export interface MountSlotDef {
    id: string;
    accepts: string | readonly string[];
    required?: boolean;
}
export interface ModularItemDef {
    id: string;
    baseStats: Record<string, number>;
    slots: readonly MountSlotDef[];
}
export interface PartDef {
    id: string;
    category: string;
    stats?: Record<string, number>;
    multipliers?: Record<string, number>;
}
export interface InstalledPart {
    slotId: string;
    part: PartDef;
}
export type InstallResult = {
    status: "ok";
    installed: readonly InstalledPart[];
} | {
    status: "rejected";
    reason: "unknown-slot" | "wrong-category" | "slot-occupied";
};
export declare function slotById(def: ModularItemDef, slotId: string): MountSlotDef | null;
/**
 * Attach parts into an item's mount slots and resolve the combined stats.
 *
 * @capability modular-item attach parts into item mount slots to compute combined stats
 */
export declare function slotAccepts(slot: MountSlotDef, category: string): boolean;
export declare function install(def: ModularItemDef, installed: readonly InstalledPart[], slotId: string, part: PartDef): InstallResult;
export declare function uninstall(installed: readonly InstalledPart[], slotId: string): readonly InstalledPart[];
export declare function partInSlot(installed: readonly InstalledPart[], slotId: string): PartDef | null;
export declare function computeEffectiveStats(def: ModularItemDef, installed: readonly InstalledPart[]): Record<string, number>;
export declare function missingRequiredSlots(def: ModularItemDef, installed: readonly InstalledPart[]): string[];
export declare function isComplete(def: ModularItemDef, installed: readonly InstalledPart[]): boolean;
export interface ModularItem {
    readonly def: ModularItemDef;
    parts(): readonly InstalledPart[];
    install(slotId: string, part: PartDef): InstallResult;
    uninstall(slotId: string): readonly InstalledPart[];
    partInSlot(slotId: string): PartDef | null;
    effectiveStats(): Record<string, number>;
    missingRequired(): string[];
    isComplete(): boolean;
}
export declare function createModularItem(def: ModularItemDef, initial?: readonly InstalledPart[]): ModularItem;