local utils = require("mp.utils")
local mpopts = require("mp.options")
local assdraw = require("mp.assdraw")
local user = os.getenv("USER") or "si"
local home = os.getenv("HOME") or ("/home/" .. user)

ON_WINDOWS = (package.config:sub(1, 1) ~= "/")
WINDOWS_ROOTDIR = false
WINDOWS_ROOT_DESC = "Select drive"
SEPARATOR_WINDOWS = "\\"

SEPARATOR = "/"

local windows_desktop = ON_WINDOWS
		and utils.join_path(os.getenv("USERPROFILE"), "Desktop"):gsub(SEPARATOR, SEPARATOR_WINDOWS) .. SEPARATOR_WINDOWS
	or nil

local settings = {
	--navigation keybinds override arrowkeys and enter when activating navigation menu, false means keys are always actíve
	dynamic_binds = true,
	navigator_mainkey = "shift+v", --the key to bring up navigator's menu, can be bound on input.conf aswell

	--dynamic binds, should not be bound in input.conf unless dynamic binds is false
	key_navfavorites = "ctrl+f",
	key_navup = "k",
	key_navdown = "j",
	key_navback = "h",
	key_navforward = "l",
	key_navopen = "ENTER",
	key_navclose = "q",

	--fallback if no file is open, should be a string that points to a path in your system
	defaultpath = windows_desktop or os.getenv("HOME") or "/",
	forcedefault = false, --force navigation to start from defaultpath instead of currently playing file
	--favorites in format { 'Path to directory, notice trailing /' }
	--on windows use double backslash c:\\my\\directory\\
	favorites = {
		home .. "/Downloads",
		home .. "/Torrents/complete",
		home .. "/Movies",
		home .. "/.config/mpv/playlists",
	},
	--list of paths to ignore. the value is anything that returns true for if-statement.
	--directory ignore entries must end with a trailing slash,
	--but files and all symlinks (even to dirs) must be without slash!
	--to help you with the format, simply run "ls -1p <parent folder>" in a terminal,
	--and you will see if the file/folder to ignore is listed as "file" or "folder/" (trailing slash).
	--you can ignore children without ignoring their parent.
	ignorePaths = {
		--general linux system paths (some are used by macOS too):
		["/bin/"] = "1",
		["/boot/"] = "1",
		["/cdrom/"] = "1",
		["/dev/"] = "1",
		["/etc/"] = "1",
		["/lib/"] = "1",
		["/lib32/"] = "1",
		["/lib64/"] = "1",
		["/tmp/"] = "1",
		["/srv/"] = "1",
		["/sys/"] = "1",
		["/snap/"] = "1",
		["/root/"] = "1",
		["/sbin/"] = "1",
		["/proc/"] = "1",
		["/opt/"] = "1",
		["/usr/"] = "1",
		["/run/"] = "1",
		--useless macOS system paths (some of these standard folders are actually files (symlinks) into /private/ subpaths, hence some repetition):
		["/cores/"] = "1",
		["/etc"] = "1",
		["/installer.failurerequests"] = "1",
		["/net/"] = "1",
		["/private/"] = "1",
		["/tmp"] = "1",
		["/var"] = "1",
	},
	--ignore folders and files that match patterns regardless of where they exist on disk.
	--make sure you use ^ (start of string) and $ (end of string) to catch the whole str instead of risking partial false positives.
	--read about patterns at https://www.lua.org/pil/20.2.html or http://lua-users.org/wiki/PatternsTutorial
	ignorePatterns = {
		"^initrd%..*/?$", --hide files and folders folders starting with "initrd.<something>"
		"^vmlinuz.*/?$", --hide files and folders starting with "vmlinuz<something>"
		"^lost%+found/?$", --hide files and folders named "lost+found"
		"^%$.*$", --ignore files starting with $
		"^.*%.ico$",
		"^.*%.txt$",
		"^.*%.ahk$",
		"^.*%.reg$",
		"^.*%.exe$",
		"^.*%.bin$",
		"^.*%.mpq$",
		"^.*%.inf$",
		"^.*%.pdf$",
		"^.*%.docx$",
		"^.*%.xlsx$",
		"^.*%.pptx$",
		"^.*%.zip$",
		"^.*%.rar$",
		"^.*%.tar$",
		"^.*%.gz$",
		"^.*%.bz2$",
		"^.*%.7z$",
		"^.*%.pkg$",
		"^.*%.deb$",
		"^.*%.rpm$",
		"^.*%.dll$",
		"^.*%.sys$",
		"^.*%.cfg$",
		"^.*%.ini$",
		"^.*%.dat$",
		"^.*%.bat$",
		"^.*%.cmd$",
		"^.*%.js$",
		"^.*%.html$",
		"^.*%.htm$",
		"^.*%.css$",
		"^.*%.xml$",
		"^.*%.json$",
		"^.*%.csv$",
		"^.*%.md$",
		"^.*%.yml$",
		"^.*%.yaml$",
		"^.*%.sql$",
		"^.*%.py$",
		"^.*%.java$",
		"^.*%.c$",
		"^.*%.cpp$",
		"^.*%.h$",
		"^.*%.rb$",
		"^.*%.pl$",
		"^.*%.php$",
		"^.*%.asp$",
		"^.*%.aspx$",
		"^.*%.jsp$",
		"^.*%.sh$",
		"^.*%.vbs$",
		"^.*%.ps1$",
		"^.*%.log$",
		"^.*%.msg$",
		"^.*%.eml$",
		"^.*%.ics$",
		"^.*%.vcard$",
		"^.*%.vcf$",
		"^.*%.mdf$",
		"^.*%.ldf$",
		"^.*%.nfo$",
		"^.*%.tmp$",
		"^.*%.bak$",
		"^.*%.hax$",
	},

	subtitleformats = {
		"srt",
		"smi",
		"ass",
		"lrc",
		"ssa",
		"ttml",
		"sbv",
		"vtt",
		"txt",
	},

	navigator_menu_favkey = "F", --this key will always be bound when the menu is open, and is the key you use to cycle your favorites list!
	menu_timeout = false, --menu timeouts and closes itself after navigator_duration seconds, else will be toggled by keybind
	navigator_duration = 13, --osd duration before the navigator closes, if timeout is set to true
	visible_item_count = 20, --how many menu items to show per screen

	--font size scales by window, if false requires larger font and padding sizes
	scale_by_window = true,
	--paddings from top left corner
	text_padding_x = 10,
	text_padding_y = 20,
	-- --ass style overrides inside curly brackets, \keyvalue is one field, extra \ for escape in lua
	-- --example {\\fnUbuntu\\fs10\\b0\\bord1} equals: font=Ubuntu, size=10, bold=no, border=1
	-- --read http://docs.aegisub.org/3.2/ASS_Tags/ for reference of tags
	-- --undeclared tags will use default osd settings
	-- --these styles will be used for the whole navigator
	-- style_ass_tags = "{}",
	-- --you can also use the ass tags mentioned above. For example:
	-- --selection_prefix="{\\c&HFF00FF&}● " - to add a color for selected file. However, if you
	-- --use ass tags you need to set them for both name and selection prefix (see https://github.com/jonniek/mpv-playlistmanager/issues/20)
	-- name_prefix = "○ ",
	-- selection_prefix = "● ",

	-- For white color:
	style_ass_tags = "{\\q2\\an7\\fnUbuntu\\fs8\\b0\\bord1\\c&HFFFFFF&}",
	name_prefix = "{\\c&HFFFFFF&}○ ",

	-- For orange selection:
	selection_prefix = "{\\c&H0080FF&}● ",
}

mpopts.read_options(settings)

--escape a file or directory path for use in shell arguments
function escapepath(dir, escapechar)
	return string.gsub(dir, escapechar, "\\" .. escapechar)
end

local sub_lookup = {}
for _, ext in ipairs(settings.subtitleformats) do
	sub_lookup[ext] = true
end

--ensures directories never accidentally end in "//" due to our added slash
function stripdoubleslash(dir)
	if string.sub(dir, -2) == "//" then
		return string.sub(dir, 1, -2) --negative 2 removes the last character
	else
		return dir
	end
end

function os.capture(cmd, raw)
	local f = assert(io.popen(cmd, "r"))
	local s = assert(f:read("*a"))
	f:close()
	return string.sub(s, 0, -2)
end

dir = nil
path = nil
cursor = 0
length = 0
--osd handler that displays your navigation and information
function handler()
	add_keybinds()
	timer:kill()
	local ass = assdraw.ass_new()
	ass:new_event()
	ass:pos(settings.text_padding_x, settings.text_padding_y)
	ass:append(settings.style_ass_tags)

	if not path then
		if mp.get_property("path") and not settings.forcedefault then
			--determine path from currently playing file...
			local workingdir = mp.get_property("working-directory")
			local playfilename = mp.get_property("filename") --just the filename, without path
			local playpath = mp.get_property("path") --can be relative or absolute depending on what args mpv was given
			local firstchar = string.sub(playpath, 1, 1)
			--first we need to remove the filename (may give us empty path if mpv was started in same dir as file)
			path = string.sub(playpath, 1, string.len(playpath) - string.len(playfilename))
			if firstchar ~= "/" and not ON_WINDOWS then --the path of the playing file wasn't absolute, so we need to add mpv's working dir to it
				path = workingdir .. "/" .. path
			end
			--now resolve that path (to resolve things like "/home/anon/Movies/../Movies/foo.mkv")
			path = resolvedir(path)
			--lastly, check if the folder exists, and if not then fall back to the current mpv working dir
			if not isfolder(path) then
				if ON_WINDOWS then
					path = workingdir .. SEPARATOR_WINDOWS
				else
					path = workingdir
				end
			end
		else
			path = settings.defaultpath
		end
		dir, length = scandirectory(path)
	end
	ass:append(path .. "\\N\\N")
	local b = cursor - math.floor(settings.visible_item_count / 2)
	if b > 0 then
		ass:append("...\\N")
	end
	if b < 0 then
		b = 0
	end
	for a = b, (b + settings.visible_item_count), 1 do
		if a == length then
			break
		end
		local prefix = (a == cursor and settings.selection_prefix or settings.name_prefix)
		ass:append(prefix .. dir[a] .. "\\N")
		if a == (b + settings.visible_item_count) then
			ass:append("...")
		end
	end
	local w, h = mp.get_osd_size()
	if settings.scale_by_window then
		w, h = 0, 0
	end
	mp.set_osd_ass(w, h, ass.text)
	if settings.menu_timeout then
		timer:resume()
	end
end

function navdown()
	if cursor ~= length - 1 then
		cursor = cursor + 1
	else
		cursor = 0
	end
	handler()
end

function navup()
	if cursor ~= 0 then
		cursor = cursor - 1
	else
		cursor = length - 1
	end
	handler()
end

--moves into selected directory, or appends to playlist incase of file
function childdir()
	local item = dir[cursor]

	-- windows only
	if ON_WINDOWS then
		if WINDOWS_ROOTDIR then
			WINDOWS_ROOTDIR = false
		end
		if item then
			local newdir = utils.join_path(path, item):gsub(SEPARATOR, SEPARATOR_WINDOWS) .. SEPARATOR_WINDOWS
			local info, error = utils.file_info(newdir)

			if info and info.is_dir then
				changepath(newdir)
			else
				if issubtitle(item) then
					loadsubs(utils.join_path(path, item))
				else
					mp.commandv("loadfile", utils.join_path(path, item), "append-play")
					mp.osd_message("Appended file to playlist: " .. item)
				end
				handler()
			end
		end

		return
	end

	if item then
		if isfolder(utils.join_path(path, item)) then
			local newdir = stripdoubleslash(utils.join_path(path, dir[cursor] .. "/"))
			changepath(newdir)
		else
			if issubtitle(item) then
				loadsubs(utils.join_path(path, item))
			else
				mp.commandv("loadfile", utils.join_path(path, item), "append-play")
				mp.osd_message("Appended file to playlist: " .. item)
			end
			handler()
		end
	end
end

function issubtitle(file)
	local ext = file:match("^.+%.(.+)$")
	return ext and sub_lookup[ext:lower()]
end

function loadsubs(file)
	mp.commandv("sub_add", file)
	mp.osd_message("Loaded subtitle: " .. file)
end

--replace current playlist with directory or file
--if directory, mpv will recursively queue all items found in the directory and its subfolders
function opendir()
	local item = dir[cursor]

	if item then
		remove_keybinds()

		local filepath = utils.join_path(path, item)
		if ON_WINDOWS then
			filepath = filepath:gsub(SEPARATOR, SEPARATOR_WINDOWS)
		end

		if issubtitle(item) then
			return loadsubs(filepath)
		end

		mp.commandv("loadfile", filepath, "replace")
	end
end

--changes the directory to the path in argument
function changepath(args)
	path = args
	if WINDOWS_ROOTDIR then
		path = WINDOWS_ROOT_DESC
	end
	dir, length = scandirectory(path)
	cursor = 0
	handler()
end

--move up to the parent directory
function parentdir()
	-- windows only
	if ON_WINDOWS then
		if path:sub(-1) == SEPARATOR_WINDOWS then
			path = path:sub(1, -2)
		end
		local parent = utils.split_path(path)
		if path == parent then
			WINDOWS_ROOTDIR = true
		end
		changepath(parent)
		return
	end

	--if path doesn't exist or can't be entered, this returns "/" (root of the drive) as the parent
	local parent = stripdoubleslash(
		os.capture('cd "' .. escapepath(path, '"') .. '" 2>/dev/null && cd .. 2>/dev/null && pwd') .. "/"
	)

	changepath(parent)
end

--resolves relative paths such as "/home/foo/../foo/Music" (to "/home/foo/Music") if the folder exists!
function resolvedir(dir)
	local safedir = escapepath(dir, '"')

	-- windows only
	if ON_WINDOWS then
		local resolved = stripdoubleslash(os.capture('cd /d "' .. safedir .. '" && cd'))
		return resolved .. SEPARATOR_WINDOWS
	end

	--if dir doesn't exist or can't be entered, this returns "/" (root of the drive) as the resolved path
	local resolved = stripdoubleslash(os.capture('cd "' .. safedir .. '" 2>/dev/null && pwd') .. "/")
	return resolved
end

--true if path exists and is a folder, otherwise false
function isfolder(dir)
	-- windows only
	if ON_WINDOWS then
		local info, error = utils.file_info(dir)
		return info and info.is_dir or nil
	end

	local lua51returncode, _, lua52returncode = os.execute('test -d "' .. escapepath(dir, '"') .. '"')
	return lua51returncode == 0 or lua52returncode == 0
end

function scandirectory(searchdir)
	local directory = {}
	--list all files, using universal utilities and flags available on both Linux and macOS
	--  ls: -1 = list one file per line, -p = append "/" indicator to the end of directory names, -v = display in natural order
	--  stderr messages are ignored by sending them to /dev/null
	--  hidden files ("." prefix) are skipped, since they exist everywhere and never contain media
	--  if we cannot list the contents (due to no permissions, etc), this returns an empty list

	-- windows only
	if ON_WINDOWS then
		-- handle drive letters
		if WINDOWS_ROOTDIR then
			local popen, err = io.popen("wmic logicaldisk get caption")
			local i = 0
			if popen then
				for direntry in popen:lines() do
					-- only single letter followed by colon (:) are valid
					if string.find(direntry, "^%a:") then
						direntry = string.sub(direntry, 1, 2)
						local matchedignore = false
						for k, pattern in pairs(settings.ignorePatterns) do
							if direntry:find(pattern) then
								matchedignore = true
								break --don't waste time scanning further patterns
							end
						end
						if not matchedignore and not settings.ignorePaths[path .. direntry] then
							directory[i] = direntry
							i = i + 1
						end
					end
				end
				popen:close()
			else
				mp.msg.error("Could not scan for files :" .. (err or ""))
			end

			return directory, i
		end

		local i = 0
		local files = utils.readdir(searchdir)

		if not files then
			mp.msg.error("Could not scan for files :" .. (err or ""))
			return directory, i
		end

		for _, direntry in ipairs(files) do
			local matchedignore = false
			for k, pattern in pairs(settings.ignorePatterns) do
				if direntry:find(pattern) then
					matchedignore = true
					break --don't waste time scanning further patterns
				end
			end
			if not matchedignore and not settings.ignorePaths[path .. direntry] then
				directory[i] = direntry
				i = i + 1
			end
		end

		return directory, i
	end

	local popen, err = io.popen('ls -1vp "' .. escapepath(searchdir, '"') .. '" 2>/dev/null')
	local i = 0
	if popen then
		for direntry in popen:lines() do
			local matchedignore = false
			for k, pattern in pairs(settings.ignorePatterns) do
				if direntry:find(pattern) then
					matchedignore = true
					break --don't waste time scanning further patterns
				end
			end
			if not matchedignore and not settings.ignorePaths[path .. direntry] then
				directory[i] = direntry
				i = i + 1
			end
		end
		popen:close()
	else
		mp.msg.error("Could not scan for files :" .. (err or ""))
	end
	return directory, i
end

favcursor = 1
function cyclefavorite()
	local firstpath = settings.favorites[1]
	if not firstpath then
		return
	end
	local favpath = nil
	local favlen = 0
	for key, fav in pairs(settings.favorites) do
		favlen = favlen + 1
		if key == favcursor then
			favpath = fav
		end
	end
	if favpath then
		changepath(favpath)
		favcursor = favcursor + 1
	else
		changepath(firstpath)
		favcursor = 2
	end
end

function add_keybinds()
	mp.add_forced_key_binding(settings.key_navdown, "navdown", navdown, "repeatable")
	mp.add_forced_key_binding(settings.key_navup, "navup", navup, "repeatable")
	mp.add_forced_key_binding(settings.key_navopen, "navopen", opendir)
	mp.add_forced_key_binding(settings.key_navforward, "navforward", childdir)
	mp.add_forced_key_binding(settings.key_navback, "navback", parentdir)
	mp.add_forced_key_binding(settings.key_navfavorites, "navfavorites", cyclefavorite)
	mp.add_forced_key_binding(settings.key_navclose, "navclose", remove_keybinds)
end

function remove_keybinds()
	timer:kill()
	mp.set_osd_ass(0, 0, "")
	if settings.dynamic_binds then
		mp.remove_key_binding("navdown")
		mp.remove_key_binding("navup")
		mp.remove_key_binding("navopen")
		mp.remove_key_binding("navforward")
		mp.remove_key_binding("navback")
		mp.remove_key_binding("navfavorites")
		mp.remove_key_binding("navclose")
	end
end

timer = mp.add_periodic_timer(settings.navigator_duration, remove_keybinds)
timer:kill()

if not settings.dynamic_binds then
	add_keybinds()
end

active = false
function activate()
	if settings.menu_timeout then
		handler()
	else
		if active then
			remove_keybinds()
			active = false
		else
			handler()
			active = true
		end
	end
end

mp.add_key_binding(settings.navigator_mainkey, "navigator", activate)