main.lua

local love = require 'love'
local lib = require 'lib'

Config = {
  controls = {
    switch = {
      normal = 'escape',
      insert = 'i',
      --command = ':'
    },
    commands = {
      runCommand = 'return',

      quit = 'q',
      ignoreUnsaved = '!',
      read = 'r',
      write = 'w',
      help = 'h'
    },
    cursor = {
      up = 'up',
      down = 'down',
      left = 'left',
      right = 'right'
    },
    editor = {
      paste = 'p',
      copy = 'y',
      cut = 'c'
    }
  },
  coloring = {
    background = { 0, 0, 0 },
    text = { 255, 255, 255 },
    lineNumbers = { 200, 200, 200 },
    cursor = {
      insert = { 240, 240, 240 },
      command = { 240, 240, 240 }
    }
  },
  editor = {
    showLineNumbers = true,
    cursorMoveInterval = 5,
    moveOverNewlines = false,
    truncateFilepath = true,
    hideUser = true,
    showCursor = {
      insert = true,
      command = true
    }
  }
}

Modes = {
  Normal = 1,
  Command = 2,
  Insert = 3,
  Help = 4
}

---@param mode number
---@return string
function GetModeName(mode)
  if mode == Modes.Normal then
    return "NORMAL"
  elseif mode == Modes.Command then
    return "COMMAND"
  elseif mode == Modes.Insert then
    return "INSERT"
  elseif mode == Modes.Help then
    return "HELP"
  end
  return "UNKNOWN"
end

KeysToChars = {
  ['return'] = '\n',
  ['tab'] = '\t',
  ['space'] = ' ',
  ['lshift'] = 0,
  ['rshift'] = 0,
  ['lctrl'] = 0,
  ['rctrl'] = 0,
  ['lalt'] = 0,
  ['ralt'] = 0,
  ['lgui'] = 0,
  ['rgui'] = 0,
  ['up'] = 0,
  ['down'] = 0,
  ['left'] = 0,
  ['right'] = 0,
  ['f1'] = 0,
  ['f2'] = 0,
  ['f3'] = 0,
  ['f4'] = 0,
  ['f5'] = 0,
  ['f6'] = 0,
  ['f7'] = 0,
  ['f8'] = 0,
  ['f9'] = 0,
  ['f10'] = 0,
  ['f11'] = 0,
  ['f12'] = 0,
}

ShiftedKeysToChars = {
  ['1'] = '!',
  ['2'] = '@',
  ['3'] = '#',
  ['4'] = '$',
  ['5'] = '%',
  ['6'] = '^',
  ['7'] = '&',
  ['8'] = '*',
  ['9'] = '(',
  ['0'] = ')',
  ['a'] = 'A',
  ['b'] = 'B',
  ['c'] = 'C',
  ['d'] = 'D',
  ['e'] = 'E',
  ['f'] = 'F',
  ['g'] = 'G',
  ['h'] = 'H',
  ['i'] = 'I',
  ['j'] = 'J',
  ['k'] = 'K',
  ['l'] = 'L',
  ['m'] = 'M',
  ['n'] = 'N',
  ['o'] = 'O',
  ['p'] = 'P',
  ['q'] = 'Q',
  ['r'] = 'R',
  ['s'] = 'S',
  ['t'] = 'T',
  ['u'] = 'U',
  ['v'] = 'V',
  ['w'] = 'W',
  ['x'] = 'X',
  ['y'] = 'Y',
  ['z'] = 'Z',
  ['`'] = '~',
  [','] = '<',
  ['.'] = '>',
  ['/'] = '?',
  ['\''] = '"',
  [';'] = ':',
  ['['] = '{',
  [']'] = '}',
  ['\\'] = '|',
  ['-'] = '_',
  ['='] = '+'
}

---@param key string
---@param shifted boolean
---@return string | number
function ConvertKeyToChar(key, shifted)
  local ch = nil
  if shifted then
    ch = ShiftedKeysToChars[key]
  else
    ch = KeysToChars[key]
  end

  if ch == nil and shifted then
    ch = KeysToChars[key]
  end

  return ch or key
end

---@param s string
---@param splitter string
---@return table
function string.split(s, splitter)
  local t = {}
  local acc = ''

  for i = 1, #s do
    local ch = s:sub(i, i)
    if ch == splitter then
      if acc ~= '' then
        t[#t + 1] = acc
        acc = ''
      end
    else
      acc = acc .. ch
    end
  end

  if acc ~= '' then
    t[#t + 1] = acc
  end

  return t
end

---@param s string
---@return string
function string.strip(s)
  while s:sub(0, 1) == '\n' or s:sub(0, 1) == '\t' or s:sub(0, 1) == ' ' do
    s = s:sub(2)
  end

  while s:sub(#s, #s) == '\n' or s:sub(#s, #s) == '\t' or s:sub(#s, #s) == ' ' do
    s = s:sub(0, #s - 1)
  end

  return s
end

function Scandir(directory)
  local t, popen = {}, io.popen

  local pfile = popen('ls -a "' .. directory .. '"')
  if pfile == nil then
    return {}
  end

  for filename in pfile:lines() do
    t[#t + 1] = filename
  end

  pfile:close()
  return t
end

function love.load()
  WindowData = {
    width = 800,
    height = 600
  }

  love.window.setTitle('Luext')
  love.window.setMode(WindowData.width, WindowData.height, {})

  MainFont = love.graphics.newFont('0xProtoNerdFontMono-Regular.ttf', 16)

  Text = ""
  Saved = true
  Filename = nil
  CursorPos = 0
  Selected = { start = -1, length = -1 }
  CommandCursorPos = 0

  Shifting, MovingLeft, MovingRight = false, false, false
  CursorMoveTick = 0

  CurrentMode = Modes.Normal
  CommandAcc = ""
  CommandHistory = {}
  CommandHistoryPos = 0
  MsgRegister = ""
end

function InsertText(text)
  Text = Text:sub(0, CursorPos) .. text .. Text:sub(CursorPos + 1)
  CursorPos = CursorPos + #text
end

---@return string
function GetHistory()
  return CommandHistory[#CommandHistory - CommandHistoryPos] or ""
end

---@param msg string
function SetMsg(msg)
  MsgRegister = msg
end

function ClearMsg()
  SetMsg("")
end

function CanCopy()
  return Selected.start > -1 and Selected.length > -1
end

function love.update()
  if (
        MovingLeft or MovingRight and
        not (MovingLeft and MovingRight) and
        ((Text:sub(CursorPos + 1, CursorPos + 1) ~= '\n' and Text:sub(CursorPos - 1, CursorPos - 1) ~= '\n') or Config.editor.moveOverNewlines or CurrentMode == Modes.Command)
      ) then
    if CursorMoveTick == Config.editor.cursorMoveInterval then
      if CurrentMode == Modes.Command then
        if MovingLeft and CommandCursorPos > 0 then
          CommandCursorPos = CommandCursorPos - 1
        elseif MovingRight and CommandCursorPos < #CommandAcc then
          CommandCursorPos = CommandCursorPos + 1
        end
      else
        CursorPos = lib.Clamp(CursorPos, 0, #Text)
        if MovingLeft and CursorPos > 0 then
          CursorPos = CursorPos - 1
        elseif MovingRight and CursorPos < #Text then
          CursorPos = CursorPos + 1
        end
      end
      CursorMoveTick = 0
    else
      CursorMoveTick = CursorMoveTick + 1
    end
  else
    CursorMoveTick = Config.editor.cursorMoveInterval
  end
end

function love.draw()
  do
    lib.DrawRect("fill", Config.coloring.background, 0, 0, WindowData.width, WindowData.height)
  end

  if CurrentMode == Modes.Help then
  else
    do
      local x, y, textXOffset = 0, 0, 0
      if Config.editor.showLineNumbers then
        textXOffset = 28
      end

      local drewNumberForLine = false
      for i = 1, #Text do
        local ch = Text:sub(i, i)

        if (x * 8) + textXOffset > WindowData.width - 5 or ch == '\n' then
          y = y + 1
          x = 0
          drewNumberForLine = false
        end

        if ch ~= '\n' then
          local revert = lib.SetColor(Config.coloring.text)
          love.graphics.print(ch, MainFont, (x * 8) + x + textXOffset, y * 16)
          revert()
          x = x + 1
        end

        local zeroes = ""
        if y < 100 then
          zeroes = "0"
        elseif y < 10 then
          zeroes = "00"
        end
        if Config.editor.showLineNumbers and not drewNumberForLine then
          local revert = lib.SetColor(Config.coloring.lineNumbers)
          love.graphics.print(zeroes .. tostring(y), MainFont, 0, y * 16)
          revert()
          drewNumberForLine = true
        end

        if CursorPos == 0 and not Config.editor.showLineNumbers then
          lib.DrawRect("fill", Config.coloring.cursor.insert, textXOffset + 5, y * 16, 2,
            16) -- draw insert cursor before the first character
        elseif i == CursorPos then
          lib.DrawRect("fill", Config.coloring.cursor.insert, (x * 8) + x + textXOffset,
            y * 16, 2, 16) -- draw insert cursor
        end
      end
    end

    lib.DrawRect("fill", { 0, 0, 0 }, 0, WindowData.height - 57, WindowData.width, 38)
    love.graphics.print(GetModeName(CurrentMode), MainFont, 2, WindowData.height - 37)

    if CurrentMode == Modes.Command then
      love.graphics.print(":", MainFont, 2, WindowData.height - 21)

      local x = 0
      for i = 1, #CommandAcc do
        local ch = CommandAcc:sub(i, i)

        local revert = lib.SetColor(Config.coloring.text)
        love.graphics.print(ch, MainFont, (x * 8) + x + 9, WindowData.height - 21)
        revert()
        x = x + 1

        if CommandCursorPos == 0 then
          lib.DrawRect("fill", Config.coloring.cursor.command, 9, WindowData.height - 21, 2,
            16) -- draw insert cursor before the first character
        elseif i == CommandCursorPos then
          lib.DrawRect("fill", Config.coloring.cursor.command, (x * 8) + x + 9,
            WindowData.height - 21, 2, 16) -- draw insert cursor
        end
      end
    else
      love.graphics.print(MsgRegister, MainFont, 2, WindowData.height - 21)
    end
  end
end

---@param command string
function ProcessCommand(command)
  if command == "" then
    return
  end

  command = command:strip()
  if CommandHistory[#CommandHistory] ~= command then
    CommandHistory[#CommandHistory + 1] = command
  end

  local args = command:split(' ')

  local com = args[1]
  com = com:strip()

  for i = 1, #com do
    local ch = com:sub(i, i)
    if ch == Config.controls.commands.quit then
      if not Saved and com:sub(i + 1, i + 1) ~= Config.controls.commands.ignoreUnsaved then
        MsgRegister = "Unsaved changes"
        return
      end
      love.event.quit()
    elseif ch == Config.controls.commands.read then
      if not Saved and com:sub(i + 1, i + 1) ~= Config.controls.commands.ignoreUnsaved then
        MsgRegister = "Unsaved changes"
        return
      end

      if #args > 1 then
        Filename = lib.ResolvePath(args[2])
      end

      if Filename == nil or Filename == '' then
        MsgRegister = "No filename given"
        return
      end

      local file = io.open(Filename, 'r')
      if file == nil then
        MsgRegister = "Failed to open file '" ..
            lib.FormatPath(Filename, Config.editor.truncateFilepath, Config.editor.hideUser) .. "'"
        return
      end
      Text = file:read('a')
      file:close()

      ClearMsg()

      Saved = true
    elseif ch == Config.controls.commands.write then
      if #args > 1 then
        Filename = lib.ResolvePath(args[2])
      end

      if Filename == nil or Filename == '' then
        MsgRegister = "No filename given"
        return
      end

      local file = io.open(Filename, "w")
      if file == nil then
        MsgRegister = "Failed to open file '" ..
            lib.FormatPath(Filename, Config.editor.truncateFilepath, Config.editor.hideUser) .. "'"
        return
      end
      file:write(Text)
      file:close()

      Saved = true
      MsgRegister = "Saved as '" ..
          lib.FormatPath(Filename, Config.editor.truncateFilepath, Config.editor.hideUser) .. "'"
    elseif ch == Config.controls.commands.help then
      CurrentMode = Modes.Help
      return
    else
      MsgRegister = "'" .. ch .. "' is not a command"
      return
    end
  end
end

function love.keypressed(k)
  if k == 'lshift' or k == 'rshift' then
    Shifting = true
  end

  --print(k, Shifting, CurrentMode)

  if CurrentMode == Modes.Normal then
    if k == ';' and Shifting then
      CurrentMode = Modes.Command
    elseif k == Config.controls.switch.insert then
      CurrentMode = Modes.Insert
    elseif k == Config.controls.cursor.up then
      local s, _, _ = lib.GetCurrentLine(Text, CursorPos)
      local linePos = CursorPos - s
      if s > 0 then
        CursorPos = s - 2
        local s2, _, _ = lib.GetCurrentLine(Text, CursorPos)
        CursorPos = s2 + linePos
      end
    elseif k == Config.controls.cursor.down then
      local s, e, _ = lib.GetCurrentLine(Text, CursorPos)
      local linePos = CursorPos - s
      if e < #Text then
        CursorPos = e + linePos + 1
      end
    elseif k == Config.controls.cursor.left then
      MovingLeft = true
    elseif k == Config.controls.cursor.right then
      MovingRight = true
    elseif k == Config.controls.editor.paste then
      local clipboard = love.system.getClipboardText()
      if clipboard ~= '' and clipboard ~= nil then
        InsertText(clipboard)
      end
    end
  elseif CurrentMode == Modes.Command then
    local converted = ConvertKeyToChar(k, Shifting)
    if k == Config.controls.switch.normal then
      CommandAcc = ""
      CurrentMode = Modes.Normal
      --[[
    elseif k == Config.controls.cursor.up then
      if CommandHistoryPos < #CommandHistory then
        CommandHistoryPos = CommandHistoryPos + 1
        if CommandHistoryPos > #CommandHistory then
          CommandHistoryPos = 0
        end
      end

      CommandAcc = GetHistory()
    elseif k == Config.controls.cursor.down then
      if CommandHistoryPos > 0 then
        CommandHistoryPos = CommandHistoryPos - 1
      end
      CommandAcc = GetHistory()
    ]]
    elseif k == Config.controls.cursor.left then
      MovingLeft = true
    elseif k == Config.controls.cursor.right then
      MovingRight = true
    elseif k == Config.controls.commands.runCommand then
      ProcessCommand(CommandAcc)
      CommandAcc = ""
      CurrentMode = Modes.Normal
    elseif k == 'backspace' then
      if #CommandAcc > 0 then
        CommandAcc = CommandAcc:sub(0, #CommandAcc - 1)
        CommandCursorPos = CommandCursorPos - 1
      end
    elseif converted ~= ':' then
      if type(converted) == "string" then
        CommandAcc = CommandAcc:sub(0, CommandCursorPos) ..
            converted .. CommandAcc:sub(CommandCursorPos + 1)
        CommandCursorPos = CommandCursorPos + 1
      end
    end
  elseif CurrentMode == Modes.Insert then
    if k == Config.controls.switch.normal then
      CurrentMode = Modes.Normal
    elseif k == 'backspace' then
      if #Text > 0 then
        CursorPos = CursorPos - 1
        Text = Text:sub(0, CursorPos) .. Text:sub(CursorPos + 2)
      end
    elseif k == Config.controls.cursor.up then
      local s, e, _ = lib.GetCurrentLine(Text, CursorPos)
      local linePos = e - CursorPos
      if s ~= 0 then
        CursorPos = (s - 2) - linePos
      end
    elseif k == Config.controls.cursor.up then
      local s, e, _ = lib.GetCurrentLine(Text, CursorPos)
      local linePos = e - CursorPos
      if s ~= 0 then
        CursorPos = (s - 2) - linePos
      end
    elseif k == Config.controls.cursor.left then
      MovingLeft = true
    elseif k == Config.controls.cursor.right then
      MovingRight = true
    else
      local converted = ConvertKeyToChar(k, Shifting)
      Saved = false
      if type(converted) == "string" then
        InsertText(converted)
      end
    end
  elseif CurrentMode == Modes.Help then
    if k == Config.controls.switch.normal then
      CurrentMode = Modes.Normal
    end
  end
end

function love.keyreleased(k)
  if k == 'lshift' or k == 'rshift' then
    Shifting = false
  elseif k == Config.controls.cursor.left then
    MovingLeft = false
  elseif k == Config.controls.cursor.right then
    MovingRight = false
  end
end