midi_scan.js

gistfile1.txt

const { spawn } = require("child_process");
const path = require("path");
const readline = require("readline");
const os = require("os");
const fs = require("fs");

// ── config ──────────────────────────────────────────────
const SCAN_DIR = process.env.SCAN_DIR || path.join(".", "scans");
const SCAN_FORMAT = "png";
const SCAN_DPI = 300;
const SCAN_MODE = "Color";
const DEBOUNCE_MS = 2000;
const IS_WIN = os.platform() === "win32";

// ── state ───────────────────────────────────────────────
let scanning = false;
let lastTrigger = 0;

// ensure output dir
if (!fs.existsSync(SCAN_DIR)) fs.mkdirSync(SCAN_DIR, { recursive: true });

// ── platform-specific scan commands ─────────────────────

function scanLinux(filename) {
  return spawn("scanimage", [
    `--mode=${SCAN_MODE}`,
    `--resolution=${SCAN_DPI}`,
    `--format=${SCAN_FORMAT}`,
    `--output-file=${filename}`,
  ]);
}

function scanWindows(filename) {
  const ps = `
    $deviceManager = New-Object -ComObject WIA.DeviceManager
    $device = $null
    foreach ($info in $deviceManager.DeviceInfos) {
      if ($info.Type -eq 1) {       # ScannerDeviceType = 1
        $device = $info.Connect()
        break
      }
    }
    if (-not $device) {
      Write-Error "No WIA scanner found."
      exit 1
    }

    $item = $device.Items[1]

    # 6146 = Color Intent (1=Color), 6147 = H-DPI, 6148 = V-DPI
    foreach ($prop in $item.Properties) {
      switch ($prop.PropertyID) {
        6146 { $prop.Value = 1 }
        6147 { $prop.Value = ${SCAN_DPI} }
        6148 { $prop.Value = ${SCAN_DPI} }
      }
    }

    $image = $item.Transfer("{B96B3CAF-0728-11D3-9D7B-0000F81EF32E}")  # PNG GUID
    $image.SaveFile("${filename.replace(/\\/g, "\\\\")}")
    Write-Host "Saved."
  `;

  return spawn("powershell", [
    "-NoProfile",
    "-ExecutionPolicy", "Bypass",
    "-Command", ps,
  ]);
}

// ── scanner ─────────────────────────────────────────────
function startScan() {
  const now = Date.now();
  if (scanning) {
    console.log("  Scan already in progress, ignoring.");
    return;
  }
  if (now - lastTrigger < DEBOUNCE_MS) return;
  lastTrigger = now;
  scanning = true;

  const timestamp = new Date().toISOString().replace(/[:.]/g, "-");
  const filename = path.join(SCAN_DIR, `scan_${timestamp}.${SCAN_FORMAT}`);

  console.log(`\n>> Starting color scan -> ${filename}`);

  const proc = IS_WIN ? scanWindows(filename) : scanLinux(filename);

  proc.stdout.on("data", (d) => process.stdout.write(d));
  proc.stderr.on("data", (d) => process.stderr.write(d));

  proc.on("close", (code) => {
    scanning = false;
    if (code === 0) {
      console.log(`>> Scan saved: ${filename}\n`);
    } else {
      console.log(`!! Scanner exited with code ${code}\n`);
    }
  });

  proc.on("error", (err) => {
    scanning = false;
    if (IS_WIN) {
      console.error(`!! Failed to run PowerShell: ${err.message}`);
      console.error("   Make sure your scanner is connected and WIA-compatible.\n");
    } else {
      console.error(`!! Failed to run scanimage: ${err.message}`);
      console.error("   Install SANE: sudo apt install sane-utils\n");
    }
  });
}

// ── midi (optional) ─────────────────────────────────────
let midiAvailable = false;

try {
  const midi = require("midi");
  const input = new midi.Input();
  const portCount = input.getPortCount();

  if (portCount > 0) {
    console.log("\nMIDI inputs:");
    for (let i = 0; i < portCount; i++) {
      console.log(`  [${i}] ${input.getPortName(i)}`);
    }

    let port = 0;
    for (let i = 0; i < portCount; i++) {
      if (input.getPortName(i).toLowerCase().includes("kontrol")) {
        port = i;
        break;
      }
    }

    console.log(`Opened: ${input.getPortName(port)}`);
    input.openPort(port);
    midiAvailable = true;

    input.on("message", (_dt, msg) => {
      const [status, data1, data2] = msg;
      const type = status & 0xf0;
      const ch = (status & 0x0f) + 1;

      if (type === 0x90 && data2 > 0) {
        console.log(`NoteOn   ch:${ch}  note:${data1}  vel:${data2}`);
      } else if (type === 0x80 || (type === 0x90 && data2 === 0)) {
        console.log(`NoteOff  ch:${ch}  note:${data1}`);
        return;
      } else if (type === 0xb0) {
        console.log(`CC       ch:${ch}  cc:${data1}  val:${data2}`);
      } else {
        console.log(`MIDI     0x${status.toString(16)}  ${data1}  ${data2}`);
      }

      startScan();
    });

    process.on("SIGINT", () => {
      input.closePort();
      process.exit();
    });
  }
} catch {
  // midi not installed or no devices
}

// ── cli ─────────────────────────────────────────────────
if (!midiAvailable) {
  console.log("\nNo MIDI device found (or `midi` package not installed).");
  console.log("Falling back to CLI mode.\n");
}

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

function prompt() {
  rl.question(
    midiAvailable
      ? 'Type "scan" or twist a knob > '
      : 'Type "scan" + enter to start > ',
    (answer) => {
      const cmd = answer.trim().toLowerCase();
      if (cmd === "scan" || cmd === "s") {
        startScan();
      } else if (cmd === "quit" || cmd === "q") {
        process.exit();
      } else if (cmd) {
        console.log('  ("scan" or "s" to scan, "q" to quit)');
      }
      prompt();
    }
  );
}

const backend = IS_WIN ? "WIA (PowerShell)" : "SANE (scanimage)";
console.log(`\nScans -> ${path.resolve(SCAN_DIR)}`);
console.log(`${SCAN_DPI}dpi | ${SCAN_MODE} | ${SCAN_FORMAT} | ${backend}\n`);
prompt();