Add InjectedDemo as in Java template

Author: johnsonr

README.md

@@ -17,7 +17,9 @@ Add your magic here!
 
 Illustrates:
 
-- A simple agent using the Embabel `@Agent` and `@Action` annotations
+- An injected demo showing how any Spring component can be injected with an Embabel `Ai` instance to enable it to
+  perform LLM operations.
+- A simple agent
 - Unit tests for an agent verifying prompts and hyperparameters
 
 > For the Java equivalent, see
@@ -42,11 +44,19 @@ When the Embabel shell comes up, invoke the story agent like this:
 x "Tell me a story about...[your topic]"
 ```
 
+Try the following other shell commands:
+
+- `demo`: Runs the same agent, invoked programmatically, instead of dynamically based on user input.
+  See [DemoCommands.kt](./src/main/kotlin/com/embabel/template/DemoShell.kt) for the
+  implementation.
+- `animal`:  Runs a simple demo using an Embabel injected `Ai` instance to call an LLM.
+  See [InjectedDemo](./src/main/kotlin/com/embabel/template/injected/InjectedDemo.kt).
+
 ## Suggested Next Steps
 
 To get a feel for working with Embabel, try the following:
 
-- Modify the prompts in `WriteAndReviewAgent`.
+- Modify the prompts in `WriteAndReviewAgent` and `InjectedDemo`.
 - Experiment with different models and hyperparameters by modifying `withLlm` calls.
 - Integrate your own services, injecting them with Spring. All Embabel `@Agent` classes are Spring beans.
 - Run the tests with `mvn test` and modify them to experiment with prompt verification.

src/main/kotlin/com/embabel/template/DemoShell.kt

@@ -0,0 +1,31 @@
+package com.embabel.template
+
+import com.embabel.agent.api.invocation.AgentInvocation
+import com.embabel.agent.core.AgentPlatform
+import com.embabel.agent.domain.io.UserInput
+import com.embabel.template.agent.ReviewedStory
+import com.embabel.template.injected.InjectedDemo
+import org.springframework.shell.standard.ShellComponent
+import org.springframework.shell.standard.ShellMethod
+
+@ShellComponent
+class DemoShell(
+    private val injectedDemo: InjectedDemo,
+    private val agentPlatform: AgentPlatform,
+) {
+
+    @ShellMethod("Demo")
+    fun demo(): String {
+        // Illustrate calling an agent programmatically,
+        // as most often occurs in real applications.
+        val reviewedStory = AgentInvocation
+            .create(agentPlatform, ReviewedStory::class.java)
+            .invoke(UserInput("Tell me a story about caterpillars"))
+        return reviewedStory.content
+    }
+
+    @ShellMethod("Invent an animal")
+    fun animal(): String {
+        return injectedDemo.inventAnimal().toString()
+    }
+}

src/main/kotlin/com/embabel/template/injected/InjectedDemo.kt

@@ -0,0 +1,40 @@
+package com.embabel.template.injected
+
+import com.embabel.agent.api.common.Ai
+import jakarta.validation.constraints.Pattern
+import org.springframework.stereotype.Component
+
+/**
+ * Demonstrate injection of Embabel's OperationContext into a Spring component.
+ *
+ * @param ai Embabel AI helper, injected by Spring
+ */
+@Component
+class InjectedDemo(private val ai: Ai) {
+
+    /**
+     * Demonstrates use of JSR-380 validation annotations on record fields
+     * to constrain generated content.
+     */
+    data class Animal(
+        val name: String,
+        @field:Pattern(regexp = ".*ox.*", message = "Species must contain 'ox'")
+        val species: String,
+    )
+
+    fun inventAnimal(): Animal {
+        return ai
+            .withDefaultLlm()
+            .withId("invent-animal")
+            .creating(Animal::class.java)
+            .withExample("good example", Animal("Fluffox", "Magicox"))
+            .withExample("bad example: does not pass validation", Animal("Sparky", "Dragon"))
+            .fromPrompt(
+                """
+                You just woke up in a magical forest.
+                Invent a fictional animal.
+                The animal should have a name and a species.
+                """.trimIndent(),
+            )
+    }
+}