package be.mygod.vpnhotspot.manage

import android.Manifest
import android.content.ComponentName
import android.content.DialogInterface
import android.content.Intent
import android.content.ServiceConnection
import android.net.wifi.SoftApConfiguration
import android.net.wifi.p2p.WifiP2pGroup
import android.os.Build
import android.os.Bundle
import android.os.IBinder
import android.os.Parcelable
import android.text.method.LinkMovementMethod
import android.view.WindowManager
import android.widget.EditText
import androidx.annotation.MainThread
import androidx.appcompat.app.AlertDialog
import androidx.core.content.ContextCompat
import androidx.databinding.BaseObservable
import androidx.databinding.Bindable
import androidx.fragment.app.viewModels
import androidx.lifecycle.ViewModel
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.RecyclerView
import be.mygod.vpnhotspot.*
import be.mygod.vpnhotspot.databinding.ListitemRepeaterBinding
import be.mygod.vpnhotspot.net.MacAddressCompat
import be.mygod.vpnhotspot.net.wifi.P2pSupplicantConfiguration
import be.mygod.vpnhotspot.net.wifi.SoftApConfigurationCompat
import be.mygod.vpnhotspot.net.wifi.WifiApDialogFragment
import be.mygod.vpnhotspot.util.ServiceForegroundConnector
import be.mygod.vpnhotspot.util.formatAddresses
import be.mygod.vpnhotspot.util.showAllowingStateLoss
import be.mygod.vpnhotspot.widget.SmartSnackbar
import kotlinx.android.parcel.Parcelize
import kotlinx.coroutines.*
import timber.log.Timber
import java.net.NetworkInterface
import java.net.SocketException

class RepeaterManager(private val parent: TetheringFragment) : Manager(), ServiceConnection {
    class ViewHolder(val binding: ListitemRepeaterBinding) : RecyclerView.ViewHolder(binding.root) {
        init {
            binding.addresses.movementMethod = LinkMovementMethod.getInstance()
        }
    }
    inner class Data : BaseObservable() {
        val switchEnabled: Boolean
            @Bindable get() = when (binder?.service?.status) {
                RepeaterService.Status.IDLE, RepeaterService.Status.ACTIVE -> true
                else -> false
            }
        val serviceStarted: Boolean
            @Bindable get() = when (binder?.service?.status) {
                RepeaterService.Status.STARTING, RepeaterService.Status.ACTIVE -> true
                else -> false
            }

        val title: CharSequence @Bindable get() {
            if (Build.VERSION.SDK_INT >= 29) binder?.group?.frequency?.let {
                if (it != 0) return parent.getString(R.string.repeater_channel,
                        it, SoftApConfigurationCompat.frequencyToChannel(it))
            }
            return parent.getString(R.string.title_repeater)
        }
        val addresses: CharSequence @Bindable get() {
            return try {
                NetworkInterface.getByName(p2pInterface ?: return "")?.formatAddresses() ?: ""
            } catch (_: SocketException) {
                ""
            }
        }

        fun onStatusChanged() {
            notifyPropertyChanged(BR.switchEnabled)
            notifyPropertyChanged(BR.serviceStarted)
            notifyPropertyChanged(BR.addresses)
        }
        fun onGroupChanged(group: WifiP2pGroup? = null) {
            p2pInterface = group?.`interface`
            if (Build.VERSION.SDK_INT >= 29) notifyPropertyChanged(BR.title)
            notifyPropertyChanged(BR.addresses)
        }

        fun toggle() {
            val binder = binder
            when (binder?.service?.status) {
                RepeaterService.Status.IDLE -> if (Build.VERSION.SDK_INT < 29) parent.requireContext().let { context ->
                    ContextCompat.startForegroundService(context, Intent(context, RepeaterService::class.java))
                } else parent.startRepeater.launch(Manifest.permission.ACCESS_FINE_LOCATION)
                RepeaterService.Status.ACTIVE -> binder.shutdown()
                else -> { }
            }
        }

        fun wps() {
            if (binder?.active == true) WpsDialogFragment().apply {
                key()
            }.showAllowingStateLoss(parent.parentFragmentManager)
        }
    }

    @Parcelize
    data class WpsRet(val pin: String?) : Parcelable
    class WpsDialogFragment : AlertDialogFragment<Empty, WpsRet>() {
        override fun AlertDialog.Builder.prepare(listener: DialogInterface.OnClickListener) {
            setTitle(R.string.repeater_wps_dialog_title)
            setView(R.layout.dialog_wps)
            setPositiveButton(android.R.string.ok, listener)
            setNegativeButton(android.R.string.cancel, null)
            setNeutralButton(R.string.repeater_wps_dialog_pbc, listener)
        }

        override val ret get() = WpsRet(dialog!!.findViewById<EditText>(android.R.id.edit)?.text?.toString())

        override fun onCreateDialog(savedInstanceState: Bundle?) = super.onCreateDialog(savedInstanceState).apply {
            window!!.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE)
        }
    }

    class ConfigHolder : ViewModel() {
        var config: P2pSupplicantConfiguration? = null
    }

    init {
        ServiceForegroundConnector(parent, this, RepeaterService::class)
        AlertDialogFragment.setResultListener<WifiApDialogFragment.Arg>(parent, javaClass.name) { which, ret ->
            if (which == DialogInterface.BUTTON_POSITIVE) GlobalScope.launch(Dispatchers.Main.immediate) {
                updateConfiguration(ret!!.configuration)
            }
        }
        AlertDialogFragment.setResultListener<WpsDialogFragment, WpsRet>(parent) { which, ret ->
            when (which) {
                DialogInterface.BUTTON_POSITIVE -> binder!!.startWps(ret!!.pin)
                DialogInterface.BUTTON_NEUTRAL -> binder!!.startWps(null)
            }
        }
    }

    private var configuring = false
    fun configure() {
        if (configuring) return
        configuring = true
        parent.viewLifecycleOwner.lifecycleScope.launchWhenCreated {
            getConfiguration()?.let { (config, readOnly) ->
                WifiApDialogFragment().apply {
                    arg(WifiApDialogFragment.Arg(config, readOnly, true))
                    key(this@RepeaterManager.javaClass.name)
                }.showAllowingStateLoss(parent.parentFragmentManager)
            }
            configuring = false
        }
    }

    override val type get() = VIEW_TYPE_REPEATER
    private val data = Data()
    internal var binder: RepeaterService.Binder? = null
    private var p2pInterface: String? = null
    private val holder by parent.viewModels<ConfigHolder>()

    override fun bindTo(viewHolder: RecyclerView.ViewHolder) {
        (viewHolder as ViewHolder).binding.data = data
    }

    override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
        binder = service as RepeaterService.Binder
        service.statusChanged[this] = data::onStatusChanged
        service.groupChanged[this] = data::onGroupChanged
        data.notifyChange()
    }

    override fun onServiceDisconnected(name: ComponentName?) {
        val binder = binder ?: return
        this.binder = null
        binder.statusChanged -= this
        binder.groupChanged -= this
        data.onStatusChanged()
    }

    @MainThread
    private suspend fun getConfiguration(): Pair<SoftApConfigurationCompat, Boolean>? {
        if (RepeaterService.safeMode) {
            val networkName = RepeaterService.networkName
            val passphrase = RepeaterService.passphrase
            if (networkName != null && passphrase != null) {
                return SoftApConfigurationCompat(
                        ssid = networkName,
                        passphrase = passphrase,
                        band = RepeaterService.operatingBand,
                        channel = RepeaterService.operatingChannel,
                        securityType = SoftApConfiguration.SECURITY_TYPE_WPA2_PSK,  // is not actually used
                        isAutoShutdownEnabled = RepeaterService.isAutoShutdownEnabled,
                        shutdownTimeoutMillis = RepeaterService.shutdownTimeoutMillis).apply {
                    bssid = RepeaterService.deviceAddress
                } to false
            }
        } else binder?.let { binder ->
            val group = binder.group ?: binder.fetchPersistentGroup().let { binder.group }
            if (group != null) return SoftApConfigurationCompat(
                    ssid = group.networkName,
                    channel = RepeaterService.operatingChannel,
                    band = SoftApConfigurationCompat.BAND_ANY,
                    securityType = SoftApConfiguration.SECURITY_TYPE_WPA2_PSK,  // is not actually used
                    isAutoShutdownEnabled = RepeaterService.isAutoShutdownEnabled,
                    shutdownTimeoutMillis = RepeaterService.shutdownTimeoutMillis).run {
                try {
                    val config = P2pSupplicantConfiguration(group)
                    config.init(binder.obtainDeviceAddress()?.toString())
                    holder.config = config
                    passphrase = config.psk
                    bssid = config.bssid
                    this to false
                } catch (e: Exception) {
                    if (e !is CancellationException) Timber.w(e)
                    passphrase = group.passphrase
                    bssid = group.owner?.deviceAddress?.let(MacAddressCompat.Companion::fromString)
                    this to true
                }
            }
        }
        SmartSnackbar.make(R.string.repeater_configure_failure).show()
        return null
    }
    private suspend fun updateConfiguration(config: SoftApConfigurationCompat) {
        if (RepeaterService.safeMode) {
            RepeaterService.networkName = config.ssid
            RepeaterService.deviceAddress = config.bssid
            RepeaterService.passphrase = config.passphrase
        } else holder.config?.let { master ->
            val binder = binder
            if (binder?.group?.networkName != config.ssid || master.psk != config.passphrase ||
                    master.bssid != config.bssid) try {
                withContext(Dispatchers.Default) { master.update(config.ssid!!, config.passphrase!!, config.bssid) }
                (this.binder ?: binder)?.group = null
            } catch (e: Exception) {
                Timber.w(e)
                SmartSnackbar.make(e).show()
            }
            holder.config = null
        }
        RepeaterService.operatingBand = config.band
        RepeaterService.operatingChannel = config.channel
        RepeaterService.isAutoShutdownEnabled = config.isAutoShutdownEnabled
        RepeaterService.shutdownTimeoutMillis = config.shutdownTimeoutMillis
    }
}