Ollama support for file attachments (#1221)

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#### Type of the changes
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Author: Rizzen

integration-tests/src/jvmTest/kotlin/ai/koog/integration/tests/executor/OllamaExecutorIntegrationTest.kt

@@ -3,6 +3,7 @@ package ai.koog.integration.tests.executor
 import ai.koog.integration.tests.InjectOllamaTestFixture
 import ai.koog.integration.tests.OllamaTestFixture
 import ai.koog.integration.tests.OllamaTestFixtureExtension
+import ai.koog.integration.tests.utils.MediaTestScenarios
 import ai.koog.integration.tests.utils.MediaTestScenarios.ImageTestScenario
 import ai.koog.integration.tests.utils.MediaTestUtils
 import ai.koog.integration.tests.utils.MediaTestUtils.checkExecutorMediaResponse
@@ -320,4 +321,27 @@ class OllamaExecutorIntegrationTest : ExecutorIntegrationTestBase() {
             }
         }
     }
+
+    @Test
+    fun `ollama_test txt file processing`() = runTest(timeout = 600.seconds) {
+        val textFile = MediaTestUtils.createTextFileForScenario(
+            MediaTestScenarios.TextTestScenario.BASIC_TEXT,
+            testResourcesDir
+        )
+
+        val prompt = prompt("text-file-test") {
+            system("You are a helpful assistant that can analyze text files.")
+
+            user {
+                markdown {
+                    +"I'm sending you a text file. Please read its content and summarize it."
+                }
+
+                textFile(KtPath(textFile.pathString), "text/plain")
+            }
+        }
+
+        val response = executor.execute(prompt, model).single()
+        response.content.shouldNotBeBlank()
+    }
 }

prompt/prompt-executor/prompt-executor-clients/prompt-executor-ollama-client/src/commonMain/kotlin/ai/koog/prompt/executor/ollama/client/dto/OllamaConverters.kt

@@ -59,10 +59,13 @@ internal fun Prompt.toOllamaChatMessages(model: LLModel): List<OllamaChatMessage
 }
 
 private fun Message.User.toOllamaChatMessage(model: LLModel): OllamaChatMessageDTO {
+    val text = StringBuilder()
     val images = buildList {
         parts.forEach { part ->
             when (part) {
-                is ContentPart.Text -> {}
+                is ContentPart.Text -> {
+                    text.append(part.text)
+                }
                 is ContentPart.Image -> {
                     require(LLMCapability.Vision.Image in model.capabilities) {
                         "Model ${model.id} doesn't support images"
@@ -76,14 +79,28 @@ private fun Message.User.toOllamaChatMessage(model: LLModel): OllamaChatMessageD
                     add(image)
                 }
 
+                is ContentPart.File -> {
+                    val fileContent = when (val actualContent = part.content) {
+                        is AttachmentContent.PlainText -> {
+                            actualContent.text
+                        }
+
+                        is AttachmentContent.Binary -> actualContent.asBase64()
+
+                        else -> throw IllegalArgumentException("Unsupported file attachment content: ${content::class}")
+                    }
+
+                    text.append("\n\n$fileContent")
+                }
+
                 else -> throw IllegalArgumentException("Unsupported attachment type: $part")
             }
         }
     }
 
     return OllamaChatMessageDTO(
         role = "user",
-        content = content,
+        content = text.toString(),
         images = images.takeIf { it.isNotEmpty() }
     )
 }