viewState.commentReactLoadingMap,
                        onReplyClicked = {
                            vm.setReplyTarget(commentId = Id(comment.id))
                            focusRequester.requestFocus()
                        },
                        onReportComment = { commentId ->
                            vm.sendEvent(
                                CommentsBottomSheetEvent.Internal.OnSetCommentToReport(
                                    commentId = Id(commentId),
                                    commentType = comment.entityType.toCommentType(),
                                ),
                            )
                            onShowReportSheet()
                        },
                        onDeleteComment = { commentId ->
                            scope.launch {
                                vm.sendEvent(
                                    CommentsBottomSheetEvent.OnDeleteComment(
                                        commentId = Id(commentId),
                                        commentType = comment.entityType.toCommentType(),
                                    ),
                                )
                            }
                        },
                        isOwnContent = authorId?.value != null && authorId.value == viewState.user?.id,
                        isOwnComment = comment.userId == viewState.user?.id,
                        showMentions = viewState.isMentionsGateEnabled,
                        entityLabelText = if (
                            mediaEntity is MediaEntity.HookEntity &&
                            comment.entityType == CommentListItemType.Clip
                        ) {
                            stringResource(CommonResR.string.on_song)
                        } else {
                            null
                        },
                        showTimestamp = mediaEntity is MediaEntity.ClipEntity,
                    )
                }
                if (viewState.loadingMore) {
                    item {
                        Box(
                            modifier = Modifier
                                .fillMaxWidth()
                                .padding(top = 16.dp),
                            contentAlignment = Alignment.TopCenter,
                        ) {
                            SunoSpinner()
                        }
                    }
                }
            }
        }
        Column(
            modifier = Modifier
                .offset {
                    IntOffset(
                        x = 0,
                        y = -sheetState.requireOffset().toInt() + 80,
                    )
                }
                .fillMaxWidth()
                .background(ExtendedTheme.colors.backgroundSecondary)
                .padding(bottom = 12.dp, start = 8.dp, end = 8.dp),
        ) {
            val replyComment =
                viewState.comments?.find { viewState.parentId != null && it.id == viewState.parentId.value }
            if (replyComment != null) {
                ReplyIndicator(
                    userDisplayName = replyComment.userDisplayName,
                    commentContent = replyComment.content,
                    onClearReply = {
                        vm.setReplyTarget(null)
                        focusManager.clearFocus()
                    },
                    modifier = Modifier
                        .fillMaxWidth()
                        .background(ExtendedTheme.colors.backgroundSecondary)
                        .padding(top = 8.dp, bottom = 16.dp),
                )
            }
            MentionTargetsList(
                mentionTargets = viewState.mentionTargets,
                onMentionClicked = { vm.addMentionToComment(it) },
                modifier = Modifier
                    .fillMaxWidth()
                    .heightIn(0.dp, 248.dp),
            )
            CommentInputSection(
                textFieldValue = viewState.textFieldValue,
                userMentions = viewState.userMentions,
                userAvatarUrl = viewState.user?.avatarImageUrl,
                timestamp = viewState.timestamp,
                parentId = viewState.parentId,
                authorHandle = authorHandle,
                focusRequester = focusRequester,
                focusManager = focusManager,
                isTextFieldFocused = isTextFieldFocused,
                hasBegunTyping = hasBegunTyping,
                onBeginWriting = onBeginWriting,
                onFocusChanged = onFocusChanged,
                onTypingStateChanged = onTypingStateChanged,
                onUpdateCommentContent = { textField, handle -> vm.updateCommentContent(textField, handle) },
                onPostComment = {
                    vm.sendEvent(
                        CommentsBottomSheetEvent.OnPostComment(
                            mediaEntity = mediaEntity,
                            replyTargetId = viewState.parentId,
                        ),
                    )
                },
                onClearReply = {
                    vm.setReplyTarget(null)
                },
                modifier = Modifier
                    .fillMaxWidth()
                    .height(80.dp)
                    .background(ExtendedTheme.colors.backgroundSecondary),
            )
        }
    }
}

@Composable
private fun CommentsHeader(
    loading: Boolean,
    totalCount: Int?,
    onDismiss: () -> Unit,
    modifier: Modifier = Modifier,
) {
    Box(
        modifier = modifier,
    ) {
        val isLoading = loading || totalCount == null
        val commentsString = pluralStringResource(
            CommonResR.plurals.commentsVARIABLE,
            totalCount ?: 0,
            totalCount ?: 0,
        )
        Text(
            modifier = Modifier.align(Alignment.Center),
            text = if (isLoading) stringResource(CommonResR.string.comments) else commentsString,
            style = ExtendedTheme.typography.introCopy,
        )

        CircleIconButton(
            modifier = Modifier
                .align(Alignment.CenterEnd)
                .padding(24.dp),
            vectorDrawableResId = CommonUIR.drawable.close,
            contentDescription = stringResource(CommonResR.string.close),
            onClick = onDismiss,
        )
    }
}

@Composable
private fun EmptyCommentsState(
    modifier: Modifier = Modifier,
) {
    Box(
        modifier = modifier,
        contentAlignment = Alignment.TopCenter,
    ) {
        Column(
            modifier = Modifier.width(240.dp),
        ) {
            Text(
                modifier = Modifier
                    .padding(bottom = 8.dp)
                    .align(Alignment.CenterHorizontally),
                text = stringResource(CommonResR.string.no_comments_yet),
                style = ExtendedTheme.typography.smallTrackName,
            )
            Text(
                text = stringResource(CommonResR.string.add_first_comment),
                textAlign = TextAlign.Center,
                style = ExtendedTheme.typography.body,
                color = ExtendedTheme.colors.textSecondary,
            )
        }
    }
}

@Composable
private fun ReplyIndicator(
    userDisplayName: String,
    commentContent: String,
    onClearReply: () -> Unit,
    modifier: Modifier = Modifier,
) {
    Row(
        modifier = modifier,
        verticalAlignment = Alignment.CenterVertically,
        horizontalArrangement = Arrangement.SpaceBetween,
    ) {
        Text(
            maxLines = 1,
            modifier = Modifier.padding(end = 4.dp),
            text = stringResource(
                CommonResR.string.reply_to,
                userDisplayName,
            ),
            style = ExtendedTheme.typography.body,
            color = ExtendedTheme.colors.textPrimary,
        )
        Text(
            modifier = Modifier
                .weight(1f)
                .padding(end = 4.dp),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
            text = commentContent,
            style = ExtendedTheme.typography.body,
            color = ExtendedTheme.colors.textSecondary,
        )
        Icon(
            modifier = Modifier
                .size(24.dp)
                .clickable {
                    onClearReply()
                },
            imageVector = ImageVector.vectorResource(CommonUIR.drawable.close),
            contentDescription = stringResource(CommonResR.string.close),
        )
    }
}

@Composable
private fun MentionTargetsList(
    mentionTargets: List<SimpleProfileInfoSchema>,
    onMentionClicked: (SimpleProfileInfoSchema) -> Unit,
    modifier: Modifier = Modifier,
) {
    LazyColumn(
        modifier = modifier,
        state = rememberLazyListState(),
    ) {
        item { Spacer(modifier = Modifier.height(8.dp)) }

        items(mentionTargets) { mention ->
            mention.handle.takeUnless { it.isNullOrBlank() }?.let { handle ->
                Row(
                    modifier = Modifier
                        .fillMaxSize()
                        .padding(vertical = 8.dp)
                        .clickable { onMentionClicked(mention) },
                ) {
                    ProfileAvatarImage(
                        avatarUrl = mention.avatarImageUrl?.let(::Url),
                        modifier = Modifier
                            .padding(end = 8.dp)
                            .size(44.dp),
                    )
                    Column(
                        modifier = Modifier.height(44.dp),
                        verticalArrangement = Arrangement.Center,
                    ) {
                        Text(
                            text = mention.displayName ?: "",
                            style = ExtendedTheme.typography.body,
                            color = ExtendedTheme.colors.textPrimary,
                        )
                        Text(
                            text = stringResource(CommonResR.string.arobas_user_handle, handle),
                            style = ExtendedTheme.typography.body,
                            color = ExtendedTheme.colors.textTertiary,
                        )
                    }
                }
            }
        }
    }
}

@Composable
private fun CommentInputSection(
    textFieldValue: TextFieldValue,
    userMentions: List<MentionState>,
    userAvatarUrl: String?,
    timestamp: kotlin.time.Duration?,
    parentId: Id<Comment>?,
    authorHandle: UserHandle?,
    focusRequester: FocusRequester,
    focusManager: FocusManager,
    isTextFieldFocused: Boolean,
    hasBegunTyping: Boolean,
    onBeginWriting: () -> Unit,
    onFocusChanged: (Boolean) -> Unit,
    onTypingStateChanged: (Boolean) -> Unit,
    onUpdateCommentContent: (TextFieldValue, UserHandle?) -> Unit,
    onPostComment: () -> Unit,
    onClearReply: () -> Unit,
    modifier: Modifier = Modifier,
) {
    val inputVal = textFieldValue

    Row(
        modifier = modifier,
    ) {
        ProfileAvatarImage(
            modifier = Modifier
                .padding(end = 8.dp)
                .size(44.dp),
            avatarUrl = userAvatarUrl?.let { Url(it) },
        )

        val mentionColor = ExtendedTheme.colors.textPrimary

        BasicTextField(
            modifier = Modifier
                .fillMaxWidth()
                .padding(horizontal = 4.dp)
                .height(44.dp)
                .background(
                    color = ExtendedTheme.colors.backgroundTertiary,
                    shape = RoundedCornerShape(8.dp),
                )
                .focusRequester(focusRequester = focusRequester)
                .onFocusChanged { focusState ->
                    onFocusChanged(focusState.isFocused)
                    onTypingStateChanged(false)
                },
            value = inputVal,
            onValueChange = {
                onUpdateCommentContent(it, authorHandle)

                // Track when the user begins typing
                if (isTextFieldFocused && !hasBegunTyping && it.text != textFieldValue.text) {
                    onBeginWriting()
                    onTypingStateChanged(true)
                }
            },
            textStyle = ExtendedTheme.typography.body.copy(color = ExtendedTheme.colors.textSecondary),
            maxLines = 1,
            cursorBrush = SolidColor(ExtendedTheme.colors.sunoPink),
            keyboardOptions = KeyboardOptions(imeAction = ImeAction.Done),
            keyboardActions = KeyboardActions(
                onDone = {
                    if (inputVal.text.isEmpty()) return@KeyboardActions
                    onPostComment()
                    onClearReply()
                    focusManager.clearFocus()
                    onUpdateCommentContent(TextFieldValue(), authorHandle)
                },
            ),
            visualTransformation = { inputText ->
                val annotatedString = buildAnnotatedString {
                    append(inputText.text)

                    userMentions.forEach { mention ->
                        addStyle(
                            style = SpanStyle(
                                fontWeight = FontWeight.Bold,
                                color = mentionColor,
                            ),
                            start = mention.start,
                            end = mention.end,
                        )
                    }
                }

                TransformedText(
                    text = annotatedString,
                    offsetMapping = OffsetMapping.Identity,
                )
            },
            decorationBox = @Composable { innerTextField ->
                Row(
                    modifier = Modifier
                        .fillMaxSize()
                        .padding(horizontal = 8.dp)
                        .background(
                            color = ExtendedTheme.colors.backgroundTertiary,
                            shape = RoundedCornerShape(8.dp),
                        ),
                    verticalAlignment = Alignment.CenterVertically,
                    horizontalArrangement = Arrangement.SpaceBetween,
                ) {
                    Box(
                        modifier = Modifier.weight(1f),
                        contentAlignment = Alignment.CenterStart,
                    ) {
                        if (inputVal.text.isEmpty()) {
                            Text(
                                text = stringResource(
                                    if (parentId == null) {
                                        CommonResR.string.add_a_comment
                                    } else {
                                        CommonResR.string.reply_to_comment
                                    },
                                ),
                                style = ExtendedTheme.typography.body,
                                color = ExtendedTheme.colors.textSecondary,
                            )
                        }
                        innerTextField()
                    }
                    timestamp?.let {
                        Text(
                            text = timestamp.xAsMinutesSecondsTimecode(),
                            style = ExtendedTheme.typography.body,
                            color = ExtendedTheme.colors.textSecondary,
                        )
                    }
                }
            },
        )
    }
}