package ch.ergon.anytask.ui

import androidx.compose.foundation.layout.Arrangement
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.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.material.Button
import androidx.compose.material.CircularProgressIndicator
import androidx.compose.material.MaterialTheme
import androidx.compose.material.OutlinedTextField
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.material.TextButton
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.rememberCoroutineScope
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.focus.FocusRequester
import androidx.compose.ui.focus.focusRequester
import androidx.compose.ui.input.key.Key
import androidx.compose.ui.input.key.KeyEventType
import androidx.compose.ui.input.key.isMetaPressed
import androidx.compose.ui.input.key.key
import androidx.compose.ui.input.key.onPreviewKeyEvent
import androidx.compose.ui.input.key.type
import androidx.compose.ui.unit.dp
import ch.ergon.anytask.api.AnyTypeApi
import kotlinx.coroutines.launch

@Composable
fun TaskWindow(client: AnyTypeApi, isVisible: Boolean, onDismiss: () -> Unit) {
    val scope = rememberCoroutineScope()
    var title by remember { mutableStateOf("") }
    var details by remember { mutableStateOf("") }
    var isLoading by remember { mutableStateOf(false) }
    var errorMessage by remember { mutableStateOf<String?>(null) }

    val focusRequester = remember { FocusRequester() }

    fun submit() {
        if (title.isBlank()) return
        scope.launch {
            isLoading = true
            errorMessage = null
            client.createTask(title = title.trim(), details = details.trim())
                .onSuccess {
                    title = ""
                    details = ""
                    onDismiss()
                }
                .onFailure { errorMessage = it.message }
            isLoading = false
        }
    }

    MaterialTheme {
        Surface(modifier = Modifier.fillMaxSize()) {
            Column(
                modifier = Modifier
                    .fillMaxSize()
                    .padding(24.dp)
                    .onPreviewKeyEvent { event ->
                        when {
                            event.type == KeyEventType.KeyDown && event.key == Key.Escape -> {
                                onDismiss(); true
                            }
                            event.type == KeyEventType.KeyDown &&
                                event.key == Key.Enter &&
                                event.isMetaPressed -> {
                                submit(); true
                            }
                            else -> false
                        }
                    },
            ) {
                Text("New Task", style = MaterialTheme.typography.h6)
                Spacer(modifier = Modifier.height(16.dp))

                OutlinedTextField(
                    value = title,
                    onValueChange = { title = it },
                    label = { Text("Title") },
                    singleLine = true,
                    modifier = Modifier
                        .fillMaxWidth()
                        .focusRequester(focusRequester),
                )
                Spacer(modifier = Modifier.height(12.dp))

                OutlinedTextField(
                    value = details,
                    onValueChange = { details = it },
                    label = { Text("Details (optional)") },
                    modifier = Modifier.fillMaxWidth().height(120.dp),
                    maxLines = 4,
                )

                if (errorMessage != null) {
                    Spacer(modifier = Modifier.height(8.dp))
                    Text(errorMessage!!, color = MaterialTheme.colors.error, style = MaterialTheme.typography.caption)
                }

                Spacer(modifier = Modifier.weight(1f))

                Row(
                    modifier = Modifier.fillMaxWidth(),
                    horizontalArrangement = Arrangement.spacedBy(8.dp, Alignment.End),
                ) {
                    TextButton(onClick = onDismiss) { Text("Cancel") }
                    Button(onClick = ::submit, enabled = title.isNotBlank() && !isLoading) {
                        if (isLoading) CircularProgressIndicator(modifier = Modifier.size(16.dp), strokeWidth = 2.dp)
                        else Text("Create  ⌘↵")
                    }
                }
            }
        }
    }

    LaunchedEffect(isVisible) { if (isVisible) focusRequester.requestFocus() }
}