/**
 * filter operators
 */
enum ApiRequestFilterOperator {
    Equals,
    NotEquals,
    GreaterThan,
    LessThan,
    GreaterThanOrEqualTo,
    LessThanOrEqualTo,
    Contains,
    StartsWith,
    CaseInsensitiveStringContains,
    CaseInsensitiveStringStartsWith,
    CaseInsensitiveStringEquals
}


/**
 * Sort directions
 */
enum ApiRequestSortDirection {
    Asc,
    Desc
}


/**
 * One filter representation
 */
interface IApiFilter {
    parameter: string;
    operator: ApiRequestFilterOperator;
    value: string;
}


/**
 * One sort representation
 */
interface IApiSort {
    parameter: string;
    direction: ApiRequestSortDirection;
}


/**
 * Api request filter common interface
 */
interface IApiRequestFilter {
    filters: IApiFilter[];
    sorts: IApiSort[];
    page: number;
    pageSize: number;
    /**
     * Build a filter object to string-filter like ?filter=&sorts=&page=&pageSize=
     */
    build(): string;
}


/**
 *
 */
class ApiRequestSieveFilter implements IApiRequestFilter {
    filters: IApiFilter[];
    sorts: IApiSort[];
    page: number;
    pageSize: number;


    constructor() {
        this.filters = new Array<IApiFilter>();
        this.sorts = new Array<IApiSort>();
        this.page = 1;
        this.pageSize = 100;
    }


    /**
     * Build filter string
     */
    build(): string {
        let result = "?filters=";

        this.filters.forEach((f, i) => {
            let translatedOperator = "";
            switch (f.operator) {
                case ApiRequestFilterOperator.Equals:
                    translatedOperator = "==";
                    break;
                case ApiRequestFilterOperator.NotEquals:
                    translatedOperator = "!=";
                    break;
                case ApiRequestFilterOperator.GreaterThan:
                    translatedOperator = ">";
                    break;
                case ApiRequestFilterOperator.LessThan:
                    translatedOperator = "<";
                    break;
                case ApiRequestFilterOperator.GreaterThanOrEqualTo:
                    translatedOperator = ">=";
                    break;
                case ApiRequestFilterOperator.LessThanOrEqualTo:
                    translatedOperator = "<=";
                    break;
                case ApiRequestFilterOperator.Contains:
                    translatedOperator = "@=";
                    break;
                case ApiRequestFilterOperator.StartsWith:
                    translatedOperator = "_=";
                    break;
                case ApiRequestFilterOperator.CaseInsensitiveStringContains:
                    translatedOperator = "@=*";
                    break;
                case ApiRequestFilterOperator.CaseInsensitiveStringStartsWith:
                    translatedOperator = "_=*";
                    break;
                case ApiRequestFilterOperator.CaseInsensitiveStringEquals:
                    translatedOperator = "==*";
                    break;
            }

            result += (i === 0 ? "" : ",") + (f.parameter + translatedOperator + f.value);
        });

        result += "&sorts=";
        this.sorts.forEach((s, i) => {
            let translatedValue = "";
            switch (s.direction) {
                case ApiRequestSortDirection.Asc:
                    translatedValue = s.parameter;
                    break;
                case ApiRequestSortDirection.Desc:
                    translatedValue = `-${s.parameter}`;
                    break;
            }
            result += (i === 0 ? "" : ",") + translatedValue;
        });

        result += `&page=${this.page}&pageSize=${this.pageSize}`;
        return result;
    }
}