import { readKey } from './ansi.ts';
import { getRuntime } from './runtime.ts';
import { getTermios } from './termios.ts';
import { Editor } from './editor.ts';

export async function main() {
	const decoder = new TextDecoder();
	const runTime = await getRuntime();
	const { term, file, onExit, onEvent } = runTime;

	// Setup raw mode, and tear down on error or normal exit
	const t = await getTermios();
	t.enableRawMode();
	onExit(() => {
		t.disableRawMode();
		t.cleanup();
	});

	// Setup error handler to log to file
	onEvent('error', (error) => {
		t.disableRawMode();
		file.appendFileSync('./scroll.err', JSON.stringify(error, null, 2));
	});

	const terminalSize = await term.getTerminalSize();

	// Create the editor itself
	const editor = new Editor(terminalSize);
	if (term.argv.length > 0) {
		const filename = term.argv[0];
		if (filename.trim() !== '') {
			await editor.open(filename);
		}
	}

	// Clear the screen
	await editor.refreshScreen();

	// The main event loop
	for await (const chunk of term.inputLoop()) {
		// Process input
		const char = readKey(decoder.decode(chunk));
		const shouldLoop = editor.processKeyPress(char);
		if (!shouldLoop) {
			return 0;
		}

		// Render output
		await editor.refreshScreen();
	}

	return -1;
}