fix: Use media directory as the base url of the CardViewers

AnkiDroid/src/main/java/com/ichi2/anki/AbstractFlashcardViewer.kt

@@ -65,7 +65,6 @@ import com.ichi2.anki.model.CardStateFilter
 import com.ichi2.anki.noteeditor.EditCardDestination
 import com.ichi2.anki.noteeditor.toIntent
 import com.ichi2.anki.pages.AnkiServer
-import com.ichi2.anki.pages.AnkiServer.Companion.LOCALHOST
 import com.ichi2.anki.pages.CongratsPage
 import com.ichi2.anki.pages.PostRequestHandler
 import com.ichi2.anki.preferences.sharedPrefs
@@ -232,9 +231,8 @@ abstract class AbstractFlashcardViewer :
     @get:VisibleForTesting
     var cardContent: String? = null
         private set
-    private val baseUrl get() = server.baseUrl()
-    private val webviewDomain
-        get() = "$LOCALHOST:${server.listeningPort}"
+    private val baseUrl
+        get() = getMediaBaseUrl(CollectionHelper.getMediaDirectory(this).path)
 
     private var viewerUrl: String? = null
     private val fadeDuration = 300
@@ -994,7 +992,6 @@ abstract class AbstractFlashcardViewer :
     }
 
     protected open fun createWebView(): WebView {
-        val resourceHandler = ViewerResourceHandler(this, webviewDomain)
         val webView: WebView = MyWebView(this).apply {
             scrollBarStyle = View.SCROLLBARS_OUTSIDE_OVERLAY
             with(settings) {
@@ -1012,7 +1009,7 @@ abstract class AbstractFlashcardViewer :
             isScrollbarFadingEnabled = true
             // Set transparent color to prevent flashing white when night mode enabled
             setBackgroundColor(Color.argb(1, 0, 0, 0))
-            CardViewerWebClient(resourceHandler, this@AbstractFlashcardViewer).apply {
+            CardViewerWebClient(this@AbstractFlashcardViewer).apply {
                 webViewClient = this
                 this@AbstractFlashcardViewer.webViewClient = this
             }
@@ -2235,7 +2232,6 @@ abstract class AbstractFlashcardViewer :
     }
 
     inner class CardViewerWebClient internal constructor(
-        private val loader: ViewerResourceHandler?,
         private val onPageFinishedCallback: OnPageFinishedCallback? = null
     ) : WebViewClient(), JavascriptEvaluator {
         private var pageFinishedFired = true
@@ -2256,14 +2252,16 @@ abstract class AbstractFlashcardViewer :
         override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
             pageRenderStopwatch.reset()
             pageFinishedFired = false
+            val script = "globalThis.ankidroid = globalThis.ankidroid || {};" +
+                "ankidroid.postBaseUrl = `${server.baseUrl()}`"
+            view?.evaluateJavascript(script, null)
         }
 
         override fun shouldInterceptRequest(
             view: WebView,
             request: WebResourceRequest
         ): WebResourceResponse? {
             val url = request.url
-            loader!!.shouldInterceptRequest(request)?.let { return it }
             if (url.toString().startsWith("file://")) {
                 url.path?.let { path -> migrationService?.migrateFileImmediately(File(path)) }
             }

AnkiDroid/src/main/java/com/ichi2/anki/pages/AnkiServer.kt

@@ -18,20 +18,13 @@
 package com.ichi2.anki.pages
 
 import fi.iki.elonen.NanoHTTPD
-import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.runBlocking
 import timber.log.Timber
 import java.io.ByteArrayInputStream
 
-const val PORT = 0
-// const val PORT = 40001
-
-// local debugging:
-// ~/Local/Android/Sdk/platform-tools/adb forward tcp:40001 tcp:40001
-
 open class AnkiServer(
     private val postHandler: PostRequestHandler
-) : NanoHTTPD(LOCALHOST, PORT) {
+) : NanoHTTPD(LOCALHOST, 0) {
 
     fun baseUrl(): String {
         return "http://$LOCALHOST:$listeningPort/"
@@ -47,26 +40,35 @@ open class AnkiServer(
                 val uri = session.uri
                 Timber.d("POST: Requested %s", uri)
                 val inputBytes = getSessionBytes(session)
-                buildResponse {
-                    postHandler.handlePostRequest(uri, inputBytes)
+
+                try {
+                    val data = runBlocking { postHandler.handlePostRequest(uri, inputBytes) }
+                    buildResponse(data)
+                } catch (exception: Exception) {
+                    Timber.w(exception, "buildResponse failure")
+                    buildResponse(exception.localizedMessage?.encodeToByteArray(), status = Response.Status.INTERNAL_ERROR)
                 }
             }
             Method.GET -> newFixedLengthResponse(Response.Status.NOT_FOUND, null, null)
+            Method.OPTIONS -> buildResponse(null)
             else -> newFixedLengthResponse(null)
         }
     }
 
     private fun buildResponse(
-        block: suspend CoroutineScope.() -> ByteArray
+        data: ByteArray?,
+        mimeType: String = "application/binary",
+        status: Response.IStatus = Response.Status.OK
     ): Response {
-        return try {
-            val data = runBlocking {
-                block()
-            }
-            newChunkedResponse(data)
-        } catch (exc: Exception) {
-            Timber.w(exc, "buildResponse failure")
-            newChunkedResponse(exc.localizedMessage?.encodeToByteArray(), status = Response.Status.INTERNAL_ERROR)
+        return if (data == null) {
+            newFixedLengthResponse(null)
+        } else {
+            newChunkedResponse(status, mimeType, ByteArrayInputStream(data))
+        }.apply {
+            addHeader("Access-Control-Allow-Origin", "*")
+            addHeader("Access-Control-Allow-Headers", "Content-Type")
+            addHeader("Access-Control-Allow-Methods", "POST")
+            addHeader("Access-Control-Max-Age", "7200")
         }
     }
 
@@ -83,17 +85,5 @@ open class AnkiServer(
             session.inputStream.read(bytes, 0, contentLength)
             return bytes
         }
-
-        fun newChunkedResponse(
-            data: ByteArray?,
-            mimeType: String = "application/binary",
-            status: Response.IStatus = Response.Status.OK
-        ): Response {
-            return if (data == null) {
-                newFixedLengthResponse(null)
-            } else {
-                newChunkedResponse(status, mimeType, ByteArrayInputStream(data))
-            }
-        }
     }
 }

AnkiDroid/src/main/java/com/ichi2/anki/previewer/CardViewerFragment.kt

@@ -23,7 +23,6 @@ import android.webkit.CookieManager
 import android.webkit.WebChromeClient
 import android.webkit.WebResourceError
 import android.webkit.WebResourceRequest
-import android.webkit.WebResourceResponse
 import android.webkit.WebView
 import android.webkit.WebViewClient
 import android.widget.FrameLayout
@@ -36,11 +35,10 @@ import androidx.core.view.WindowInsetsControllerCompat
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.flowWithLifecycle
 import androidx.lifecycle.lifecycleScope
+import com.ichi2.anki.CollectionHelper
 import com.ichi2.anki.R
-import com.ichi2.anki.ViewerResourceHandler
 import com.ichi2.anki.dialogs.TtsVoicesDialogFragment
 import com.ichi2.anki.localizedErrorMessage
-import com.ichi2.anki.pages.AnkiServer
 import com.ichi2.anki.snackbar.showSnackbar
 import com.ichi2.themes.Themes
 import kotlinx.coroutines.flow.launchIn
@@ -85,8 +83,9 @@ abstract class CardViewerFragment(@LayoutRes layout: Int) : Fragment(layout) {
                 // allow videos to autoplay via our JavaScript eval
                 mediaPlaybackRequiresUserGesture = false
             }
+            val baseUrl = CollectionHelper.getMediaDirectory(requireContext()).toURI().toString()
             loadDataWithBaseURL(
-                "http://${AnkiServer.LOCALHOST}/",
+                baseUrl,
                 stdHtml(requireContext(), Themes.currentTheme.isNightMode),
                 "text/html",
                 null,
@@ -122,15 +121,7 @@ abstract class CardViewerFragment(@LayoutRes layout: Int) : Fragment(layout) {
     }
 
     private fun onCreateWebViewClient(savedInstanceState: Bundle?): WebViewClient {
-        val resourceHandler = ViewerResourceHandler(requireContext(), AnkiServer.LOCALHOST)
         return object : WebViewClient() {
-            override fun shouldInterceptRequest(
-                view: WebView?,
-                request: WebResourceRequest
-            ): WebResourceResponse? {
-                return resourceHandler.shouldInterceptRequest(request)
-            }
-
             override fun onPageFinished(view: WebView?, url: String?) {
                 viewModel.onPageFinished(isAfterRecreation = savedInstanceState != null)
             }

AnkiDroid/src/main/java/com/ichi2/libanki/Sound.kt

@@ -28,10 +28,13 @@ package com.ichi2.libanki
 import android.text.TextUtils
 import anki.config.ConfigKey
 import com.ichi2.anki.CollectionManager
+import com.ichi2.compat.CompatHelper
 import com.ichi2.libanki.TemplateManager.TemplateRenderContext.TemplateRenderOutput
 import com.ichi2.libanki.utils.NotInLibAnki
 import org.intellij.lang.annotations.Language
+import org.jetbrains.annotations.VisibleForTesting
 import java.io.File
+import java.net.URI
 import java.nio.file.Paths
 import java.util.regex.Pattern
 
@@ -270,3 +273,36 @@ data class AvRef(val side: String, val index: Int) {
         val REGEX = Regex("\\[anki:(play:(.):(\\d+))]")
     }
 }
+
+/** Similar to [File.toURI], but doesn't use the absolute file to simplify testing */
+@NotInLibAnki
+@VisibleForTesting
+fun getFileUri(path: String): URI {
+    var p = path
+    if (File.separatorChar != '/') p = p.replace(File.separatorChar, '/')
+    if (!p.startsWith("/")) p = "/$p"
+    if (!p.startsWith("//")) p = "//$p"
+    return URI("file", p, null)
+}
+
+/**
+ * Whether a video file only contains an audio stream
+ *
+ * @return `null` - file is not a video, or not found
+ */
+@NotInLibAnki
+@VisibleForTesting
+fun isAudioFileInVideoContainer(file: File): Boolean? {
+    if (file.extension !in Sound.VIDEO_ONLY_EXTENSIONS && file.extension !in Sound.AUDIO_OR_VIDEO_EXTENSIONS) {
+        return null
+    }
+
+    if (file.extension in Sound.VIDEO_ONLY_EXTENSIONS) return false
+
+    // file.extension is in AUDIO_OR_VIDEO_EXTENSIONS
+    if (!file.exists()) return null
+
+    // Also check that there is a video thumbnail, as some formats like mp4 can be audio only
+    val isVideo = CompatHelper.compat.hasVideoThumbnail(file.absolutePath) ?: return null
+    return !isVideo
+}