feat: add minimal api

GeoPulse Pipeline/Program.cs

@@ -0,0 +1,91 @@
+using System.Text.Json;
+using Confluent.Kafka;
+using GeoPulse_Pipeline;
+using Microsoft.AspNetCore.Mvc;
+using Npgsql;
+
+var builder = WebApplication.CreateBuilder(args);
+var kafkaHost = builder.Configuration.GetValue<string>("KafkaHost");
+var producerConfig = new ProducerConfig()
+{
+	BootstrapServers = kafkaHost,
+	Acks = Acks.Leader
+};
+
+
+var kafkaProducer = new ProducerBuilder<Null, string>(producerConfig).Build();
+builder.Services.AddSingleton(kafkaProducer);
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen();
+builder.Services.AddHostedService<KafkaConsumer>();
+
+var app = builder.Build();
+
+if (app.Environment.IsDevelopment())
+{
+	app.UseSwagger();
+	app.UseSwaggerUI();
+}
+
+app.UseHttpsRedirection();
+
+app.MapPost("/api/telemetry", async (
+    [FromBody] TelemetryRequest request, 
+    [FromQuery] bool useKafka,
+    IProducer<Null, string> producer,
+    IConfiguration config) =>
+{
+    if (string.IsNullOrWhiteSpace(request.DeviceId))
+        return Results.BadRequest("Device ID is required.");
+
+    if (useKafka)
+    {
+        var message = JsonSerializer.Serialize(request);
+        try
+        {
+            await producer.ProduceAsync("telemetry-events", new Message<Null, string> { Value = message });
+            return Results.Ok(new { Status = "Success", Route = "Kafka", Message = "已推入消息佇列" });
+        }
+        catch (ProduceException<Null, string> ex)
+        {
+            Console.WriteLine($"Kafka Delivery failed: {ex.Error.Reason}");
+            return Results.Problem("Kafka 寫入失敗");
+        }
+    }
+    else
+    {
+        try
+        {
+            var connString = config.GetConnectionString("DefaultConnection");
+            
+            await using var dataSource = NpgsqlDataSource.Create(connString!);
+            await using var cmd = dataSource.CreateCommand(@"
+                INSERT INTO telemetry_table (id, device_id, geom, timestamp) 
+                VALUES (gen_random_uuid(), $1, ST_SetSRID(ST_MakePoint($2, $3), 4326), $4)");
+
+            cmd.Parameters.AddWithValue(request.DeviceId);
+            cmd.Parameters.AddWithValue(request.Lng);
+            cmd.Parameters.AddWithValue(request.Lat);
+            cmd.Parameters.AddWithValue(request.Timestamp);
+
+            await cmd.ExecuteNonQueryAsync();
+            
+            return Results.Ok(new { Status = "Success", Route = "Direct-DB", Message = "已直接寫入資料庫" });
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"DB Insert failed: {ex.Message}");
+            return Results.Problem("資料庫寫入失敗");
+        }
+    }
+});
+
+app.Lifetime.ApplicationStopping.Register(() =>
+{
+	kafkaProducer.Flush(TimeSpan.FromSeconds(10));
+	kafkaProducer.Dispose();
+});
+
+app.Run();
+
+record TelemetryRequest(string DeviceId, double Lng, double Lat, DateTimeOffset Timestamp);