import { UndoRedoStep } from './undoRedoStep';
import { UndoRedoRecord, UndoRedoActionCollection } from './types';
import { UndoRedoStepManager } from './undoRedoStepManager';

export interface IUndoRedo<T> {
    readonly isMin: boolean;
    readonly isMax: boolean;

    getRecord(): T | undefined;
    setAndStoreRecord(record: T): void;
    undo(): void;
    redo(): void;
}

export class UndoRedo implements IUndoRedo<UndoRedoRecord> {

    private _undoRedoRecord?: UndoRedoRecord;
    private _undoRedoStepManager: UndoRedoStepManager;
    private _actionCollection: UndoRedoActionCollection;

    constructor(
        capacity: number,
        actionCollection: UndoRedoActionCollection
    ) {
        this._undoRedoStepManager = new UndoRedoStepManager(capacity);
        this._actionCollection = actionCollection;
        this.setAndStoreRecord({ set: { params: [], action: '' }, restore: { params: [], action: '' } });
    }

    get isMin() { return this._undoRedoStepManager.isMin; }
    get isMax() { return this._undoRedoStepManager.isMax; }

    private _setRecord(record: UndoRedoRecord, isUndo: boolean) {
        this._undoRedoRecord = record;
        let action = this._actionCollection[isUndo ? record.restore.action : record.set.action];
        action && action(...(isUndo ? record.restore.params : record.set.params));
    }

    private _createStep() {
        if (this._undoRedoRecord) {
            return new UndoRedoStep(this._undoRedoRecord);
        }
    }

    private _restoreStep(step: UndoRedoStep, undo: boolean) {
        let record = step.getRecord()!;
        record && this._setRecord(record, undo);
    }

    getRecord() {
        return this._undoRedoRecord;
    }

    setAndStoreRecord(record: UndoRedoRecord) {
        this._setRecord(record, false);
        const step = this._undoRedoStepManager.getStep();
        step && step.setRecord({ ...step.getRecord()!, restore: record.restore });
        this._undoRedoStepManager.addStep(this._createStep()!);
    }

    undo() {
        let step = this._undoRedoStepManager.undoStep();
        step && this._restoreStep(step, true);
    }

    redo() {
        let step = this._undoRedoStepManager.redoStep();
        step && this._restoreStep(step, false);
    }

}