use actix_web::{get, post, web, App, HttpResponse, HttpServer, Responder};
use serde::{Deserialize, Serialize};

// 定义响应数据结构
#[derive(Serialize)]
struct GreetingResponse {
    message: String,
}

// 定义请求数据结构
#[derive(Deserialize)]
struct UserRequest {
    name: String,
    age: u8,
}

// 健康检查端点
#[get("/health")]
async fn health_check() -> impl Responder {
    HttpResponse::Ok().body("Service is healthy")
}

// 根路径处理
#[get("/")]
async fn index() -> impl Responder {
    HttpResponse::Ok().body("Welcome to Rust Web Backend!")
}

// 带参数的问候端点
#[get("/greet/{name}")]
async fn greet(name: web::Path<String>) -> impl Responder {
    let response = GreetingResponse {
        message: format!("Hello, {}!", name),
    };
    HttpResponse::Ok().json(response)
}

// POST 请求处理
#[post("/user")]
async fn create_user(user: web::Json<UserRequest>) -> impl Responder {
    let response = GreetingResponse {
        message: format!("Created user: {} (age {})", user.name, user.age),
    };
    HttpResponse::Created().json(response)
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    println!("Starting server at http://localhost:8080");

    HttpServer::new(|| {
        App::new()
            .service(health_check)
            .service(index)
            .service(greet)
            .service(create_user)
    })
    .bind("0.0.0.0:8080")?
    .run()
    .await
}