Flutter Install

-- Lua Script System --
-- set local variables
local advanced = term.isColor()
local scrwidth, scrheight = term.getSize()
local oldsetTextColor = term.setTextColor
local oldsetBackgroundColor = term.setBackgroundColor
local splabg = colors.gray
local LuaSSdir = "Flutter/"
local folderStructureS
_G.shell = shell

-- set the new global os.pullEvent function
function os.pullEvent(...)
    local eventType, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10 = os.pullEventRaw(...)
    if eventType == "terminate" then
        error("Terminated installation", 0)
        return
    end
    return eventType, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10
end

-- change color functions to fallback when not advanced computer
if not advanced then
    function term.setTextColor( color )
        if color == colors.black then
            oldsetTextColor(color)
        else
            oldsetTextColor(colors.white)
        end
    end
    function term.setBackgroundColor( color )
        if color == colors.white then
            oldsetBackgroundColor(color)
        else
            oldsetBackgroundColor(colors.black)
        end
    end
end
-- draw a loading screen --
term.setBackgroundColor( splabg )
term.clear()
if loadingimage then
    paintutils.drawImage(loadingimage, math.floor(scrwidth*.5 - 6), math.floor(scrheight*.5 - 2))
end
term.setCursorPos( 1, 1 )

local loadingstring, oldloadingstring = "", ""
local loadingframe = -scrwidth*.2
local setCursorPos = term.setCursorPos
local function drawLoadingProgressIndicator()
    while true do -- run a loop to prevent it from stopping the loading function before it returns.
        loadingframe = loadingframe + 1
        if loadingframe > scrwidth*1.2 then
            loadingframe = -scrwidth*.2
        end
        if loadingstring ~= oldloadingstring then
            setCursorPos( scrwidth*.5 - (#loadingstring*.5) + 1, scrheight - 1)
            term.setBackgroundColor( splabg )
            term.clearLine()
            term.write(loadingstring)
        end
        setCursorPos( loadingframe - 1, scrheight )
        term.setBackgroundColor( colors.blue )
        term.clearLine()
        term.setBackgroundColor( colors.lightBlue )
        term.write(string.rep(" ", scrwidth*.2))
        sleep()
    end
end

local function outOfSpaceError()
    term.setBackgroundColor(colors.blue)
    local outofspaceTitle = "Out of space"
    term.clear()
    term.setCursorPos((scrwidth - #outofspaceTitle)*.5, 1)
    term.write(outofspaceTitle)
    term.setCursorPos(1, 8)
    print("You need to free at least "..#folderStructureS - fs.getFreeSpace("").." bytes on your hard disk to install Flutter.")
    print("After freeing enough disk space restart the script.")
    error("Cannot continue installing Flutter!", 0)
end

local function createFolderForFile(path)
    local curpath = path
    local startHere = 1
    while true do
        local nextSlash = string.find(string.sub(path, startHere, -1), "/")
        if not nextSlash then return end
        nextSlash = nextSlash + startHere
        local folderToCreate = string.sub(curpath, 0, nextSlash - 1)
        if not fs.isDir(folderToCreate) then
            local ok, err = pcall(fs.makeDir, folderToCreate)
            if not ok then
                if string.find(err, "Out of space") then
                    outOfSpaceError()
                end
            end
        end
        startHere = nextSlash
    end
end

local function installLuaScriptSystem()
    local urlToDownload = "http://pastebin.com/raw/7a3QYQ7p"
    local handle = http.get(urlToDownload)
    folderStructureS = handle.readAll()
    handle.close()
    local folderStructure = textutils.unserialize(folderStructureS)
    if fs.getFreeSpace("") < #folderStructureS then
        loadingstring = ""
    end
    for k, v in pairs(folderStructure) do
        createFolderForFile(k)
        local file = fs.open(k, "w")
        if file then
            file.write(v)
            local ok, err = pcall(file.close)
            if not ok then
                if string.find(err, "Out of space") then
                    outOfSpaceError()
                end
            end
        end
        sleep()
    end
end

parallel.waitForAny(drawLoadingProgressIndicator, installLuaScriptSystem)

local file = fs.open("startup", "w")
file.write('shell.run("Flutter/startup")')
file.close()

shell.run(LuaSSdir.."startup")