PersonalWebApplication/Server/src/routes/web.rs

//! 前端（React）专用接口。挂 CORS，仅放行前端开发源。

use std::net::SocketAddr;

use axum::{
    Json, Router,
    extract::{ConnectInfo, State},
    http::{HeaderMap, Method, StatusCode, header},
    routing::{get, post},
};
use serde::{Deserialize, Serialize};
use serde_json::{Value, json};
use tower_http::cors::{AllowOrigin, CorsLayer};

use crate::{monitor::Stats, state::AppState, weather::WeatherOutcome};

pub fn router(state: AppState) -> Router {
    // CORS：只有浏览器会校验。放行前端开发源（Vite 默认 5173，被占用时会用 5174）。
    // 登录是 POST + JSON，所以要额外放行 POST 方法与 Content-Type 请求头，
    // 否则浏览器的预检（OPTIONS）会被拦下。
    let cors = CorsLayer::new()
        .allow_origin(AllowOrigin::list([
            "http://localhost:5173".parse().unwrap(),
            "http://127.0.0.1:5173".parse().unwrap(),
            "http://localhost:5174".parse().unwrap(),
            "http://127.0.0.1:5174".parse().unwrap(),
        ]))
        .allow_methods([Method::GET, Method::POST])
        .allow_headers([header::CONTENT_TYPE]);

    Router::new()
        .route("/api/web/stats", get(stats))
        .route("/api/web/login", post(login))
        .route("/api/web/weather", get(weather))
        .layer(cors)
        .with_state(state)
}

/// 返回最新系统状态快照。
async fn stats(State(state): State<AppState>) -> Json<Stats> {
    let snapshot = state.snapshot.read().await.clone();
    Json(snapshot)
}

/// 登录请求体：用户名 + 明文密码（开发期走 HTTP；生产应套 HTTPS）。
#[derive(Deserialize)]
struct LoginRequest {
    username: String,
    password: String,
}

/// 登录成功响应。`token` 目前只是给前端持久化「登录态」用的标识，
/// 暂无受保护接口去校验它；将来加鉴权中间件时再赋予真实含义。
#[derive(Serialize)]
struct LoginResponse {
    ok: bool,
    username: String,
    token: String,
}

/// 校验用户名/密码。成功 200 + token，失败 401。
async fn login(
    State(state): State<AppState>,
    Json(req): Json<LoginRequest>,
) -> Result<Json<LoginResponse>, StatusCode> {
    if state.users.verify(&req.username, &req.password) {
        Ok(Json(LoginResponse {
            ok: true,
            username: req.username,
            token: crate::auth::issue_token(),
        }))
    } else {
        Err(StatusCode::UNAUTHORIZED)
    }
}

/// 天气 + 定位：高德按访问者 IP 定位取城市，和风取实时天气。
/// 内部自带每日限流（高德 300 / 和风 900，北京时间 0 点归零）与短期缓存。
async fn weather(
    State(state): State<AppState>,
    ConnectInfo(addr): ConnectInfo<SocketAddr>,
    headers: HeaderMap,
) -> Json<Value> {
    let ip = client_ip(&headers, addr);
    let outcome = state.weather.get(&ip).await;

    let q = state.weather.quota_snapshot();
    let quota = json!({
        "amap": { "remaining": q.amap_remaining, "limit": q.amap_limit },
        "qweather": { "remaining": q.qweather_remaining, "limit": q.qweather_limit },
    });

    let body = match outcome {
        WeatherOutcome::Fresh(d) => json!({
            "ok": true, "cached": false,
            "city": d.city, "text": d.text, "temp": d.temp, "icon": d.icon, "obsTime": d.obs_time,
            "quota": quota,
        }),
        WeatherOutcome::Cached(d) => json!({
            "ok": true, "cached": true,
            "city": d.city, "text": d.text, "temp": d.temp, "icon": d.icon, "obsTime": d.obs_time,
            "quota": quota,
        }),
        WeatherOutcome::QuotaExceeded { provider } => json!({
            "ok": false, "reason": "quota_exceeded", "provider": provider,
            "quota": quota,
        }),
        WeatherOutcome::NotConfigured => json!({
            "ok": false, "reason": "not_configured",
        }),
        WeatherOutcome::Failed(message) => json!({
            "ok": false, "reason": "failed", "message": message,
        }),
    };

    Json(body)
}

/// 取访问者真实 IP：优先反代透传的 `X-Forwarded-For` 首段，否则用对端 socket 地址。
fn client_ip(headers: &HeaderMap, addr: SocketAddr) -> String {
    if let Some(xff) = headers.get("x-forwarded-for").and_then(|v| v.to_str().ok()) {
        if let Some(first) = xff.split(',').next() {
            let ip = first.trim();
            if !ip.is_empty() {
                return ip.to_string();
            }
        }
    }
    addr.ip().to_string()
}