var term;
var termfit;
var emulator;

var booted = false;

document.addEventListener("DOMContentLoaded", () => {
    // Debug
    var v86_display = undefined;
    if(window.location.hash == "#debug") {
        document.getElementById("screen").classList.add("visible");
    }

    // Initialize the v86 emulator
    emulator = new V86Starter({
        wasm_path: "assets/v86.wasm",
        memory_size: 512 * 1024 * 1024,
        vga_memory_size: 100 * 1024 * 1024,
        screen_container: document.getElementById("screen"),
        bios: {
            url: "images/seabios.bin",
        },
        vga_bios: {
            url: "images/vgabios.bin",
        },
        cdrom: {
            url: "images/os.iso",
        },
        autostart: true,
    });

    // Initialize xterm.js
    term = new Terminal({
        rendererType: 'dom',
    });
    termcontainer = document.getElementById('terminal');
    term.open(termcontainer);
    // Fit xterm to the size of the container
    termfit = new FitAddon.FitAddon();
    term.loadAddon(termfit);
    termfit.fit()    
    // Write a "Booting WebTerm ..." message
    term.write('\033[1;34mDownloading\033[0m OS images ...\r\n')

    // Forward keystrokes from xterm to v86
    term.onKey(key => onConsoleInput(key));   
    // Forward output from v86 to xterm and other functions 
    emulator.add_listener("serial0-output-char", (char) => onConsoleOutput(char));
    emulator.add_listener("serial0-output-line", (line) => onConsoleLine(line));

    // Wait for the emulator to get ready
    emulator.add_listener("emulator-ready", () => {
        term.write('Booting \x1B[1;3;31mWebTerm\x1B[0m ...\r\n')
    })
})

function onConsoleOutput(char) {
    // Only write to the xterm if the system is fully booted
    if(booted) {
        term.write(char);
    }
    // If the char is the shell prompt after the login message start
    // the welcome script and set bootet to true
    if(char == "#" && previous_line.includes("buildroot login: root")) {
        emulator.serial0_send("/etc/init.d/S99welcome\n")
        booted = true;
    }
}

var debugcnt = 0;
var debugword = "+++debug+++"
function onConsoleInput(key) {
    // Send keys from xterm to v86
    emulator.serial0_send(key.key)

    // Listen for the debug key combination
    if(key.key == debugword[debugcnt]) {
        debugcnt++;
    } else {
        debugcnt = 0;
    }
    if(debugcnt == debugword.length) {
        document.getElementById("screen").classList.toggle("visible"); 
    }
    console.log(debugcnt)
}

var previous_line = "";
function onConsoleLine(line) {
    // Enter username on the login prompt
    if (line.startsWith("Welcome to WebTerm")) {
        emulator.serial0_send("root\n")
    }
    // Save the line
    previous_line = line;
}

// Fit xterm to the container on window resize
window.addEventListener("resize", () => {
    termfit.fit()
})