A simple command line tool for uploading files to imgur, whether it be through an account or anonymously.

imgur-upload.lua

#!/usr/bin/luajit

local https = require"ssl.https"
local json = require"json"
local ltn12 = require"ltn12"
local socket = require"socket"
local url = require"socket.url"
local lgi = require"lgi"
local mime = require"mime"

local GLib   = lgi.require("GLib")
local notify = lgi.require("Notify")
notify.init("imgur")

math.randomseed(socket.gettime())

local HOME = os.getenv("HOME")

local imgur = {
	client_id = "bc79e7073db68d0",
	client_secret = "046f28f131f882bebf6ca1cef72b563d3ee60e81",

	-- BAD TOUCH
	copy_url = false,
	open_url = false,
	save_path = nil,
	login = false,
	album = nil,
	credentials_file = HOME .. "/.config/imgur-upload.conf",
	credentials = {},
	files = {},
	version = "0.4",
	debug = true,

	notification = nil,

	upload = {
		start = socket.gettime(),
		speed = 0,
		samples = 0,
		last_percent = 0,
		size = 0,
		uploaded = 0,
	}
}

function debug(message)
	if imgur.debug then
		print(message)
	end
end

local charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"

function imgur.random_string(len)
	local str = ""
	for i=1,len or 10 do
		local char = math.random(1,#charset)
		str = str .. string.sub(charset, char, char)
	end
	return str
end

function imgur.file_exists(name)
	local f = io.open(name,"r")
	if f ~= nil then io.close(f) return true else return false end
end

function imgur.tmp_file(folder,filename)
	local filename = filename or (imgur.random_string() .. ".png")
	local path = string.format("%s/%s", folder, filename)
	if imgur.file_exists(path) then
		-- Try to generate a new random file
		return imgur.tmp_file(folder,nil)
	end
	return io.open(path,"wb")
end

function imgur.notify_start()
	imgur.notification = notify.Notification.new("Imgur Uploader", "Starting upload..", "shotwell")
	imgur.notification:show()

	imgur.upload.start = socket.gettime()
	imgur.upload.speed = 0
	imgur.upload.samples = 0
	imgur.upload.last_percent = 0
end

function imgur.print_progress(cur, max)
	local maxbars = 30
	local perc = cur/max

	local bars		= string.rep("=", math.floor(perc*maxbars))
	local spaces	= string.rep(" ", math.ceil((1-perc)*maxbars))

	-- Stuff to debug upload speed
	imgur.upload.samples = imgur.upload.samples + 1
	imgur.upload.speed = cur / (socket.gettime() - imgur.upload.start)

	local percNum = math.floor(perc*100)

	if imgur.upload.last_percent ~= percNum then -- Only update when a new bar is needed
		io.stdout:write(("%4s%% [%s>%s] %4.1f Mbps %s"):format(percNum, bars, spaces, imgur.upload.speed/125000, percNum < 100 and "\r" or "\n"))
		io.stdout:flush()
		imgur.upload.last_percent = percNum
	end
end

function imgur.notify_percent(cur, max)
	imgur.print_progress(cur, max)

	if not imgur.notification then return end

	local var = GLib.Variant("i", math.floor(cur/max*100))
	--imgur.notification:set_hint_int32("value", math.floor(cur/max*100))
	imgur.notification:set_hint("value", var)
	imgur.notification:show()
end

function imgur.notify_end(title, message)
	if not imgur.notification then return end
	imgur.notification:clear_hints()
	imgur.notification.summary = title
	imgur.notification.body = message
	imgur.notification:show()
end

function imgur.encodepost(args)
	if args == nil or next(args) == nil then   -- no args or empty args?
		return ""
	end
	local strp = ""
	for key, vals in pairs(args) do
		if type(vals) ~= "table" then
			vals = {vals}
		end
		for i,val in ipairs(vals) do
			if type(val) == "boolean" then
				strp = strp.."&"..key.."="..( val and 1 or 0 )
			elseif val and #val > 0 then
				strp = strp.."&"..key.."="..url.escape(val)
			end
		end
	end
	-- remove first & 
	return string.sub(strp,2)
end

function imgur.load_token()
	local f, err = io.open(imgur.credentials_file, "r")

	if not f then return end

	local credentials = {}
	local pattern = "([%w_]+)%s*=%s*([%w_]+)"

	for k, v in string.gmatch(f:read("*all"), pattern) do
		credentials[k] = v
	end

	f:close()

	return credentials
end

function imgur.check_token()
	imgur.credentials = imgur.load_token()

	local time = os.time()
	if imgur.credentials and imgur.credentials.refresh_token then
		if time > tonumber(imgur.credentials.token_expire_time) then
			imgur.refresh_token()
		end
	else
		imgur.aquire_token()
	end
end

function imgur.refresh_token()
	local data = imgur.post("https://api.imgur.com/oauth2/token", {
		refresh_token = imgur.credentials.refresh_token,
		client_id = imgur.client_id,
		client_secret = imgur.client_secret,
		grant_type = "refresh_token",
	})
	if not data.status then
		imgur.credentials = {
			access_token = data.access_token,
			refresh_token = data.refresh_token,
			token_expire_time = os.time() + data.expires_in,
		}
	end
	imgur.save_token()
end

function imgur.aquire_token()
	local authorize_url = ("https://api.imgur.com/oauth2/authorize?client_id=%s&response_type=pin"):format(imgur.client_id)

	print "Please go to"
	print(authorize_url)
  	print "and grant access to this application."

  	io.stdout:write("Enter PIN: ")
  	local pin = io.read()

  	print("PIN", pin)

  	local data = imgur.post("https://api.imgur.com/oauth2/token", {
  		client_id = imgur.client_id,
  		client_secret = imgur.client_secret,
  		grant_type = "pin",
  		pin = pin,
  	})

  	if not data.status then
		imgur.credentials = {
			access_token = data.access_token,
			refresh_token = data.refresh_token,
			token_expire_time = os.time() + data.expires_in,
		}
	end
	imgur.save_token()
end

function imgur.save_token()
	local f = assert(io.open(imgur.credentials_file, "w"))
	local data = {}
	for k,v in pairs(imgur.credentials) do
		table.insert(data, ("%s = %s"):format(k,v))
	end
	f:write(table.concat(data, "\n"))
	f:close()
end

local chunk, src_err
local ret, snk_err

-- Allows us to calculate how far along in the upload we are
function imgur.step(src, snk)
	chunk, src_err = src()
	ret, snk_err = snk(chunk, src_err)
	if chunk and ret then
		imgur.upload.uploaded = imgur.upload.uploaded + #chunk
		imgur.notify_percent(imgur.upload.uploaded, imgur.upload.size)
		return 1
	else return nil, src_err or snk_err end
end

function imgur.upload_image(image)
	local parameters = imgur.encodepost({
		["image"] = mime.b64(image),
		["type"] = "base64",
		["album"] = imgur.album,
	})

	imgur.upload.size = #parameters
	imgur.upload.uploaded = 0

	print(("Uploading file (%.2f MB)"):format(#parameters/125000))

	local token = imgur.credentials.access_token

	local response = {} -- for the response body
	local result, respcode, respheaders, respstatus = https.request{
	    url = "https://api.imgur.com/3/image",
	    method = "POST",
	    source = ltn12.source.string(parameters),
	    headers = {
	        ["content-length"] = tostring(#parameters),
	        ["content-type"] = "application/x-www-form-urlencoded",
	        ["Authorization"] = imgur.login and ("Bearer " .. token) or ("Client-ID " .. imgur.client_id),
	    },
	    step = imgur.step,
	    sink = ltn12.sink.table(response),
	}
	local resp = table.concat(response)
	debug(("Upload response: %s"):format(resp))
	return json.decode(resp)
end

function imgur.post(url, data)
	data = imgur.encodepost(data)
	local response = {} -- for the response body
	local result, respcode, respheaders, respstatus = https.request{
	    url = url,
	    method = "POST",
	    source = ltn12.source.string(data),
	    headers = {
	        ["content-length"] = tostring(#data),
	        ["content-type"] = "application/x-www-form-urlencoded",
	    },
	    sink = ltn12.sink.table(response),
	}
	return json.decode(table.concat(response))
end

function imgur.error(message)
	io.stderr:write(("%s\n"):format(message))
end

function imgur.notify(title, message)
	os.execute(("notify-send -i shotwell %q %q"):format(title, message))
end

function imgur.print_help(prog)
	print("Usage: " .. prog ..  " [options] [files ...]" .. [[ 
Options
	-V, --version     Output the version number
	-h, --help        Show this help text
	-,  --stdin       Upload raw image data from stdin
	-l, --login       Connect to an imgur account
	-a, --album       Upload the images to an album
	-c, --clipboard   Copy the image URL to clipboard
	-o, --open        Open the image URL in your browser
	-s, --save        Save the image to a file
	-d, --debug       Debug messages]])
end

function main(args)
	local prog = args[0]:match("([^/\\]+)$")

	if #args <= 0 then
		imgur.print_help(prog)
		return
	end

	local arg
	local skip = false
	for i=1,#args do
		if not skip then
			arg = args[i]
			if arg == "-h" or arg == "--help" then
				imgur.print_help(prog)
			elseif arg == "-V" or arg == "--version" then
				print("version: " .. imgur.version)
			elseif arg == "-l" or arg == "--login" then
				imgur.login = true
			elseif arg == "-a" or arg == "--album" then
				skip = true
				imgur.album = args[i+1]
				print("Upload images to album: " .. imgur.album)
			elseif arg == "-c" or arg == "--clipboard" then
				imgur.copy_url = true
			elseif arg == "-o" or arg == "--open" then
				imgur.open_url = true
			elseif arg == '-s' or arg == "--save" then
				skip = true
				imgur.save_path = args[i+1]
				print("Save images to path: " .. imgur.save_path)
			elseif arg == '-' or arg == "--stdin" then
				table.insert(imgur.files, io.stdin)
			elseif arg == "-d" or arg == "--debug" then
				imgur.debug = true
			else
				local file, err = io.open(arg, "rb")
				if file then
					table.insert(imgur.files, file)
				else
					imgur.error(err)
				end
			end
		else
			skip = false
		end
	end

	if imgur.login then
		imgur.check_token()
	end

	for _,file in pairs(imgur.files) do
		local raw = file:read("*all")
		file:close()

		if #raw > 0 then
			imgur.notify_start()

			local filename
			local result = imgur.upload_image(raw)

			if result.success then
				print "Upload complete.."
				if imgur.copy_url then
					os.execute(("echo -n %q | xclip -selection clipboard"):format(result.data.link))
				end
				filename = result.data.link:match("([^/\\]+)$")
				imgur.notify_end("Upload complete", result.data.link)
				print(result.data.link)
				if imgur.open_url then
					os.execute(("xdg-open %q"):format(result.data.link))
				end
			else
				imgur.notify_end("Upload failed", result.data.error or "No result data")
				imgur.error(("Upload failed: %s"):format(result.data.error))
			end

			if imgur.save_path then
				local folderpath = string.format("%s/%s", imgur.save_path, os.date("%Y-%m"))

				os.execute(string.format("mkdir -p %q", folderpath))

				-- If we failed to upload, we generate our own filename
				local tmp = imgur.tmp_file(folderpath,filename)
				if tmp then
					tmp:write(raw)
					tmp:close()
				else
					imgur.error(("Save failed: %s"):format(err))
				end
			end
		end
	end
end
main(arg)