import fs from "fs";
import { getDirname } from '../util/dirname';
import path from "path";
import { Mathuscript, parseMathuscript } from "../src/client/player/parse";
import { writeFileSync, mkdirSync, rmSync } from 'fs';
import {execa} from 'execa';
import hash from "object-hash";

const __dirname = getDirname(import.meta);

// Function to convert LaTeX to SVG
async function latexToSvg(latex: string, dir: string, tempDir: string | null): Promise<string> {
	try {
		// const dir = path.join(__dirname, "..", "src", "server", "public", "svgs");
		tempDir = tempDir ?? path.join(dir, "temp");

		mkdirSync(tempDir, {recursive: true});

		const fname = hash(latex);
		const tempFileName = path.join(tempDir, fname);
		const outFileName = path.join(dir, fname);
		writeFileSync(`${tempFileName}.tex`, latex);
		
		// Run LaTeX to generate a DVI file
		console.log("generating dvi file");
		await execa('latex', ['-halt-on-error', `-output-directory=${tempDir}`, `${tempFileName}.tex`]);
		
		// Convert DVI to SVG
		console.log("converting to svg");
		await execa('dvisvgm', [`${tempFileName}.dvi`, '-n', '-o', `${outFileName}.svg`]);

		console.log("cleaning up temp files");
		rmSync(tempDir, {force: true, recursive: true});
		
		return `${fname}.svg`;
	} catch (error) {
		console.error('Error converting LaTeX to SVG:', error);
		throw Error('Error converting LaTeX to SVG');
	}
}

const contentDir = path.join(__dirname, "..", "src", "content");
const publicDir = path.join(__dirname, "..", "src", "server", "public");
const assetsDir = path.join(publicDir, "assets");
const compiledAssetsDir = path.join(assetsDir, "compiled");
const compileToDir = path.join(__dirname, "..", "src", "client", "content");

const preamblePath = path.join(contentDir, "preamble.tex");
const sectionsDir = path.join(contentDir, "sections");

const compileContents = async () => {
	fs.rmSync(compileToDir, {force: true, recursive: true});
	fs.mkdirSync(compileToDir, {recursive: true});
	const sectionFiles = fs.readdirSync(sectionsDir);
	const sections: {name: string; text: string, parsed: Mathuscript}[] = [];
	sectionFiles.forEach(sectionFile => {
		const fullName = path.join(sectionsDir, sectionFile);
		console.log("Reading", sectionFile);
		const fileText = fs.readFileSync(fullName, "utf8");
		sections.push({
			name: sectionFile,
			text: fileText,
			parsed: parseMathuscript(fileText),
		});
	})
	const preamble = fs.readFileSync(preamblePath, "utf8");
	for (const section of sections) {
		console.log("Processing", section.name);
		for (const step of section.parsed.filter(step => step.name === "board")) {
			console.log('Step');
			if (step.text.trim()) {
				const svgPath = await latexToSvg(`${preamble}\n\n\\begin{document}\n${step.text}\n\\end{document}\n`, compiledAssetsDir, null);
				step.text = svgPath;
			}
		}
	}
	fs.writeFileSync(path.join(compileToDir, "content.ts"), `export const content = {sections: ${JSON.stringify(sections)}}`);
}

await compileContents();