import { isDecorator, Node, isIdentifier, Decorator } from 'typescript';

export interface DecoratorMap {
    [name: string]: Decorator;
}

function _getDecoratorName(aDecorator: Decorator) {
    const token = aDecorator.expression.getFirstToken();
    if (isIdentifier(token)) {
        return token.text;
    }
}

function _getDecorators(aNode: Node): DecoratorMap {
    const result: DecoratorMap = {};
    const decs = aNode.decorators;
    if (decs) {
        decs.forEach(dec => {
            if (isDecorator(dec)) {
                const key = _getDecoratorName(dec);
                if (key) {
                    result[key] = dec;
                }
            }
        });
    }
    return result;
}

export {
    _getDecoratorName as tsGetDecoratorName,
    _getDecorators as tsGetDecorators
};