use actix_web::{HttpResponse, web};
use serde::Serialize;
use uuid::Uuid;

use crate::api::response::{ApiErrorResponse, ApiResponse};
use crate::error::AppError;
use crate::models::users::User;
use crate::service::AppService;
use crate::service::auth::register::RegisterParams;
use crate::session::Session;

#[derive(Debug, Serialize, utoipa::ToSchema)]
pub struct RegisterResponse {
    /// Newly created user id.
    pub id: Uuid,
    /// Unique username used for login and profile URL.
    pub username: String,
    /// Display name initialized from username.
    pub display_name: Option<String>,
    /// Avatar URL; usually absent right after registration.
    pub avatar_url: Option<String>,
}

impl From<User> for RegisterResponse {
    fn from(user: User) -> Self {
        Self {
            id: user.id,
            username: user.username,
            display_name: user.display_name,
            avatar_url: user.avatar_url,
        }
    }
}

#[utoipa::path(
    post,
    path = "/api/v1/auth/register",
    tag = "Auth",
    operation_id = "authRegister",
    summary = "Register a new account",
    description = "Create an account after validating username, email, password, captcha, and email verification code. password must be encrypted with the current session RSA public key; captcha and email_code are one-time credentials. On successful registration, the new user is written to the session and does not need to log in again.",
    request_body(
        content = RegisterParams,
        description = "Registration parameters. email_code comes from /auth/register/email-code; password is a Base64 ciphertext encrypted with RSA-OAEP-SHA256.",
        content_type = "application/json"
    ),
    responses(
        (status = 200, description = "Registration succeeded; the current session is automatically signed in as the new user.", body = ApiResponse<RegisterResponse>),
        (status = 400, description = "Captcha error, email verification code error, weak password, RSA decryption failure, or missing required fields.", body = ApiErrorResponse),
        (status = 409, description = "The username or email is already in use.", body = ApiErrorResponse),
        (status = 500, description = "Database transaction, password hashing, cache, or session write failed.", body = ApiErrorResponse)
    )
)]
pub async fn handle(
    service: web::Data<AppService>,
    session: Session,
    params: web::Json<RegisterParams>,
) -> Result<HttpResponse, AppError> {
    let user = service
        .auth
        .auth_register(params.into_inner(), &session)
        .await?;
    Ok(HttpResponse::Ok().json(ApiResponse::new(RegisterResponse::from(user))))
}