const { num2hex, bool2bit } = require('./logging.js');

const CFG = require('./machine.config.js');
const CPU = require('./cpu.js');
const io = require('./io.js');


// TODO - replace with reading STDIN:
  const assembler = require('./assembler.js');
  const fs = require('fs');

  const filename = process.argv[2];
  const inputFile_str = fs.readFileSync(filename, 'utf8');
  let assemblerOutput = assembler.assemble(inputFile_str);

let cpu = new CPU(CFG.initialIP, CFG.defaultCycleLimit);

cpu.loadMemory(assemblerOutput.machineCode);
cpu.loadSourceInfo(assemblerOutput.debugInfo);

cpu.onCycleEnd(tick);
cpu.onCycleEnd(logCPUState);

cpu.start();
io.getKeypadInput(cpu);
cpu.step();

async function tick() {
  const sleep = ms => new Promise(resolve => setTimeout(resolve, ms))
  await sleep(100);
  cpu.step();
  if (!cpu.running) {
    console.log('Halted');
    process.exit();
  }
}

function logCPUState() {
  let lineInfo = cpu.dbg.sourceInfo[cpu.dbg.previousIP];
  console.group(`Step ${cpu.dbg.cycleCounter}`);
    console.log();
    io.showDisplay(cpu.memory, true); // FIXME - display - allow printing hex as well as pretty-printing
    console.log();
    if (lineInfo) {
      console.log(`Line ${lineInfo.lineNumber}: ${lineInfo.source}`);
      console.log();
    }
    console.log('Mnemonic:', cpu.dbg.currentMnemonic);
    console.log(`Machine:  $${num2hex(cpu.instruction.opcode)} $${num2hex(cpu.instruction.operand)}`);
    console.log();
    console.log(`IP: $${num2hex(cpu.IP)}  Acc: $${num2hex(cpu.acc)}  ONZC ${bool2bit(cpu.flags.O)}${bool2bit(cpu.flags.N)}${bool2bit(cpu.flags.Z)}${bool2bit(cpu.flags.C)}`);
    console.log(`KEY: ${io.readKeyMem(cpu.memory)}   ${cpu.running ? "running" : "halted" }`);
    console.log();
  console.groupEnd();
};


/*
(async function() {
  let input = await readPipedStdin();
  console.log(input);
})()
*/

async function readPipedStdin() {
  // https://wellingguzman.com/notes/node-pipe-input
  return new Promise(function (resolve, reject) {
    const stdin = process.stdin;
    stdin.setEncoding('utf8');
    let data = '';
    stdin.on('data', function (chunk) { data += chunk; });
    stdin.on('end', function () { resolve(data); });
    stdin.on('error', reject);
  });
}