dsh

-- Config
root = "/fsdsh"
ver = "0.1.0"

-- Environment Variables
running = true
user = ""
pass = ""
path = "/"
shvar = {}
pipe = ""
input = ""
output = ""
last = ""

-- Helper Functions
function abs_path(dir)
   if dir:sub(1, 1) == "/" then
      return dir
   else
      return path..dir
   end
end

function true_path(dir)
   return root..abs_path(dir)
end

-- Main Functions
function parse(cmd)
   pipe = ""
   local cmds = {""}
   local cmdm = {""}
   local i = 1

   while i <= #cmd do
      if cmd:sub(i, i) == "\n" or cmd:sub(i, i) == "\r" then
         cmds[#cmds + 1] = ""
         cmdm[#cmdm + 1] = ""
      elseif cmd:sub(i, i+1) == "&&" then
         cmds[#cmds + 1] = ""
         cmdm[#cmdm + 1] = ""
         i = i + 2
      elseif cmd:sub(i, i) == "|" then
         cmds[#cmds] = cmds[#cmds]..cmd:sub(i, i)
         cmds[#cmds + 1] = ""
         cmdm[#cmdm + 1] = ""
         i = i + 1
      else
         cmds[#cmds] = cmds[#cmds]..cmd:sub(i, i)
      end
      i = i + 1
   end

   for i = 1, #cmds do
      run(cmds[i])
   end
end

function run(cmd)
   output = ""

   -- Output Path Detection
   local outpath = "stdout"
   local sep = cmd:find(">")

   if sep ~= nil then
      outpath = cmd:sub(sep, #cmd)
      cmd = cmd:sub(1, sep - 1)
   else
      sep = cmd:find("|")
      if sep ~= nil then
         outpath = "pipe"
         cmd = cmd:sub(1, sep - 1)
      end
   end

   -- Main Command Checking
   if cmd:sub(1,2) == "sh" then
      if #cmd >= 4 then
         local cmdpath = true_path(cmd:sub(4, #cmd))
         if fs.exists(cmdpath) and not fs.isDir(cmdpath) then
            local f = io.open(cmdpath, "r")
            local c = f:read("*a")
            f:close()
            parse(c)
         end
      end
   elseif cmd:sub(1, 3) == "lua" then
      if #cmd >= 5 then
         local cmdpath = true_path(cmd:sub(5, #cmd))
         if fs.exists(cmdpath) and not fs.isDir(cmdpath) then
            shell.run(cmdpath)
         end
      end
   elseif cmd:sub(1, 5) == "mkdir" then
      local p = ""
      if cmd:len() >= 7 then
         p = cmd:sub(7, #cmd)
      elseif pipe ~= "" then
         p = pipe
      end
      shell.run("mkdir "..true_path(p))
   elseif cmd:sub(1, 2) == "ls" then
      local oldDir = shell.dir()
      shell.setDir(true_path(path))
      shell.run("ls")
      shell.setDir(oldDir)
   elseif cmd:sub(1, 2) == "cd" then
      if cmd:len() >= 4 then
         local p = cmd:sub(4, #cmd)
         if p == ".." then
            parse("cd "..path:sub(1, path:match(".*/()") - 1))
         else
            if fs.isDir(true_path(p)) then
               path = abs_path(p)
            end
         end
      end
   elseif cmd:sub(1, 3) == "pwd" then
      print(path)
   elseif cmd:sub(1, 4) == "echo" then
      if cmd:len() >= 6 then
         output = cmd:sub(6, #cmd).."\n"
      end
      output = output..pipe
   elseif cmd:sub(1, 4) == "exit" then
      shell.run("clear")
      running = false
   end


   -- Output Handling
   if outpath == "stdout" then
      io.write(output)
   elseif outpath == "pipe" then
      pipe = output
   else
      local p = true_path(outpath)
      if not fs.isDir(p) then
         local f = io.open(p, "w")
         f:write(output)
         f:close()
      end
   end
end

-- Environment Setup
if not fs.exists(root) or not fs.isDir(root) then
   shell.run("mkdir "..root)
   local dshrc = fs.open(root.."/.dshrc", "w")
   dshrc:close()
end

-- Greeting Header
shell.run("clear")
print("-----------------------------")
print("Digi's Shell (dsh) ver. "..ver)
print("-----------------------------")
print("")

-- User Login
io.write("Username: ")
user = read()
io.write("Password: ")
pass = read("*")
print("")

-- Password Checking

-- Autorun

parse("sh /.dshrc")

-- Main Loop
while running do
   io.write(user.."@dsh:"..path.."$ ")
   io.flush()
   input = io.read()
   parse(input)
end