function getSetOffset()

in charts/shared/moment.js [3312:3353]
42 lines of code
17 McCabe index (conditional complexity)

function getSetOffset(input, keepLocalTime, keepMinutes) {
    var offset = this._offset || 0,
        localAdjust;
    if (!this.isValid()) {
        return input != null ? this : NaN;
    }
    if (input != null) {
        if (typeof input === 'string') {
            input = offsetFromString(matchShortOffset, input);
            if (input === null) {
                return this;
            }
        } else if (Math.abs(input) < 16 && !keepMinutes) {
            input = input * 60;
        }
        if (!this._isUTC && keepLocalTime) {
            localAdjust = getDateOffset(this);
        }
        this._offset = input;
        this._isUTC = true;
        if (localAdjust != null) {
            this.add(localAdjust, 'm');
        }
        if (offset !== input) {
            if (!keepLocalTime || this._changeInProgress) {
                addSubtract(
                    this,
                    createDuration(input - offset, 'm'),
                    1,
                    false
                );
            } else if (!this._changeInProgress) {
                this._changeInProgress = true;
                hooks.updateOffset(this, true);
                this._changeInProgress = null;
            }
        }
        return this;
    } else {
        return this._isUTC ? offset : getDateOffset(this);
    }
}