punchnet-android/app/src/main/java/com/jihe/punchnet/helper/Screens.kt

package com.jihe.punchnet.helper

import android.app.Activity
import android.content.Context
import android.content.SharedPreferences
import com.jihe.punchnet.data.RouteItem
import com.jihe.punchnet.sdlan.network.maskDigitToInt

const val PreferenceRepositoryName = "pref"
sealed class PreferenceName(val name: String) {
    object PreferenceToken: PreferenceName("token")
}

private fun getEncryptedSharedPrefs(context: Context): SharedPreferences {
    val masterKey = androidx.security.crypto.MasterKey.Builder(context)
        .setKeyScheme(androidx.security.crypto.MasterKey.KeyScheme.AES256_GCM)
        .build()

    return androidx.security.crypto.EncryptedSharedPreferences.create(
        context,
        PreferenceRepositoryName,
        masterKey,
        androidx.security.crypto.EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
        androidx.security.crypto.EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
    )
}

private fun getPlainSharedPrefs(context: Context): SharedPreferences {
    return context.getSharedPreferences(PreferenceRepositoryName, Activity.MODE_PRIVATE)
}

private fun migratePlainPreference(context: Context, name: PreferenceName, encryptedPrefs: SharedPreferences) {
    if (encryptedPrefs.contains(name.name)) return

    val plainPrefs = getPlainSharedPrefs(context)
    if (!plainPrefs.contains(name.name)) return

    when (val value = plainPrefs.all[name.name]) {
        is String -> encryptedPrefs.edit().putString(name.name, value).apply()
        is Int -> encryptedPrefs.edit().putInt(name.name, value).apply()
    }
    plainPrefs.edit().remove(name.name).apply()
}

fun getPreferenceString(context: Context, name: PreferenceName): String? {
    try {
        val preference = getEncryptedSharedPrefs(context)
        migratePlainPreference(context, name, preference)
        return preference.getString(name.name, "")
    } catch (e: Exception) {
        return null
    }
}

fun getPreferenceInt(context: Context, name: PreferenceName): Int? {
    try {
        val preference = getEncryptedSharedPrefs(context)
        migratePlainPreference(context, name, preference)
        return preference.getInt(name.name, 0)
    } catch (e: Exception) {
        return null
    }
}

fun setPreferenceString(context: Context, name: PreferenceName, value: String) {
    try {
        val preference = getEncryptedSharedPrefs(context)
        preference.edit().putString(name.name, value).apply()
    } catch (e: Exception) {
        return
    }
}

fun setPreferenceInt(context: Context, name: PreferenceName, value: Int) {
    try {
        val preference = getEncryptedSharedPrefs(context)
        preference.edit().putInt(name.name, value).apply()
    } catch (e: Exception) {
        return
    }
}


sealed class Screen(val route: String) {
    object ScreenRoutes: Screen("routes")
    object ScreenMain: Screen("main")
}

fun IntToIPString(ip: Int): String {
    val one = ((ip ushr 24) and 0x000000ff)
    val two = ((ip ushr 16) and 0x000000ff)
    val three = ((ip ushr 8) and 0x000000ff)
    val four = ((ip) and 0x000000ff)
    return "${one}.${two}.${three}.${four}"
}

fun IPStringToInt(ipStr: String): Int? {
    val digits = ipStr.split('.').filter{
        val single = try {
            it.toInt()
        } catch(e: Exception) {
            return@filter false
        }
        single in 0..255
    }
    if (digits.size != 4) {
        return null
    }
    val result: Int
    try {
        result = (digits[0].toInt() shl 24) +
                (digits[1].toInt() shl 16) +
                (digits[2].toInt() shl 8) +
                (digits[3].toInt())
    } catch(e: Exception) {
        return null
    }

    return result
}

fun parseCIDRAndGW(cidr: String, gw: String): RouteItem? {
    val cidrSplit = cidr.split('/')
    var ip = 0
    var digit = 0

    if (cidrSplit.size == 1) {
        digit = 32
    } else if (cidrSplit.size == 2) {
        try {
            val k = cidrSplit[1].toInt()
            if (k in 1..32) {
                digit = k
            } else {
                return null
            }
        } catch (e: Exception) {
            return null
        }
    } else {
        return null
    }

    val ipvalue = IPStringToInt(cidrSplit[0])
    val gateway = IPStringToInt(gw)
    if (ipvalue == null) {
        return null
    }
    if (gateway == null) {
        return null
    }
    val mask = maskDigitToInt(digit)!!
    return RouteItem(
        net_ip = ipvalue,
        gateway = gateway,
        mask_ip = mask,
    )
}