import { peekMeta } from 'ember-meta';
import { peekCacheFor } from './computed_cache';
import { eachProxyArrayDidChange, eachProxyArrayWillChange } from './each_proxy_events';
import { sendEvent } from './events';
import { notifyPropertyChange } from './property_events';
export function arrayContentWillChange(array, startIdx, removeAmt, addAmt) {
    // if no args are passed assume everything changes
    if (startIdx === undefined) {
        startIdx = 0;
        removeAmt = addAmt = -1;
    }
    else {
        if (removeAmt === undefined) {
            removeAmt = -1;
        }
        if (addAmt === undefined) {
            addAmt = -1;
        }
    }
    eachProxyArrayWillChange(array, startIdx, removeAmt, addAmt);
    sendEvent(array, '@array:before', [array, startIdx, removeAmt, addAmt]);
    return array;
}
export function arrayContentDidChange(array, startIdx, removeAmt, addAmt) {
    // if no args are passed assume everything changes
    if (startIdx === undefined) {
        startIdx = 0;
        removeAmt = addAmt = -1;
    }
    else {
        if (removeAmt === undefined) {
            removeAmt = -1;
        }
        if (addAmt === undefined) {
            addAmt = -1;
        }
    }
    let meta = peekMeta(array);
    if (addAmt < 0 || removeAmt < 0 || addAmt - removeAmt !== 0) {
        notifyPropertyChange(array, 'length', meta);
    }
    notifyPropertyChange(array, '[]', meta);
    eachProxyArrayDidChange(array, startIdx, removeAmt, addAmt);
    sendEvent(array, '@array:change', [array, startIdx, removeAmt, addAmt]);
    let cache = peekCacheFor(array);
    if (cache !== undefined) {
        let length = array.length;
        let addedAmount = addAmt === -1 ? 0 : addAmt;
        let removedAmount = removeAmt === -1 ? 0 : removeAmt;
        let delta = addedAmount - removedAmount;
        let previousLength = length - delta;
        let normalStartIdx = startIdx < 0 ? previousLength + startIdx : startIdx;
        if (cache.has('firstObject') && normalStartIdx === 0) {
            notifyPropertyChange(array, 'firstObject', meta);
        }
        if (cache.has('lastObject')) {
            let previousLastIndex = previousLength - 1;
            let lastAffectedIndex = normalStartIdx + removedAmount;
            if (previousLastIndex < lastAffectedIndex) {
                notifyPropertyChange(array, 'lastObject', meta);
            }
        }
    }
    return array;
}