const compareObjects = require('../helpers/compareObjects');
const matchesProp = require('../helpers/matchesProperty');
const isProp = require('../helpers/isProp');

function funcSplice(array, pred) {
    let index = 0;

    for (let i = 0; i < array.length; i += 1) {
        if (!pred(array[i])) {
            index = i;
            break;
        }
    }

    return array.splice(index);
}

function objSplice(array, pred) {
    let index = 0;

    for (let i = 0; i < array.length; i += 1) {
        if (!compareObjects(array[i], pred)) {
            index = i;
            break;
        }
    }

    return array.splice(index);
}

function arrSplice(array, pred) {
    let index = 0;

    for (let i = 0; i < array.length; i += 1) {
        if (!matchesProp(array[i], pred[0], pred[1])) {
            index = i;
            break;
        }
    }

    return array.splice(index);
}

function strSplice(array, pred) {
    let index = 0;

    for (let i = 0; i < array.length; i += 1) {
        if (!isProp(array[i], pred)) {
            index = i;
            break;
        }
    }

    return array.splice(index);
}

function dropWhile(array, pred) {
    const tempArr = [...array];

    if (pred instanceof Function) return funcSplice(tempArr, pred);
    if (pred instanceof Array) return arrSplice(tempArr, pred);
    if (pred instanceof Object) return objSplice(tempArr, pred);
    if (typeof pred === 'string') return strSplice(tempArr, pred);

    return null;
}


module.exports = dropWhile;