package net.bluemangoo.indpjsk.ui

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.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.material3.Checkbox
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.OutlinedTextField
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.material3.TopAppBar
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
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.platform.LocalContext
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import net.bluemangoo.indpjsk.R
import net.bluemangoo.indpjsk.data.AppEntry
import net.bluemangoo.indpjsk.data.InstalledApps

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AppSelectionScreen(
    selected: Set<String>,
    onToggle: (AppEntry) -> Unit,
    onBack: () -> Unit,
) {
    val context = LocalContext.current
    var allApps by remember { mutableStateOf<List<AppEntry>>(emptyList()) }
    var loading by remember { mutableStateOf(true) }
    var query by remember { mutableStateOf("") }

    LaunchedEffect(Unit) {
        val list = withContext(Dispatchers.IO) { InstalledApps.list(context) }
        allApps = list
        loading = false
    }

    val filtered = remember(query, allApps) {
        if (query.isBlank()) {
            allApps
        } else {
            allApps.filter {
                it.label.contains(query, ignoreCase = true) ||
                    it.packageName.contains(query, ignoreCase = true)
            }
        }
    }

    Scaffold(
        topBar = {
            TopAppBar(
                title = { Text("选择忽略的应用") },
                navigationIcon = {
                    IconButton(onClick = onBack) {
                        Icon(
                            painter = painterResource(R.drawable.arrow_back_24px),
                            contentDescription = "返回"
                        )
                    }
                }
            )
        }
    ) { padding ->
        Column(
            modifier = Modifier
                .padding(padding)
                .fillMaxSize()
        ) {
            OutlinedTextField(
                value = query,
                onValueChange = { query = it },
                modifier = Modifier
                    .fillMaxWidth()
                    .padding(horizontal = 16.dp, vertical = 8.dp),
                placeholder = { Text("搜索应用名称或包名…") },
                singleLine = true
            )

            if (loading) {
                Box(
                    modifier = Modifier
                        .weight(1f)
                        .fillMaxWidth(),
                    contentAlignment = Alignment.Center
                ) {
                    CircularProgressIndicator()
                }
            } else if (filtered.isEmpty()) {
                Box(
                    modifier = Modifier
                        .weight(1f)
                        .fillMaxWidth(),
                    contentAlignment = Alignment.Center
                ) {
                    Text(
                        "没有找到相关的应用",
                        color = MaterialTheme.colorScheme.onSurfaceVariant
                    )
                }
            } else {
                LazyColumn(
                    modifier = Modifier
                        .weight(1f)
                        .fillMaxWidth()
                ) {
                    items(filtered, key = { it.packageName }) { app ->
                        val checked = app.packageName in selected
                        Row(
                            modifier = Modifier
                                .fillMaxWidth()
                                .clickable { onToggle(app) }
                                .padding(horizontal = 16.dp, vertical = 12.dp),
                            verticalAlignment = Alignment.CenterVertically
                        ) {
                            AppIcon(icon = app.icon, label = app.label)
                            Spacer(modifier = Modifier.width(16.dp))
                            Column(
                                modifier = Modifier.weight(1f),
                                verticalArrangement = Arrangement.spacedBy(2.dp)
                            ) {
                                Text(
                                    text = app.label,
                                    style = MaterialTheme.typography.bodyLarge,
                                    maxLines = 1,
                                    overflow = TextOverflow.Ellipsis
                                )
                                Text(
                                    text = app.packageName,
                                    style = MaterialTheme.typography.bodySmall,
                                    color = MaterialTheme.colorScheme.onSurfaceVariant,
                                    maxLines = 1,
                                    overflow = TextOverflow.Ellipsis
                                )
                            }
                            Checkbox(
                                checked = checked,
                                onCheckedChange = { onToggle(app) }
                            )
                        }
                    }
                }
            }
        }
    }
}