tv-controller-android/app/src/main/java/com/example/tvcontroller/services/BluetoothService.kt

package com.example.tvcontroller.services

import android.bluetooth.BluetoothAdapter
import android.bluetooth.BluetoothManager
import android.content.Context
import android.content.Intent
import android.content.BroadcastReceiver
import android.content.IntentFilter
import android.content.pm.PackageManager
import android.os.Build
import android.util.Log
import androidx.core.content.ContextCompat.getSystemService
import com.example.tvcontroller.data.BluetoothDevice
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.StateFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.flow.update

class BluetoothService(private val context: Context) {
    private var bluetoothManager: BluetoothManager =
        getSystemService(context, BluetoothManager::class.java)!!;
    private var bluetoothAdapter: BluetoothAdapter = bluetoothManager.adapter
    private var bluetoothStateChangedCallbacks: MutableList<(Int) -> Unit> = mutableListOf()
    private val _scannedDevices = MutableStateFlow<List<BluetoothDevice>>(emptyList())
    var scannedDevices: StateFlow<List<BluetoothDevice>> = _scannedDevices.asStateFlow()
    private val _pairedDevices = MutableStateFlow<List<BluetoothDevice>>(emptyList())
    var pairedDevices: StateFlow<List<BluetoothDevice>> = _pairedDevices.asStateFlow()

    private var bluetoothStateReceiver: BroadcastReceiver? = object : BroadcastReceiver() {
        override fun onReceive(context: Context, intent: Intent) {
            val state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR)
            bluetoothStateChangedCallbacks.forEach { it(state) }
        }
    }
    private var foundDeviceReceiver: BroadcastReceiver? = object : BroadcastReceiver() {
        override fun onReceive(context: Context, intent: Intent) {
            val device = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
                intent.getParcelableExtra(
                    android.bluetooth.BluetoothDevice.EXTRA_DEVICE,
                    android.bluetooth.BluetoothDevice::class.java
                )
            } else {
                intent.getParcelableExtra(android.bluetooth.BluetoothDevice.EXTRA_DEVICE)
            }
            if (device != null) {
                val newDevice = BluetoothDevice.fromBluetoothDevice(device)
                Log.i("BluetoothService", "Found device: $newDevice")
                _scannedDevices.update { devices -> if (newDevice in devices) devices else devices + newDevice }
            }
        }
    }

    init {
        registerBluetoothStateReceiver()
        updatePairedDevices()
    }

    fun isBluetoothEnabled(): Boolean {
        return bluetoothAdapter.isEnabled ?: false
    }

    private fun registerBluetoothStateReceiver() {
        context.registerReceiver(
            bluetoothStateReceiver, IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED)
        )
    }

    fun onBluetoothStateChanged(callback: (Int) -> Unit) {
        bluetoothStateChangedCallbacks.add(callback)
    }

    fun offBluetoothStateChanged(callback: (Int) -> Unit) {
        bluetoothStateChangedCallbacks.remove(callback)
    }

    fun cleanUp() {
        context.unregisterReceiver(bluetoothStateReceiver)
        context.unregisterReceiver(foundDeviceReceiver)
    }

    fun updatePairedDevices() {
        try {
            _pairedDevices.update {
                bluetoothAdapter.bondedDevices.toList()
                    .map { device -> BluetoothDevice.fromBluetoothDevice(device) }
            }
        } catch (e: SecurityException) {
            println("Error updating paired devices: $e")
        }
    }

    fun startDiscovery() {
        try {
            if (bluetoothAdapter.isDiscovering) return

            Log.i("BluetoothService", "Starting discovery")
            context.registerReceiver(
                foundDeviceReceiver,
                IntentFilter(android.bluetooth.BluetoothDevice.ACTION_FOUND)
            )
            updatePairedDevices()
            bluetoothAdapter.startDiscovery()
        } catch (e: SecurityException) {
            println("Error starting discovery: $e")
            Log.e("BluetoothService", "Error starting discovery: $e")
        }
    }

    fun stopDiscovery() {
        context.unregisterReceiver(foundDeviceReceiver)
        try {
            bluetoothAdapter.cancelDiscovery()
        } catch (e: SecurityException) {
            println("Error stopping discovery: $e")
        }
    }

    fun hasRequiredPermissions(): Boolean {
        return BLUETOOTH_PERMISSIONS.all {
            context.checkSelfPermission(it) == PackageManager.PERMISSION_GRANTED
        }
    }

    fun getBluetoothState(): Int {
        return bluetoothAdapter.state
    }

    companion object {
        val BLUETOOTH_PERMISSIONS = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            arrayOf(
                android.Manifest.permission.BLUETOOTH,
                android.Manifest.permission.BLUETOOTH_CONNECT,
                android.Manifest.permission.BLUETOOTH_SCAN,
                android.Manifest.permission.BLUETOOTH_ADMIN
            )
        } else {
            arrayOf(
                android.Manifest.permission.BLUETOOTH,
                android.Manifest.permission.BLUETOOTH_ADMIN
            )
        }
    }
}