package com.bitcointxoko.gudariwallet

import android.Manifest
import android.content.ActivityNotFoundException
import android.content.Intent
import android.net.Uri
import android.os.Build
import android.os.Bundle
import android.os.PowerManager
import android.provider.Settings
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.activity.result.contract.ActivityResultContracts
import androidx.activity.viewModels
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.app.AppCompatActivity
import androidx.compose.runtime.*
import androidx.core.content.edit
import androidx.core.net.toUri
import com.bitcointxoko.gudariwallet.security.EncryptedSecretStore
import com.bitcointxoko.gudariwallet.service.WalletNotificationService
import com.bitcointxoko.gudariwallet.ui.OnboardingScreen
import com.bitcointxoko.gudariwallet.ui.WalletScreen
import com.bitcointxoko.gudariwallet.ui.WalletViewModel
import com.bitcointxoko.gudariwallet.ui.WalletViewModelFactory
import com.bitcointxoko.gudariwallet.ui.theme.GudariWalletTheme
import com.bitcointxoko.gudariwallet.util.NotificationHelper
import com.bitcointxoko.gudariwallet.util.IntentUtils
import kotlinx.coroutines.flow.MutableSharedFlow

class MainActivity : AppCompatActivity() {

    private lateinit var secretStore: EncryptedSecretStore

    private val vm: WalletViewModel by viewModels {
        WalletViewModelFactory(application)
    }

    // Holds a paymentHash that arrived via notification tap.
    // WalletScreen observes this and navigates to the detail screen.
    // MutableState so Compose recomposes when it changes.
    private val pendingPaymentHash = mutableStateOf<String?>(null)

    // Holds a payment URI that arrived via deep link / intent (BTCPay, external apps).
    private val pendingPaymentUri  = mutableStateOf<String?>(null)

    private val requestNotificationPermission =
        registerForActivityResult(ActivityResultContracts.RequestPermission()) { /* informational */ }

    // Broadcasts window focus gains to any observer in the composition
    val windowFocusEvents = MutableSharedFlow<Unit>(extraBufferCapacity = 1)

    override fun onWindowFocusChanged(hasFocus: Boolean) {
        super.onWindowFocusChanged(hasFocus)
        if (hasFocus) windowFocusEvents.tryEmit(Unit)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        secretStore = EncryptedSecretStore(applicationContext)

        // Must be first — before any notification is posted
        NotificationHelper.createChannels(applicationContext)

        // Read hash from the intent that launched the activity (cold start from notification)
        pendingPaymentHash.value = intent.getStringExtra(NotificationHelper.EXTRA_PAYMENT_HASH)
        // Read payment URI from the intent that launched the activity (cold start from deep link)
        pendingPaymentUri.value = IntentUtils.extractPaymentUri(intent)

        enableEdgeToEdge()

        setContent {
            GudariWalletTheme {
                var isOnboarded by remember { mutableStateOf(secretStore.isOnboarded) }

                if (isOnboarded) {
                    LaunchedEffect(Unit) {
                        WalletNotificationService.start(this@MainActivity)
                        requestNotificationPermissionIfNeeded()
                        promptBatteryOptimizationIfNeeded()
                    }
                    // Pass pendingPaymentHash so WalletScreen can consume it
                    WalletScreen(
                        vm                  = vm,
                        pendingPaymentHash  = pendingPaymentHash,
                        pendingPaymentUri  = pendingPaymentUri
                    )
                } else {
                    OnboardingScreen(
                        secretStore = secretStore,
                        onComplete  = { isOnboarded = true }
                    )
                }
            }
        }
    }

    // Called when the activity is already running and a notification is tapped
    // (FLAG_ACTIVITY_SINGLE_TOP prevents a new instance being created)
    override fun onNewIntent(intent: Intent) {
        super.onNewIntent(intent)
        setIntent(intent)
        val hash = intent.getStringExtra(NotificationHelper.EXTRA_PAYMENT_HASH)
        if (hash != null) {
            pendingPaymentHash.value = hash
        }
        val uri = IntentUtils.extractPaymentUri(intent)
        if (uri != null) {
            pendingPaymentUri.value = uri
        }
    }



    // ── Permission / battery helpers (unchanged) ──────────────────────────────

    private fun requestNotificationPermissionIfNeeded() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
            requestNotificationPermission.launch(Manifest.permission.POST_NOTIFICATIONS)
        }
    }

    private fun promptBatteryOptimizationIfNeeded() {
        val pm = getSystemService(POWER_SERVICE) as PowerManager
        if (pm.isIgnoringBatteryOptimizations(packageName)) return

        val prefs = getSharedPreferences("gudari_ui_prefs", MODE_PRIVATE)
        if (prefs.getBoolean("battery_opt_prompted", false)) return
        prefs.edit { putBoolean("battery_opt_prompted", true) }

        AlertDialog.Builder(this)
            .setTitle("Enable background notifications")
            .setMessage(
                "To receive payment alerts when the app is closed, allow Gudari Wallet " +
                        "to run without battery restrictions.\n\n" +
                        "Tap 'Open Settings', then select Battery → Unrestricted."
            )
            .setPositiveButton("Open Settings") { _, _ -> openBatterySettings() }
            .setNegativeButton("Not now", null)
            .show()
    }

    private fun openBatterySettings() {
        val appDetailsIntent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS).apply {
            data = "package:$packageName".toUri()
        }
        if (tryStartActivity(appDetailsIntent)) return
        tryStartActivity(Intent(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS))
    }

    private fun tryStartActivity(intent: Intent): Boolean {
        return try { startActivity(intent); true } catch (e: ActivityNotFoundException) { false }
    }
}