// Copyright (c) Microsoft. All rights reserved.

// This sample shows how to host an AI agent with Azure Functions (DurableAgents).
//
// Prerequisites:
//   - Azure Functions Core Tools
//   - Foundry project endpoint and credentials
//
// Environment variables:
//   FOUNDRY_PROJECT_ENDPOINT
//   FOUNDRY_MODEL (defaults to "gpt-5.4-mini")
//
// Run with: func start
// Then call: POST http://localhost:7071/api/agents/HostedAgent/run

using Azure.AI.Projects;
using Azure.Identity;
using Microsoft.Agents.AI;
using Microsoft.Agents.AI.Hosting.AzureFunctions;
using Microsoft.Azure.Functions.Worker.Builder;
using Microsoft.Extensions.Hosting;

var endpoint = Environment.GetEnvironmentVariable("FOUNDRY_PROJECT_ENDPOINT")
    ?? throw new InvalidOperationException("FOUNDRY_PROJECT_ENDPOINT is not set.");
var model = Environment.GetEnvironmentVariable("FOUNDRY_MODEL") ?? "gpt-5.4-mini";

// Set up an AI agent following the standard Microsoft Agent Framework pattern.
// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
AIAgent agent = new AIProjectClient(new Uri(endpoint), new DefaultAzureCredential())
    .AsAIAgent(model: model, instructions: "You are a helpful assistant hosted in Azure Functions.", name: "HostedAgent");

// Configure the function app to host the AI agent.
// This will automatically generate HTTP API endpoints for the agent.
using IHost app = FunctionsApplication
    .CreateBuilder(args)
    .ConfigureFunctionsWebApplication()
    .ConfigureDurableAgents(options => options.AddAIAgent(agent, timeToLive: TimeSpan.FromHours(1)))
    .Build();
app.Run();
