/*
 * Copyright (c) 2025 Element Creations Ltd.
 * Copyright 2023-2025 New Vector Ltd.
 *
 * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
 * Please see LICENSE files in the repository root for full details.
 */

package id.databisnis.android.bachot.features.home.impl.components

import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.WindowInsets
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.statusBarsPadding
import androidx.compose.foundation.pager.VerticalPager
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.material3.TopAppBarScrollBehavior
import androidx.compose.material3.rememberTopAppBarState
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.derivedStateOf
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.setValue
import androidx.compose.runtime.snapshotFlow
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.semantics.heading
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import id.databisnis.android.bachot.appconfig.RoomListConfig
import id.databisnis.android.bachot.compound.theme.ElementTheme
import id.databisnis.android.bachot.compound.tokens.generated.CompoundIcons
import id.databisnis.android.bachot.features.home.impl.R
import id.databisnis.android.bachot.features.home.impl.filters.RoomListFiltersState
import id.databisnis.android.bachot.features.home.impl.filters.RoomListFiltersView
import id.databisnis.android.bachot.features.home.impl.filters.aRoomListFiltersState
import id.databisnis.android.bachot.libraries.designsystem.atomic.atoms.RedIndicatorAtom
import id.databisnis.android.bachot.libraries.designsystem.components.TopAppBarScrollBehaviorLayout
import id.databisnis.android.bachot.libraries.designsystem.components.avatar.Avatar
import id.databisnis.android.bachot.libraries.designsystem.components.avatar.AvatarSize
import id.databisnis.android.bachot.libraries.designsystem.components.avatar.AvatarType
import id.databisnis.android.bachot.libraries.designsystem.modifiers.backgroundVerticalGradient
import id.databisnis.android.bachot.libraries.designsystem.preview.ElementPreview
import id.databisnis.android.bachot.libraries.designsystem.preview.PreviewsDayNight
import id.databisnis.android.bachot.libraries.designsystem.theme.aliasScreenTitle
import id.databisnis.android.bachot.libraries.designsystem.theme.components.DropdownMenu
import id.databisnis.android.bachot.libraries.designsystem.theme.components.DropdownMenuItem
import id.databisnis.android.bachot.libraries.designsystem.theme.components.Icon
import id.databisnis.android.bachot.libraries.designsystem.theme.components.IconButton
import id.databisnis.android.bachot.libraries.designsystem.theme.components.Text
import id.databisnis.android.bachot.libraries.designsystem.theme.components.TopAppBar
import id.databisnis.android.bachot.libraries.matrix.api.core.SessionId
import id.databisnis.android.bachot.libraries.matrix.api.core.UserId
import id.databisnis.android.bachot.libraries.matrix.api.user.MatrixUser
import id.databisnis.android.bachot.libraries.matrix.ui.components.aMatrixUserList
import id.databisnis.android.bachot.libraries.matrix.ui.model.getAvatarData
import id.databisnis.android.bachot.libraries.testtags.TestTags
import id.databisnis.android.bachot.libraries.testtags.testTag
import id.databisnis.android.bachot.libraries.ui.strings.CommonStrings
import kotlinx.collections.immutable.ImmutableList
import kotlinx.collections.immutable.persistentListOf
import kotlinx.collections.immutable.toImmutableList

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun HomeTopBar(
    title: String,
    currentUserAndNeighbors: ImmutableList<MatrixUser>,
    showAvatarIndicator: Boolean,
    areSearchResultsDisplayed: Boolean,
    onToggleSearch: () -> Unit,
    onMenuActionClick: (RoomListMenuAction) -> Unit,
    onOpenSettings: () -> Unit,
    onAccountSwitch: (SessionId) -> Unit,
    scrollBehavior: TopAppBarScrollBehavior,
    displayMenuItems: Boolean,
    canReportBug: Boolean,
    displayFilters: Boolean,
    filtersState: RoomListFiltersState,
    modifier: Modifier = Modifier,
) {
    Column(modifier) {
        TopAppBar(
            modifier = Modifier
                .backgroundVerticalGradient(
                    isVisible = !areSearchResultsDisplayed,
                )
                .statusBarsPadding(),
            colors = TopAppBarDefaults.topAppBarColors(
                containerColor = Color.Transparent,
                scrolledContainerColor = Color.Transparent,
            ),
            title = {
                Text(
                    modifier = Modifier.semantics {
                        heading()
                    },
                    style = ElementTheme.typography.aliasScreenTitle,
                    text = title,
                )
            },
            navigationIcon = {
                NavigationIcon(
                    currentUserAndNeighbors = currentUserAndNeighbors,
                    showAvatarIndicator = showAvatarIndicator,
                    onAccountSwitch = onAccountSwitch,
                    onClick = onOpenSettings,
                )
            },
            actions = {
                if (displayMenuItems) {
                    IconButton(
                        onClick = onToggleSearch,
                    ) {
                        Icon(
                            imageVector = CompoundIcons.Search(),
                            contentDescription = stringResource(CommonStrings.action_search),
                        )
                    }
                    if (RoomListConfig.HAS_DROP_DOWN_MENU) {
                        var showMenu by remember { mutableStateOf(false) }
                        IconButton(
                            onClick = { showMenu = !showMenu }
                        ) {
                            Icon(
                                imageVector = CompoundIcons.OverflowVertical(),
                                contentDescription = null,
                            )
                        }
                        DropdownMenu(
                            expanded = showMenu,
                            onDismissRequest = { showMenu = false }
                        ) {
                            if (RoomListConfig.SHOW_INVITE_MENU_ITEM) {
                                DropdownMenuItem(
                                    onClick = {
                                        showMenu = false
                                        onMenuActionClick(RoomListMenuAction.InviteFriends)
                                    },
                                    text = { Text(stringResource(id = CommonStrings.action_invite)) },
                                    leadingIcon = {
                                        Icon(
                                            imageVector = CompoundIcons.ShareAndroid(),
                                            tint = ElementTheme.colors.iconSecondary,
                                            contentDescription = null,
                                        )
                                    }
                                )
                            }
                            if (RoomListConfig.SHOW_REPORT_PROBLEM_MENU_ITEM && canReportBug) {
                                DropdownMenuItem(
                                    onClick = {
                                        showMenu = false
                                        onMenuActionClick(RoomListMenuAction.ReportBug)
                                    },
                                    text = { Text(stringResource(id = CommonStrings.common_report_a_problem)) },
                                    leadingIcon = {
                                        Icon(
                                            imageVector = CompoundIcons.ChatProblem(),
                                            tint = ElementTheme.colors.iconSecondary,
                                            contentDescription = null,
                                        )
                                    }
                                )
                            }
                        }
                    }
                }
            },
            // We want a 16dp left padding for the navigationIcon :
            // 4dp from default TopAppBarHorizontalPadding
            // 8dp from AccountIcon default padding (because of IconButton)
            // 4dp extra padding using left insets
            windowInsets = WindowInsets(left = 4.dp),
        )
        if (displayFilters) {
            TopAppBarScrollBehaviorLayout(scrollBehavior = scrollBehavior) {
                RoomListFiltersView(
                    state = filtersState,
                    modifier = Modifier.padding(bottom = 16.dp)
                )
            }
        }
    }
}

@Composable
private fun NavigationIcon(
    currentUserAndNeighbors: ImmutableList<MatrixUser>,
    showAvatarIndicator: Boolean,
    onAccountSwitch: (SessionId) -> Unit,
    onClick: () -> Unit,
) {
    if (currentUserAndNeighbors.size == 1) {
        AccountIcon(
            matrixUser = currentUserAndNeighbors.single(),
            isCurrentAccount = true,
            showAvatarIndicator = showAvatarIndicator,
            onClick = onClick,
        )
    } else {
        // Render a vertical pager
        val pagerState = rememberPagerState(initialPage = 1) { currentUserAndNeighbors.size }
        // Listen to page changes and switch account if needed
        val latestOnAccountSwitch by rememberUpdatedState(onAccountSwitch)
        LaunchedEffect(pagerState) {
            snapshotFlow { pagerState.settledPage }.collect { page ->
                latestOnAccountSwitch(SessionId(currentUserAndNeighbors[page].userId.value))
            }
        }
        VerticalPager(
            state = pagerState,
            modifier = Modifier.height(48.dp),
        ) { page ->
            AccountIcon(
                matrixUser = currentUserAndNeighbors[page],
                isCurrentAccount = page == 1,
                showAvatarIndicator = page == 1 && showAvatarIndicator,
                onClick = if (page == 1) {
                    onClick
                } else {
                    {}
                },
            )
        }
    }
}

@Composable
private fun AccountIcon(
    matrixUser: MatrixUser,
    isCurrentAccount: Boolean,
    showAvatarIndicator: Boolean,
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
) {
    val testTag = if (isCurrentAccount) Modifier.testTag(TestTags.homeScreenSettings) else Modifier
    IconButton(
        modifier = modifier.then(testTag),
        onClick = onClick,
    ) {
        Box {
            val avatarData by remember(matrixUser) {
                derivedStateOf {
                    matrixUser.getAvatarData(size = AvatarSize.CurrentUserTopBar)
                }
            }
            Avatar(
                avatarData = avatarData,
                avatarType = AvatarType.User,
                contentDescription = if (isCurrentAccount) stringResource(CommonStrings.common_settings) else null,
            )
            if (showAvatarIndicator) {
                RedIndicatorAtom(
                    modifier = Modifier.align(Alignment.TopEnd)
                )
            }
        }
    }
}

@OptIn(ExperimentalMaterial3Api::class)
@PreviewsDayNight
@Composable
internal fun HomeTopBarPreview() = ElementPreview {
    HomeTopBar(
        title = stringResource(R.string.screen_roomlist_main_space_title),
        currentUserAndNeighbors = persistentListOf(MatrixUser(UserId("@id:domain"), "Alice")),
        showAvatarIndicator = false,
        areSearchResultsDisplayed = false,
        scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState()),
        onOpenSettings = {},
        onAccountSwitch = {},
        onToggleSearch = {},
        displayMenuItems = true,
        canReportBug = true,
        displayFilters = true,
        filtersState = aRoomListFiltersState(),
        onMenuActionClick = {},
    )
}

@OptIn(ExperimentalMaterial3Api::class)
@PreviewsDayNight
@Composable
internal fun HomeTopBarWithIndicatorPreview() = ElementPreview {
    HomeTopBar(
        title = stringResource(R.string.screen_roomlist_main_space_title),
        currentUserAndNeighbors = persistentListOf(MatrixUser(UserId("@id:domain"), "Alice")),
        showAvatarIndicator = true,
        areSearchResultsDisplayed = false,
        scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState()),
        onOpenSettings = {},
        onAccountSwitch = {},
        onToggleSearch = {},
        displayMenuItems = true,
        canReportBug = true,
        displayFilters = true,
        filtersState = aRoomListFiltersState(),
        onMenuActionClick = {},
    )
}

@OptIn(ExperimentalMaterial3Api::class)
@PreviewsDayNight
@Composable
internal fun HomeTopBarMultiAccountPreview() = ElementPreview {
    HomeTopBar(
        title = stringResource(R.string.screen_roomlist_main_space_title),
        currentUserAndNeighbors = aMatrixUserList().take(3).toImmutableList(),
        showAvatarIndicator = false,
        areSearchResultsDisplayed = false,
        scrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(rememberTopAppBarState()),
        onOpenSettings = {},
        onAccountSwitch = {},
        onToggleSearch = {},
        displayMenuItems = true,
        canReportBug = true,
        displayFilters = true,
        filtersState = aRoomListFiltersState(),
        onMenuActionClick = {},
    )
}
