package com.example.ichwillheim

import androidx.activity.compose.BackHandler
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.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.text.KeyboardOptions
import androidx.compose.material3.Button
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedTextField
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
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.res.stringResource
import androidx.compose.ui.text.input.KeyboardType
import androidx.compose.ui.text.input.PasswordVisualTransformation
import androidx.compose.ui.unit.dp

const val SETTINGS_PIN = "1234"

@Composable
fun PinScreen(
    onCorrectPin: () -> Unit,
    onCancel: () -> Unit
) {
    BackHandler { onCancel() }

    var pin by remember { mutableStateOf("") }
    var error by remember { mutableStateOf(false) }

    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(32.dp),
        verticalArrangement = Arrangement.Center,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        Text(stringResource(R.string.pin_screen_title), style = MaterialTheme.typography.headlineSmall)
        Spacer(modifier = Modifier.height(24.dp))

        OutlinedTextField(
            value = pin,
            onValueChange = { input ->
                if (input.length <= 4 && input.all { it.isDigit() }) {
                    pin = input
                    error = false
                }
            },
            label = { Text(stringResource(R.string.field_pin)) },
            visualTransformation = PasswordVisualTransformation(),
            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.NumberPassword),
            isError = error,
            supportingText = { if (error) Text(stringResource(R.string.pin_error_incorrect)) }
        )

        Spacer(modifier = Modifier.height(24.dp))

        Row {
            TextButton(onClick = onCancel) { Text(stringResource(R.string.action_cancel)) }
            Spacer(modifier = Modifier.width(16.dp))
            Button(onClick = {
                if (pin == SETTINGS_PIN) {
                    onCorrectPin()
                } else {
                    error = true
                    pin = ""
                }
            }) {
                Text(stringResource(R.string.action_confirm))
            }
        }
    }
}