package io.oxygenhub.android.ui.dashboard

import androidx.compose.foundation.clickable

import androidx.compose.foundation.layout.Arrangement

import androidx.compose.foundation.layout.BoxWithConstraints

import androidx.compose.foundation.layout.Column

import androidx.compose.foundation.layout.Row

import androidx.compose.foundation.layout.Spacer

import androidx.compose.foundation.layout.fillMaxWidth

import androidx.compose.foundation.layout.height

import androidx.compose.foundation.layout.padding

import androidx.compose.foundation.rememberScrollState

import androidx.compose.foundation.verticalScroll

import androidx.compose.material.icons.Icons

import androidx.compose.material.icons.outlined.Inbox

import androidx.compose.material.icons.outlined.MarkEmailUnread

import androidx.compose.material3.Card

import androidx.compose.material3.HorizontalDivider

import androidx.compose.material3.Icon

import androidx.compose.material3.ListItem

import androidx.compose.material3.MaterialTheme

import androidx.compose.material3.Text

import androidx.compose.material3.TextButton

import androidx.compose.runtime.Composable

import androidx.compose.runtime.getValue

import androidx.compose.ui.Modifier

import androidx.compose.ui.text.font.FontWeight

import androidx.compose.ui.unit.dp

import androidx.lifecycle.compose.collectAsStateWithLifecycle

import io.oxygenhub.android.api.Inbox

import io.oxygenhub.android.api.Repository

import io.oxygenhub.android.ui.common.AppScreen

import io.oxygenhub.android.ui.common.Load

import io.oxygenhub.android.ui.common.LoadContent

import io.oxygenhub.android.ui.repos.RepositoryRow

@Composable

fun DashboardScreen(

    vm: DashboardViewModel,

    hub: String,

    inbox: Load<Inbox>,

    onRefreshInbox: () -> Unit,

    onOpenRepository: (Repository) -> Unit,

    onAllRepositories: () -> Unit,

    onInbox: () -> Unit,

) {

    val state by vm.state.collectAsStateWithLifecycle()

    AppScreen(title = "Dashboard", subtitle = hub.substringAfter("://")) {

        LoadContent(state, onRefresh = { vm.refresh(); onRefreshInbox() }) { d ->

            DashboardContent(d, inbox, onOpenRepository, onAllRepositories, onInbox)

        }

    }

}

@Composable

fun DashboardContent(

    d: Dashboard,

    inbox: Load<Inbox>,

    onOpenRepository: (Repository) -> Unit,

    onAllRepositories: () -> Unit,

    onInbox: () -> Unit,

) {

    BoxWithConstraints {

        // Side by side once there is room (a tablet, or a foldable open).

        val wide = maxWidth >= 720.dp

        Column(

            Modifier

                .fillMaxWidth()

                .verticalScroll(rememberScrollState())

                .padding(16.dp),

        ) {

            Text(d.greeting, style = MaterialTheme.typography.headlineMedium, fontWeight = FontWeight.Bold)

            Spacer(Modifier.height(16.dp))

            if (wide) {

                Row(horizontalArrangement = Arrangement.spacedBy(16.dp)) {

                    Column(Modifier.weight(2f)) { Recent(d, onOpenRepository, onAllRepositories) }

                    Column(Modifier.weight(1f)) { Unread(inbox, onInbox) }

                }

            } else {

                Unread(inbox, onInbox)

                Spacer(Modifier.height(16.dp))

                Recent(d, onOpenRepository, onAllRepositories)

            }

        }

    }

}

@Composable

private fun Unread(inbox: Load<Inbox>, onInbox: () -> Unit) {

    Card(Modifier.fillMaxWidth().clickable(onClick = onInbox)) {

        ListItem(

            leadingContent = {

                Icon(if ((inbox.valueOrNull?.unread ?: 0) > 0) Icons.Outlined.MarkEmailUnread else Icons.Outlined.Inbox, contentDescription = null)

            },

            headlineContent = {

                Text(

                    when (inbox) {

                        Load.Loading -> "Inbox"

                        is Load.Failed -> "Inbox unavailable"

                        is Load.Ready -> when (val n = inbox.value.unread) {

                            0L -> "Nothing unread"

                            1L -> "1 unread notification"

                            else -> "$n unread notifications"

                        }

                    },

                )

            },

            supportingContent = (inbox as? Load.Failed)?.let { f -> { Text(f.message) } },

        )

    }

}

@Composable

private fun Recent(d: Dashboard, onOpenRepository: (Repository) -> Unit, onAllRepositories: () -> Unit) {

    Card(Modifier.fillMaxWidth()) {

        Text(

            if (d.recentAreYours) "Your recent repositories" else "Recently updated on the hub",

            style = MaterialTheme.typography.titleMedium,

            modifier = Modifier.padding(start = 16.dp, top = 16.dp, end = 16.dp),

        )

        if (!d.recentAreYours) {

            Text(

                "You have no repositories of your own yet.",

                style = MaterialTheme.typography.bodySmall,

                color = MaterialTheme.colorScheme.onSurfaceVariant,

                modifier = Modifier.padding(horizontal = 16.dp),

            )

        }

        if (d.recent.isEmpty()) {

            Text("No repositories to show.", modifier = Modifier.padding(16.dp))

        }

        d.recent.forEachIndexed { i, repo ->

            if (i > 0) HorizontalDivider()

            RepositoryRow(repo, onClick = { onOpenRepository(repo) })

        }

        TextButton(onClick = onAllRepositories, modifier = Modifier.padding(8.dp)) { Text("All repositories") }

    }

}