import { FilterDescriptor, CompositeFilterDescriptor } from './filtering/filter-descriptor.interface';
import { isString, isDate } from './utils';

/**
 * @hidden
 */
export type Transformation = (x: FilterDescriptor) => FilterDescriptor;

/**
 * @hidden
 * Creates a single arity function which wraps the value based on the provided predicate.
 * @example
 * ```
 * wrapIf(() => ignoreCase) `tolower(${field})`
 * //ignoreCase=true -> tolower(${field})`
 * //ignoreCase=false -> ${field}`
 * ```
 */
export const wrapIf = predicate => (str, ...args) => predicate() ? `${str[0]}${args[0]}${str[1]}` : args[0];

/**
 * @hidden
 */
export const toUTC = (date: Date) =>
    new Date(Date.UTC(
        date.getFullYear(),
        date.getMonth(),
        date.getDate(),
        date.getHours(),
        date.getMinutes(),
        date.getSeconds(),
        date.getMilliseconds()
    ));

/**
 * @hidden
 */
export const quote: Transformation = ({ field, value, ignoreCase, operator }) => ({
    value: `'${value.replace(/'/g, "''")}'`,
    field,
    ignoreCase,
    operator
});

/**
 * @hidden
 */
export const encodeValue: Transformation = ({ field, value, ignoreCase, operator }) => ({
    value: `${encodeURIComponent(value)}`,
    field,
    ignoreCase,
    operator
});

/**
 * @hidden
 */
export const toLower: Transformation = ({ field, value, ignoreCase, operator }) => ({
    field: wrapIf(() => ignoreCase)`tolower(${field})`,
    value,
    ignoreCase,
    operator
});

/**
 * @hidden
 */
export const normalizeField: Transformation = ({ field, value, ignoreCase, operator }) => ({
    value,
    field: (<string>field).replace(/\./g, "/"),
    ignoreCase,
    operator
});

/**
 * @hidden
 */
export const isStringValue = x => isString(x.value);
/**
 * @hidden
 */
export const isDateValue = x => isDate(x.value);

/**
 * @hidden
 */
export const serializeFilters = (map, join) => (filter: CompositeFilterDescriptor): string => {
    const brackets = wrapIf(() => filter.filters.length > 1);
    return brackets`(${
        filter.filters
            .map(map)
            .join(join(filter))
        })`;
};