--[[
	This file is part of mdmenu.
	
	mdmenu is free software: you can redistribute it and/or modify it
	under the terms of the GNU Affero General Public License as published by the
	Free Software Foundation, either version 3 of the License, or (at your
	option) any later version.
	
	mdmenu is distributed in the hope that it will be useful, but WITHOUT
	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
	for more details.
	
	You should have received a copy of the GNU Affero General Public License
	along with mdmenu. If not, see <https://www.gnu.org/licenses/>.
]]

local msg = require("mp.msg")
local mpopt = require("mp.options")
local utils = require("mp.utils")

local state = {
	playlist = nil,
	playlist_current = nil,
	tracklist = nil,
	chapters = nil,
	chapters_raw = nil,
	wid = nil,
}

local opt = {
	embed = true,
	preselect = false,
	cmd = { "dmenu", "-i", "-l", "16" },

	debug = false,
}

local zassert = function() end
local ob = function(b)
	return b and "[" or " "
end
local cb = function(b)
	return b and "]" or " "
end

local function format_time(t)
	local h = math.floor(t / (60 * 60))
	t = t - (h * 60 * 60)
	local m = math.floor(t / 60)
	local s = t - (m * 60)
	return string.format("%.2d:%.2d:%.2d", h, m, s)
end

local function humantime_to_sec(str)
	zassert(string.len(str) >= 8)
	local h = tonumber(string.sub(str, 1, 2))
	local m = tonumber(string.sub(str, 4, 5))
	local s = tonumber(string.sub(str, 7, 8))
	if h and m and s and string.sub(str, 3, 3) == ":" and string.sub(str, 6, 6) == ":" then
		return (h * 60 * 60) + (m * 60) + s
	end
	return nil
end

local function grab_xid(kind, isconfigured)
	zassert(kind == "vo-configured")
	state.wid = nil -- clear it to account for runtime vo change
	if isconfigured then
		local wid = mp.get_property("window-id")
		local vo_null = (wid == nil) and (mp.get_property("current-vo") == "null")
		if wid == nil and not vo_null then
			local pid = mp.get_property("pid")
			local r = mp.command_native({
				name = "subprocess",
				playback_only = false,
				capture_stdout = true,
				args = { "xdo", "id", "-p", pid },
			})
			if r.status == 0 and string.len(r.stdout) > 0 then
				wid = string.match(r.stdout, "0x%x+")
			end
		end
		if wid then
			state.wid = wid
		elseif not vo_null then
			msg.warn("couldn't get mpv's xwindow id. make sure `xdo` is installed.")
		end
	end
	msg.debug("[grab_xid]: isconfigured = " .. tostring(isconfigured) .. " wid = " .. tostring(state.wid))
end

local function set_playlist(kind, plist)
	zassert(kind == "playlist")
	local s = ""
	local f = "%" .. (string.len(#plist) + ob(true):len() + cb(true):len()) .. "s"
	state.playlist_current = nil
	for k, pl in ipairs(plist) do
		state.playlist_current = pl.current and k or state.playlist_current
		s = s .. string.format(f, ob(pl.current) .. k .. cb(pl.current)) .. " "
		s = s .. (pl.title or select(2, utils.split_path(pl.filename))) .. "\n"
	end
	state.playlist = s
end

local function set_tracklist(kind, tlist)
	zassert(kind == "track-list")
	local s = ""
	for _, t in ipairs(tlist) do
		s = s .. ob(t.selected) .. string.sub(t.type, 1, 1)
		s = s .. t.id .. cb(t.selected) .. " "

		if t.title then
			s = s .. t.title .. " "
		end
		if t.lang then
			s = s .. t.lang .. " "
		end
		s = s .. "\n"
	end
	state.tracklist = s
end

local function set_chapter_list(kind, c)
	zassert(kind == "chapter-list")
	if c and #c > 0 then
		local s = ""
		for _, ch in ipairs(c) do
			s = s .. format_time(ch.time) .. " "
			s = s .. ch.title .. "\n"
		end
		state.chapters = s
		state.chapters_raw = c
	else
		state.chapters = nil
		state.chapters_raw = nil
	end
end

local function table_append(a, b)
	for _, v in ipairs(b) do
		table.insert(a, v)
	end
end

local function call_dmenu(stdin, extra_arg)
	local cmd = {}
	table_append(cmd, opt.cmd)
	if state.wid then
		table.insert(cmd, "-w")
		table.insert(cmd, state.wid)
	end
	if extra_arg then
		table_append(cmd, extra_arg)
	end
	msg.debug("[call_dmenu]: " .. table.concat(cmd, " "))
	return mp.command_native({
		name = "subprocess",
		playback_only = false,
		stdin_data = stdin,
		capture_stdout = true,
		args = cmd,
	})
end

local function menu_playlist()
	if state.playlist == nil then
		return
	end
	local narg = nil
	if opt.preselect and state.playlist_current ~= nil then
		narg = { "-n", tostring(state.playlist_current - 1) }
	end
	local r = call_dmenu(state.playlist, narg)
	if r.status == 0 and string.len(r.stdout) > 2 then
		s = string.match(r.stdout, "[%s%[]*(%d+)")
		if tonumber(s) then
			mp.set_property("playlist-pos-1", s)
		else
			msg.warn("bad playlist position: " .. r.stdout)
		end
	end
end

local function menu_tracklist()
	if state.tracklist == nil then
		return
	end

	local r = call_dmenu(state.tracklist)
	if r.status == 0 and string.len(r.stdout) > 4 then
		local active = string.sub(r.stdout, 1, 1) == "["
		local type = string.sub(r.stdout, 2, 2)
		local cmd = { ["v"] = "vid", ["a"] = "audio", ["s"] = "sub" }
		local num = tonumber(string.sub(r.stdout, 3):match("%d+"))
		local arg = { [false] = num, [true] = "no" }

		if cmd[type] and num ~= nil then
			mp.commandv("set", cmd[type], arg[active])
		else
			msg.warn("messed up input: " .. r.stdout)
		end
	end
end

local function menu_chapters()
	if state.chapters == nil then
		return
	end
	local narg = nil
	if opt.preselect then
		local t = mp.get_property_native("time-pos") or 0
		local n = 0
		for i, c in ipairs(state.chapters_raw) do
			if t > c.time then
				n = i - 1
			end
		end
		narg = { "-n", tostring(n) }
	end

	local r = call_dmenu(state.chapters, narg)
	if r.status == 0 and string.len(r.stdout) > 8 then
		local t = humantime_to_sec(r.stdout)
		if t then
			mp.set_property("time-pos", t)
		else
			msg.warn("bad chapter position: " .. r.stdout)
		end
	end
end

local function menu_bindings()
	local s = ""
	local bind = mp.get_property_native("input-bindings")
	for k, v in pairs(bind) do
		s = s .. string.format("%-16s ", v.key) .. v.cmd .. "\n"
	end
	local r = call_dmenu(s)
	-- if (r.status == 0 and string.len(r.stdout) > 0) then
	-- 	local _, cmd = string.match(r.stdout, "(%w+)%s+(.+)\n");
	-- 	if (cmd ~= nil and string.len(cmd) > 0) then
	-- 		mp.command(cmd)
	-- 	end
	-- end
end

local function init()
	mpopt.read_options(opt, "mdmenu")
	if type(opt.cmd) == "string" then -- what a pain
		local s = opt.cmd
		opt.cmd = {}
		for arg in string.gmatch(s, "[^,]+") do
			table.insert(opt.cmd, arg)
		end
	end

	if opt.debug then
		msg.debug("[ASSERTIONS] enabled")
		zassert = assert
	else
		zassert(false)
	end

	-- grab mpv's xwindow id
	if opt.embed then
		-- HACK: mpv doesn't open the window instantly by default.
		-- so wait for 'vo-configured' to be true before trying to
		-- grab the xid.
		mp.observe_property("vo-configured", "native", grab_xid)
	end

	mp.observe_property("playlist", "native", set_playlist)
	mp.add_key_binding(nil, "playlist", menu_playlist)

	mp.observe_property("track-list", "native", set_tracklist)
	mp.add_key_binding(nil, "tracklist", menu_tracklist)

	mp.observe_property("chapter-list", "native", set_chapter_list)
	mp.add_key_binding(nil, "chapters", menu_chapters)

	mp.add_key_binding(nil, "bindings", menu_bindings)
end

init()