//! 认证 HTTP 处理器

use axum::{extract::{State, ConnectInfo}, Json};
use axum_extra::extract::CookieJar;
use axum_extra::extract::cookie::{Cookie, SameSite};
use std::net::SocketAddr;
use secrecy::ExposeSecret;
use crate::state::AppState;
use crate::error::{SaasError, SaasResult};
use crate::models::{AccountAuthRow, AccountLoginRow};
use super::{
    jwt::{create_token, create_refresh_token, verify_token, verify_token_skip_expiry},
    password::{hash_password_async, verify_password_async},
    types::{AuthContext, LoginRequest, LoginResponse, RegisterRequest, ChangePasswordRequest, AccountPublic, RefreshRequest},
};

/// Cookie 配置常量
const ACCESS_TOKEN_COOKIE: &str = "zclaw_access_token";
const REFRESH_TOKEN_COOKIE: &str = "zclaw_refresh_token";

/// 构建 auth cookies 并附加到 CookieJar
/// secure 标记在开发环境 (ZCLAW_SAAS_DEV=true) 设为 false，生产设为 true
fn set_auth_cookies(jar: CookieJar, token: &str, refresh_token: &str) -> CookieJar {
    let access_max_age = std::time::Duration::from_secs(2 * 3600); // 2h
    let refresh_max_age = std::time::Duration::from_secs(7 * 86400); // 7d
    let secure = !is_dev_mode();

    // cookie crate 需要 time::Duration，从 std 转换
    let access = Cookie::build((ACCESS_TOKEN_COOKIE, token.to_string()))
        .http_only(true)
        .secure(secure)
        .same_site(SameSite::Strict)
        .path("/api")
        .max_age(access_max_age.try_into().unwrap_or_else(|_| std::time::Duration::from_secs(3600).try_into().unwrap()))
        .build();

    let refresh = Cookie::build((REFRESH_TOKEN_COOKIE, refresh_token.to_string()))
        .http_only(true)
        .secure(secure)
        .same_site(SameSite::Strict)
        .path("/api/v1/auth")
        .max_age(refresh_max_age.try_into().unwrap_or_else(|_| std::time::Duration::from_secs(86400).try_into().unwrap()))
        .build();

    jar.add(access).add(refresh)
}

/// 检查是否为开发模式（Cookie Secure、CORS 等安全策略依据此判断）
fn is_dev_mode() -> bool {
    std::env::var("ZCLAW_SAAS_DEV")
        .map(|v| v == "true" || v == "1")
        .unwrap_or(false)
}

/// 清除 auth cookies
fn clear_auth_cookies(jar: CookieJar) -> CookieJar {
    jar.remove(Cookie::build(ACCESS_TOKEN_COOKIE).path("/api"))
      .remove(Cookie::build(REFRESH_TOKEN_COOKIE).path("/api/v1/auth"))
}

/// POST /api/v1/auth/register
/// 注册成功后自动签发 JWT，返回与 login 一致的 LoginResponse
pub async fn register(
    State(state): State<AppState>,
    ConnectInfo(addr): ConnectInfo<SocketAddr>,
    jar: CookieJar,
    Json(req): Json<RegisterRequest>,
) -> SaasResult<(CookieJar, Json<LoginResponse>)> {
    if req.username.len() < 3 {
        return Err(SaasError::InvalidInput("用户名至少 3 个字符".into()));
    }
    if req.username.len() > 32 {
        return Err(SaasError::InvalidInput("用户名最多 32 个字符".into()));
    }
    static USERNAME_RE: std::sync::OnceLock<regex::Regex> = std::sync::OnceLock::new();
    let username_re = USERNAME_RE.get_or_init(|| regex::Regex::new(r"^[a-zA-Z0-9_-]+$").unwrap());
    if !username_re.is_match(&req.username) {
        return Err(SaasError::InvalidInput("用户名只能包含字母、数字、下划线和连字符".into()));
    }
    if !req.email.contains('@') || !req.email.contains('.') {
        return Err(SaasError::InvalidInput("邮箱格式不正确".into()));
    }
    // M3: 严格邮箱格式校验
    static EMAIL_RE: std::sync::OnceLock<regex::Regex> = std::sync::OnceLock::new();
    let email_re = EMAIL_RE.get_or_init(|| regex::Regex::new(
        r"^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$"
    ).unwrap());
    if !email_re.is_match(&req.email) {
        return Err(SaasError::InvalidInput("邮箱格式不正确".into()));
    }
    if req.password.len() < 8 {
        return Err(SaasError::InvalidInput("密码至少 8 个字符".into()));
    }
    if req.password.len() > 128 {
        return Err(SaasError::InvalidInput("密码最多 128 个字符".into()));
    }
    if let Some(ref name) = req.display_name {
        if name.len() > 64 {
            return Err(SaasError::InvalidInput("显示名称最多 64 个字符".into()));
        }
    }

    let existing: Vec<(String,)> = sqlx::query_as(
        "SELECT id FROM accounts WHERE username = $1 OR email = $2"
    )
    .bind(&req.username)
    .bind(&req.email)
    .fetch_all(&state.db)
    .await?;

    if !existing.is_empty() {
        return Err(SaasError::AlreadyExists("用户名或邮箱已存在".into()));
    }

    let password_hash = hash_password_async(req.password.clone()).await?;
    let account_id = uuid::Uuid::new_v4().to_string();
    let role = "user".to_string(); // 注册固定为普通用户，角色由管理员分配
    let display_name = req.display_name.unwrap_or_default();
    let now = chrono::Utc::now();

    sqlx::query(
        "INSERT INTO accounts (id, username, email, password_hash, display_name, role, status, created_at, updated_at, llm_routing)
         VALUES ($1, $2, $3, $4, $5, $6, 'active', $7, $7, 'local')"
    )
    .bind(&account_id)
    .bind(&req.username)
    .bind(&req.email)
    .bind(&password_hash)
    .bind(&display_name)
    .bind(&role)
    .bind(&now)
    .execute(&state.db)
    .await?;

    let client_ip = addr.ip().to_string();
    log_operation(&state.db, &account_id, "account.create", "account", &account_id, None, Some(&client_ip)).await?;

    // 注册成功后自动签发 JWT + Refresh Token
    let permissions = get_role_permissions(&state.db, &state.role_permissions_cache, &role).await?;
    // 查询新创建账户的 password_version (默认为 1)
    let (pwv,): (i32,) = sqlx::query_as(
        "SELECT password_version FROM accounts WHERE id = $1"
    )
    .bind(&account_id)
    .fetch_one(&state.db)
    .await?;
    let config = state.config.read().await;
    let token = create_token(
        &account_id, &role, permissions.clone(),
        state.jwt_secret.expose_secret(),
        config.auth.jwt_expiration_hours,
        pwv as u32,
    )?;
    let refresh_token = create_refresh_token(
        &account_id, &role, permissions,
        state.jwt_secret.expose_secret(),
        config.auth.refresh_token_hours,
        pwv as u32,
    )?;
    drop(config);

    store_refresh_token(
        &state.db, &account_id, &refresh_token,
        state.jwt_secret.expose_secret(), 168,
    ).await?;

    let resp = LoginResponse {
        token,
        refresh_token: refresh_token.clone(),
        account: AccountPublic {
            id: account_id,
            username: req.username,
            email: req.email,
            display_name,
            role,
            status: "active".into(),
            totp_enabled: false,
            created_at: now.to_rfc3339(),
            llm_routing: "local".into(),
        },
    };
    let jar = set_auth_cookies(jar, &resp.token, &refresh_token);
    Ok((jar, Json(resp)))
}

/// POST /api/v1/auth/login
pub async fn login(
    State(state): State<AppState>,
    ConnectInfo(addr): ConnectInfo<SocketAddr>,
    jar: CookieJar,
    Json(req): Json<LoginRequest>,
) -> SaasResult<(CookieJar, Json<LoginResponse>)> {
    // 一次查询获取用户信息 + password_hash + totp_secret + 安全字段（合并原来的 3 次查询）
    let row: Option<AccountLoginRow> =
        sqlx::query_as(
            "SELECT id, username, email, display_name, role, status, totp_enabled,
                    password_hash, totp_secret, created_at::TEXT, llm_routing,
                    password_version, failed_login_count, locked_until::TEXT
             FROM accounts WHERE username = $1 OR email = $1"
        )
        .bind(&req.username)
        .fetch_optional(&state.db)
        .await?;

    let r = row.ok_or_else(|| SaasError::AuthError("用户名或密码错误".into()))?;

    if r.status != "active" {
        return Err(SaasError::Forbidden(format!("账号已{}，请联系管理员", r.status)));
    }

    // M2: 检查账号是否被临时锁定
    if let Some(ref locked_until_str) = r.locked_until {
        if let Ok(locked_time) = chrono::DateTime::parse_from_rfc3339(locked_until_str) {
            if chrono::Utc::now() < locked_time.with_timezone(&chrono::Utc) {
                return Err(SaasError::AuthError("账号已被临时锁定，请稍后再试".into()));
            }
        }
    }

    if !verify_password_async(req.password.clone(), r.password_hash.clone()).await? {
        // M2: 密码错误，递增失败计数
        let new_count = r.failed_login_count + 1;
        if new_count >= 5 {
            // 锁定 15 分钟
            let locked_until = chrono::Utc::now() + chrono::Duration::minutes(15);
            sqlx::query(
                "UPDATE accounts SET failed_login_count = $1, locked_until = $2 WHERE id = $3"
            )
            .bind(new_count)
            .bind(&locked_until)
            .bind(&r.id)
            .execute(&state.db)
            .await?;
        } else {
            sqlx::query(
                "UPDATE accounts SET failed_login_count = $1 WHERE id = $2"
            )
            .bind(new_count)
            .bind(&r.id)
            .execute(&state.db)
            .await?;
        }
        return Err(SaasError::AuthError("用户名或密码错误".into()));
    }

    // TOTP 验证: 如果用户已启用 2FA，必须提供有效 TOTP 码
    if r.totp_enabled {
        let code = req.totp_code.as_deref()
            .ok_or_else(|| SaasError::Totp("此账号已启用双因素认证，请提供 TOTP 码".into()))?;

        let secret = r.totp_secret.clone().ok_or_else(|| {
            SaasError::Internal("TOTP 已启用但密钥丢失，请联系管理员".into())
        })?;

        // 解密 TOTP secret (兼容旧的明文格式)
        let config = state.config.read().await;
        let enc_key = config.totp_encryption_key()
            .map_err(|e| SaasError::Internal(e.to_string()))?;
        let secret = super::totp::decrypt_totp_for_login(&secret, &enc_key)?;

        if !super::totp::verify_totp_code(&secret, code) {
            return Err(SaasError::Totp("TOTP 码错误或已过期".into()));
        }
    }

    let permissions = get_role_permissions(&state.db, &state.role_permissions_cache, &r.role).await?;
    let config = state.config.read().await;
    let pwv = r.password_version as u32;
    let token = create_token(
        &r.id, &r.role, permissions.clone(),
        state.jwt_secret.expose_secret(),
        config.auth.jwt_expiration_hours,
        pwv,
    )?;
    let refresh_token = create_refresh_token(
        &r.id, &r.role, permissions,
        state.jwt_secret.expose_secret(),
        config.auth.refresh_token_hours,
        pwv,
    )?;
    drop(config);

    let now = chrono::Utc::now();
    // 登录成功: 重置失败计数和锁定状态
    sqlx::query("UPDATE accounts SET last_login_at = $1, failed_login_count = 0, locked_until = NULL WHERE id = $2")
        .bind(&now).bind(&r.id)
        .execute(&state.db).await?;
    let client_ip = addr.ip().to_string();
    log_operation(&state.db, &r.id, "account.login", "account", &r.id, None, Some(&client_ip)).await?;

    store_refresh_token(
        &state.db, &r.id, &refresh_token,
        state.jwt_secret.expose_secret(), 168,
    ).await?;

    let resp = LoginResponse {
        token,
        refresh_token: refresh_token.clone(),
        account: AccountPublic {
            id: r.id, username: r.username, email: r.email, display_name: r.display_name,
            role: r.role, status: r.status, totp_enabled: r.totp_enabled, created_at: r.created_at,
            llm_routing: r.llm_routing,
        },
    };
    let jar = set_auth_cookies(jar, &resp.token, &refresh_token);
    Ok((jar, Json(resp)))
}

/// POST /api/v1/auth/refresh
/// 使用 refresh_token 换取新的 access + refresh token 对
/// refresh_token 一次性使用，使用后立即失效
pub async fn refresh(
    State(state): State<AppState>,
    jar: CookieJar,
    Json(req): Json<RefreshRequest>,
) -> SaasResult<(CookieJar, Json<serde_json::Value>)> {
    // 1. 验证 refresh token 签名 (跳过过期检查，但有 7 天窗口限制)
    let claims = verify_token_skip_expiry(&req.refresh_token, state.jwt_secret.expose_secret())?;

    // 2. 确认是 refresh 类型 token
    if claims.token_type != "refresh" {
        return Err(SaasError::AuthError("无效的 refresh token".into()));
    }

    let jti = claims.jti.as_deref()
        .ok_or_else(|| SaasError::AuthError("refresh token 缺少 jti".into()))?;

    // 3. 从 DB 查找 refresh token，确保未被使用
    let row: Option<(String,)> = sqlx::query_as(
        "SELECT account_id FROM refresh_tokens WHERE jti = $1 AND used_at IS NULL AND expires_at > $2"
    )
    .bind(jti)
    .bind(&chrono::Utc::now())
    .fetch_optional(&state.db)
    .await?;

    let token_account_id = row
        .ok_or_else(|| SaasError::AuthError("refresh token 已使用、已过期或不存在".into()))?
        .0;

    // 4. 验证 token 中的 account_id 与 DB 中的一致
    if token_account_id != claims.sub {
        return Err(SaasError::AuthError("refresh token 账号不匹配".into()));
    }

    // 5. 标记旧 refresh token 为已使用 (一次性)
    let now = chrono::Utc::now();
    sqlx::query("UPDATE refresh_tokens SET used_at = $1 WHERE jti = $2")
        .bind(&now).bind(jti)
        .execute(&state.db).await?;

    // 6. 获取最新角色权限 + password_version
    let (role,): (String,) = sqlx::query_as(
        "SELECT role FROM accounts WHERE id = $1 AND status = 'active'"
    )
    .bind(&claims.sub)
    .fetch_optional(&state.db)
    .await?
    .ok_or_else(|| SaasError::AuthError("账号不存在或已禁用".into()))?;

    let (pwv,): (i32,) = sqlx::query_as(
        "SELECT password_version FROM accounts WHERE id = $1"
    )
    .bind(&claims.sub)
    .fetch_one(&state.db)
    .await?;

    let permissions = get_role_permissions(&state.db, &state.role_permissions_cache, &role).await?;

    // 7. 创建新的 access token + refresh token
    let config = state.config.read().await;
    let new_access = create_token(
        &claims.sub, &role, permissions.clone(),
        state.jwt_secret.expose_secret(),
        config.auth.jwt_expiration_hours,
        pwv as u32,
    )?;
    let new_refresh = create_refresh_token(
        &claims.sub, &role, permissions.clone(),
        state.jwt_secret.expose_secret(),
        config.auth.refresh_token_hours,
        pwv as u32,
    )?;
    drop(config);

    // 8. 存储新 refresh token 到 DB
    let new_claims = verify_token(&new_refresh, state.jwt_secret.expose_secret())?;
    let new_jti = new_claims.jti.unwrap_or_default();
    let new_id = uuid::Uuid::new_v4().to_string();
    let refresh_expires = chrono::Utc::now() + chrono::Duration::hours(168);
    sqlx::query(
        "INSERT INTO refresh_tokens (id, account_id, jti, token_hash, expires_at, created_at)
         VALUES ($1, $2, $3, $4, $5, $6)"
    )
    .bind(&new_id).bind(&claims.sub).bind(&new_jti)
    .bind(sha256_hex(&new_refresh)).bind(&refresh_expires).bind(&now)
    .execute(&state.db).await?;

    // 9. 清理过期/已使用的 refresh tokens 已迁移到 Scheduler 定期执行
    // 不再在每次 refresh 时阻塞请求

    let jar = set_auth_cookies(jar, &new_access, &new_refresh);
    Ok((jar, Json(serde_json::json!({
        "token": new_access,
        "refresh_token": new_refresh,
    }))))
}

/// GET /api/v1/auth/me — 返回当前认证用户的公开信息
pub async fn me(
    State(state): State<AppState>,
    axum::extract::Extension(ctx): axum::extract::Extension<AuthContext>,
) -> SaasResult<Json<AccountPublic>> {
    let row: Option<AccountAuthRow> =
        sqlx::query_as(
            "SELECT id, username, email, display_name, role, status, totp_enabled, created_at::TEXT, llm_routing
             FROM accounts WHERE id = $1"
        )
        .bind(&ctx.account_id)
        .fetch_optional(&state.db)
        .await?;

    let r = row.ok_or_else(|| SaasError::NotFound("账号不存在".into()))?;

    Ok(Json(AccountPublic {
        id: r.id, username: r.username, email: r.email, display_name: r.display_name,
        role: r.role, status: r.status, totp_enabled: r.totp_enabled, created_at: r.created_at,
        llm_routing: r.llm_routing,
    }))
}

/// PUT /api/v1/auth/password — 修改密码
pub async fn change_password(
    State(state): State<AppState>,
    axum::extract::Extension(ctx): axum::extract::Extension<AuthContext>,
    Json(req): Json<ChangePasswordRequest>,
) -> SaasResult<Json<serde_json::Value>> {
    if req.new_password.len() < 8 {
        return Err(SaasError::InvalidInput("新密码至少 8 个字符".into()));
    }

    // 获取当前密码哈希
    let (password_hash,): (String,) = sqlx::query_as(
        "SELECT password_hash FROM accounts WHERE id = $1"
    )
    .bind(&ctx.account_id)
    .fetch_one(&state.db)
    .await?;

    // 验证旧密码
    if !verify_password_async(req.old_password.clone(), password_hash.clone()).await? {
        return Err(SaasError::AuthError("旧密码错误".into()));
    }

    // 更新密码 + 递增 password_version 使旧 token 失效
    let new_hash = hash_password_async(req.new_password.clone()).await?;
    let now = chrono::Utc::now();
    sqlx::query("UPDATE accounts SET password_hash = $1, updated_at = $2, password_version = password_version + 1 WHERE id = $3")
        .bind(&new_hash)
        .bind(&now)
        .bind(&ctx.account_id)
        .execute(&state.db)
        .await?;

    log_operation(&state.db, &ctx.account_id, "account.change_password", "account", &ctx.account_id,
        None, ctx.client_ip.as_deref()).await?;

    Ok(Json(serde_json::json!({"ok": true, "message": "密码修改成功"})))
}

pub(crate) async fn get_role_permissions(
    db: &sqlx::PgPool,
    cache: &dashmap::DashMap<String, Vec<String>>,
    role: &str,
) -> SaasResult<Vec<String>> {
    // Check cache first
    if let Some(cached) = cache.get(role) {
        return Ok(cached.clone());
    }

    let row: Option<(String,)> = sqlx::query_as(
        "SELECT permissions FROM roles WHERE id = $1"
    )
    .bind(role)
    .fetch_optional(db)
    .await?;

    let permissions_str = row
        .ok_or_else(|| SaasError::Internal(format!("角色 {} 不存在", role)))?
        .0;

    let permissions: Vec<String> = serde_json::from_str(&permissions_str)?;
    cache.insert(role.to_string(), permissions.clone());
    Ok(permissions)
}

/// 检查权限 (admin:full 自动通过所有检查)
pub fn check_permission(ctx: &AuthContext, permission: &str) -> SaasResult<()> {
    if ctx.permissions.contains(&"admin:full".to_string()) {
        return Ok(());
    }
    if !ctx.permissions.contains(&permission.to_string()) {
        return Err(SaasError::Forbidden(format!("需要 {} 权限", permission)));
    }
    Ok(())
}

/// 记录操作日志
pub async fn log_operation(
    db: &sqlx::PgPool,
    account_id: &str,
    action: &str,
    target_type: &str,
    target_id: &str,
    details: Option<serde_json::Value>,
    ip_address: Option<&str>,
) -> SaasResult<()> {
    let now = chrono::Utc::now();
    sqlx::query(
        "INSERT INTO operation_logs (account_id, action, target_type, target_id, details, ip_address, created_at)
         VALUES ($1, $2, $3, $4, $5, $6, $7)"
    )
    .bind(account_id)
    .bind(action)
    .bind(target_type)
    .bind(target_id)
    .bind(details.map(|d| d.to_string()))
    .bind(ip_address)
    .bind(&now)
    .execute(db)
    .await?;
    Ok(())
}

/// 存储 refresh token 到 DB
async fn store_refresh_token(
    db: &sqlx::PgPool,
    account_id: &str,
    refresh_token: &str,
    secret: &str,
    refresh_hours: i64,
) -> SaasResult<()> {
    let claims = verify_token(refresh_token, secret)?;
    let jti = claims.jti.unwrap_or_default();
    let id = uuid::Uuid::new_v4().to_string();
    let now = chrono::Utc::now();
    let expires_at = chrono::Utc::now() + chrono::Duration::hours(refresh_hours);

    sqlx::query(
        "INSERT INTO refresh_tokens (id, account_id, jti, token_hash, expires_at, created_at)
         VALUES ($1, $2, $3, $4, $5, $6)"
    )
    .bind(&id).bind(account_id).bind(&jti)
    .bind(sha256_hex(refresh_token)).bind(&expires_at).bind(&now)
    .execute(db).await?;
    Ok(())
}

/// 清理过期和已使用的 refresh tokens
/// 注意: 现已迁移到 Worker/Scheduler 定期执行，此函数保留作为备用
#[allow(dead_code)]
async fn cleanup_expired_refresh_tokens(db: &sqlx::PgPool) -> SaasResult<()> {
    let now = chrono::Utc::now();
    // 删除过期超过 30 天的已使用 token (减少 DB 膨胀)
    sqlx::query(
        "DELETE FROM refresh_tokens WHERE (used_at IS NOT NULL AND used_at < $1) OR (expires_at < $1)"
    )
    .bind(&now)
    .execute(db).await?;
    Ok(())
}

/// SHA-256 hex digest
fn sha256_hex(input: &str) -> String {
    use sha2::{Sha256, Digest};
    hex::encode(Sha256::digest(input.as_bytes()))
}

/// POST /api/v1/auth/logout — 撤销 refresh token 并清除 auth cookies
pub async fn logout(
    State(state): State<AppState>,
    jar: CookieJar,
) -> (CookieJar, axum::http::StatusCode) {
    // 尝试从 cookie 中获取 refresh token 并撤销
    if let Some(refresh_cookie) = jar.get(REFRESH_TOKEN_COOKIE) {
        let token = refresh_cookie.value();
        if let Ok(claims) = verify_token_skip_expiry(token, state.jwt_secret.expose_secret()) {
            if claims.token_type == "refresh" {
                if let Some(jti) = claims.jti {
                    let now = chrono::Utc::now();
                    // 标记 refresh token 为已使用（等效于撤销/黑名单）
                    let result = sqlx::query(
                        "UPDATE refresh_tokens SET used_at = $1 WHERE jti = $2 AND used_at IS NULL"
                    )
                    .bind(&now).bind(&jti)
                    .execute(&state.db)
                    .await;

                    match result {
                        Ok(r) => {
                            if r.rows_affected() > 0 {
                                tracing::info!(account_id = %claims.sub, jti = %jti, "Refresh token revoked on logout");
                            }
                        }
                        Err(e) => {
                            tracing::warn!(jti = %jti, error = %e, "Failed to revoke refresh token on logout");
                        }
                    }
                }
            }
        }
    }

    (clear_auth_cookies(jar), axum::http::StatusCode::NO_CONTENT)
}