package soy.iko.opencode.ui.components

import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.size
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.automirrored.filled.ArrowBack
import androidx.compose.material3.CircularProgressIndicator
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.material3.TopAppBar
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.material3.TopAppBarScrollBehavior
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import soy.iko.opencode.R

/**
 * The app's standard top bar: a title (with optional subtitle), an optional up/back button, an
 * optional inline loading indicator, and trailing actions. Extracted so the many plain
 * back-title-actions screens share one implementation instead of hand-rolling a [TopAppBar] each.
 * Screens with a bespoke title (dropdown server switcher, clickable model picker) keep their own bar.
 */
@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AppTopBar(
    title: String,
    onBack: (() -> Unit)? = null,
    scrollBehavior: TopAppBarScrollBehavior? = null,
    subtitle: String? = null,
    loading: Boolean = false,
    actions: @Composable RowScope.() -> Unit = {},
) {
    TopAppBar(
        title = {
            if (subtitle != null) {
                Column {
                    Text(title, maxLines = 1, overflow = TextOverflow.Ellipsis)
                    Text(
                        subtitle,
                        style = MaterialTheme.typography.labelMedium,
                        color = MaterialTheme.colorScheme.onSurfaceVariant,
                        maxLines = 1,
                        overflow = TextOverflow.Ellipsis,
                    )
                }
            } else {
                Text(title, maxLines = 1, overflow = TextOverflow.Ellipsis)
            }
        },
        navigationIcon = {
            if (onBack != null) {
                IconButton(onClick = onBack) {
                    Icon(
                        Icons.AutoMirrored.Filled.ArrowBack,
                        contentDescription = stringResource(R.string.back),
                    )
                }
            }
        },
        actions = {
            if (loading) {
                Box(modifier = Modifier.size(40.dp), contentAlignment = Alignment.Center) {
                    CircularProgressIndicator(
                        Modifier.size(20.dp),
                        strokeWidth = 2.dp,
                        color = MaterialTheme.colorScheme.onSurfaceVariant,
                    )
                }
            }
            actions()
        },
        scrollBehavior = scrollBehavior,
        colors = TopAppBarDefaults.topAppBarColors(),
    )
}