package eu.kanade.presentation.updates

import androidx.compose.foundation.background
import androidx.compose.foundation.combinedClickable
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.sizeIn
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.lazy.LazyListScope
import androidx.compose.foundation.lazy.items
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Bookmark
import androidx.compose.material3.Icon
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.alpha
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalDensity
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import eu.kanade.domain.updates.model.UpdatesWithRelations
import eu.kanade.presentation.components.ChapterDownloadAction
import eu.kanade.presentation.components.ChapterDownloadIndicator
import eu.kanade.presentation.components.MangaCover
import eu.kanade.presentation.components.RelativeDateHeader
import eu.kanade.presentation.util.ReadItemAlpha
import eu.kanade.presentation.util.horizontalPadding
import eu.kanade.tachiyomi.R
import eu.kanade.tachiyomi.data.download.model.Download
import eu.kanade.tachiyomi.ui.recent.updates.UpdatesItem
import java.text.DateFormat

fun LazyListScope.updatesUiItems(
    uiModels: List<UpdatesUiModel>,
    itemUiModels: List<UpdatesUiModel.Item>,
    selected: MutableList<UpdatesUiModel.Item>,
    selectedPositions: Array<Int>,
    onClickCover: (UpdatesItem) -> Unit,
    onClickUpdate: (UpdatesItem) -> Unit,
    onDownloadChapter: (List<UpdatesItem>, ChapterDownloadAction) -> Unit,
    relativeTime: Int,
    dateFormat: DateFormat,
) {
    items(
        items = uiModels,
        contentType = {
            when (it) {
                is UpdatesUiModel.Header -> "header"
                is UpdatesUiModel.Item -> "item"
            }
        },
        key = {
            when (it) {
                is UpdatesUiModel.Header -> it.hashCode()
                is UpdatesUiModel.Item -> it.item.update.chapterId
            }
        },
    ) { item ->
        when (item) {
            is UpdatesUiModel.Header -> {
                RelativeDateHeader(
                    modifier = Modifier.animateItemPlacement(),
                    date = item.date,
                    relativeTime = relativeTime,
                    dateFormat = dateFormat,
                )
            }
            is UpdatesUiModel.Item -> {
                val value = item.item
                val update = value.update
                UpdatesUiItem(
                    modifier = Modifier.animateItemPlacement(),
                    update = update,
                    selected = selected.contains(item),
                    onClick = {
                        onUpdatesItemClick(
                            updatesItem = item,
                            selected = selected,
                            updates = itemUiModels,
                            selectedPositions = selectedPositions,
                            onUpdateClicked = onClickUpdate,
                        )
                    },
                    onLongClick = {
                        onUpdatesItemLongClick(
                            updatesItem = item,
                            selected = selected,
                            updates = itemUiModels,
                            selectedPositions = selectedPositions,
                        )
                    },
                    onClickCover = { if (selected.size == 0) onClickCover(value) },
                    onDownloadChapter = {
                        if (selected.size == 0) onDownloadChapter(listOf(value), it)
                    },
                    downloadStateProvider = value.downloadStateProvider,
                    downloadProgressProvider = value.downloadProgressProvider,
                )
            }
        }
    }
}

@Composable
fun UpdatesUiItem(
    modifier: Modifier,
    update: UpdatesWithRelations,
    selected: Boolean,
    onClick: () -> Unit,
    onLongClick: () -> Unit,
    onClickCover: () -> Unit,
    onDownloadChapter: (ChapterDownloadAction) -> Unit,
    // Download Indicator
    downloadStateProvider: () -> Download.State,
    downloadProgressProvider: () -> Int,
) {
    Row(
        modifier = modifier
            .background(if (selected) MaterialTheme.colorScheme.surfaceVariant else Color.Transparent)
            .combinedClickable(
                onClick = onClick,
                onLongClick = onLongClick,
            )
            .height(56.dp)
            .padding(horizontal = horizontalPadding),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        MangaCover.Square(
            modifier = Modifier
                .padding(vertical = 6.dp)
                .fillMaxHeight(),
            data = update.coverData,
            onClick = onClickCover,
        )
        Column(
            modifier = Modifier
                .padding(horizontal = horizontalPadding)
                .weight(1f),
        ) {
            val bookmark = remember(update.bookmark) { update.bookmark }
            val read = remember(update.read) { update.read }

            val textAlpha = remember(read) { if (read) ReadItemAlpha else 1f }

            val secondaryTextColor = if (bookmark && !read) {
                MaterialTheme.colorScheme.primary
            } else {
                MaterialTheme.colorScheme.onSurface
            }

            Text(
                text = update.mangaTitle,
                maxLines = 1,
                style = MaterialTheme.typography.bodyMedium,
                overflow = TextOverflow.Ellipsis,
                modifier = Modifier.alpha(textAlpha),
            )
            Row(verticalAlignment = Alignment.CenterVertically) {
                var textHeight by remember { mutableStateOf(0) }
                if (bookmark) {
                    Icon(
                        imageVector = Icons.Default.Bookmark,
                        contentDescription = stringResource(R.string.action_filter_bookmarked),
                        modifier = Modifier
                            .sizeIn(maxHeight = with(LocalDensity.current) { textHeight.toDp() - 2.dp }),
                        tint = MaterialTheme.colorScheme.primary,
                    )
                    Spacer(modifier = Modifier.width(2.dp))
                }
                Text(
                    text = update.chapterName,
                    maxLines = 1,
                    style = MaterialTheme.typography.bodySmall
                        .copy(color = secondaryTextColor),
                    overflow = TextOverflow.Ellipsis,
                    onTextLayout = { textHeight = it.size.height },
                    modifier = Modifier.alpha(textAlpha),
                )
            }
        }
        ChapterDownloadIndicator(
            modifier = Modifier.padding(start = 4.dp),
            downloadStateProvider = downloadStateProvider,
            downloadProgressProvider = downloadProgressProvider,
            onClick = onDownloadChapter,
        )
    }
}

private fun onUpdatesItemLongClick(
    updatesItem: UpdatesUiModel.Item,
    selected: MutableList<UpdatesUiModel.Item>,
    updates: List<UpdatesUiModel.Item>,
    selectedPositions: Array<Int>,
): Boolean {
    if (!selected.contains(updatesItem)) {
        val selectedIndex = updates.indexOf(updatesItem)
        if (selected.isEmpty()) {
            selected.add(updatesItem)
            selectedPositions[0] = selectedIndex
            selectedPositions[1] = selectedIndex
            return true
        }

        // Try to select the items in-between when possible
        val range: IntRange
        if (selectedIndex < selectedPositions[0]) {
            range = selectedIndex until selectedPositions[0]
            selectedPositions[0] = selectedIndex
        } else if (selectedIndex > selectedPositions[1]) {
            range = (selectedPositions[1] + 1)..selectedIndex
            selectedPositions[1] = selectedIndex
        } else {
            // Just select itself
            range = selectedIndex..selectedIndex
        }

        range.forEach {
            val toAdd = updates[it]
            if (!selected.contains(toAdd)) {
                selected.add(toAdd)
            }
        }
        return true
    }
    return false
}

private fun onUpdatesItemClick(
    updatesItem: UpdatesUiModel.Item,
    selected: MutableList<UpdatesUiModel.Item>,
    updates: List<UpdatesUiModel.Item>,
    selectedPositions: Array<Int>,
    onUpdateClicked: (UpdatesItem) -> Unit,
) {
    val selectedIndex = updates.indexOf(updatesItem)
    when {
        selected.contains(updatesItem) -> {
            val removedIndex = updates.indexOf(updatesItem)
            selected.remove(updatesItem)

            if (removedIndex == selectedPositions[0]) {
                selectedPositions[0] = updates.indexOfFirst { selected.contains(it) }
            } else if (removedIndex == selectedPositions[1]) {
                selectedPositions[1] = updates.indexOfLast { selected.contains(it) }
            }
        }
        selected.isNotEmpty() -> {
            if (selectedIndex < selectedPositions[0]) {
                selectedPositions[0] = selectedIndex
            } else if (selectedIndex > selectedPositions[1]) {
                selectedPositions[1] = selectedIndex
            }
            selected.add(updatesItem)
        }
        else -> onUpdateClicked(updatesItem.item)
    }
}