export default function transformTopLevelComponent( /* env */) {
    return {
        name: 'transform-top-level-component',
        visitor: {
            Program(node) {
                hasSingleComponentNode(node, (component) => {
                    component.tag = `@${component.tag}`;
                    component.isStatic = true;
                });
            },
        },
    };
}
function hasSingleComponentNode(program, componentCallback) {
    let { loc, body } = program;
    if (!loc || loc.start.line !== 1 || loc.start.column !== 0) {
        return;
    }
    let lastComponentNode;
    let nodeCount = 0;
    for (let i = 0; i < body.length; i++) {
        let curr = body[i];
        // text node with whitespace only
        if (curr.type === 'TextNode' && /^[\s]*$/.test(curr.chars)) {
            continue;
        }
        // has multiple root elements if we've been here before
        if (nodeCount++ > 0) {
            return false;
        }
        if (curr.type === 'ComponentNode' || curr.type === 'ElementNode') {
            lastComponentNode = curr;
        }
    }
    if (!lastComponentNode) {
        return;
    }
    if (lastComponentNode.type === 'ComponentNode') {
        componentCallback(lastComponentNode);
    }
}