/* @internal */
namespace ts {
    export interface Refactor {
        /** An unique code associated with each refactor */
        name: string;

        /** Description of the refactor to display in the UI of the editor */
        description: string;

        /** Compute the associated code actions */
        getEditsForAction(context: RefactorContext, actionName: string): RefactorEditInfo | undefined;

        /** Compute (quickly) which actions are available here */
        getAvailableActions(context: RefactorContext): ApplicableRefactorInfo[] | undefined;
    }

    export interface RefactorContext {
        file: SourceFile;
        startPosition: number;
        endPosition?: number;
        program: Program;
        newLineCharacter: string;
        rulesProvider?: formatting.RulesProvider;
        cancellationToken?: CancellationToken;
    }

    export namespace refactor {
        // A map with the refactor code as key, the refactor itself as value
        // e.g.  nonSuggestableRefactors[refactorCode] -> the refactor you want
        const refactors: Map<Refactor> = createMap<Refactor>();

        export function registerRefactor(refactor: Refactor) {
            refactors.set(refactor.name, refactor);
        }

        export function getApplicableRefactors(context: RefactorContext): ApplicableRefactorInfo[] | undefined {
            let results: ApplicableRefactorInfo[];
            const refactorList: Refactor[] = [];
            refactors.forEach(refactor => {
                refactorList.push(refactor);
            });
            for (const refactor of refactorList) {
                if (context.cancellationToken && context.cancellationToken.isCancellationRequested()) {
                    return results;
                }
                const infos = refactor.getAvailableActions(context);
                if (infos && infos.length) {
                    (results || (results = [])).push(...infos);
                }
            }
            return results;
        }

        export function getEditsForRefactor(context: RefactorContext, refactorName: string, actionName: string): RefactorEditInfo | undefined {
            const refactor = refactors.get(refactorName);
            return refactor && refactor.getEditsForAction(context, actionName);
        }
    }
}