Add setting to use the flaresolverr response (#990)

server/src/main/kotlin/eu/kanade/tachiyomi/network/interceptor/CloudflareInterceptor.kt

@@ -23,6 +23,7 @@ import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
+import okhttp3.ResponseBody.Companion.toResponseBody
 import suwayomi.tachidesk.server.serverConfig
 import uy.kohesive.injekt.injectLazy
 import java.io.IOException
@@ -56,11 +57,38 @@ class CloudflareInterceptor(
             originalResponse.close()
             // network.cookieStore.remove(originalRequest.url.toUri())
 
-            val request =
+            val flareResponseFallback = serverConfig.flareSolverrAsResponseFallback.value
+            val flareResponse =
                 runBlocking {
-                    CFClearance.resolveWithFlareSolverr(setUserAgent, originalRequest)
+                    CFClearance.resolveWithFlareSolver(originalRequest, !flareResponseFallback)
                 }
 
+            if (flareResponse.message.contains("not detected", ignoreCase = true)) {
+                logger.debug { "FlareSolverr failed to detect Cloudflare challenge" }
+
+                if (flareResponseFallback &&
+                    flareResponse.solution.status in 200..299 &&
+                    flareResponse.solution.response != null
+                ) {
+                    val isImage = flareResponse.solution.response.contains(CHROME_IMAGE_TEMPLATE_REGEX)
+                    if (!isImage) {
+                        logger.debug { "Falling back to FlareSolverr response" }
+
+                        setUserAgent(flareResponse.solution.userAgent)
+
+                        return originalResponse
+                            .newBuilder()
+                            .code(flareResponse.solution.status)
+                            .body(flareResponse.solution.response.toResponseBody())
+                            .build()
+                    } else {
+                        logger.debug { "FlareSolverr response is an image html template, not falling back" }
+                    }
+                }
+            }
+
+            val request = CFClearance.requestWithFlareSolverr(flareResponse, setUserAgent, originalRequest)
+
             chain.proceed(request)
         } catch (e: Exception) {
             // Because OkHttp's enqueue only handles IOExceptions, wrap the exception so that
@@ -73,6 +101,7 @@ class CloudflareInterceptor(
         private val ERROR_CODES = listOf(403, 503)
         private val SERVER_CHECK = arrayOf("cloudflare-nginx", "cloudflare")
         private val COOKIE_NAMES = listOf("cf_clearance")
+        private val CHROME_IMAGE_TEMPLATE_REGEX = Regex("""<title>(.*?) \(\d+×\d+\)</title>""")
     }
 }
 
@@ -153,13 +182,13 @@ object CFClearance {
         val version: String,
     )
 
-    suspend fun resolveWithFlareSolverr(
+    suspend fun resolveWithFlareSolver(
-        setUserAgent: (String) -> Unit,
         originalRequest: Request,
-    ): Request {
+        onlyCookies: Boolean,
+    ): FlareSolverResponse {
         val timeout = serverConfig.flareSolverrTimeout.value.seconds
-        val flareSolverResponse =
+
-            with(json) {
+        return with(json) {
             mutex.withLock {
                 client.value.newCall(
                     POST(
@@ -175,7 +204,7 @@ object CFClearance {
                                         network.cookieStore.get(originalRequest.url).map {
                                             FlareSolverCookie(it.name, it.value)
                                         },
-                                        returnOnlyCookies = true,
+                                    returnOnlyCookies = onlyCookies,
                                     maxTimeout = timeout.inWholeMilliseconds.toInt(),
                                 ),
                             ).toRequestBody(jsonMediaType),
@@ -183,7 +212,13 @@ object CFClearance {
                 ).awaitSuccess().parseAs<FlareSolverResponse>()
             }
         }
+    }
 
+    fun requestWithFlareSolverr(
+        flareSolverResponse: FlareSolverResponse,
+        setUserAgent: (String) -> Unit,
+        originalRequest: Request,
+    ): Request {
         if (flareSolverResponse.solution.status in 200..299) {
             setUserAgent(flareSolverResponse.solution.userAgent)
             val cookies =

server/src/main/kotlin/suwayomi/tachidesk/graphql/mutations/SettingsMutation.kt

@@ -98,6 +98,7 @@ class SettingsMutation {
         updateSetting(settings.flareSolverrTimeout, serverConfig.flareSolverrTimeout)
         updateSetting(settings.flareSolverrSessionName, serverConfig.flareSolverrSessionName)
         updateSetting(settings.flareSolverrSessionTtl, serverConfig.flareSolverrSessionTtl)
+        updateSetting(settings.flareSolverrAsResponseFallback, serverConfig.flareSolverrAsResponseFallback)
     }
 
     fun setSettings(input: SetSettingsInput): SetSettingsPayload {

server/src/main/kotlin/suwayomi/tachidesk/graphql/types/SettingsType.kt

@@ -89,6 +89,7 @@ interface Settings : Node {
     val flareSolverrTimeout: Int?
     val flareSolverrSessionName: String?
     val flareSolverrSessionTtl: Int?
+    val flareSolverrAsResponseFallback: Boolean?
 }
 
 data class PartialSettingsType(
@@ -151,6 +152,7 @@ data class PartialSettingsType(
     override val flareSolverrTimeout: Int?,
     override val flareSolverrSessionName: String?,
     override val flareSolverrSessionTtl: Int?,
+    override val flareSolverrAsResponseFallback: Boolean?,
 ) : Settings
 
 class SettingsType(
@@ -213,6 +215,7 @@ class SettingsType(
     override val flareSolverrTimeout: Int,
     override val flareSolverrSessionName: String,
     override val flareSolverrSessionTtl: Int,
+    override val flareSolverrAsResponseFallback: Boolean,
 ) : Settings {
     constructor(config: ServerConfig = serverConfig) : this(
         config.ip.value,
@@ -270,5 +273,6 @@ class SettingsType(
         config.flareSolverrTimeout.value,
         config.flareSolverrSessionName.value,
         config.flareSolverrSessionTtl.value,
+        config.flareSolverrAsResponseFallback.value,
     )
 }

server/src/main/kotlin/suwayomi/tachidesk/server/ServerConfig.kt

@@ -141,6 +141,7 @@ class ServerConfig(getConfig: () -> Config, val moduleName: String = SERVER_CONF
     val flareSolverrTimeout: MutableStateFlow<Int> by OverrideConfigValue(IntConfigAdapter)
     val flareSolverrSessionName: MutableStateFlow<String> by OverrideConfigValue(StringConfigAdapter)
     val flareSolverrSessionTtl: MutableStateFlow<Int> by OverrideConfigValue(IntConfigAdapter)
+    val flareSolverrAsResponseFallback: MutableStateFlow<Boolean> by OverrideConfigValue(BooleanConfigAdapter)
 
     @OptIn(ExperimentalCoroutinesApi::class)
     fun <T> subscribeTo(

server/src/main/resources/server-reference.conf

@@ -67,3 +67,4 @@ server.flareSolverrUrl = "http://localhost:8191"
 server.flareSolverrTimeout = 60 # time in seconds
 server.flareSolverrSessionName = "suwayomi"
 server.flareSolverrSessionTtl = 15 # time in minutes
+server.flareSolverrAsResponseFallback = false

server/src/test/resources/server-reference.conf

@@ -67,3 +67,4 @@ server.flareSolverrUrl = "http://localhost:8191"
 server.flareSolverrTimeout = 60 # time in seconds
 server.flareSolverrSessionName = "suwayomi"
 server.flareSolverrSessionTtl = 15 # time in minutes
+server.flareSolverrAsResponseFallback = false