Magisk/app/src/main/java/com/topjohnwu/magisk/ui/surequest/SuRequestViewModel.kt

package com.topjohnwu.magisk.ui.surequest

import android.annotation.SuppressLint
import android.content.Context
import android.content.Intent
import android.content.SharedPreferences
import android.content.res.Resources
import android.graphics.drawable.Drawable
import android.os.Bundle
import android.os.CountDownTimer
import android.view.MotionEvent
import android.view.View
import android.view.ViewGroup
import android.view.accessibility.AccessibilityEvent
import android.view.accessibility.AccessibilityNodeInfo
import android.view.accessibility.AccessibilityNodeProvider
import android.widget.Toast
import androidx.databinding.Bindable
import androidx.lifecycle.viewModelScope
import com.topjohnwu.magisk.BR
import com.topjohnwu.magisk.R
import com.topjohnwu.magisk.arch.BaseViewModel
import com.topjohnwu.magisk.core.Config
import com.topjohnwu.magisk.core.magiskdb.PolicyDao
import com.topjohnwu.magisk.core.model.su.SuPolicy
import com.topjohnwu.magisk.core.model.su.SuPolicy.Companion.ALLOW
import com.topjohnwu.magisk.core.model.su.SuPolicy.Companion.DENY
import com.topjohnwu.magisk.core.su.SuRequestHandler
import com.topjohnwu.magisk.core.utils.BiometricHelper
import com.topjohnwu.magisk.events.DieEvent
import com.topjohnwu.magisk.events.ShowUIEvent
import com.topjohnwu.magisk.events.dialog.BiometricEvent
import com.topjohnwu.magisk.ktx.get
import com.topjohnwu.magisk.utils.TextHolder
import com.topjohnwu.magisk.utils.Utils
import com.topjohnwu.magisk.utils.set
import kotlinx.coroutines.launch
import me.tatarka.bindingcollectionadapter2.ItemBinding
import java.util.concurrent.TimeUnit.SECONDS

class SuRequestViewModel(
    policyDB: PolicyDao,
    private val timeoutPrefs: SharedPreferences
) : BaseViewModel() {

    lateinit var icon: Drawable
    lateinit var title: String
    lateinit var packageName: String

    @get:Bindable
    val denyText = DenyText()

    @get:Bindable
    var selectedItemPosition = 0
        set(value) = set(value, field, { field = it }, BR.selectedItemPosition)

    @get:Bindable
    var grantEnabled = false
        set(value) = set(value, field, { field = it }, BR.grantEnabled)

    @SuppressLint("ClickableViewAccessibility")
    val grantTouchListener = View.OnTouchListener { _: View, event: MotionEvent ->
        // Filter obscured touches by consuming them.
        if (event.flags and MotionEvent.FLAG_WINDOW_IS_OBSCURED != 0
            || event.flags and MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED != 0) {
            if (event.action == MotionEvent.ACTION_UP) {
                Utils.toast(R.string.touch_filtered_warning, Toast.LENGTH_SHORT)
            }
            return@OnTouchListener Config.suTapjack
        }
        false
    }

    val itemBinding = ItemBinding.of<String>(BR.item, R.layout.item_spinner)

    private val handler = SuRequestHandler(get<Context>().packageManager, policyDB)
    private lateinit var timer: CountDownTimer

    fun grantPressed() {
        cancelTimer()
        if (BiometricHelper.isEnabled) {
            BiometricEvent {
                onSuccess {
                    respond(ALLOW)
                }
            }.publish()
        } else {
            respond(ALLOW)
        }
    }

    fun denyPressed() {
        respond(DENY)
    }

    fun spinnerTouched(): Boolean {
        cancelTimer()
        return false
    }

    fun handleRequest(intent: Intent) {
        viewModelScope.launch {
            if (handler.start(intent))
                showDialog(handler.policy)
            else
                DieEvent().publish()
        }
    }

    private fun showDialog(policy: SuPolicy) {
        icon = policy.icon
        title = policy.appName
        packageName = policy.packageName
        selectedItemPosition = timeoutPrefs.getInt(policy.packageName, 0)

        // Set timer
        val millis = SECONDS.toMillis(Config.suDefaultTimeout.toLong())
        timer = SuTimer(millis, 1000).apply { start() }

        // Actually show the UI
        ShowUIEvent(if (Config.suTapjack) EmptyAccessibilityDelegate else null).publish()
    }

    private fun respond(action: Int) {
        timer.cancel()

        val pos = selectedItemPosition
        timeoutPrefs.edit().putInt(handler.policy.packageName, pos).apply()
        handler.respond(action, Config.Value.TIMEOUT_LIST[pos])

        // Kill activity after response
        DieEvent().publish()
    }

    private fun cancelTimer() {
        timer.cancel()
        denyText.seconds = 0
    }

    private inner class SuTimer(
        private val millis: Long,
        interval: Long
    ) : CountDownTimer(millis, interval) {

        override fun onTick(remains: Long) {
            if (!grantEnabled && remains <= millis - 1000) {
                grantEnabled = true
            }
            denyText.seconds = (remains / 1000).toInt() + 1
        }

        override fun onFinish() {
            denyText.seconds = 0
            respond(DENY)
        }

    }

    inner class DenyText : TextHolder() {
        var seconds = 0
            set(value) = set(value, field, { field = it }, BR.denyText)

        override val isEmpty get() = false

        override fun getText(resources: Resources): CharSequence {
            return if (seconds != 0)
                "${resources.getString(R.string.deny)} ($seconds)"
            else
                resources.getString(R.string.deny)
        }
    }

    // Invisible for accessibility services
    object EmptyAccessibilityDelegate : View.AccessibilityDelegate() {
        override fun sendAccessibilityEvent(host: View?, eventType: Int) {}
        override fun performAccessibilityAction(host: View?, action: Int, args: Bundle?) = true
        override fun sendAccessibilityEventUnchecked(host: View?, event: AccessibilityEvent?) {}
        override fun dispatchPopulateAccessibilityEvent(host: View?, event: AccessibilityEvent?) = true
        override fun onPopulateAccessibilityEvent(host: View?, event: AccessibilityEvent?) {}
        override fun onInitializeAccessibilityEvent(host: View?, event: AccessibilityEvent?) {}
        override fun onInitializeAccessibilityNodeInfo(host: View, info: AccessibilityNodeInfo) {}
        override fun addExtraDataToAccessibilityNodeInfo(host: View, info: AccessibilityNodeInfo, extraDataKey: String, arguments: Bundle?) {}
        override fun onRequestSendAccessibilityEvent(host: ViewGroup?, child: View?, event: AccessibilityEvent?): Boolean = false
        override fun getAccessibilityNodeProvider(host: View?): AccessibilityNodeProvider? = null
    }
}