import { ApiError, request } from './client';

export type User = {
    id: string;
    username: string;
    created_at: string;
    is_admin: boolean;
};

export type Credentials = {
    username: string;
    password: string;
};

type AuthResponse = { user: User };

export async function register(creds: Credentials): Promise<User> {
    const r = await request<AuthResponse>('/v1/auth/register', {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify(creds)
    });
    return r.user;
}

export async function login(creds: Credentials): Promise<User> {
    const r = await request<AuthResponse>('/v1/auth/login', {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify(creds)
    });
    return r.user;
}

export async function logout(): Promise<void> {
    await request<void>('/v1/auth/logout', {
        method: 'POST',
        // Consistent with the other POST/PATCH helpers in this module.
        // axum doesn't require it (no body), but keeping the header
        // on every mutation request avoids the false-flag in logs and
        // matches the project's style.
        headers: { 'content-type': 'application/json' }
    });
}

export type ChangePassword = {
    current_password: string;
    new_password: string;
};

/**
 * Rotates the password. Backend signs out every other session for this
 * user and mints a fresh cookie for the caller (returned as Set-Cookie,
 * applied automatically by the browser). Bot tokens are left alone.
 *
 * Throws ApiError with `status=401, code='unauthenticated'` for wrong
 * `current_password`; `status=400, code='invalid_input'` for a weak new
 * password.
 */
export async function changePassword(input: ChangePassword): Promise<void> {
    await request<void>(
        '/v1/auth/me/password',
        {
            method: 'PATCH',
            headers: { 'content-type': 'application/json' },
            body: JSON.stringify(input)
        },
        // A 401 here means the *current* password was wrong, not that the
        // session expired — don't let the global hook clear the user and
        // bounce them to /login; the form surfaces the error inline.
        { suppressOn401: true }
    );
}

/**
 * Returns the current user, or `null` if no valid session.
 * Re-throws any non-401 error.
 */
export async function me(): Promise<User | null> {
    try {
        const r = await request<AuthResponse>('/v1/auth/me');
        return r.user;
    } catch (e) {
        if (e instanceof ApiError && e.status === 401) return null;
        throw e;
    }
}

export type ApiToken = {
    id: string;
    user_id: string;
    name: string;
    created_at: string;
    last_used_at: string | null;
};

export type CreatedToken = ApiToken & { bearer: string };

export async function createToken(name: string): Promise<CreatedToken> {
    return request<CreatedToken>('/v1/auth/tokens', {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify({ name })
    });
}

export async function deleteToken(id: string): Promise<void> {
    await request<void>(`/v1/auth/tokens/${encodeURIComponent(id)}`, { method: 'DELETE' });
}

export type AuthConfig = {
    /** Effective value (`allow_self_register && !private_mode`).
     * When false, /v1/auth/register returns 403 and the UI should
     * hide its register affordance. Admins can still mint accounts
     * via POST /v1/admin/users. */
    self_register_enabled: boolean;
    /** When true, every read endpoint requires auth and anonymous
     * visitors are redirected to `/login` (see `+layout.ts`). */
    private_mode: boolean;
};

/** Public — no auth, no cookie required. */
export async function getAuthConfig(): Promise<AuthConfig> {
    return request<AuthConfig>('/v1/auth/config');
}
