//! 认证模块

pub mod jwt;
pub mod password;
pub mod types;
pub mod handlers;
pub mod totp;

use axum::{
    extract::{Request, State},
    http::header,
    middleware::Next,
    response::{IntoResponse, Response},
    extract::ConnectInfo,
};
use secrecy::ExposeSecret;
use crate::error::SaasError;
use crate::state::AppState;
use types::AuthContext;
use std::net::SocketAddr;

/// 通过 API Token 验证身份
///
/// 流程: SHA-256 哈希 → 查 api_tokens 表 → 检查有效期 → 获取关联账号角色权限 → 更新 last_used_at
async fn verify_api_token(state: &AppState, raw_token: &str, client_ip: Option<String>) -> Result<AuthContext, SaasError> {
    use sha2::{Sha256, Digest};

    let token_hash = hex::encode(Sha256::digest(raw_token.as_bytes()));

    let row: Option<(String, Option<String>, String)> = sqlx::query_as(
        "SELECT account_id, expires_at, permissions FROM api_tokens
         WHERE token_hash = $1 AND revoked_at IS NULL"
    )
    .bind(&token_hash)
    .fetch_optional(&state.db)
    .await?;

    let (account_id, expires_at, permissions_json) = row
        .ok_or(SaasError::Unauthorized)?;

    // 检查是否过期
    if let Some(ref exp) = expires_at {
        let now = chrono::Utc::now();
        if let Ok(exp_time) = chrono::DateTime::parse_from_rfc3339(exp) {
            if now >= exp_time.with_timezone(&chrono::Utc) {
                return Err(SaasError::Unauthorized);
            }
        }
    }

    // 查询关联账号的角色
    let (role,): (String,) = sqlx::query_as(
        "SELECT role FROM accounts WHERE id = $1 AND status = 'active'"
    )
    .bind(&account_id)
    .fetch_optional(&state.db)
    .await?
    .ok_or(SaasError::Unauthorized)?;

    // 合并 token 权限与角色权限（去重）
    let role_permissions = handlers::get_role_permissions(&state.db, &state.role_permissions_cache, &role).await?;
    let token_permissions: Vec<String> = serde_json::from_str(&permissions_json).unwrap_or_default();
    let mut permissions = role_permissions;
    for p in token_permissions {
        if !permissions.contains(&p) {
            permissions.push(p);
        }
    }

    // 异步更新 last_used_at（不阻塞请求）
    let db = state.db.clone();
    tokio::spawn(async move {
        let now = chrono::Utc::now().to_rfc3339();
        let _ = sqlx::query("UPDATE api_tokens SET last_used_at = $1 WHERE token_hash = $2")
            .bind(&now).bind(&token_hash)
            .execute(&db).await;
    });

    Ok(AuthContext {
        account_id,
        role,
        permissions,
        client_ip,
    })
}

/// 从请求中提取客户端 IP
fn extract_client_ip(req: &Request) -> Option<String> {
    // 优先从 ConnectInfo 获取
    if let Some(ConnectInfo(addr)) = req.extensions().get::<ConnectInfo<SocketAddr>>() {
        return Some(addr.ip().to_string());
    }
    // 回退到 X-Forwarded-For / X-Real-IP
    if let Some(forwarded) = req.headers()
        .get("x-forwarded-for")
        .and_then(|v| v.to_str().ok())
    {
        return Some(forwarded.split(',').next()?.trim().to_string());
    }
    req.headers()
        .get("x-real-ip")
        .and_then(|v| v.to_str().ok())
        .map(|s| s.to_string())
}

/// 认证中间件: 从 JWT Cookie / Authorization Header / API Token 提取身份
pub async fn auth_middleware(
    State(state): State<AppState>,
    jar: axum_extra::extract::cookie::CookieJar,
    mut req: Request,
    next: Next,
) -> Response {
    let client_ip = extract_client_ip(&req);
    let auth_header = req.headers()
        .get(header::AUTHORIZATION)
        .and_then(|v| v.to_str().ok());

    // 尝试从 Authorization header 提取 token
    let header_token = auth_header.and_then(|auth| auth.strip_prefix("Bearer "));

    // 尝试从 HttpOnly cookie 提取 token (仅当 header 不存在时)
    let cookie_token = jar.get("zclaw_access_token").map(|c| c.value().to_string());

    let token = header_token
        .or(cookie_token.as_deref());

    let result = if let Some(token) = token {
        if token.starts_with("zclaw_") {
            // API Token 路径
            verify_api_token(&state, token, client_ip.clone()).await
        } else {
            // JWT 路径
            match jwt::verify_token(token, state.jwt_secret.expose_secret()) {
                Ok(claims) => {
                    // H1: 验证 password_version — 密码变更后旧 token 失效
                    let pwv_row: Option<(i32,)> = sqlx::query_as(
                        "SELECT password_version FROM accounts WHERE id = $1"
                    )
                    .bind(&claims.sub)
                    .fetch_optional(&state.db)
                    .await
                    .ok()
                    .flatten();

                    match pwv_row {
                        Some((current_pwv,)) if (current_pwv as u32) == claims.pwv => {
                            Ok(AuthContext {
                                account_id: claims.sub,
                                role: claims.role,
                                permissions: claims.permissions,
                                client_ip,
                            })
                        }
                        _ => {
                            tracing::warn!(
                                account_id = %claims.sub,
                                token_pwv = claims.pwv,
                                "Token rejected: password_version mismatch or account not found"
                            );
                            Err(SaasError::Unauthorized)
                        }
                    }
                }
                Err(_) => Err(SaasError::Unauthorized),
            }
        }
    } else {
        Err(SaasError::Unauthorized)
    };

    match result {
        Ok(ctx) => {
            req.extensions_mut().insert(ctx);
            next.run(req).await
        }
        Err(e) => e.into_response(),
    }
}

/// 路由 (无需认证的端点)
pub fn routes() -> axum::Router<AppState> {
    use axum::routing::post;

    axum::Router::new()
        .route("/api/v1/auth/register", post(handlers::register))
        .route("/api/v1/auth/login", post(handlers::login))
        .route("/api/v1/auth/refresh", post(handlers::refresh))
        .route("/api/v1/auth/logout", post(handlers::logout))
}

/// 需要认证的路由
pub fn protected_routes() -> axum::Router<AppState> {
    use axum::routing::{get, post, put};

    axum::Router::new()
        .route("/api/v1/auth/me", get(handlers::me))
        .route("/api/v1/auth/password", put(handlers::change_password))
        .route("/api/v1/auth/totp/setup", post(totp::setup_totp))
        .route("/api/v1/auth/totp/verify", post(totp::verify_totp))
        .route("/api/v1/auth/totp/disable", post(totp::disable_totp))
}