SyncFlow/app/src/main/kotlin/com/syncflow/MainActivity.kt

package com.syncflow

import android.os.Build
import android.os.Bundle
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.biometric.BiometricManager
import androidx.biometric.BiometricManager.Authenticators.BIOMETRIC_STRONG
import androidx.biometric.BiometricManager.Authenticators.DEVICE_CREDENTIAL
import androidx.biometric.BiometricPrompt
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.material3.CircularProgressIndicator
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.runtime.*
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.core.content.ContextCompat
import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
import androidx.lifecycle.lifecycleScope
import androidx.navigation.compose.rememberNavController
import com.syncflow.data.preferences.AppPreferences
import com.syncflow.ui.navigation.SyncFlowNavGraph
import com.syncflow.ui.theme.SyncFlowTheme
import dagger.hilt.android.AndroidEntryPoint
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.launch
import javax.inject.Inject

@AndroidEntryPoint
class MainActivity : AppCompatActivity() {

    @Inject lateinit var appPreferences: AppPreferences

    private var isLocked by mutableStateOf(false)

    override fun onCreate(savedInstanceState: Bundle?) {
        installSplashScreen()
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContent {
            SyncFlowTheme {
                Surface(modifier = Modifier.fillMaxSize()) {
                    SyncFlowNavGraph(rememberNavController())
                }
                if (isLocked) {
                    LockOverlay()
                    LaunchedEffect(Unit) {
                        showBiometricPrompt(onSuccess = { isLocked = false })
                    }
                }
            }
        }
    }

    override fun onStop() {
        super.onStop()
        if (isChangingConfigurations) return
        lifecycleScope.launch {
            if (appPreferences.biometricLockEnabled.first() && canAuthenticate()) {
                isLocked = true
            }
        }
    }

    private fun canAuthenticate(): Boolean {
        val authenticators = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R)
            BIOMETRIC_STRONG or DEVICE_CREDENTIAL
        else
            BIOMETRIC_STRONG
        return BiometricManager.from(this).canAuthenticate(authenticators) ==
            BiometricManager.BIOMETRIC_SUCCESS
    }

    private fun showBiometricPrompt(onSuccess: () -> Unit) {
        val executor = ContextCompat.getMainExecutor(this)
        val prompt = BiometricPrompt(this, executor, object : BiometricPrompt.AuthenticationCallback() {
            override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult) {
                onSuccess()
            }
        })
        val promptInfo = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
            BiometricPrompt.PromptInfo.Builder()
                .setTitle("Unlock SyncFlow")
                .setSubtitle("Confirm your identity to continue")
                .setAllowedAuthenticators(BIOMETRIC_STRONG or DEVICE_CREDENTIAL)
                .build()
        } else {
            BiometricPrompt.PromptInfo.Builder()
                .setTitle("Unlock SyncFlow")
                .setSubtitle("Confirm your identity to continue")
                .setNegativeButtonText("Cancel")
                .build()
        }
        prompt.authenticate(promptInfo)
    }
}

@Composable
private fun LockOverlay() {
    Box(
        modifier = Modifier
            .fillMaxSize()
            .background(MaterialTheme.colorScheme.background),
        contentAlignment = Alignment.Center,
    ) {
        CircularProgressIndicator()
    }
}