ldd-CC/gitget.lua

--[[
  Gitget for ComputerCraft
 A simple GitHub repo downloader!

   pastebin get TZd5PYgz gitget
                              --]]
local verbose = true

local tArg = {...}
local reponame = tArg[1]
local repopath = tArg[2]
local outpath = tArg[3] or ""

if outpath:sub(1,1) ~= "/" then
	outpath = fs.combine(shell.dir(), outpath)
end

--thank you ElvishJerricco
local controls = {["\n"]="\\n", ["\r"]="\\r", ["\t"]="\\t", ["\b"]="\\b", ["\f"]="\\f", ["\""]="\\\"", ["\\"]="\\\\"}
local function isArray(t)
	local max = 0
	for k,v in pairs(t) do
		if type(k) ~= "number" then
			return false
		elseif k > max then
			max = k
		end
	end
	return max == #t
end
local whites = {['\n']=true; ['\r']=true; ['\t']=true; [' ']=true; [',']=true; [':']=true}
function removeWhite(str)
	while whites[str:sub(1, 1)] do str = str:sub(2) end return str
end
local function encodeCommon(val, pretty, tabLevel, tTracking)
	local str = ""
	local function tab(s)
		str = str .. ("\t"):rep(tabLevel) .. s
	end
	local function arrEncoding(val, bracket, closeBracket, iterator, loopFunc)
		str = str .. bracket
		if pretty then
			str = str .. "\n"
			tabLevel = tabLevel + 1
		end
		for k,v in iterator(val) do
			tab("")
			loopFunc(k,v)
			str = str .. ","
			if pretty then str = str .. "\n" end
		end
		if pretty then tabLevel = tabLevel - 1 end
		if str:sub(-2) == ",\n" then str = str:sub(1, -3) .. "\n"
		elseif str:sub(-1) == "," then str = str:sub(1, -2) end
		tab(closeBracket)
	end
	if type(val) == "table" then
		assert(not tTracking[val], "Cannot encode a table holding itself recursively")
		tTracking[val] = true
		if isArray(val) then
			arrEncoding(val, "[", "]", ipairs, function(k,v)
				str = str .. encodeCommon(v, pretty, tabLevel, tTracking)
			end)
		else
			arrEncoding(val, "{", "}", pairs, function(k,v)
				assert(type(k) == "string", "JSON object keys must be strings", 2)
				str = str .. encodeCommon(k, pretty, tabLevel, tTracking)
				str = str .. (pretty and ": " or ":") .. encodeCommon(v, pretty, tabLevel, tTracking)
			end)
		end
	elseif type(val) == "string" then str = '"' .. val:gsub("[%c\"\\]", controls) .. '"'
	elseif type(val) == "number" or type(val) == "boolean" then str = tostring(val)
	else error("JSON only supports arrays, objects, numbers, booleans, and strings", 2) end
	return str
end
local function encode(val)
	return encodeCommon(val, false, 0, {})
end
local function encodePretty(val)
	return encodeCommon(val, true, 0, {})
end
local decodeControls = {}
for k,v in pairs(controls) do
	decodeControls[v] = k
end
local function parseBoolean(str)
	if str:sub(1, 4) == "true" then
		return true, removeWhite(str:sub(5))
	else
		return false, removeWhite(str:sub(6))
	end
end
local function parseNull(str)
	return nil, removeWhite(str:sub(5))
end
local numChars = {['e']=true; ['E']=true; ['+']=true; ['-']=true; ['.']=true}
local function parseNumber(str)
	local i = 1
	while numChars[str:sub(i, i)] or tonumber(str:sub(i, i)) do
		i = i + 1
	end
	local val = tonumber(str:sub(1, i - 1))
	str = removeWhite(str:sub(i))
	return val, str
end
local function parseString(str)
	str = str:sub(2)
	local s = ""
	while str:sub(1,1) ~= "\"" do
		local next = str:sub(1,1)
		str = str:sub(2)
		assert(next ~= "\n", "Unclosed string")

		if next == "\\" then
			local escape = str:sub(1,1)
			str = str:sub(2)

			next = assert(decodeControls[next..escape], "Invalid escape character")
		end

		s = s .. next
	end
	return s, removeWhite(str:sub(2))
end
local parseValue, parseMember
local function parseArray(str)
	str = removeWhite(str:sub(2))
	local val = {}
	local i = 1
	while str:sub(1, 1) ~= "]" do
		local v = nil
		v, str = parseValue(str)
		val[i] = v
		i = i + 1
		str = removeWhite(str)
	end
	str = removeWhite(str:sub(2))
	return val, str
end
local function parseObject(str)
	str = removeWhite(str:sub(2))
	local val = {}
	while str:sub(1, 1) ~= "}" do
		local k, v = nil, nil
		k, v, str = parseMember(str)
		val[k] = v
		str = removeWhite(str)
	end
	str = removeWhite(str:sub(2))
	return val, str
end
function parseMember(str)
	local k = nil
	k, str = parseValue(str)
	local val = nil
	val, str = parseValue(str)
	return k, val, str
end
function parseValue(str)
	local fchar = str:sub(1, 1)
	if fchar == "{" then
		return parseObject(str)
	elseif fchar == "[" then
		return parseArray(str)
	elseif tonumber(fchar) ~= nil or numChars[fchar] then
		return parseNumber(str)
	elseif str:sub(1, 4) == "true" or str:sub(1, 5) == "false" then
		return parseBoolean(str)
	elseif fchar == "\"" then
		return parseString(str)
	elseif str:sub(1, 4) == "null" then
		return parseNull(str)
	end
	return nil
end
local function decode(str)
	str = removeWhite(str)
	t = parseValue(str)
	return t
end

local writeToFile = function(filename,contents)
	local file = fs.open(filename,"w")
	file.write(contents)
	file.close()
end

local getFromGitHub
getFromGitHub = function(reponame,repopath,filepath,verbose)
	local jason = http.get("https://api.github.com/repos/"..reponame.."/contents/"..(repopath or ""))
	if not jason then return false end
	local repo = decode(jason.readAll())
	for k,v in pairs(repo) do
		if v.message then
			return false
		else
			if v.type == "file" then
				if verbose then print("'"..fs.combine(filepath,v.name).."'") end
				writeToFile(fs.combine(filepath,v.name),http.get(v.download_url).readAll())
			elseif v.type == "dir" then
				if verbose then print("'"..fs.combine(filepath,v.name).."'") end
				fs.makeDir(fs.combine(filepath,v.name))
				getFromGitHub(reponame,fs.combine(repopath,v.name),fs.combine(filepath,v.name),verbose)
			end
		end
	end
end

local displayHelp = function()
	local progname = fs.getName(shell.getRunningProgram())
	print(progname.." [owner/repo] [repopath] [output dir]")
end

if not (reponame and repopath and outpath) then
	return displayHelp()
else
	if fs.exists(outpath) and not fs.isDir(outpath) then
		write("'"..outpath.."' already exists!")
		write("Overwrite?")
		print(" (Y/N)")
		local evt,key
		while true do
			evt,key = os.pullEvent("key")
			if key == keys.y then
				if (not fs.isDir(outpath)) then fs.delete(outpath) end
				break
			elseif key == keys.n then
				print("Abort.")
				coroutine.yield()
				return
			end
		end
	end
	if repopath == "*" then repopath = "" end
	local oldtxt = (term.getTextColor and term.getTextColor()) or colors.white
	print("Downloading...")
	term.setTextColor(term.isColor() and colors.green or colors.lightGray)
	getFromGitHub(reponame,repopath,outpath,verbose)
	term.setTextColor(oldtxt)
	print("Downloaded to /"..fs.combine("",outpath))
end