/**
 * @file /src/utils/page.ts
 * @name Page
 * @description Utility functions for page nodes in the editor.
 */

import { Node as PMNode, ResolvedPos } from "@tiptap/pm/model";
import { EditorState } from "@tiptap/pm/state";
import { PAGE_NODE_NAME } from "../../../constants/page";
import { NodePosArray, NullableNodePos } from "../../../types/node";
import { Nullable } from "../../../types/record";
import { getParentNodePosOfType } from "../node";
import { BODY_NODE_NAME } from "../../../constants/body";
import { HEADER_FOOTER_NODE_NAME } from "../../../constants/pageRegions";

/**
 * Check if the given node is a page node.
 *
 * @param node - The node to check.
 * @returns {boolean} True if the node is a page node, false otherwise.
 */
export const isPageNode = (node: Nullable<PMNode>): boolean => {
    if (!node) {
        console.warn("No node provided");
        return false;
    }

    return node.type.name === PAGE_NODE_NAME;
};

/**
 * Check if the document has page nodes.
 *
 * @param state - The editor state.
 * @returns {boolean} True if the document has page nodes, false otherwise.
 */
export const doesDocHavePageNodes = (state: EditorState): boolean => {
    const { schema } = state;
    const pageType = schema.nodes.page;

    let hasPageNodes = false;

    state.doc.forEach((node) => {
        if (node.type === pageType) {
            hasPageNodes = true;
            return false;
        }
    });

    return hasPageNodes;
};

/**
 * Collect page nodes and their positions in the document.
 *
 * @param doc - The document node.
 * @returns {NodePosArray} A map of page positions to page nodes.
 */
export const collectPageNodes = (doc: PMNode): NodePosArray => {
    const pageNodes: NodePosArray = [];
    doc.forEach((node, offset) => {
        if (isPageNode(node)) {
            pageNodes.push({ node, pos: offset });
        }
    });

    return pageNodes;
};

/**
 * Given a position in the document, get the child node of the page node at that position.
 * I.e. that will be a header/footer node or a body node.
 * @param doc - The document node.
 * @param $pos - The resolved position in the document.
 * @returns {NullableNodePos} The child node position of the page node at the given position.
 */
export const getPageChildNodePosFromPosition = (doc: PMNode, $pos: ResolvedPos | number): NullableNodePos => {
    if (typeof $pos === "number") {
        return getPageChildNodePosFromPosition(doc, doc.resolve($pos));
    }

    const pageChildPos = getParentNodePosOfType(doc, $pos, [BODY_NODE_NAME, HEADER_FOOTER_NODE_NAME]);
    const pageChildNode = doc.nodeAt(pageChildPos.pos);
    if (!pageChildNode) {
        console.warn("No page child node found");
        return { pos: -1, node: pageChildNode };
    }

    return { pos: pageChildPos.pos, node: pageChildNode };
};