Mob destroyer

if not turtle then
    printError("This is a turtle program")
    return
end

local w, h = term.getSize()
local junk = true
local junkside = "top"
local lootchest = "bottom"

if fs.exists( "melee_turtle" ) then
    local file = fs.open( "melee_turtle", "r" )
    local content = textutils.unserialize( file.readAll() )
    file.close()
    junk = content.junk
    junkside = content.junkside
    lootchest = content.lootchest
end

local popupSides = function()
    term.setCursorPos( w - 14, 1 )
    term.write( "+" )

    for i = 1, 6 do
        term.setCursorPos( w - 14, i + 1 )
        term.write( "|" )
    end

    term.setCursorPos( w - 14, 8 )
    term.write( "+" .. string.rep( "-", 13 ) .. "+" )

    for k, v in pairs( rs.getSides() ) do
        term.setCursorPos( w - 13 , k + 1 )
        term.write( "[" .. k .. "] = " .. v )
    end
    local event, char = nil
    repeat
        event, char = os.pullEvent("char")
    until char:find("[1-6]")

    term.setCursorPos( w - 14, 1 )
    term.write( "-" )

    for i = 1, 6 do
        term.setCursorPos( w - 14, i + 1 )
        term.write( string.rep( " ", 14 ) .. "|" )
    end

    term.setCursorPos( w - 14, 8 )
    term.write( string.rep( " ", 14 ) .. "|" )

    return char
end

local screenManagement = function()
    while true do
        term.setCursorPos( 1, 1 )
        term.write( "+" .. string.rep("-", w - 2) .. "+" )
        term.setCursorPos( 1, h )
        term.write( "+" .. string.rep("-", w - 2) .. "+" )

        for i = 1, h - 2 do
            term.setCursorPos( 1, i + 1 )
            term.write( "|" .. string.rep(" ", w - 2) .. "|" )
        end

        term.setCursorPos( 2, 2 )
        term.write( "[j] = " .. ( junk and "Enable junkloot" or "Disable junkloot" ) )
        if junk then
            term.setCursorPos( 2, 3 )
            term.write( "[k] = Current junk side: " .. junkside )
        end
        term.setCursorPos( 2, junk and 4 or 3 )
        term.write( "[c] = Current loot chest: ".. lootchest )
        term.setCursorPos( 2, junk and 5 or 4 )
        print( "\n[s] = Save settings" )
        local _, c = os.pullEvent("char")
        if c == "j" then
            junk = not junk
        elseif c == "k" then
            junkside = rs.getSides()[tonumber(popupSides())]
        elseif c == "c" then
            lootchest = rs.getSides()[tonumber(popupSides())]
        elseif c == "s" then
            local file = fs.open( "melee_turtle", "w" )
            file.write( textutils.serialize({ junk = junk; lootchest = lootchest; junkside = junkside;}))
            file.close()
        end
    end
end

local fight = function()
    local turn = function( s, x )
        if s == "right" then
            if x then
                turtle.turnRight()
            else
                turtle.turnLeft()
            end
        elseif s == "left" then
            if x then
                turtle.turnLeft()
            else
                turtle.turnRight()
            end
        elseif s == "back" then
            turtle.turnRight()
            turtle.turnRight()
        end
    end
    local drop = function( s )
        if s == "top" then
            turtle.dropUp()
        elseif s == "down" then
            turtle.dropDown()
        else
            turtle.drop()
        end
    end
    while true do
        turtle.attack()
        if turtle.getItemCount( 16 ) > 0 then
            if junk then
                turn( junkside )
                for i = 1, 16 do
                    turtle.select(i)
                    if turtle.compareTo( 1 ) then
                        drop( junkside )
                    end
                end
                turn( junkside, true )
            end
            turn( lootchest )
            for i = 1, 16 do
                turtle.select( i )
                drop( lootchest )
            end
            turn( lootchest, true )
        end
    end
end

parallel.waitForAny( fight, screenManagement )