MineChat v1.0.0

-- MineChat v1.0.0 by Codian
-- no stealing

local term = require "term"
local colors = require "colors"
local component = require "component"
local gpu = component.gpu
local w, h = gpu.getResolution()

uname = 'Player'

message_buffer = {}
commands = {
    ['exit'] = exit_to_shell,
    ['quit'] = exit_to_shell,
    ['help'] = show_help,
    ['clear'] = clear_buffer
}
help_msg = [===[
----------------------
MineChat Command List:
----------------------
/help - Show this message
/clear - Clear the messages on screen
/exit|quit - Quit MineChat
----------------------
]===]

function print_reverse_buffer(t)
    out = {}
    y = h - 3

    if #t > h - 4 then
        table.remove(t, #t - (h - 4))
    end

    for i = #t, 1, -1 do
        mdata = t[i]
        _, linecount = string.gsub(mdata['content'], '\n', '\n')
        if linecount == 0 then
            linecount = 1
        end
        y = y - linecount

        term.setCursor(1, y)
        gpu.setForeground(mdata['fg'])
        gpu.setBackground(mdata['bg'])
        term.write(mdata['author'] .. ' ' .. mdata['content'])
    end
    return out
end

function read_input()
    return term.read()
end

function update()
    term.clear()
    gpu.setForeground(0x000000)
    gpu.setBackground(0xffffff)
    gpu.fill(1, h-1, w, h, " ")
    term.setCursor(1, h-1)
    term.write("MineChat Client - [Logged in as " .. uname .. "]")
    term.setCursor(w-6, h-1)
    term.write("v1.0.0")
    print_reverse_buffer(message_buffer)
    gpu.setForeground(0x828282)
    gpu.setBackground(0x000000)
    term.setCursor(1, h)
    term.clearLine()
    term.write('> ')
    gpu.setForeground(0xffffff)
end

function show_new_message(content, author, fg, bg)
    author = author or '[System]'
    fg = fg or 0xffffff
    bg = bg or 0x000000

    m_table = {
        ['author'] = author,
        ['fg'] = fg,
        ['bg'] = bg,
        ['content'] = content
    }

    table.insert(message_buffer, m_table)
    update()
end

function exit_to_shell()
    term.clear()
    term.setCursor(1, 1)
    gpu.setForeground(0xffffff)
    gpu.setBackground(0x000000)
    print('Thank you for using MineChat!')
    print('Exiting to shell.')
    os.exit()
end

function show_help()
    show_new_message(help_msg)
end

function clear_buffer()
    message_buffer = {}
    update()
end

term.clear()
term.setCursor(1, 1)
gpu.setForeground(0xffffff)
gpu.setBackground(0x000000)

while true do
    gpu.setForeground(0xffff00)
    term.write('Set your username: ')
    gpu.setForeground(0xffffff)
    x = string.gsub(string.gsub(term.read(), "\n", ""), ' ', '')

    if string.len(x) > 2 and string.len(x) < 32 then
        uname = x
        break
    else
        gpu.setForeground(0xff0000)
        print('Username needs to be between 3 and 32 characters in length.')
    end
end

show_new_message('Welcome to MineChat!', nil, 0xffff00)
show_new_message('Type in /help for command help.', nil, 0xffff00)
show_new_message(uname..' joined the chatroom.', '*', 0x00ff00)

while true do
    x = string.gsub(string.gsub(string.lower(term.read()), "\n", ""), ' ', '')

    if string.len(x) > 0 then
        is_command = false
        slash_pos = string.find(x, '/')
        if slash_pos ~= nil then
            if slash_pos == 1 then
                is_command = true
            end
        end

        if is_command then
            callback = commands[string.gsub(x, '/', '')]
            if callback == nil then
                show_new_message('Unknown command. Type /help for list of commands.', nil, 0xff0000)
            else
                callback()
            end
        else
            show_new_message(x, uname .. ':')
        end
    else
        update()
    end
end