/**
 * @file /src/utils/nodes/text.ts
 * @name Text
 * @description Utility functions for text nodes.
 */

import { Node as PMNode, ResolvedPos } from "@tiptap/pm/model";
import { Nullable } from "../../types/record";
import { NullableNodePos } from "../../types/node";
import { getParentNodePosOfType } from "./node";

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

    return node.type.name === "text";
};

/**
 * Check if the given position is at the start of the text node.
 *
 * @param doc - The document node.
 * @param $pos - The resolved position in the document or the absolute position of the node.
 * @returns {boolean} True if the position is at the start of the text node, false otherwise.
 */
export const isAtStartOfTextNode = (doc: PMNode, $pos: ResolvedPos | number): boolean => {
    if (typeof $pos === "number") {
        return isAtStartOfTextNode(doc, doc.resolve($pos));
    }

    const { pos: textPos, node: textNode } = getTextNodeAndPosition(doc, $pos);
    if (!textNode) {
        return false;
    }

    return $pos.pos === textPos;
};

/**
 * Check if the given position is at the end of the text node.
 *
 * @param doc - The document node.
 * @param $pos - The resolved position in the document or the absolute position of the node.
 * @returns {boolean} True if the position is at the end of the text node, false otherwise.
 */
export const isAtEndOfTextNode = (doc: PMNode, $pos: ResolvedPos | number): boolean => {
    if (typeof $pos === "number") {
        return isAtEndOfTextNode(doc, doc.resolve($pos));
    }

    const { pos: textPos, node: textNode } = getTextNodeAndPosition(doc, $pos);
    if (!textNode) {
        return false;
    }

    return $pos.pos + 1 === textPos + textNode.nodeSize;
};

/**
 * Get the position of the text node.
 *
 * @param doc - The document node.
 * @param pos - The resolved position in the document or the absolute position of the node.
 * @returns {number} The position of the text node.
 */
export const getThisTextNodePosition = (doc: PMNode, pos: ResolvedPos | number): number => {
    return getParentNodePosOfType(doc, pos, "text").pos;
};

/**
 * Get the text node and the position of the text node.
 *
 * @param doc - The document node.
 * @param pos - The resolved position in the document or the absolute position of the node.
 * @returns {NullableNodePos} The text node and the position of the text node.
 */
export const getTextNodeAndPosition = (doc: PMNode, pos: ResolvedPos | number): NullableNodePos => {
    if (typeof pos === "number") {
        return getTextNodeAndPosition(doc, doc.resolve(pos));
    }

    const textPos = getThisTextNodePosition(doc, pos);
    const textNode = doc.nodeAt(textPos);
    if (!isTextNode(textNode)) {
        console.warn("No text node found");
        return { pos: -1, node: textNode };
    }

    return { pos: textPos, node: textNode };
};

/**
 * Measure the width and height of a text node.
 *
 * @param text - The text content of the node.
 * @param computedStyles - The computed styles of the node.
 * @returns {DOMRect} The bounding rectangle of the text node.
 */
export const measureText = (text: string, computedStyles: CSSStyleDeclaration): DOMRect => {
    const span = document.createElement("span");
    span.textContent = text;
    span.style.position = "absolute";
    span.style.visibility = "hidden";
    span.style.whiteSpace = "nowrap";
    span.style.font = computedStyles.font;
    span.style.letterSpacing = computedStyles.letterSpacing;
    span.style.wordSpacing = computedStyles.wordSpacing;
    span.style.lineHeight = computedStyles.lineHeight;

    document.body.appendChild(span);

    const clientBoundingRect = span.getBoundingClientRect();
    document.body.removeChild(span);

    return clientBoundingRect;
};

/**
 * Measure the cumulative width of each character in a text node.
 *
 * @param textContent - The text content of the node.
 * @param computedStyles - The computed styles of the node.
 * @returns {number[]} The cumulative width of each character in the text node.
 */
export const measureCumulativeTextWidths = (textContent: string, computedStyles: CSSStyleDeclaration): number[] => {
    const cumulativeWidths: number[] = [];

    let cumulativeWidth = 0;

    for (let i = 0; i < textContent.length; i++) {
        const char = textContent[i];
        const { width } = measureText(char, computedStyles);
        cumulativeWidth += width;
        cumulativeWidths.push(cumulativeWidth);
    }

    return cumulativeWidths;
};