fallback if alternative file does not exist

windymelt · Feb 5, 2024 · 47561a6 · 47561a6
1 parent 3cf6d88
commit 47561a6
Showing 1 changed file with 40 additions and 3 deletions.
diff --git a/src/main/scala/com/github/windymelt/zmm/domain/model/Filter.scala b/src/main/scala/com/github/windymelt/zmm/domain/model/Filter.scala
@@ -1,7 +1,9 @@
-package com.github.windymelt.zmm.domain.model
+package com.github.windymelt.zmm
+package domain.model
 
 import cats.data.Kleisli
 import cats.implicits._
+import scala.jdk.CollectionConverters.ConcurrentMapHasAsScala
 
 object Filter {
   def talkingMouthFilter: Filter[Seq] = Kleisli { (ctx: Context) =>
@@ -11,11 +13,13 @@ object Filter {
         val ExtRe = """(.+)\.(.+)""".r.anchored
 
         // この関数に通すと口を閉じる
+        // 口を閉じている立ち絵のファイルが存在する場合はそれを利用する。存在しない場合は元々の画像にフォールバックする
         // TODO: CharacterConfigにもtachieUrlがあるけど？
         val swapTachie: Context => Context = ctx =>
           ctx.copy(tachieUrl = ctx.tachieUrl.map {
-            case ExtRe(file: String, ext: String) =>
-              s"${file}!.$ext"
+            case originalPath @ ExtRe(file: String, ext: String) =>
+              val alternativePath = s"${file}!.$ext"
+              alternativeFileIfExists(originalPath, alternativePath)
           })
 
         val spokenCtxs = vs.map { v =>
@@ -40,6 +44,39 @@ object Filter {
     }
   }
 
+  private val ExtRe = """(.+)\.(.+)""".r.anchored
+
+  // caution: invokes side effect.
+  private def alternativeFileIfExists(
+      originalPath: String,
+      alternativePath: String
+  ): String = originalPath match {
+    case originalPath @ ExtRe(file: String, ext: String) =>
+      tachieExistenceCache.get(alternativePath) match {
+        case Some(true)  => alternativePath
+        case Some(false) => originalPath
+        case None =>
+          val pathToFind = os.pwd / os.RelPath(
+            util.PathAlias.resolve(
+              alternativePath,
+              "ffmpeg" /* ffmpeg refers `./`. we should define stub Purpose */
+            )
+          )
+          if (os.exists(pathToFind)) {
+            tachieExistenceCache += alternativePath -> true
+            alternativePath
+          } else {
+            // fallback to original path.
+            tachieExistenceCache += alternativePath -> false
+            originalPath
+          }
+      }
+    case _ => ??? // should not be reached
+  }
+
+  private val tachieExistenceCache =
+    new java.util.concurrent.ConcurrentHashMap[String, Boolean]().asScala
+
   private def shouldCloseMouth(vowel: String): Boolean =
     vowel.toLowerCase match {
       case "u"  => true