/**
 * [WHO]: Provides ExtensionCommand, ArgumentCompletionContext, CommandCompletionItem
 * [FROM]: No dependencies — context is generic so lifecycle/host can supply their own context type
 * [TO]: Consumed by extensions registering slash commands and by the host command registry
 * [HERE]: packages/protocol/src/commands.ts - stable command registration contract
 *
 * Host note: the host may pass a richer command context to handlers, but the protocol
 * contract stays minimal so published packages and third-party extensions do not depend
 * on host-only session controls.
 */
/** Structured context supplied while completing command arguments. */
export interface ArgumentCompletionContext {
    commandName: string;
    argumentText: string;
    argumentPrefix: string;
    tokenIndex: number;
    previousTokens: string[];
}
/** A single command-completion candidate. */
export interface CommandCompletionItem {
    value: string;
    label: string;
    description?: string;
}
/** A slash command an extension registers via `api.registerCommand(...)`. */
export interface ExtensionCommand<TContext = unknown> {
    /** Help text shown in command lists. */
    description?: string;
    /** Optional argument-completion provider. */
    getArgumentCompletions?: (argumentPrefix: string, context?: ArgumentCompletionContext) => CommandCompletionItem[] | null;
    /** Command body. `args` is the raw argument string (may be empty). */
    handler: (args: string, ctx: TContext) => void | Promise<void>;
}