print([[
  _______ ______ _____  __  __ _____ _   _          _      
 |__   __|  ____|  __ \|  \/  |_   _| \ | |   /\   | |     
    | |  | |__  | |__) | \  / | | | |  \| |  /  \  | |     
    | |  |  __| |  _  /| |\/| | | | | . ` | / /\ \ | |     
    | |  | |____| | \ \| |  | |_| |_| |\  |/ ____ \| |____ 
    |_|  |______|_|  \_\_|  |_|_____|_| \_/_/    \_\______|

]]) 
local system = { 
    version = "1.0.5", 
    status = "READY.", 
    pashint = "password is Password!", 
    update = "2004/3/9", 
    files = { ["memo.txt"] = { content = "Password is 'password!'", time = "2004/3/9" }, 
        ["hint.sys"] = { content = "The update date might be important...", time = "2004/3/9" } 
    }
}
setmetatable(system, { __index = function(t, key) 
            return ">>ERROR: '" .. tostring(key) .. "' は無効な命令です" 
        end 
    }
) 
local commands = {}

commands.help = function() 
    print("AVAILABLE: status, update, help, ls, cat, write, exit") 
end 

commands.status = function() print("VERSION: " .. system.version) end 
commands.update = function() print("LAST UPDATED: " .. system.update) end 

commands.ls = function()
    print("--- VIRTUAL FILES ---")
    for name, data in pairs(system.files) do
        local time = (type(data) == "table") and data.time or system.update
        print(string.format("- %-12s [%s]", name, time))
    end
end

commands.cat = function()
    io.write("ENTER FILENAME: ")
    io.flush()
    local target = io.read():lower()
    local file = system.files[target]
    if file and type(file) == "table" then
        print("----------------------------")
        print("FILE:    " .. target)
        print("TIME:    " .. file.time)
        print("CONTENT: " .. file.content)
        print("----------------------------")
    else
        print(">>ERROR: ファイルが見つかりません")
    end
end

commands.write = function()
    io.write("ENTER FILENAME: ")
    io.flush()
    local name = io.read():lower()
    io.write("ENTER CONTENT: ")
    io.flush()
    local body = io.read()
    system.files[name] = { 
        content = body, 
        time = os.date("%Y/%m/%d %H:%M:%S") 
    }
    print("\nSYSTEM@admin: The `write` command is still under development and the method for saving data hasn't been finalized yet, so you won't be able to view it later:( sorry guys")
    print("SUCCESS: FILE CREATED?") 
end
print("--- SYSTEM TERMINAL BOOTING ---") 
while true do 
    io.write("\nTYPE 'START' TO LOGIN: ") 
    io.flush()
    local raw_input = io.read() 
    if raw_input == nil then return end 

    local cmd = raw_input:lower() 
    if cmd == "start" then 
        io.write("ENTER PASSWORD: ") 
        io.flush()
        local pass = io.read()
        if pass == "password!" then 
            print("OS INITIALIZED. WELCOME ADMIN.") 
            break
        else 
            print("ACCESS DENIED.") 
        end 
    elseif cmd == "exit" then return end
end 

while true do 
    io.write("\nADMIN@ROOT: ") 
    io.flush()
    local input = io.read() 
    if input == nil then break end 

    local cmd = input:lower() 
    if cmd == "exit" then 
        print("-- SYSTEM SHUTDOWN ... --") 
        break 
    elseif commands[cmd] then 
        commands[cmd]() 
    else 
        print(system[cmd]) 
    end 
end