import { IFunctionParameterCollection } from './IFunctionParameterCollection';
import { IFunctionParameter } from './IFunctionParameter';

export class FunctionParameterCollection implements IFunctionParameterCollection {
    private parameters = new Array<IFunctionParameter>();

    public get all(): readonly IFunctionParameter[] {
        return this.parameters;
    }
    public addParameter(parameter: IFunctionParameter) {
        this.ensureValidParameter(parameter);
        this.parameters.push(parameter);
    }

    private includesName(name: string) {
        return this.parameters.find((existingParameter) => existingParameter.name === name);
    }
    private ensureValidParameter(parameter: IFunctionParameter) {
        if (!parameter) {
            throw new Error('undefined parameter');
        }
        if (this.includesName(parameter.name)) {
            throw new Error(`duplicate parameter name: "${parameter.name}"`);
        }
    }
}