import isUndefined  from 'lodash/isUndefined';
import isNull       from 'lodash/isNull';
import isNaN        from 'lodash/isNaN';
import toPrimitive  from '../toPrimitive';

/**
 * Compare two objects
 *
 * @param a First object
 * @param b Second object
 * @returns 0 if a == b; -1 if a < b; 1 if a > b
 */
export function compare(x: unknown, y: unknown): number {
    const px = toPrimitive(x, 'number');
    const py = toPrimitive(y, 'number');

    if(isUndefined(px) && isUndefined(py)) {
        return 0;
    } else if(isUndefined(px)) {
        return -1;
    } else if(isUndefined(py)) {
        return 1;
    } else if(isNull(px) && isNull(py)) {
        return 0;
    } else if(isNull(px)) {
        return -1;
    } else if(isNull(py)) {
        return 1;
    } else if(typeof px !== 'string' && typeof py !== 'string') {
        const nx = Number(px);
        const ny = Number(py);

        if(isNaN(nx) && isNaN(py))
            return 0;
        else
        if(isNaN(nx))
            return -1;
        else
        if(isNaN(ny))
            return 1;
        else
        if(nx === ny)
            return 0;
        else
        if(nx < ny)
            return -1;
        return 1;
    }
    if(px === py)
        return 0;
    else
    if(px < py)
        return -1;
    return 1;
}

export default compare;