fantasy-console/repl.ts

import faux from "./builtins.ts";
import { getKeysPressed, shiftKeyDown, shiftMap, K } from "./keyboard.ts";
import { font } from "./font.ts";
import { runCode } from "./runcode.ts";

const lineHeight = 6;

let maxLineLen = 0;
let line = "";
let index = 0;
let y = 0;
let result = "";

const update = () => {
	if (result) {
		console.log("result:", result);
		y += lineHeight; // TODO: multiply if multiline
		result = "";
	}
	for (const key of getKeysPressed()) {
		let char = String.fromCharCode(key).toLowerCase();
		if (shiftKeyDown()) {
			if (char in shiftMap) {
				char = shiftMap[char as keyof typeof shiftMap];
			} else {
				char = char.toUpperCase();
			}
		}
		if (char in font) {
			line = line.slice(0, index)+char+line.slice(index);
			index += 1;
		} else if (key === K.BACKSPACE) {
			if (index > 0) {
				line = line.slice(0, index-1)+line.slice(index);
				index -= 1;
			}
		} else if (key === K.ARROW_LEFT) {
			index -= 1;
			if (index < 0) {
				index = 0;
			}
		} else if (key === K.ARROW_RIGHT) {
			index += 1;
			if (index > line.length) {
				index = line.length;
			}
		} else if (key === K.ENTER) {
			const ran = runCode('return '+line);
			console.log('ran:', ran);
			result = ran?.toString?.();
			maxLineLen = 0;
			line = "";
			index = 0;
			y += lineHeight;
		}
	}
	maxLineLen = Math.max(maxLineLen, line.length);
}

const draw = () => {
	if (result) {
		faux.draw_rect(0, y, 4*result.length+1, lineHeight+1, 6);
		faux.draw_text(0, y, result);
	} else {
		faux.draw_rect(0, y, 4*(2+maxLineLen+1)+1, lineHeight+1, 6);
		faux.draw_rect((2+index)*4, y+1, 4, lineHeight-1, 3);
		faux.draw_text(0, y, "> "+line);
	}
}

export const repl = {
	update, draw
}