// Take a JavaScript date and convert it to DOS like `DIR` date
function dirDate(date) {
  var month = ('0' + (date.getMonth() + 1)).slice(-2),
      day = ('0' + (date.getDate())).slice(-2),
      year = (date.getFullYear().toString().slice(-2)),
      timeString = date.toLocaleString(
        'en-US',
        {minute: 'numeric', hour: 'numeric', hour12: true }
      ).replace(" AM", "a").replace(" PM", "p");

  return `${month}-${day}-${year}\t${timeString}`;
}

// Used for slowing down output to feel more "real"
function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

// Used when getJSON fails
function createFailedTerminal(termElement, error) {
  $(termElement).terminal({},
    {
      greetings: null,
      onInit: async function typeMessage(term) {
        await sleep(1);
        term.set_prompt('');
        term.echo("Starting WEB-DOS", {newline: false});
        var i;
        for(i = 1; i <= 3; i++) {
          await sleep(200);
          term.echo(".", {newline: false});
        }
        await sleep(200);
        term.echo("\n");
        term.echo("ERROR: Failed to start WEB-DOS.\n");
        term.echo("[[;red;]"+error.toString());
        term.set_prompt('');
      },
    }
  );
}

// Create a jsquery.terminal in a given element with a set of commands
function createTerminal(termElement, commands) {
  $(termElement).terminal(
    function(command) {
      var upcaseCommand = command.toUpperCase();

      comFunc = commands[upcaseCommand];
      if(typeof comFunc !== 'undefined') {
        comFunc(this);
      } else {
        this.echo("Bad command or file name (Try HELP)\n");
      }
    },
    {
      greetings: null,
      onInit: async function typeMessage(term) {
        function sleep(ms) {
          return new Promise(resolve => setTimeout(resolve, ms));
        }
        await sleep(1);
        term.set_prompt('');
        term.echo("Starting WEB-DOS", {newline: false});
        var i;
        for(i = 1; i <= 3; i++) {
          await sleep(200);
          term.echo(".", {newline: false});
        };
        await sleep(200);
        term.echo("\n");
        term.set_prompt('C:\>');
      },
    }
  );
}

// Takes in a 'game' object and returns a function to run it in js-dos
function createGameCommand(game, canvas, termElement) {
  return function() {
    canvas.style.display = "";
    termElement.style.display = "none";

    Dos(canvas, {
      wdosboxUrl: "https://js-dos.com/6.22/current/wdosbox.js",
      cycles: game.cycles,
      autolock: true,
    }).ready(function (fs, main) {
      fs.extract(game.url, "/" + game.dataFolder).then(function () {
        var runCommand = [];
        if(typeof game.runCommand == 'undefined') {
          runCommand = ["-c", "cd " + game.dataFolder, "-c", game.executable];
        } else {
          runCommand = game.runCommand;
        }
        main(runCommand).then(function (ci) {
          window.ci = ci;
          document.title = game.executable;
        });
      });
    });
  };
}

// Given data from a config.json, create commands for a jsquery.template
function createCommands(data, canvas, termElement) {
  var commands = {};

  // Load commands from JSON
  data.games.forEach(function(game) {
    gameCommand = createGameCommand(game, canvas, termElement);
    commands[game.executable] = gameCommand;
    commands[game.executable + "." + game.extension] = gameCommand;
  });

  commands["DIR"] = function(term){
    var largestSizeLen = 0;
    data.games.forEach(function(game) {
      var localeStringLength = game.size.toLocaleString().length;
      if(localeStringLength > largestSizeLen) {
        largestSizeLen = localeStringLength;
      }
    });

    var totalSize = 0;
    data.games.forEach(function(game) {
      totalSize = totalSize + game.size;

      var exe = game.executable.padEnd(8);
      var ext = game.extension;
      var size = game.size.toLocaleString().padStart(largestSizeLen);
      var date = dirDate(new Date(game.dateAdded));
      term.echo(`${exe}\t${ext}\t\t\t${size}\t${date}`);
    });

    var gameCount = data.games.length;
    var localeSize = totalSize.toLocaleString();
    term.echo(`\t\t${gameCount} file(s)\t\t       ${localeSize} bytes`);
    term.echo(`\t\t\t\t\t\t    42,821,632 bytes free`);
  };

  commands["HELP"] = function(term){
    term.echo("Supported commands:");
    term.echo("\tDIR    List all \"executables\" you can run");
    term.echo("\tHELP   You're reading it");
    term.echo("\n");
    term.echo("Or, just run one of these:");
    data.games.forEach(function(game) {
      term.echo("\t" + game.executable);
    });
  };

  return commands;
}

// Load config.json, create commands, then launch jsquery.terminal
function initTerminal(dataJSONPath, canvas, termElement) {
  var commands = {};
  $.getJSON(
    dataJSONPath,
    function(data) { commands = createCommands(data, canvas, termElement); }
  ).fail(
    function(_, _, error) { terminal = createFailedTerminal(termElement, error); }
  ).done(
    function() { terminal = createTerminal(termElement, commands); }
  );
}