[DO NOT USE] Restore DOH support

app/src/main/java/com/hippo/ehviewer/client/EhDns.kt

@@ -3,6 +3,7 @@ package com.hippo.ehviewer.client
 import android.os.Build
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.builtInHosts
+import com.hippo.ehviewer.ui.settings.EhDoH
 import okhttp3.AsyncDns
 import okhttp3.Dns
 import okhttp3.android.AndroidAsyncDns
@@ -29,5 +30,5 @@ fun HostsMap.hosts(vararg hosts: String, builder: HostMapBuilder.() -> Unit) = a
 val systemDns = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) AsyncDns.toDns(AndroidAsyncDns.IPv4, AndroidAsyncDns.IPv6) else Dns.SYSTEM
 
 object EhDns : Dns {
-    override fun lookup(hostname: String): List<InetAddress> = builtInHosts[hostname].takeIf { Settings.builtInHosts } ?: systemDns.lookup(hostname)
+    override fun lookup(hostname: String): List<InetAddress> = builtInHosts[hostname].takeIf { Settings.builtInHosts } ?: EhDoH.lookup(hostname) ?: systemDns.lookup(hostname)
 }

app/src/main/java/com/hippo/ehviewer/ui/settings/AdvancedScreen.kt

@@ -1,6 +1,7 @@
 package com.hippo.ehviewer.ui.settings
 
 import android.annotation.SuppressLint
+import android.content.DialogInterface
 import android.content.Intent
 import android.net.Uri
 import android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS
@@ -32,12 +33,15 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import com.hippo.ehviewer.AppConfig
 import com.hippo.ehviewer.BuildConfig
+import com.hippo.ehviewer.EhApplication
 import com.hippo.ehviewer.EhDB
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.client.EhEngine
 import com.hippo.ehviewer.client.data.FavListUrlBuilder
+import com.hippo.ehviewer.client.systemDns
 import com.hippo.ehviewer.ui.legacy.BaseDialogBuilder
+import com.hippo.ehviewer.ui.legacy.EditTextDialogBuilder
 import com.hippo.ehviewer.ui.login.LocalNavController
 import com.hippo.ehviewer.util.LogCat
 import com.hippo.ehviewer.util.ReadableTime
@@ -46,7 +50,10 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import moe.tarsin.coroutines.runSuspendCatching
+import okhttp3.HttpUrl.Companion.toHttpUrl
+import okhttp3.dnsoverhttps.DnsOverHttps
 import java.io.File
+import java.net.InetAddress
 import java.util.zip.ZipEntry
 import java.util.zip.ZipOutputStream
 
@@ -138,7 +145,23 @@ fun AdvancedScreen() {
             )
             Preference(
                 title = stringResource(id = R.string.settings_advanced_dns_over_http_title),
-            )
+            ) {
+                val builder = EditTextDialogBuilder(context, Settings.dohUrl, context.getString(R.string.settings_advanced_dns_over_http_hint))
+                builder.setTitle(R.string.settings_advanced_dns_over_http_title)
+                builder.setPositiveButton(android.R.string.ok, null)
+                val dialog = builder.create().apply { show() }
+                dialog.getButton(DialogInterface.BUTTON_POSITIVE).setOnClickListener {
+                    val text = builder.text.trim()
+                    runCatching {
+                        doh = if (text.isNotBlank()) buildDoHDNS(text) else null
+                    }.onFailure {
+                        builder.setError("Invalid URL!")
+                    }.onSuccess {
+                        Settings.dohUrl = text
+                        dialog.dismiss()
+                    }
+                }
+            }
             SwitchPreference(
                 title = stringResource(id = R.string.settings_advanced_domain_fronting_title),
                 summary = stringResource(id = R.string.settings_advanced_domain_fronting_summary),
@@ -265,3 +288,18 @@ fun AdvancedScreen() {
         }
     }
 }
+
+private fun buildDoHDNS(url: String): DnsOverHttps {
+    return DnsOverHttps.Builder().apply {
+        client(EhApplication.okHttpClient)
+        url(url.toHttpUrl())
+        post(true)
+        systemDns(systemDns)
+    }.build()
+}
+
+private var doh: DnsOverHttps? = Settings.dohUrl.runCatching { buildDoHDNS(this) }.getOrNull()
+
+object EhDoH {
+    fun lookup(hostname: String): List<InetAddress>? = doh?.runCatching { lookup(hostname).takeIf { it.isNotEmpty() } }?.onFailure { it.printStackTrace() }?.getOrNull()
+}