var emulator;

// Whether or not to restore the VM state from a file. Set to false to perform a regular boot.
let restoreState = true;

function testy(cmd) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve("testy!!" + cmd);
    }, 100);
  });
}
window.testy = testy;

// Run a command via the serial port (/dev/ttyS0) and return the output.
function run_in_vm(cmd) {
  emulator.serial0_send(cmd + "\n");

  return new Promise((resolve, reject) => {
    var output = "";
    var listener = (char) => {
      if (char !== "\r") {
        output += char;
      }

      if (output.endsWith("# ")) {
        emulator.remove_listener("serial0-output-char", listener);
        let outputWithoutPrompt = output.slice(0, -4);
        let outputWithoutFirstLine = outputWithoutPrompt.slice(
          outputWithoutPrompt.indexOf("\n") + 1
        );
        if (outputWithoutFirstLine.endsWith("\n")) {
          outputWithoutFirstLine = outputWithoutFirstLine.slice(0, -1);
        }
        emulator.remove_listener("serial0-output-char", listener);
        resolve(outputWithoutFirstLine);
      }
    };
    emulator.add_listener("serial0-output-char", listener);
  });
}
window.run_in_vm = run_in_vm;
window.web_shell = { run_in_vm, testy };

/*

// Run a test command and return true if the exit code is 0, false otherwise.
async function test(condition) {
    let result = await run(`test ${condition} && echo 'yes' || echo 'no'`)
    return result == "yes"
}

*/

// Set emulator config.
let config = {
  wasm_path: "web-shell/lib/v86.wasm",
  memory_size: 64 * 1024 * 1024,
  vga_memory_size: 2 * 1024 * 1024,
  screen_container: document.getElementById("screen_container"),
  bios: { url: "web-shell/images/seabios.bin" },
  vga_bios: { url: "web-shell/images/vgabios.bin" },
  cdrom: { url: "web-shell/images/image.iso.zst" },
  disable_mouse: true,
  autostart: true,
};
if (restoreState) {
  config.initial_state = {
    url: "web-shell/images/booted-state.bin.zst",
  };
}

function boot() {
  return new Promise((resolve, reject) => {
    // Start the emulator!
    emulator = window.emulator = new V86Starter(config);

    // Wait for the emulator to start, then resolve the promise.
    var interval = setInterval(() => {
      if (emulator.is_running()) {
        clearInterval(interval);
        resolve();
      }
    }, 100);
  });
}

/*

// Allow saving and restoring the state using the buttons below the console.
var state
document.getElementById("save_restore").onclick = async function () {
    var button = this

    if (state) {
        button.value = "Save state"
        await emulator.restore_state(state)
        state = undefined
    } else {
        const new_state = await emulator.save_state()
        console.log("Saved state of " + new_state.byteLength + " bytes")
        button.value = "Restore state"
        state = new_state
    }

    button.blur()
}
document.getElementById("save_file").onclick = async function () {
    const new_state = await emulator.save_state()
    var a = document.createElement("a")
    a.download = "v86state.bin"
    a.href = window.URL.createObjectURL(new Blob([new_state]))
    a.dataset.downloadurl =
        "application/octet-stream:" + a.download + ":" + a.href
    a.click()

    this.blur()
}
document.getElementById("restore_file").onchange = function () {
    if (this.files.length) {
        var filereader = new FileReader()
        emulator.stop()

        filereader.onload = async function (e) {
            await emulator.restore_state(e.target.result)
            emulator.run()
        }

        filereader.readAsArrayBuffer(this.files[0])

        this.value = ""
    }

    this.blur()
}

*/