import { TextSelection, AllSelection, EditorState, Transaction } from "@tiptap/pm/state";
import { Node as ProsemirrorNode, NodeType } from "@tiptap/pm/model";
import type { Command } from "@tiptap/core";

export const LINE_HEIGHT_100 = 1.7;
export const DEFAULT_LINE_HEIGHT = "100%";

export const ALLOWED_NODE_TYPES = ["paragraph", "heading", "list_item", "todo_item"];

const NUMBER_VALUE_PATTERN = /^\d+(.\d+)?$/;

export function isLineHeightActive(state: EditorState, lineHeight: string): boolean {
	const { selection, doc } = state;
	const { from, to } = selection;

	let keepLooking = true;
	let active = false;

	doc.nodesBetween(from, to, (node) => {
		const nodeType = node.type;
		const lineHeightValue = node.attrs.lineHeight || DEFAULT_LINE_HEIGHT;

		if (ALLOWED_NODE_TYPES.includes(nodeType.name)) {
			if (keepLooking && lineHeight === lineHeightValue) {
				keepLooking = false;
				active = true;

				return false;
			}
			return nodeType.name !== "list_item" && nodeType.name !== "todo_item";
		}
		return keepLooking;
	});

	return active;
}

export function transformLineHeightToCSS(value: string | number): string {
	if (!value) return "";

	let strValue = String(value);

	if (NUMBER_VALUE_PATTERN.test(strValue)) {
		const numValue = parseFloat(strValue);
		strValue = String(Math.round(numValue * 100)) + "%";
	}

	return parseFloat(strValue) * LINE_HEIGHT_100 + "%";
}

export function transformCSStoLineHeight(value: string): string {
	if (!value) return "";
	if (value === DEFAULT_LINE_HEIGHT) return "";

	let strValue = value;

	if (NUMBER_VALUE_PATTERN.test(value)) {
		const numValue = parseFloat(value);
		strValue = String(Math.round(numValue * 100)) + "%";
		if (strValue === DEFAULT_LINE_HEIGHT) return "";
	}

	return parseFloat(strValue) / LINE_HEIGHT_100 + "%";
}

interface SetLineHeightTask {
	node: ProsemirrorNode;
	nodeType: NodeType;
	pos: number;
}

export function setTextLineHeight(tr: Transaction, lineHeight: string | null): Transaction {
	const { selection, doc } = tr;

	if (!selection || !doc) return tr;

	if (!(selection instanceof TextSelection || selection instanceof AllSelection)) {
		return tr;
	}

	const { from, to } = selection;

	const tasks: Array<SetLineHeightTask> = [];
	const lineHeightValue = lineHeight && lineHeight !== DEFAULT_LINE_HEIGHT ? lineHeight : null;

	doc.nodesBetween(from, to, (node, pos) => {
		const nodeType = node.type;
		if (ALLOWED_NODE_TYPES.includes(nodeType.name)) {
			const lineHeight = node.attrs.lineHeight || null;
			if (lineHeight !== lineHeightValue) {
				tasks.push({
					node,
					pos,
					nodeType,
				});
			}
			return nodeType.name !== "list_item" && nodeType.name !== "todo_item";
		}
		return true;
	});

	if (!tasks.length) return tr;

	tasks.forEach((task) => {
		const { node, pos, nodeType } = task;
		let { attrs } = node;

		attrs = {
			...attrs,
			lineHeight: lineHeightValue,
		};

		tr = tr.setNodeMarkup(pos, nodeType, attrs, node.marks);
	});

	return tr;
}

export function createLineHeightCommand(lineHeight: string): Command {
	return ({ state, dispatch }) => {
		const { selection } = state;
		let { tr } = state;
		tr = tr.setSelection(selection);

		tr = setTextLineHeight(tr, lineHeight);

		if (tr.docChanged) {
			dispatch && dispatch(tr);
			return true;
		}

		return false;
	};
}