Download APIs

--------------------------
-- Download APIs script --
--------------------------
if not http then
	print("This is a script that allows the download of APIs.")
	return
end
local tAPIs = {}
local topString = "-- This portion of the startup script was automatically added by the Download APIs script. --"
local startupString = [[
	-- Load APIs --
	local apis = "apis"
	if fs.isDir(apis) then
		local folder = fs.list(apis)
		if #folder > 0 then
			print("Loading APIs...")
			for k, v in ipairs(folder) do
				os.loadAPI(apis.."/"..v)
			end
		end
	end

	-- Set program aliases --
	local programs = "programs"
	if fs.isDir(programs) then
		local folder = fs.list(programs)
		if #folder > 0 then
			print("Aliasing programs...")
			for k, v in ipairs(folder) do
				shell.setAlias(apis.."/"..v)
			end
		end
	end

	-- And now back to your startup script. --
]]

-- Set Up Variables --
local scrX, scrY = term.getSize()

local menuTitleColor = colors.lightBlue
local menuBGColor = colors.gray
local menuBGSelectionColor = colors.blue
local menuScrollColor = colors.white
local menuBGScrollColor = colors.lightGray

function drawMenuFront(Title, ControlBarText)
	term.setCursorPos(1, 1)
	term.setBackgroundColor(menuTitleColor)
	term.clearLine()
	term.write(Title)
	ControlBarText = ControlBarText or "Select an option then press Enter."
	term.setCursorPos(1, scrY + 1 - math.ceil(#ControlBarText/scrX))
	term.setBackgroundColor(menuTitleColor)
	term.clearLine()
	term.write(ControlBarText)
end

-- Draws a menu prompt.
function drawMenu(Title, Options, Scroll, Selected)
	local y = 1
	for k=math.max(Scroll + 1, 1), math.min(Scroll + 1 + scrY - 2, #Options) do
		y = y + 1
		term.setCursorPos(1, y)
		if Selected == k then
			term.setBackgroundColor(menuBGSelectionColor)
		else
			term.setBackgroundColor(menuBGColor)
		end
		term.clearLine()
		if type(Options[k]) == "table" then
			term.write(Options[k]["Name"] or Options[k][1])
		else
			term.write(Options[k])
		end
	end
	if #Options > scrY - 2 then -- Draw a scroll bar
		term.setBackgroundColor(menuBGScrollColor)
		for k=2, scrY - 1 do
			term.setCursorPos(scrX, k)
			term.write(" ")
		end
		term.setBackgroundColor(menuScrollColor)
		local barHeight = (scrY - 2)/(#Options - (scrY - 2))
		local barPos = math.max((Scroll/(#Options - (scrY - 2)))*(scrY - 1 - barHeight), 1) + 1
		for k=barPos, barPos + barHeight do
			term.setCursorPos(scrX, k)
			term.write(" ")
		end
	end
	drawMenuFront(Title, ControlBar)
end

-- Shows a menu prompt.
function menuPrompt(Title, Options)
	term.setBackgroundColor(menuBGColor)
	term.clear()
	if not SuppressCancel then
		if tostring(Options[#Options]) ~= "Cancel" then
			Options[#Options + 1] = "Cancel"
		end
	end
	local Scroll, Selected = 0, 1
	while true do
		if #Options > scrY - 2 then
			Scroll = math.min(math.max(Selected - math.ceil((scrY - 2)*.5), 0), #Options - (scrY - 2))
		else
			Scroll = 0
		end
		drawMenu(Title, Options, Scroll, Selected)
		local event, key, clx, cly = os.pullEvent()
		if event == "key" then
			if key == keys.up then
				Selected = math.max(Selected - 1, 1)
			elseif key == keys.down then
				Selected = math.min(Selected + 1, #Options)
			elseif key == keys.pageUp then
				Selected = math.max(Selected - (height - 1), 1)
			elseif key == keys.pageDown then
				Selected = math.min(Selected + (height - 1), #Options)
			elseif key == keys.home then
				Selected = 1
			elseif key == keys["end"] then
				Selected = #Options
			elseif key == keys.f5 then
				-- Refresh
			elseif(key == keys.tab) then
				term.setCursorBlink(false)
				return false
			elseif key == (keys.enter or 28) then
				if Selected > #Options - 1 and not SuppressCancel then
					return false
				else
					return Selected
				end
			end
		elseif event == "mouse_click" then
			if cly > 1 and cly < scrY then
				local Clicked = Scroll + cly - 1
				if Clicked <= #Options then
					if Clicked == Selected then
						if Selected > #Options - 1 and not SuppressCancel then
							return false
						else
							return Selected
						end
					else
						Selected = Clicked
					end
				end
			end
		end
	end
end

function testIfMainElement(str)
	if string.lower(str) == "description" then
		return true
	elseif string.lower(str) == "body" then
		return true
	elseif string.lower(str) == "message" then
		return true
	elseif string.lower(str) == "details" then
		return true
	elseif string.lower(str) == "code" then
		return true
	end
	return false
end

function testIfVisibleElement(str)
	if string.lower(str) == "name" then
		return false
	elseif string.lower(str) == "title" then
		return false
	elseif string.lower(str) == "id" then
		return false
	elseif string.lower(str) == "turtle api" then
		return false
	elseif string.lower(str) == "command api" then
		return false
	end
	return true
end

function drawDescriptionMenu(Title, ControlBarText, TableElements, Layout, MainElement)
	term.setBackgroundColor(menuBGColor)
	term.clear()
	local currentRow = 0
	for k, v in ipairs(Layout) do
		if not v["MainElement"] and v["Visible"] then -- If it is not the MainElement and it is visible
			currentRow = currentRow + 1
			term.setCursorPos(1, currentRow + 1)
			term.write((v["Name"] or v[1])..": ")
			term.setCursorPos(#(v[1]..": "), currentRow + 1)
			term.write(tostring(TableElements[v[1]]))
		end
	end
	currentRow = currentRow + 1
	term.setCursorPos(1, currentRow + 1)
	term.write(Layout[MainElement]["Name"] or Layout[MainElement][1])
	term.setCursorPos(1, currentRow + 2)
	print(tostring(TableElements[Layout[MainElement][1]]))
	drawMenuFront(Title, "Press Enter to confirm or Tab to return.")
end

-- Draws a frame of a description menu.
function descriptionMenuWindow(Title, ControlBarText, TableElements, Layout)
	local MainElement = 0
	if type(Layout) ~= "table" then
		Layout = {}
		for k, v in pairs(TableElements) do
			Layout[#Layout + 1] = {k}
			if testIfMainElement(k) then
				MainElement = #Layout
				Layout[#Layout]["MainElement"] = true
			else
				Layout[#Layout]["MainElement"] = false
			end
			Layout[#Layout]["Visible"] = testIfVisibleElement(Layout[#Layout][1])
		end
		if not MainElement then
			MainElement = #Layout
			Layout[#Layout]["MainElement"] = true
		end
	else
		for k, v in pairs(Layout) do
			if v[2] then
				MainElement = #Layout
				break
			end
		end
	end
	drawDescriptionMenu(Title, ControlBarText, TableElements, Layout, MainElement)
end

function showAPIMenu(selectedAPI)
	descriptionMenuWindow(tAPIs[selectedAPI]["Name"], selectedAPI, tAPIs[selectedAPI], Layout)
	while true do
		local event, key = os.pullEvent("key")
		if(key == keys.tab) then
			term.setCursorBlink(false)
			return false
		elseif key == (keys.enter or 28) then
			return true
		end
	end
end

function overwriteFileRaw(contents, destination)
	local file, err = fs.open(destination, "w")
	if file then
		file.write(contents)
		file.close()
		return true
	end
	return false, err
end

function overwriteFile(contents, destination)
	local pcallSuccess, returnCondition, errorString = pcall(overwriteFileRaw, contents, destination)
	if pcallSuccess then
		return returnCondition, errorString
	end
	return false, returnCondition
end

function pullFileRaw(url, header, post)
	if http then
		local handle, str
		if not post then
			handle, str = http.get(url, header), ""
		else
			handle, str = http.post(url, post, header), ""
		end
		if handle then
			str = handle.readAll()
			handle.close()
			return str
		end
		return false, str
	end
	return false, "Http API is not enabled"
end

function pullFile(url, header, post)
	local pcallSuccess, returnCondition, errorString = pcall(pullFileRaw, url, header, post)
	if pcallSuccess then
		return returnCondition, errorString
	end
	return false, returnCondition
end
for k=1, 4 do
	tAPIs = textutils.unserialize(pullFile("https://pastebin.com/raw/Eare8WYE"))
	if tAPIs then
		break
	end
end
if not tAPIs then
	error("There was a problem while loading the API list.")
end

function downloadFileRaw(url, destination, header, post)
	if http then
		local handle, str
		if not post then
			handle, str = http.get(url, header), ""
		else
			handle, str = http.post(url, post, header), ""
		end
		if handle then
			str = handle.readAll()
			handle.close()
			return overwriteFile(str, destination)
		end
		return str
	end
	return false, "Http API is not enabled"
end

function downloadFile(url, destination, header, post)
	local pcallSuccess, returnCondition, errorString = pcall(downloadFileRaw, url, destination, header, post)
	if pcallSuccess then
		return returnCondition, errorString
	end
	return false, returnCondition
end

function setUpStartup()
	local file, str = fs.open("startup", "r"), ""
	if file then
		str = file.readAll()
		file.close()
	end
	if not string.find(str, topString) then
		file = fs.open("startup", "w")
		if file then
			file.writeLine(topString.."\n")
			file.writeLine(startupString.."\n")
			file.writeLine(str)
			file.close()
		end
		print("Your startup script has been automatically changed.")
	end
end

while true do
	local selectedAPI = menuPrompt("API list", tAPIs)
	if not selectedAPI then term.setBackgroundColor(colors.black) term.clear() return term.setCursorPos(1, 1) end
	if showAPIMenu(selectedAPI) then
		term.clear()
		term.setCursorPos(1, 1)
		--print("Save to where? To automatically load this API on startup leave this space empty.")
		local name = ""
		term.write("Downloading File...")
		local response, err
		if #name > 0 then
			response, err = downloadFile("http://pastebin.com/raw.php?i="..tAPIs[selectedAPI]["ID"], name)
		else
			fs.makeDir("apis")
			response, err = downloadFile("http://pastebin.com/raw.php?i="..tAPIs[selectedAPI]["ID"], "apis/"..(tAPIs[selectedAPI]["DefaultName"] or tAPIs[selectedAPI]["Name"]))
			setUpStartup()
			if tAPIs[selectedAPI]["SampleApplications"] then
				fs.makeDir("programs")
				for k, v in ipairs(tAPIs[selectedAPI]["SampleApplications"]) do
					downloadFile("http://pastebin.com/raw.php?i="..v[1], "programs/"..(tAPIs[selectedAPI]["DefaultName"] or tAPIs[selectedAPI]["Name"]))
				end
			end
		end
		if not response then
			print(err)
			print("Press any key to continue...")
			os.pullEvent("key")
		end
	end
end