feat: add generation source handling for task creation and updates

backend/src/main/kotlin/com/condado/newsletter/dto/EntityTaskDtos.kt

@@ -1,6 +1,7 @@
 package com.condado.newsletter.dto
 
 import com.condado.newsletter.model.EntityTask
+import com.condado.newsletter.model.TaskGenerationSource
 import jakarta.validation.constraints.NotBlank
 import jakarta.validation.constraints.NotNull
 import java.time.LocalDateTime
@@ -11,7 +12,8 @@ data class EntityTaskCreateDto(
     @field:NotBlank val name: String,
     val prompt: String,
     @field:NotBlank val scheduleCron: String,
-    @field:NotBlank val emailLookback: String
+    @field:NotBlank val emailLookback: String,
+    val generationSource: TaskGenerationSource = TaskGenerationSource.LLAMA
 )
 
 data class EntityTaskUpdateDto(
@@ -19,7 +21,8 @@ data class EntityTaskUpdateDto(
     @field:NotBlank val name: String,
     @field:NotBlank val prompt: String,
     @field:NotBlank val scheduleCron: String,
-    @field:NotBlank val emailLookback: String
+    @field:NotBlank val emailLookback: String,
+    val generationSource: TaskGenerationSource? = null
 )
 
 data class EntityTaskResponseDto(
@@ -29,6 +32,7 @@ data class EntityTaskResponseDto(
     val prompt: String,
     val scheduleCron: String,
     val emailLookback: String,
+    val generationSource: TaskGenerationSource,
     val active: Boolean,
     val createdAt: LocalDateTime?
 ) {
@@ -41,6 +45,7 @@ data class EntityTaskResponseDto(
                 prompt = task.prompt,
                 scheduleCron = task.scheduleCron,
                 emailLookback = task.emailLookback,
+                generationSource = task.generationSource,
                 active = task.active,
                 createdAt = task.createdAt
             )

backend/src/main/kotlin/com/condado/newsletter/model/EntityTask.kt

@@ -3,6 +3,8 @@ package com.condado.newsletter.model
 import jakarta.persistence.CascadeType
 import jakarta.persistence.Column
 import jakarta.persistence.Entity
+import jakarta.persistence.EnumType
+import jakarta.persistence.Enumerated
 import jakarta.persistence.FetchType
 import jakarta.persistence.GeneratedValue
 import jakarta.persistence.GenerationType
@@ -37,6 +39,10 @@ class EntityTask(
     @Column(name = "email_lookback", nullable = false)
     val emailLookback: String,
 
+    @Enumerated(EnumType.STRING)
+    @Column(name = "generation_source", nullable = false)
+    val generationSource: TaskGenerationSource = TaskGenerationSource.LLAMA,
+
     @Column(nullable = false)
     val active: Boolean = true,
 

backend/src/main/kotlin/com/condado/newsletter/model/TaskGenerationSource.kt

@@ -0,0 +1,19 @@
+package com.condado.newsletter.model
+
+import com.fasterxml.jackson.annotation.JsonCreator
+import com.fasterxml.jackson.annotation.JsonValue
+
+enum class TaskGenerationSource(
+    @get:JsonValue val value: String
+) {
+    OPENAI("openai"),
+    LLAMA("llama");
+
+    companion object {
+        @JvmStatic
+        @JsonCreator
+        fun from(value: String): TaskGenerationSource =
+            entries.firstOrNull { it.value.equals(value, ignoreCase = true) }
+                ?: throw IllegalArgumentException("Invalid generationSource: $value")
+    }
+}

backend/src/main/kotlin/com/condado/newsletter/service/EntityTaskService.kt

@@ -47,6 +47,7 @@ class EntityTaskService(
             prompt = dto.prompt,
             scheduleCron = dto.scheduleCron,
             emailLookback = dto.emailLookback,
+            generationSource = dto.generationSource,
             active = true
         )
 
@@ -66,6 +67,7 @@ class EntityTaskService(
             prompt = dto.prompt,
             scheduleCron = dto.scheduleCron,
             emailLookback = dto.emailLookback,
+            generationSource = dto.generationSource ?: existing.generationSource,
             active = existing.active,
             createdAt = existing.createdAt
         ).apply { id = existing.id }
@@ -83,6 +85,7 @@ class EntityTaskService(
             prompt = existing.prompt,
             scheduleCron = existing.scheduleCron,
             emailLookback = existing.emailLookback,
+            generationSource = existing.generationSource,
             active = false,
             createdAt = existing.createdAt
         ).apply { id = existing.id }
@@ -100,6 +103,7 @@ class EntityTaskService(
             prompt = existing.prompt,
             scheduleCron = existing.scheduleCron,
             emailLookback = existing.emailLookback,
+            generationSource = existing.generationSource,
             active = true,
             createdAt = existing.createdAt
         ).apply { id = existing.id }

backend/src/main/kotlin/com/condado/newsletter/service/TaskGeneratedMessageService.kt

@@ -3,6 +3,7 @@ package com.condado.newsletter.service
 import com.condado.newsletter.dto.GeneratedMessageHistoryResponseDto
 import com.condado.newsletter.dto.TaskPreviewGenerateRequestDto
 import com.condado.newsletter.model.GeneratedMessageHistory
+import com.condado.newsletter.model.TaskGenerationSource
 import com.condado.newsletter.repository.EntityTaskRepository
 import com.condado.newsletter.repository.GeneratedMessageHistoryRepository
 import org.springframework.stereotype.Service
@@ -16,7 +17,8 @@ import java.util.UUID
 class TaskGeneratedMessageService(
     private val generatedMessageHistoryRepository: GeneratedMessageHistoryRepository,
     private val entityTaskRepository: EntityTaskRepository,
-    private val llamaPreviewService: LlamaPreviewService
+    private val llamaPreviewService: LlamaPreviewService,
+    private val aiService: AiService
 ) {
 
     /** Lists persisted generated messages for a task. */
@@ -25,15 +27,19 @@ class TaskGeneratedMessageService(
             .findAllByTask_IdOrderByCreatedAtDesc(taskId)
             .map { GeneratedMessageHistoryResponseDto.from(it) }
 
-    /**
-     * Generates a new message using local Llama, persists it, and returns it.
-     */
+    /** Generates a new message with the task-selected provider, persists it, and returns it. */
     @Transactional
     fun generateAndSave(taskId: UUID, request: TaskPreviewGenerateRequestDto): GeneratedMessageHistoryResponseDto {
         val task = entityTaskRepository.findById(taskId)
             .orElseThrow { IllegalArgumentException("Task not found: $taskId") }
         val prompt = buildPrompt(request)
-        val generatedContent = llamaPreviewService.generate(prompt)
+        val generatedContent = when (task.generationSource) {
+            TaskGenerationSource.LLAMA -> llamaPreviewService.generate(prompt)
+            TaskGenerationSource.OPENAI -> {
+                val parsed = aiService.generate(prompt)
+                "SUBJECT: ${parsed.subject}\nBODY:\n${parsed.body}"
+            }
+        }
         val nextLabel = "Message #${generatedMessageHistoryRepository.countByTask_Id(taskId) + 1}"
 
         val saved = generatedMessageHistoryRepository.save(