✨ added BilibiliThumbnailFinder

songfinder-app/src/main/kotlin/mikufan/cx/songfinder/backend/component/thumbnailfinder/BilibiliThumbnailFinder.kt

@@ -0,0 +1,49 @@
+package mikufan.cx.songfinder.backend.component.thumbnailfinder
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.ObjectMapper
+import io.ktor.client.*
+import io.ktor.client.call.*
+import io.ktor.client.request.*
+import io.ktor.client.statement.*
+import kotlinx.coroutines.withContext
+import mikufan.cx.songfinder.backend.db.entity.PvService
+import mikufan.cx.songfinder.backend.model.PVInfo
+import mikufan.cx.songfinder.backend.model.ThumbnailInfo
+import mikufan.cx.songfinder.backend.util.MyDispatchers
+import org.springframework.stereotype.Component
+
+@Component
+class BilibiliThumbnailFinder(
+  private val client: HttpClient,
+  private val objectMapper: ObjectMapper
+) : ThumbnailFinder {
+  override val matchedPvService = PvService.Bilibili
+
+  override suspend fun findThumbnail(pv: PVInfo): ThumbnailInfo {
+    val bvid: String? = tryGetBvid(pv.extendedMetadata)
+    val rsp: HttpResponse = withContext(MyDispatchers.ioDispatcher) {
+      if (bvid == null) {
+        client.get("https://api.bilibili.com/x/web-interface/view?aid=${pv.id}")
+      } else {
+        client.get("https://api.bilibili.com/x/web-interface/view?bvid=$bvid")
+      }
+    }
+
+    val json = rsp.body<JsonNode>()
+    val code = json["code"].asInt()
+    if (code != 0) {
+      throw ThumbnailNotAvailableException(
+        "The $matchedPvService video ${pv.id} is not available, " +
+            "code: $code, message: ${json["message"].asText()}"
+      )
+    } else {
+      return ThumbnailInfo(json["data"]["pic"].asText())
+    }
+  }
+
+  private fun tryGetBvid(extendedMetadata: String?): String? = extendedMetadata?.let { metadataStr ->
+    val metadata: JsonNode = objectMapper.readTree(metadataStr)
+    metadata["json"]?.get("Bvid")?.asText()
+  }
+}