import { warnOnce } from 'motion-utils';
import { axisKeys } from './info.mjs';
import { resolveOffsets } from './offsets/index.mjs';
import { calcInset } from './offsets/inset.mjs';

function getTargetSize(target) {
    return "getBBox" in target && target.tagName !== "svg"
        ? target.getBBox()
        : { width: target.clientWidth, height: target.clientHeight };
}
function createOnScrollHandler(container, onScroll, info, options = {}) {
    const { target } = options;
    /**
     * In development mode ensure scroll containers aren't position: static as this makes
     * it difficult to measure their relative positions. The document scrolling element
     * is exempt: offsetParent measurements naturally resolve relative to the document.
     */
    if (process.env.NODE_ENV !== "production") {
        if (target &&
            target !== container &&
            container !== document.documentElement &&
            container !== document.scrollingElement &&
            container !== document.body) {
            warnOnce(getComputedStyle(container).position !== "static", "Please ensure that the container has a non-static position, like 'relative', 'fixed', or 'absolute' to ensure scroll offset is calculated correctly.");
        }
    }
    /**
     * Handlers without a target or offset are notified with the container's
     * shared info object, so they measure nothing themselves.
     */
    const needsOwnInfo = target || options.offset;
    return {
        measure: (containerInfo) => {
            if (!needsOwnInfo)
                return;
            info.time = containerInfo.time;
            for (const key in axisKeys) {
                const axis = key;
                const { offset } = info[axis];
                Object.assign(info[axis], containerInfo[axis]);
                info[axis].offset = offset;
            }
            if (target && target !== container) {
                const inset = calcInset(target, container);
                const size = getTargetSize(target);
                info.x.targetOffset = inset.x;
                info.y.targetOffset = inset.y;
                info.x.targetLength = size.width;
                info.y.targetLength = size.height;
            }
            resolveOffsets(info, options);
        },
        notify: (containerInfo) => onScroll(needsOwnInfo ? info : containerInfo),
    };
}

export { createOnScrollHandler };
//# sourceMappingURL=on-scroll-handler.mjs.map