use axum::{
    Json, Router,
    extract::{OriginalUri, Path, Request, State},
    http::{HeaderMap, HeaderValue, Method, StatusCode, header},
    middleware::{self, Next},
    response::sse::{Event, KeepAlive, Sse},
    response::{Html, IntoResponse, Response},
    routing::{get, patch, post, put},
};
use include_dir::{Dir, include_dir};
use std::{convert::Infallible, net::SocketAddr, sync::Arc, time::Duration};
use tokio::sync::{broadcast, oneshot};
use tower_http::{
    cors::{Any, CorsLayer},
    services::ServeDir,
    trace::TraceLayer,
};
use tracing::{info, warn};

use crate::config::Config;
use crate::db::Db;
use crate::error::StashError;
use crate::listing::{AppProject, scan_projects};
use crate::watcher;

/// build.rs 会把 `stash-web/dist` 同步到 `$OUT_DIR/web`，
/// 这里把整棵目录树在编译期内嵌，最终产出带前端的单文件二进制。
static WEB: Dir<'static> = include_dir!("$OUT_DIR/web");

/// Vite 产物文件名带内容 hash，可以长期强缓存；HTML 每次都要回源校验。
const HASHED_ASSET_CACHE: &str = "public, max-age=31536000, immutable";
const HTML_CACHE: &str = "no-cache";

#[derive(Clone)]
pub struct AppState {
    pub config: Arc<Config>,
    pub project_updates: broadcast::Sender<Vec<AppProject>>,
    /// 内容库：分类 / 分组 / 条目的唯一数据源
    pub db: Arc<Db>,
    /// 内容库写入后的广播：SSE 用它对所有打开的页面推「该重拉」。
    /// 不能只靠 `PRAGMA data_version`——服务自己的连接写完不会让它变化。
    pub catalog_updates: broadcast::Sender<()>,
    /// 登录失败计数（单用户本地场景，一个进程一份就够）
    pub login_guard: Arc<std::sync::Mutex<LoginGuard>>,
}

/// 连续登录失败 5 次 → 锁 60 秒。
#[derive(Debug, Default)]
pub struct LoginGuard {
    failures: u32,
    locked_until: Option<std::time::Instant>,
}

impl LoginGuard {
    fn locked(&mut self) -> bool {
        if let Some(until) = self.locked_until {
            if std::time::Instant::now() < until {
                return true;
            }
            self.failures = 0;
            self.locked_until = None;
        }
        false
    }

    fn record_failure(&mut self) {
        self.failures += 1;
        if self.failures >= 5 {
            self.locked_until = Some(std::time::Instant::now() + Duration::from_secs(60));
            self.failures = 0;
        }
    }

    fn reset(&mut self) {
        self.failures = 0;
        self.locked_until = None;
    }
}

pub struct ServerHandle {
    shutdown_tx: oneshot::Sender<()>,
    pub local_addr: SocketAddr,
}

impl ServerHandle {
    pub fn stop(self) {
        let _ = self.shutdown_tx.send(());
    }
}

/// 根路径：返回内嵌前端的入口页。
async fn web_index() -> Response {
    embedded_file("index.html").unwrap_or_else(|| not_found_page("/"))
}

/// `/assets/**`：Vite 产出的 CSS / JS / 图片。
async fn web_asset(OriginalUri(uri): OriginalUri, Path(path): Path<String>) -> Response {
    let file = format!("assets/{path}");
    embedded_file(&file).unwrap_or_else(|| not_found_page(uri.path()))
}

/// 前端放在 dist 根目录的其他文件（favicon 等）。
async fn web_root_file(OriginalUri(uri): OriginalUri) -> Response {
    let path = uri.path().trim_start_matches('/');
    embedded_file(path).unwrap_or_else(|| not_found_page(uri.path()))
}

/// 从内嵌目录取文件并组装响应；找不到返回 `None`。
fn embedded_file(path: &str) -> Option<Response> {
    let file = WEB.get_file(path)?;

    let mime = mime_guess::from_path(path).first_or_octet_stream();
    let content_type = HeaderValue::from_str(mime.as_ref())
        .unwrap_or_else(|_| HeaderValue::from_static("application/octet-stream"));
    let cache = if path.starts_with("assets/") {
        HeaderValue::from_static(HASHED_ASSET_CACHE)
    } else {
        HeaderValue::from_static(HTML_CACHE)
    };

    Some(
        (
            StatusCode::OK,
            [
                (header::CONTENT_TYPE, content_type),
                (header::CACHE_CONTROL, cache),
            ],
            file.contents(),
        )
            .into_response(),
    )
}

/// 统一 404：内嵌前端没有这个文件，托管目录里也没有这个路径。
fn not_found_page(path: &str) -> Response {
    let body = format!(
        r#"<!doctype html>
<html lang="zh-CN">
<head><meta charset="utf-8"><title>404 · 页面不存在</title></head>
<body style="margin:0;display:grid;place-items:center;min-height:100vh;background:#f7f9fb;color:#1e293b;font-family:system-ui,-apple-system,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif">
<main style="text-align:center;padding:24px">
<p style="margin:0;font-size:64px;font-weight:800;line-height:1;color:#cbd5e1">404</p>
<h1 style="margin:12px 0 8px;font-size:18px;font-weight:600">资源或页面不存在</h1>
<p style="margin:0 0 20px;color:#64748b"><code style="font-family:ui-monospace,Consolas,monospace;font-size:13px">{}</code></p>
<a href="/" style="display:inline-block;padding:8px 16px;border-radius:8px;background:#3b82f6;color:#fff;text-decoration:none;font-size:14px">返回本地应用</a>
</main>
</body>
</html>"#,
        escape_html(path)
    );

    (StatusCode::NOT_FOUND, Html(body)).into_response()
}

/// 前端客户端路由占用的路径前缀（见 `stash-web/src/data/view.ts`）。
///
/// 这些地址在服务端没有对应文件：`/c/apps` 刷新时 `ServeDir` 找不到东西，
/// 会落到下面的兜底处理器，由这里回落到内嵌的 `index.html`，
/// 前端再按 `location.pathname` 还原出同一页。
///
/// 只接管明确列出的前缀，托管目录里写错的路径仍然返回 404 页面：
/// 把所有未命中都冒充成 200 的「万能 SPA 回落」，会让人分不清
/// 到底是路由拼错了还是文件真的不存在。
const SPA_PREFIXES: &[&str] = &["/c/", "/g/"];

/// 精确匹配的前端页面（没有实体文件，返回入口页）
const SPA_PAGES: &[&str] = &["/login", "/admin", "/interface"];

/// 是否为前端路由路径（没有实体文件，应该返回入口页）。
fn is_spa_path(path: &str) -> bool {
    SPA_PAGES.contains(&path) || SPA_PREFIXES.iter().any(|prefix| path.starts_with(prefix))
}

/// `ServeDir` 的兜底：前端路由回落到入口页，其余路径仍是 404 页面。
async fn fallback_handler(OriginalUri(uri): OriginalUri, method: Method) -> Response {
    let is_page = method == Method::GET || method == Method::HEAD;

    if is_page && is_spa_path(uri.path()) {
        return web_index().await;
    }

    not_found_page(uri.path())
}

fn escape_html(value: &str) -> String {
    value
        .replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
}

/// API: 健康检查
async fn health_check() -> impl IntoResponse {
    Json(serde_json::json!({
        "status": "ok",
        "service": "stash"
    }))
}

/// API: 项目列表
async fn list_projects_api(State(state): State<AppState>) -> impl IntoResponse {
    let projects = scan_projects(&state.config.root);
    Json(serde_json::json!({
        "projects": projects
    }))
}

/// SSE：内容库被外部修改时通知前端重新拉取。
///
/// 这里轮询 `PRAGMA data_version` 而不是监听数据库文件：
/// SQLite 在 journal 模式下会产生临时文件的频繁读写，文件监听会误报，
/// 而 data_version 恰好在「其它连接提交了事务」时才变化，语义正好对上。
async fn catalog_events(State(state): State<AppState>) -> impl IntoResponse {
    let db = state.db.clone();
    let mut updates = state.catalog_updates.subscribe();

    let stream = async_stream::stream! {
        let mut last = db.data_version().unwrap_or(0);
        let mut ticker = tokio::time::interval(Duration::from_secs(5));

        loop {
            // 两条来源：本进程的写接口主动广播（快、准），
            // 以及 data_version 轮询兜底（外部工具直接改库时用）。
            let changed = tokio::select! {
                _ = ticker.tick() => match db.data_version() {
                    Ok(current) if current != last => {
                        last = current;
                        true
                    }
                    _ => false,
                },
                received = updates.recv() => received.is_ok(),
            };

            if !changed {
                continue;
            }

            // 只告诉前端「变了」，具体内容由它重新 GET /api/catalog
            yield Ok::<Event, Infallible>(
                Event::default().event("catalog").data(r#"{"changed":true}"#),
            );
        }
    };

    Sse::new(stream).keep_alive(
        KeepAlive::new()
            .interval(Duration::from_secs(15))
            .text("keep-alive"),
    )
}

/// 任何写请求成功后，通知所有打开的页面「内容库变了」。
///
/// 放在中间件里而不是逐个 handler 调：以后新增写接口不用再记得挂号。
/// 登录相关接口不涉及内容库，跳过以免无谓刷新。
async fn notify_catalog_writes(
    State(state): State<AppState>,
    request: Request,
    next: Next,
) -> Response {
    let method = request.method().clone();
    let path = request.uri().path().to_owned();

    let response = next.run(request).await;

    let mutating = matches!(
        method,
        Method::POST | Method::PATCH | Method::PUT | Method::DELETE
    );
    if mutating
        && path.starts_with("/api/")
        && !path.starts_with("/api/auth/")
        && response.status().is_success()
    {
        // 没人订阅（没有开着的页面）时 send 会失败，忽略即可
        let _ = state.catalog_updates.send(());
    }

    response
}

/// SSE：先发送当前快照，再持续推送文件监听产生的项目列表变化。
async fn project_events(State(state): State<AppState>) -> impl IntoResponse {
    let root = state.config.root.clone();
    let initial_projects = scan_projects(&root);
    let mut updates = state.project_updates.subscribe();

    let stream = async_stream::stream! {
        yield Ok::<Event, Infallible>(project_event(initial_projects));

        loop {
            match updates.recv().await {
                Ok(projects) => yield Ok(project_event(projects)),
                Err(broadcast::error::RecvError::Lagged(skipped)) => {
                    warn!("项目事件订阅落后 {skipped} 条，正在重新扫描");
                    yield Ok(project_event(scan_projects(&root)));
                }
                Err(broadcast::error::RecvError::Closed) => break,
            }
        }
    };

    Sse::new(stream).keep_alive(
        KeepAlive::new()
            .interval(Duration::from_secs(15))
            .text("keep-alive"),
    )
}

fn project_event(projects: Vec<AppProject>) -> Event {
    Event::default()
        .event("projects")
        .json_data(serde_json::json!({ "projects": projects }))
        .unwrap_or_else(|_| {
            warn!("序列化项目事件失败，将发送空项目列表");
            Event::default()
                .event("projects")
                .data(r#"{"projects":[]}"#)
        })
}

// ---------------- 登录 / 会话 ----------------

const SESSION_COOKIE: &str = "stash_session";

#[derive(serde::Deserialize)]
struct PasswordBody {
    password: String,
}

#[derive(serde::Deserialize)]
struct SetupBody {
    password: String,
    username: Option<String>,
}

#[derive(serde::Deserialize)]
struct ChangePasswordBody {
    current: String,
    next: String,
}

fn cookie_token(headers: &HeaderMap) -> Option<String> {
    let raw = headers.get(header::COOKIE)?.to_str().ok()?;
    raw.split(';')
        .filter_map(|part| part.trim().split_once('='))
        .find(|(key, _)| *key == SESSION_COOKIE)
        .map(|(_, value)| value.to_string())
}

fn session_cookie(token: &str) -> String {
    format!(
        "{SESSION_COOKIE}={token}; HttpOnly; SameSite=Strict; Path=/; Max-Age={}",
        crate::db::auth::SESSION_TTL_SECS
    )
}

fn clear_cookie() -> String {
    format!("{SESSION_COOKIE}=; HttpOnly; SameSite=Strict; Path=/; Max-Age=0")
}

fn api_error(status: StatusCode, message: &str) -> Response {
    (status, Json(serde_json::json!({ "error": message }))).into_response()
}

fn with_cookie(mut response: Response, cookie: String) -> Response {
    if let Ok(value) = HeaderValue::from_str(&cookie) {
        response.headers_mut().append(header::SET_COOKIE, value);
    }
    response
}

/// 同源校验：跨站请求带 Origin 且 host 不匹配时拒绝。
/// 和 Cookie 的 `SameSite=Strict` 互为补充，不依赖浏览器实现。
fn same_origin(headers: &HeaderMap) -> bool {
    let Some(origin) = headers
        .get(header::ORIGIN)
        .and_then(|value| value.to_str().ok())
    else {
        return true;
    };
    let Some(host) = headers.get(header::HOST).and_then(|value| value.to_str().ok()) else {
        return false;
    };
    origin.ends_with(host)
}

fn login_locked(state: &AppState) -> bool {
    state
        .login_guard
        .lock()
        .map(|mut guard| guard.locked())
        .unwrap_or(true)
}

fn login_failed(state: &AppState) {
    if let Ok(mut guard) = state.login_guard.lock() {
        guard.record_failure();
    }
}

fn login_ok(state: &AppState) {
    if let Ok(mut guard) = state.login_guard.lock() {
        guard.reset();
    }
}

async fn issue_token(state: &AppState) -> Result<String, Response> {
    let db = Arc::clone(&state.db);
    tokio::task::spawn_blocking(move || db.issue_session())
        .await
        .map_err(|error| api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()))?
        .map_err(|error| api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()))
}

async fn read_session(state: &AppState, headers: &HeaderMap) -> Result<crate::db::SessionState, Response> {
    let token = cookie_token(headers);
    let db = Arc::clone(&state.db);
    tokio::task::spawn_blocking(move || db.auth_state(token.as_deref()))
        .await
        .map_err(|error| api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()))?
        .map_err(|error| api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()))
}

/// GET /api/auth/session
async fn auth_session(State(state): State<AppState>, headers: HeaderMap) -> Response {
    match read_session(&state, &headers).await {
        Ok(session) => Json(session).into_response(),
        Err(response) => response,
    }
}

/// POST /api/auth/setup —— 只在还没有管理员时可用
async fn auth_setup(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<SetupBody>,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }

    let username = body.username.unwrap_or_else(|| "admin".into());
    let password = body.password;
    let db = Arc::clone(&state.db);
    let created = tokio::task::spawn_blocking(move || db.setup_admin(&username, &password)).await;

    match created {
        Ok(Ok(())) => match issue_token(&state).await {
            Ok(token) => with_cookie(
                Json(serde_json::json!({ "ok": true })).into_response(),
                session_cookie(&token),
            ),
            Err(response) => response,
        },
        Ok(Err(error)) => api_error(StatusCode::BAD_REQUEST, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// POST /api/auth/login
async fn auth_login(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<PasswordBody>,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }
    if login_locked(&state) {
        return api_error(StatusCode::TOO_MANY_REQUESTS, "尝试过多，请一分钟后再试");
    }

    let password = body.password;
    let db = Arc::clone(&state.db);
    let verified = tokio::task::spawn_blocking(move || db.login(&password)).await;

    match verified {
        Ok(Ok(Some(_username))) => {
            login_ok(&state);
            match issue_token(&state).await {
                Ok(token) => with_cookie(
                    Json(serde_json::json!({ "ok": true })).into_response(),
                    session_cookie(&token),
                ),
                Err(response) => response,
            }
        }
        Ok(Ok(None)) => {
            login_failed(&state);
            api_error(StatusCode::UNAUTHORIZED, "密码错误")
        }
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// POST /api/auth/logout
async fn auth_logout(State(state): State<AppState>, headers: HeaderMap) -> Response {
    if let Some(token) = cookie_token(&headers) {
        let db = Arc::clone(&state.db);
        let _ = tokio::task::spawn_blocking(move || db.logout(&token)).await;
    }

    with_cookie(
        Json(serde_json::json!({ "ok": true })).into_response(),
        clear_cookie(),
    )
}

/// PATCH /api/auth/password —— 必须已登录，成功后所有会话失效
async fn auth_password(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<ChangePasswordBody>,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }

    match read_session(&state, &headers).await {
        Ok(session) if session.authenticated => {}
        Ok(_) => return api_error(StatusCode::UNAUTHORIZED, "请先登录"),
        Err(response) => return response,
    }

    let db = Arc::clone(&state.db);
    let (current, next) = (body.current, body.next);
    let changed =
        tokio::task::spawn_blocking(move || db.change_password(&current, &next)).await;

    match changed {
        Ok(Ok(true)) => with_cookie(
            Json(serde_json::json!({ "ok": true })).into_response(),
            clear_cookie(),
        ),
        Ok(Ok(false)) => api_error(StatusCode::UNAUTHORIZED, "当前密码不正确"),
        Ok(Err(error)) => api_error(StatusCode::BAD_REQUEST, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

// ---------------- 站点设置 ----------------

#[derive(serde::Deserialize)]
struct SettingsPatch {
    version: i64,
    settings: crate::db::Settings,
}

/// GET /api/settings —— 读接口公开，前端首屏直接取
async fn get_settings(State(state): State<AppState>) -> Response {
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.load_settings()).await {
        Ok(Ok(document)) => Json(document).into_response(),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// PATCH /api/settings —— 需要登录；`version` 做乐观锁
async fn patch_settings(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<SettingsPatch>,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }

    match read_session(&state, &headers).await {
        Ok(session) if session.authenticated => {}
        Ok(_) => return api_error(StatusCode::UNAUTHORIZED, "请先登录"),
        Err(response) => return response,
    }

    let db = Arc::clone(&state.db);
    let (settings, version) = (body.settings, body.version);
    match tokio::task::spawn_blocking(move || db.save_settings(settings, version)).await {
        Ok(Ok(document)) => Json(document).into_response(),
        Ok(Err(StashError::Conflict(message))) => api_error(StatusCode::CONFLICT, &message),
        Ok(Err(StashError::InvalidDirectory(message))) => {
            api_error(StatusCode::BAD_REQUEST, &message)
        }
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

// ---------------- 字体 ----------------

/// 字体文件后缀：后台字体下拉只列这几种。
const FONT_EXTENSIONS: [&str; 4] = ["woff2", "woff", "ttf", "otf"];

/// GET /api/fonts —— `font/` 目录里的字体文件（后台字体下拉用，公开读）
async fn list_fonts(State(state): State<AppState>) -> Response {
    let dir = state.config.font_dir.clone();
    match tokio::task::spawn_blocking(move || scan_fonts(&dir)).await {
        Ok(Ok(fonts)) => Json(serde_json::json!({ "fonts": fonts })).into_response(),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// 列目录：目录不存在按「没有字体」处理，不让后台报错。
fn scan_fonts(dir: &std::path::Path) -> std::io::Result<Vec<serde_json::Value>> {
    let entries = match std::fs::read_dir(dir) {
        Ok(entries) => entries,
        Err(error) if error.kind() == std::io::ErrorKind::NotFound => return Ok(Vec::new()),
        Err(error) => return Err(error),
    };

    let mut fonts: Vec<(String, serde_json::Value)> = Vec::new();
    for entry in entries.flatten() {
        let path = entry.path();
        if !path.is_file() {
            continue;
        }
        let Some(extension) = path.extension().and_then(|value| value.to_str()) else {
            continue;
        };
        if !FONT_EXTENSIONS.contains(&extension.to_ascii_lowercase().as_str()) {
            continue;
        }
        let Some(name) = path.file_name().and_then(|value| value.to_str()) else {
            continue;
        };
        fonts.push((
            name.to_string(),
            serde_json::json!({ "name": name, "url": format!("/fonts/{name}") }),
        ));
    }
    fonts.sort_by(|a, b| a.0.cmp(&b.0));
    Ok(fonts.into_iter().map(|(_, value)| value).collect())
}

/// GET /fonts/{path} —— `font/` 目录里的字体文件。
/// 只认一级文件名：`..`、子目录一律 404，避免越界读文件。
async fn font_asset(State(state): State<AppState>, Path(path): Path<String>) -> Response {
    let reject = || not_found_page(&format!("/fonts/{path}"));
    if path.is_empty() || path.contains('/') || path.contains('\\') || path.contains("..") {
        return reject();
    }

    let file = state.config.font_dir.join(&path);
    let bytes = match tokio::fs::read(&file).await {
        Ok(bytes) => bytes,
        Err(_) => return reject(),
    };

    let mime = mime_guess::from_path(&path).first_or_octet_stream();
    let content_type = HeaderValue::from_str(mime.as_ref())
        .unwrap_or_else(|_| HeaderValue::from_static("application/octet-stream"));
    (
        [
            (header::CONTENT_TYPE, content_type),
            (header::CACHE_CONTROL, HeaderValue::from_static(HTML_CACHE)),
        ],
        bytes,
    )
        .into_response()
}

// ---------------- 条目编辑 / 备份 ----------------

/// GET /api/items/{key} —— 编辑表单的初始值（公开，便于未登录时预览）
async fn get_item(State(state): State<AppState>, Path(key): Path<String>) -> Response {
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.load_entry(&key)).await {
        Ok(Ok(Some(entry))) => Json(entry).into_response(),
        Ok(Ok(None)) => api_error(StatusCode::NOT_FOUND, "条目不存在"),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

#[derive(serde::Deserialize)]
struct ItemPatchBody {
    #[serde(rename = "updatedAt")]
    updated_at: i64,
    item: crate::db::EntryPatch,
}

/// PATCH /api/items/{key} —— 需要登录，`updatedAt` 乐观锁
async fn patch_item(
    State(state): State<AppState>,
    Path(key): Path<String>,
    headers: HeaderMap,
    Json(body): Json<ItemPatchBody>,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }

    match read_session(&state, &headers).await {
        Ok(session) if session.authenticated => {}
        Ok(_) => return api_error(StatusCode::UNAUTHORIZED, "请先登录"),
        Err(response) => return response,
    }

    let db = Arc::clone(&state.db);
    let (patch, updated_at) = (body.item, body.updated_at);
    match tokio::task::spawn_blocking(move || db.update_entry(&key, patch, updated_at)).await {
        Ok(Ok(entry)) => Json(entry).into_response(),
        Ok(Err(StashError::Conflict(message))) => api_error(StatusCode::CONFLICT, &message),
        Ok(Err(StashError::NotFound(message))) => api_error(StatusCode::NOT_FOUND, &message),
        Ok(Err(StashError::InvalidDirectory(message))) => {
            api_error(StatusCode::BAD_REQUEST, &message)
        }
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// GET /api/backup —— 下载整库快照（需要登录）。
///
/// 用 SQLite 的 `VACUUM INTO` 生成一致性副本，避免直接复制正在写的文件。
async fn backup_db(State(state): State<AppState>, headers: HeaderMap) -> Response {
    match read_session(&state, &headers).await {
        Ok(session) if session.authenticated => {}
        Ok(_) => return api_error(StatusCode::UNAUTHORIZED, "请先登录"),
        Err(response) => return response,
    }

    let db_path = state.config.db_path.clone();
    let created = tokio::task::spawn_blocking(move || -> Result<Vec<u8>, String> {
        let target = db_path.with_file_name(format!(
            "stash-backup-{}.db",
            std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .map(|duration| duration.as_secs())
                .unwrap_or(0)
        ));

        let conn = rusqlite::Connection::open(&db_path).map_err(|error| error.to_string())?;
        conn.execute("VACUUM INTO ?1", [target.to_string_lossy().as_ref()])
            .map_err(|error| error.to_string())?;
        let bytes = std::fs::read(&target).map_err(|error| error.to_string())?;
        let _ = std::fs::remove_file(&target);
        Ok(bytes)
    })
    .await;

    match created {
        Ok(Ok(bytes)) => {
            let filename = format!(
                "stash-backup-{}.db",
                std::time::SystemTime::now()
                    .duration_since(std::time::UNIX_EPOCH)
                    .map(|duration| duration.as_secs())
                    .unwrap_or(0)
            );
            (
                [
                    (header::CONTENT_TYPE, "application/octet-stream".to_string()),
                    (
                        header::CONTENT_DISPOSITION,
                        format!("attachment; filename=\"{filename}\""),
                    ),
                ],
                bytes,
            )
                .into_response()
        }
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// POST /api/items/{key}/view —— 记一次浏览（公开）
async fn post_view(State(state): State<AppState>, Path(key): Path<String>) -> Response {
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.bump_view(&key)).await {
        Ok(Ok((views, likes))) => Json(serde_json::json!({ "views": views, "likes": likes })).into_response(),
        Ok(Err(StashError::NotFound(message))) => api_error(StatusCode::NOT_FOUND, &message),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

#[derive(serde::Deserialize)]
struct LikeBody {
    liked: bool,
}

/// POST /api/items/{key}/like —— 点赞 / 取消（公开，前端用 localStorage 记是否已赞）
async fn post_like(
    State(state): State<AppState>,
    Path(key): Path<String>,
    Json(body): Json<LikeBody>,
) -> Response {
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.set_like(&key, body.liked)).await {
        Ok(Ok((views, likes))) => Json(serde_json::json!({ "views": views, "likes": likes })).into_response(),
        Ok(Err(StashError::NotFound(message))) => api_error(StatusCode::NOT_FOUND, &message),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// POST /api/items —— 新建条目（需要登录）
async fn create_item(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<crate::db::entries::NewEntry>,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }
    match read_session(&state, &headers).await {
        Ok(session) if session.authenticated => {}
        Ok(_) => return api_error(StatusCode::UNAUTHORIZED, "请先登录"),
        Err(response) => return response,
    }

    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.create_entry(body)).await {
        Ok(Ok(entry)) => Json(entry).into_response(),
        Ok(Err(StashError::Conflict(message))) => api_error(StatusCode::CONFLICT, &message),
        Ok(Err(StashError::NotFound(message))) => api_error(StatusCode::NOT_FOUND, &message),
        Ok(Err(StashError::InvalidDirectory(message))) => {
            api_error(StatusCode::BAD_REQUEST, &message)
        }
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// DELETE /api/items/{key} —— 删除条目（需要登录）
async fn delete_item(
    State(state): State<AppState>,
    Path(key): Path<String>,
    headers: HeaderMap,
) -> Response {
    if !same_origin(&headers) {
        return api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝");
    }
    match read_session(&state, &headers).await {
        Ok(session) if session.authenticated => {}
        Ok(_) => return api_error(StatusCode::UNAUTHORIZED, "请先登录"),
        Err(response) => return response,
    }

    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.remove_entry(&key)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(StashError::NotFound(message))) => api_error(StatusCode::NOT_FOUND, &message),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

// ---------- 原子模型：分组树 / 卡片 ----------

/// GET /api/catalog2 —— 分组树 + 卡片（公开读，新首页/侧栏用）
async fn catalog2_api(State(state): State<AppState>) -> Response {
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || -> Result<serde_json::Value, StashError> {
        Ok(serde_json::json!({
            "groups": db.load_tree()?,
            "cards": db.load_cards()?,
        }))
    })
    .await
    {
        Ok(Ok(payload)) => Json(payload).into_response(),
        Ok(Err(error)) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

async fn require_login(state: &AppState, headers: &HeaderMap) -> Result<(), Response> {
    if !same_origin(headers) {
        return Err(api_error(StatusCode::FORBIDDEN, "跨站请求被拒绝"));
    }
    match read_session(state, headers).await {
        Ok(session) if session.authenticated => Ok(()),
        Ok(_) => Err(api_error(StatusCode::UNAUTHORIZED, "请先登录")),
        Err(response) => Err(response),
    }
}

fn node_error(error: StashError) -> Response {
    match error {
        StashError::Conflict(message) => api_error(StatusCode::CONFLICT, &message),
        StashError::NotFound(message) => api_error(StatusCode::NOT_FOUND, &message),
        StashError::InvalidDirectory(message) => api_error(StatusCode::BAD_REQUEST, &message),
        other => api_error(StatusCode::INTERNAL_SERVER_ERROR, &other.to_string()),
    }
}

/// POST /api/groups —— 新建根分组 / 子分组
async fn create_node(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<crate::db::groups::NewNode>,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.create_node(body)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// PATCH /api/groups/{key} —— 改名 / 移动 / 排序 / 根分组格式
async fn update_node(
    State(state): State<AppState>,
    Path(key): Path<String>,
    headers: HeaderMap,
    Json(body): Json<crate::db::groups::UpdateNode>,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.update_node(&key, body)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// DELETE /api/groups/{key} —— 删除分组（级联子分组与条目）
async fn delete_node(
    State(state): State<AppState>,
    Path(key): Path<String>,
    headers: HeaderMap,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.remove_node(&key)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// POST /api/cards —— 新建卡片
async fn create_card(
    State(state): State<AppState>,
    headers: HeaderMap,
    Json(body): Json<crate::db::cards::NewCard>,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.create_card(body)).await {
        Ok(Ok(id)) => Json(serde_json::json!({ "id": id })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// PATCH /api/cards/{id} —— 卡片标题 / 顺序
async fn update_card(
    State(state): State<AppState>,
    Path(id): Path<i64>,
    headers: HeaderMap,
    Json(body): Json<crate::db::cards::UpdateCard>,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.update_card(id, body)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// DELETE /api/cards/{id} —— 删除卡片（不影响内容）
async fn delete_card(
    State(state): State<AppState>,
    Path(id): Path<i64>,
    headers: HeaderMap,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.remove_card(id)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// PUT /api/cards/{id}/groups —— 整组替换卡片勾选的分组
async fn set_card_groups(
    State(state): State<AppState>,
    Path(id): Path<i64>,
    headers: HeaderMap,
    Json(body): Json<Vec<crate::db::cards::CardGroupInput>>,
) -> Response {
    if let Err(response) = require_login(&state, &headers).await {
        return response;
    }
    let db = Arc::clone(&state.db);
    match tokio::task::spawn_blocking(move || db.set_card_groups(id, body)).await {
        Ok(Ok(())) => Json(serde_json::json!({ "ok": true })).into_response(),
        Ok(Err(error)) => node_error(error),
        Err(error) => api_error(StatusCode::INTERNAL_SERVER_ERROR, &error.to_string()),
    }
}

/// 组装路由：API + 内嵌前端 + 托管目录。
/// 单独抽出来是为了测试能直接对 `Router` 发请求：`start` 要绑定端口、
/// 起监听任务，没法在单元测试里用。
fn build_router(state: AppState) -> Router {
    let root = state.config.root.clone();
    let enable_cors = state.config.enable_cors;

    // 顺序就是优先级：显式路由（API / 内嵌前端）→ 托管目录 → 前端路由回落 → 404
    let serve_dir = ServeDir::new(&root)
        .append_index_html_on_directories(true)
        .fallback(axum::handler::HandlerWithoutStateExt::into_service(
            fallback_handler,
        ));

    let mut app = Router::new()
        .route("/api/health", get(health_check))
        .route("/api/projects", get(list_projects_api))
        .route("/api/projects/events", get(project_events))
        .route("/api/catalog2", get(catalog2_api))
        .route("/api/nodes", post(create_node))
        .route("/api/nodes/{key}", patch(update_node).delete(delete_node))
        .route("/api/cards", post(create_card))
        .route("/api/cards/{id}", patch(update_card).delete(delete_card))
        .route("/api/cards/{id}/groups", put(set_card_groups))
        .route("/api/catalog/events", get(catalog_events))
        .route("/api/auth/session", get(auth_session))
        .route("/api/auth/setup", post(auth_setup))
        .route("/api/auth/login", post(auth_login))
        .route("/api/auth/logout", post(auth_logout))
        .route("/api/auth/password", patch(auth_password))
        .route("/api/settings", get(get_settings).patch(patch_settings))
        .route("/api/fonts", get(list_fonts))
        .route("/fonts/{*path}", get(font_asset))
        .route("/api/items/{key}", get(get_item).patch(patch_item).delete(delete_item))
        .route("/api/items", post(create_item))
        .route("/api/items/{key}/view", post(post_view))
        .route("/api/items/{key}/like", post(post_like))
        .route("/api/backup", get(backup_db))
        .route("/", get(web_index))
        .route("/index.html", get(web_index))
        .route("/favicon.svg", get(web_root_file))
        .route("/assets/{*path}", get(web_asset))
        .fallback_service(serve_dir)
        .with_state(state.clone())
        // 写接口成功后广播「内容库变了」，让所有打开的页面自己重拉
        .layer(middleware::from_fn_with_state(
            state,
            notify_catalog_writes,
        ))
        .layer(TraceLayer::new_for_http());

    if enable_cors {
        app = app.layer(
            CorsLayer::new()
                .allow_origin(Any)
                .allow_methods(Any)
                .allow_headers(Any),
        );
    }

    app
}

pub async fn start(config: Config) -> Result<ServerHandle, StashError> {
    if !config.root.exists() {
        return Err(StashError::InvalidDirectory(
            config.root.display().to_string(),
        ));
    }

    let (project_updates, _) = broadcast::channel(32);
    watcher::start(config.root.clone(), project_updates.clone())?;
    let (catalog_updates, _) = broadcast::channel(16);

    // 内容库在启动时打开：建库 / 建表 / 空库时灌种子都在这里完成
    let db = Arc::new(Db::open(&config)?);

    let shared_state = AppState {
        config: Arc::new(config.clone()),
        project_updates,
        db,
        catalog_updates,
        login_guard: Arc::new(std::sync::Mutex::new(LoginGuard::default())),
    };

    let app = build_router(shared_state);

    let addr: SocketAddr = format!("{}:{}", config.host, config.port).parse()?;
    let listener = tokio::net::TcpListener::bind(addr)
        .await
        .map_err(|e| StashError::ServerBind(format!("端口 {} 绑定失败: {}", config.port, e)))?;

    let local_addr = listener.local_addr()?;
    info!("Stash 服务运行于: http://{}", local_addr);

    let (shutdown_tx, shutdown_rx) = oneshot::channel::<()>();

    tokio::spawn(async move {
        let server = axum::serve(listener, app).with_graceful_shutdown(async move {
            let _ = shutdown_rx.await;
            info!("Stash 优雅停机...");
        });

        if let Err(err) = server.await {
            warn!("服务异常退出: {}", err);
        }
    });

    Ok(ServerHandle {
        shutdown_tx,
        local_addr,
    })
}

#[cfg(test)]
mod tests {
    use super::*;
    use axum::{body::Body, http::Request};
    use std::path::PathBuf;
    use tower::ServiceExt;

    /// 测试用的托管目录：放在 `target/` 下，不依赖系统临时目录的权限。
    fn hosted_root() -> PathBuf {
        let root =
            std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("target/test-tmp/spa-root");

        std::fs::create_dir_all(root.join("demo")).expect("应能创建测试项目");
        std::fs::write(
            root.join("demo/index.html"),
            "<!doctype html><title>demo</title>",
        )
        .expect("应能写入项目入口页");
        std::fs::write(root.join("note.txt"), "plain file").expect("应能写入普通文件");

        root
    }

    fn router() -> Router {
        let mut config = Config::default();
        config.root = hosted_root();
        // 测试不关心 CORS 标头
        config.enable_cors = false;

        let (project_updates, _) = broadcast::channel(4);
        let (catalog_updates, _) = broadcast::channel(4);

        build_router(AppState {
            config: Arc::new(config),
            project_updates,
            db: Arc::new(Db::in_memory()),
            catalog_updates,
            login_guard: Arc::new(std::sync::Mutex::new(LoginGuard::default())),
        })
    }

    #[test]
    fn scan_fonts_lists_only_font_files() {
        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("target/test-tmp/font-scan");
        let _ = std::fs::remove_dir_all(&dir);
        std::fs::create_dir_all(&dir).expect("应能建目录");
        std::fs::write(dir.join("b.ttf"), b"x").expect("应能写入");
        std::fs::write(dir.join("a.WOFF2"), b"x").expect("应能写入");
        std::fs::write(dir.join("note.txt"), b"x").expect("应能写入");

        let fonts = scan_fonts(&dir).expect("应能列目录");
        let names: Vec<_> = fonts
            .iter()
            .map(|font| font["name"].as_str().unwrap_or_default())
            .collect();
        assert_eq!(names, vec!["a.WOFF2", "b.ttf"]);
        assert_eq!(fonts[0]["url"], "/fonts/a.WOFF2");

        std::fs::remove_dir_all(&dir).ok();
    }

    #[test]
    fn scan_fonts_treats_missing_dir_as_empty() {
        let dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("target/test-tmp/no-such-font-dir");
        let _ = std::fs::remove_dir_all(&dir);
        assert!(scan_fonts(&dir).expect("目录不存在不应报错").is_empty());
    }

    /// 发一个 GET，返回（状态码，Content-Type，响应体）。
    async fn get(path: &str) -> (StatusCode, String, String) {
        let response = router()
            .oneshot(
                Request::builder()
                    .uri(path)
                    .body(Body::empty())
                    .expect("请求应能构造"),
            )
            .await
            .expect("路由应能处理请求");

        let status = response.status();
        let content_type = response
            .headers()
            .get(header::CONTENT_TYPE)
            .and_then(|value| value.to_str().ok())
            .unwrap_or_default()
            .to_string();

        let bytes = axum::body::to_bytes(response.into_body(), usize::MAX)
            .await
            .expect("应能读出响应体");

        (
            status,
            content_type,
            String::from_utf8_lossy(&bytes).into_owned(),
        )
    }

    /// 刷新分类明细页：服务端没有 `/c/apps` 这个文件，必须回落到前端入口页。
    #[tokio::test]
    async fn spa_routes_fall_back_to_the_embedded_index() {
        let (status, content_type, body) = get("/c/apps").await;

        assert_eq!(status, StatusCode::OK);
        assert!(
            content_type.starts_with("text/html"),
            "应返回 HTML: {content_type}"
        );
        assert!(body.contains(r#"<div id="root">"#), "应返回前端入口页");
    }

    /// 条目详情地址（含分组）同样回落：`/c/` 前缀下的任意层级都是前端路由。
    #[tokio::test]
    async fn item_routes_fall_back_to_the_embedded_index() {
        let (status, _, body) = get("/c/apps/common/i/github").await;
        assert_eq!(status, StatusCode::OK);
        assert!(body.contains(r#"<div id="root">"#));

        // 本地项目：条目 id 是项目名，可能带空格 / 中文，照样要能落到入口页
        let (status, _, _) = get("/c/local/local-all/i/demo").await;
        assert_eq!(status, StatusCode::OK);
    }

    /// 托管目录里的真实文件优先于回落，不能被前端路由吞掉。
    #[tokio::test]
    async fn hosted_files_still_win_over_the_spa_fallback() {
        let (status, _, body) = get("/demo/").await;
        assert_eq!(status, StatusCode::OK);
        assert!(
            body.contains("<title>demo</title>"),
            "应直接返回项目入口页: {body}"
        );

        let (status, _, body) = get("/note.txt").await;
        assert_eq!(status, StatusCode::OK);
        assert_eq!(body, "plain file");
    }

    /// 不是前端路由的路径仍然返回 404 页面（带请求路径，便于排错）。
    #[tokio::test]
    async fn unknown_paths_still_return_the_404_page() {
        let (status, content_type, body) = get("/missing.txt").await;

        assert_eq!(status, StatusCode::NOT_FOUND);
        assert!(content_type.starts_with("text/html"));
        assert!(body.contains("404"));
        assert!(body.contains("/missing.txt"), "404 页面应显示请求路径");
    }

    /// API 不能被回落影响。
    #[tokio::test]
    async fn api_routes_are_not_swallowed_by_the_fallback() {
        let (status, content_type, body) = get("/api/health").await;

        assert_eq!(status, StatusCode::OK);
        assert!(content_type.starts_with("application/json"));
        assert!(body.contains("\"status\":\"ok\""));
    }

    /// 只接管登记过的前缀：`/c` 本身与 `/css/...` 都还是普通路径。
    #[test]
    fn only_registered_prefixes_fall_back() {
        assert!(is_spa_path("/c/apps"));
        assert!(is_spa_path("/c/"));
        assert!(!is_spa_path("/c"));
        assert!(!is_spa_path("/css/app.css"));
    }
}