import { usePage } from '@inertiajs/vue3';
import { computed } from 'vue';
import type { SharedProps, SlotPayload } from '@/types';

/**
 * Translate a string using the JSON catalog shared by the server.
 *
 * Mirrors Laravel's __() helper: the English string is the key, and :placeholder
 * tokens are replaced from the supplied arguments.
 */
export function useTranslations() {
    const page = usePage<SharedProps>();

    const __ = (key: string, replacements: Record<string, string | number> = {}): string => {
        // `||` rather than `??` to mirror Laravel's `$line ?: $key`. Plugins ship
        // English catalogs whose values are empty strings, and those must fall
        // back to the key exactly as they do server side.
        let line = page.props.translations?.[key] || key;

        for (const [token, value] of Object.entries(replacements)) {
            line = line.replace(`:${token}`, String(value));
        }

        return line;
    };

    return { __ };
}

/**
 * Permission and role checks, replacing the @permission / @role Blade directives.
 */
export function usePermissions() {
    const page = usePage<SharedProps>();

    const permissions = computed(() => page.props.auth.permissions ?? []);

    /** True when the user has every one of the given permissions. */
    const can = (...required: string[]): boolean =>
        required.every((permission) => permissions.value.includes(permission));

    /** True when the user has at least one of the given permissions. */
    const canAny = (...required: string[]): boolean =>
        required.some((permission) => permissions.value.includes(permission));

    return { permissions, can, canAny };
}

/**
 * The authenticated user, or null for guest pages.
 */
export function useAuth() {
    const page = usePage<SharedProps>();

    return {
        user: computed(() => page.props.auth.user),
        impersonating: computed(() => page.props.auth.impersonating),
    };
}

/**
 * A shared application setting.
 */
export function useSettings() {
    const page = usePage<SharedProps>();

    const setting = <T = unknown>(key: string, fallback: T | null = null): T | null =>
        (page.props.settings?.[key] as T) ?? fallback;

    return { setting };
}

/**
 * Components registered by plugins for a named slot position.
 */
export function useSlot(name: string) {
    const page = usePage<SharedProps>();

    return computed<SlotPayload[]>(() => page.props.vanguard?.slots?.[name] ?? []);
}