add latestVersion to support the latest date version

Author: mssfang

openai-java-core/src/main/kotlin/com/openai/azure/AzureOpenAIServiceVersion.kt

@@ -1,12 +1,19 @@
 package com.openai.azure
 
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
 import java.util.concurrent.ConcurrentHashMap
 
 class AzureOpenAIServiceVersion private constructor(@get:JvmName("value") val value: String) {
 
     companion object {
         private val values: ConcurrentHashMap<String, AzureOpenAIServiceVersion> =
             ConcurrentHashMap()
+        private val dateFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd")
+
+        private fun extractDate(version: String): LocalDate {
+            return LocalDate.parse(version, dateFormatter)
+        }
 
         @JvmStatic
         fun latestStableVersion(): AzureOpenAIServiceVersion {
@@ -20,6 +27,15 @@ class AzureOpenAIServiceVersion private constructor(@get:JvmName("value") val va
             return V2025_01_01_PREVIEW
         }
 
+        @JvmStatic
+        fun latestVersion(): AzureOpenAIServiceVersion {
+            val stableVersion = latestStableVersion()
+            val previewVersion = latestPreviewVersion()
+            val stableDate = extractDate(stableVersion.value)
+            val previewDate = extractDate(previewVersion.value.substring(0, 10))
+            return if (stableDate.isAfter(previewDate)) stableVersion else previewVersion
+        }
+
         @JvmStatic
         fun fromString(version: String): AzureOpenAIServiceVersion =
             values.computeIfAbsent(version) { AzureOpenAIServiceVersion(version) }

openai-java-core/src/main/kotlin/com/openai/core/ClientOptions.kt

@@ -262,7 +262,7 @@ private constructor(
                 // specific a service API version in 'queryParams'.
                 replaceQueryParams(
                     "api-version",
-                    (azureServiceVersion ?: AzureOpenAIServiceVersion.latestStableVersion()).value
+                    (azureServiceVersion ?: AzureOpenAIServiceVersion.latestVersion()).value,
                 )
             }