[FEATURE]Get response headers from messages api

openai-client/src/commonMain/kotlin/com.aallam.openai.client/Messages.kt

@@ -3,11 +3,11 @@ package com.aallam.openai.client
 import com.aallam.openai.api.BetaOpenAI
 import com.aallam.openai.api.core.RequestOptions
 import com.aallam.openai.api.core.SortOrder
-import com.aallam.openai.api.file.FileId
 import com.aallam.openai.api.message.Message
 import com.aallam.openai.api.message.MessageId
 import com.aallam.openai.api.message.MessageRequest
 import com.aallam.openai.api.thread.ThreadId
+import io.ktor.http.*
 
 /**
  * Create messages within threads
@@ -85,4 +85,29 @@ public interface Messages {
         before: MessageId? = null,
         requestOptions: RequestOptions? = null
     ): List<Message>
+
+    /**
+     * Returns a list of messages for a given thread with response headers.
+     *
+     * @param threadId the identifier of the thread
+     * @param limit a limit on the number of objects to be returned.
+     * The Limit can range between 1 and 100, and the default is 20.
+     * @param order sort order by the `created_at` timestamp of the objects.
+     * @param after a cursor for use in pagination. [after] is an object ID that defines your place in the list.
+     * For instance, if you make a list request and receive 100 objects, ending with `obj_foo`, your subsequent call
+     * can include `after = MessageId("obj_foo")` in order to fetch the next page of the list.
+     * @param before a cursor for use in pagination. [before] is an object ID that defines your place in the list.
+     * For instance, if you make a list request and receive 100 objects, ending with `obj_foo`, your subsequent call
+     * can include `before = MessageId("obj_foo")` in order to fetch the previous page of the list.
+     * @param requestOptions request options.
+     */
+    @BetaOpenAI
+    public suspend fun messagesWithHeaders(
+        threadId: ThreadId,
+        limit: Int? = null,
+        order: SortOrder? = null,
+        after: MessageId? = null,
+        before: MessageId? = null,
+        requestOptions: RequestOptions? = null
+    ): Pair<Headers, List<Message>>
 }

openai-client/src/commonMain/kotlin/com.aallam.openai.client/internal/api/MessagesApi.kt

@@ -12,6 +12,7 @@ import com.aallam.openai.client.internal.extension.beta
 import com.aallam.openai.client.internal.extension.requestOptions
 import com.aallam.openai.client.internal.http.HttpRequester
 import com.aallam.openai.client.internal.http.perform
+import com.aallam.openai.client.internal.http.performGetHeaders
 import io.ktor.client.call.*
 import io.ktor.client.request.*
 import io.ktor.http.*
@@ -74,7 +75,29 @@ internal class MessagesApi(val requester: HttpRequester) : Messages {
         before: MessageId?,
         requestOptions: RequestOptions?
     ): PaginatedList<Message> {
-        return requester.perform {
+        return requester.perform{
+            it.get {
+                url(path = "${ApiPath.Threads}/${threadId.id}/messages") {
+                    limit?.let { value -> parameter("limit", value) }
+                    order?.let { value -> parameter("order", value.order) }
+                    before?.let { value -> parameter("before", value.id) }
+                    after?.let { value -> parameter("after", value.id) }
+                }
+                beta("assistants", 2)
+                requestOptions(requestOptions)
+            }.body()
+        }
+    }
+
+    override suspend fun messagesWithHeaders(
+        threadId: ThreadId,
+        limit: Int?,
+        order: SortOrder?,
+        after: MessageId?,
+        before: MessageId?,
+        requestOptions: RequestOptions?
+    ): Pair<Headers, PaginatedList<Message>> {
+        return requester.performGetHeaders{
             it.get {
                 url(path = "${ApiPath.Threads}/${threadId.id}/messages") {
                     limit?.let { value -> parameter("limit", value) }

openai-client/src/commonMain/kotlin/com.aallam.openai.client/internal/http/HttpRequester.kt

@@ -4,6 +4,7 @@ import com.aallam.openai.client.Closeable
 import io.ktor.client.*
 import io.ktor.client.request.*
 import io.ktor.client.statement.*
+import io.ktor.http.*
 import io.ktor.util.reflect.*
 
 /**
@@ -16,6 +17,11 @@ internal interface HttpRequester : Closeable {
      */
     suspend fun <T : Any> perform(info: TypeInfo, block: suspend (HttpClient) -> HttpResponse): T
 
+    /**
+     * Perform an HTTP request and get a result with headers
+     */
+    suspend fun <T : Any> performGetHeaders(info: TypeInfo, block: suspend (HttpClient) -> HttpResponse): Pair<Headers, T>
+
     /**
      * Perform an HTTP request and get a result.
      *
@@ -33,3 +39,10 @@ internal interface HttpRequester : Closeable {
 internal suspend inline fun <reified T> HttpRequester.perform(noinline block: suspend (HttpClient) -> HttpResponse): T {
     return perform(typeInfo<T>(), block)
 }
+
+/**
+ * Perform an HTTP request and get a result with headers
+ */
+internal suspend inline fun <reified T> HttpRequester.performGetHeaders(noinline block: suspend (HttpClient) -> HttpResponse): Pair<Headers, T> {
+    return performGetHeaders(typeInfo<T>(), block)
+}

openai-client/src/commonMain/kotlin/com.aallam.openai.client/internal/http/HttpTransport.kt

@@ -7,6 +7,7 @@ import io.ktor.client.network.sockets.*
 import io.ktor.client.plugins.*
 import io.ktor.client.request.*
 import io.ktor.client.statement.*
+import io.ktor.http.*
 import io.ktor.util.reflect.*
 import io.ktor.utils.io.errors.*
 import kotlinx.coroutines.CancellationException
@@ -35,6 +36,15 @@ internal class HttpTransport(private val httpClient: HttpClient) : HttpRequester
         }
     }
 
+    override suspend fun <T : Any> performGetHeaders(info: TypeInfo, block: suspend (HttpClient) -> HttpResponse): Pair<Headers, T> {
+        try {
+            val response = block(httpClient)
+            return Pair(response.headers,response.body(info))
+        } catch (e: Exception) {
+            throw handleException(e)
+        }
+    }
+
     override fun close() {
         httpClient.close()
     }