A Chrome(-ium) Bookmark downloader for youtube videos

config.lua

return {
	-- file extensions that are possibly a downloaded youtube video
	file_extensions = {"mp3", "opus", "m4a", "ogg"},
	
	-- directorys to scan for youtube id's
	local_dirs = {
		"/media/your/music/library/folder/that/contains/youtube_dl/downloaded/videos/"
	},
	
	-- where to store the downloaded files
	download_dir = "/media/your/music/library/folder/some/download/folder/",
	
	-- The filename of the bookmarks JSON file
	bookmarks_file = "/home/max/.config/chromium/Default/Bookmarks",
	
	-- list of folder names that are scanned for youtube id's(recursivly)
	bookmarks_folders = {
		"Music"
	},
	
	-- where to write the list of failed downloads
	failed_file = "failed.txt",
	
	-- enable better output using terminal escape sequences(disable if writing to log)
	enable_term = true,
	
	-- (internal) command used to find the files in a folder
	_find_cmd = "find %s -type f",
	
	-- (internal) command used to download a youtube URL to a path
	_download_cmd = "cd %s; youtube-dl -x %s"
}

download_bookmarks.lua

#!/usr/bin/env lua5.1
local config = require("config")
local json = require("cjson")

local function youtube_id_from_path(filepath)
	for _, extension in ipairs(config.file_extensions) do
		local lower = filepath:lower()
		if lower:match("%-...........%." .. extension .. "$") then
			local youtube_id = filepath:match("%-(...........)%." .. extension .. "$")
			return youtube_id
		end
	end
end

local function find_local_files()
	local match = {}
	local miss = {}
	for _, local_dir in ipairs(config.local_dirs) do
		local proc = io.popen(config._find_cmd:format(local_dir))
		for line in proc:lines() do
			local youtube_id = youtube_id_from_path(line)
			if youtube_id then
				table.insert(match, {
					filepath = line,
					youtube_id = youtube_id
				})
			else
				table.insert(miss, {
					filepath = line,
				})
			end
		end
		proc:close()
	end
	return match, miss
end

local function get_bookmark_folder_recursive(folder, folder_name)
	for _,child in ipairs(folder.children) do
		if child.type == "folder" then
			if child.name == folder_name then
				return child
			end
			local ret = get_bookmark_folder_recursive(child, folder_name)
			if ret then
				return ret
			end
		end
	end
end

local function get_bookmark_urls_recursive(folder, urls)
	local urls = urls or {}
	for _,child in ipairs(folder.children) do
		if child.type == "url" then
			table.insert(urls, child)
		elseif child.type == "folder" then
			get_bookmark_urls_recursive(child, urls)
		end
	end
end

local function youtube_id_from_url(url)
	local args = url:match("%?(.+)$")
	if args then
		local youtube_id = args:match("&?v=(...........)")
		return youtube_id
	end
end

local function get_bookmarks_urls()
	local json_f = assert(io.open(config.bookmarks_file, "rb"), "Can't open bookmarks file!")
	local obj = json.decode(json_f:read("*a"))
	json_f:close()
	local _urls = {}
	for _,folder_name in ipairs(config.bookmarks_folders) do
		local folder = assert(get_bookmark_folder_recursive(obj.roots.bookmark_bar, folder_name), "Can't find folder in bookmarks!")
		get_bookmark_urls_recursive(folder, _urls)
	end
	local urls = {}
	for _,entry in ipairs(_urls) do
		local youtube_id = youtube_id_from_url(entry.url)
		if youtube_id then
			table.insert(urls, {
				youtube_id = youtube_id,
				entry = entry
			})
		end
	end
	return urls
end

local function download_youtube_id(youtube_id)
	local youtube_url = "https://youtube.com/watch?v=" .. youtube_id
	local ret = os.execute(config._download_cmd:format(config.download_dir, youtube_url))
	--local ret = os.execute(("echo %s; sleep 1; echo %s; sleep 1"):format(config.download_dir, youtube_url))
	return ret == 0
end

local function download_youtube_ids(entries)
	local len = #entries
	local failed = {}
	local j = 0
	for i, entry in ipairs(entries) do
		if config.enable_term then
			print(("\027[2J\027[HDownloading %d/%d, ok: %d, failed: %d ... "):format(i, len, j, #failed))
		else
			print(("Downloading %d/%d, ok: %d, failed: %d ... "):format(i, len, j, #failed))
		end
		print()
		if download_youtube_id(entry.youtube_id) then
			j = j + 1
		else
			print("Download failed!")
			table.insert(failed, entry)
		end
	end
	return failed
end


print("Collecting bookmarks...")
local bookmarks_ids = get_bookmarks_urls()

print("Collecting files...")
local local_ids = find_local_files()

local missing_files = {}
local by_youtube_id = {}
for _,entry in ipairs(local_ids) do
	by_youtube_id[entry.youtube_id] = entry
end
for _,entry in ipairs(bookmarks_ids) do
	if not by_youtube_id[entry.youtube_id] then
		table.insert(missing_files, entry)
	end
end

print("total bookmarks:", #bookmarks_ids)
print("total files:", #local_ids)
print("total missing files:", #missing_files)

print("Starting download...")
local failed = download_youtube_ids(missing_files)
print("total failed:", #failed)

if config.failed_file then
	local failed_f = assert(io.open(config.failed_file, "w"))
	for i, fail in ipairs(failed) do
		failed_f:write("https://youtube.com/watch?v=" .. fail.youtube_id)
	end
end

print("Done!")