--[[

     Awesome-Freedesktop
     Freedesktop.org compliant desktop entries and menu

     Desktop section

     Licensed under GNU General Public License v2
      * (c) 2016,      Luke Bonham
      * (c) 2009-2015, Antonio Terceiro

--]]

local awful = require('awful')
local theme = require('beautiful')
local utils = require('menubar.utils')
local wibox = require('wibox')

local io = io
local ipairs = ipairs
local mouse = mouse
local os = os
local string = string
local screen = screen
local table = table

-- Desktop icons
-- freedesktop.desktop
local desktop = {
	-- Default desktop basic icons
	baseicons = {
		[1] = {
			label = 'This PC',
			icon = 'computer',
			onclick = 'computer://',
		},
		[2] = {
			label = 'Home',
			icon = 'user-home',
			onclick = os.getenv('HOME'),
		},
		[3] = {
			label = 'Trash',
			icon = 'user-trash',
			onclick = 'trash://',
		},
	},
	-- Default parameters
	iconsize = { width = 48, height = 48 },
	labelsize = { width = 140, height = 20 },
	margin = { x = 20, y = 20 },
}

-- MIME types list
local mime_types = {}

-- Icons positioning
desktop.current_pos = {}

-- @return iterator on input pipe
local function pipelines(...)
	local f = assert(io.popen(...))
	return function()
		local data = f:read()
		if data == nil then
			f:close()
		end
		return data
	end
end

-- Adds an icon to desktop
-- @param args settings from desktop.add_icons
-- @param label icon string label
-- @param icon icon string file path
-- @param onclick function to execute on click
function desktop.add_single_icon(args, label, icon, onclick)
	local s = args.screen
	local dcp = desktop.current_pos

	-- define icon dimensions and position
	if not dcp[s] then
		dcp[s] = {
			x = (screen[s].geometry.x + args.iconsize.width + args.margin.x),
			y = screen[s].geometry.y + 20 + args.margin.y,
		}
	end

	local tot_height = (icon and args.iconsize.height or 0) + (label and args.labelsize.height or 0)
	if tot_height == 0 then
		return
	end

	if dcp[s].y + tot_height > screen[s].geometry.y + screen[s].geometry.height - 20 - args.margin.y then
		dcp[s].x = dcp[s].x + args.labelsize.width + args.iconsize.width + args.margin.x
		dcp[s].y = 20 + args.margin.y
	end

	local common = { screen = s, bg = '#00000000', visible = true, type = 'desktop' }

	-- create icon container
	if icon then
		common.width = args.iconsize.width
		common.height = args.iconsize.height
		common.x = dcp[s].x
		common.y = dcp[s].y

		icon = wibox.widget({
			image = icon,
			resize = false,
			widget = wibox.widget.imagebox,
		})

		icon:buttons(awful.button({}, 1, nil, onclick))

		icon_container = wibox(common)
		icon_container:set_widget(icon)

		dcp[s].y = dcp[s].y + args.iconsize.height + 5
	end

	-- create label container
	if label then
		common.width = args.labelsize.width
		common.height = args.labelsize.height
		common.x = dcp[s].x - (args.labelsize.width / 2) + args.iconsize.width / 2
		common.y = dcp[s].y

		caption = wibox.widget({
			text = label,
			align = 'center',
			forced_width = common.width,
			forced_height = common.height,
			ellipsize = 'middle',
			widget = wibox.widget.textbox,
		})

		caption:buttons(awful.button({}, 1, onclick))
		caption_container = wibox(common)
		caption_container:set_widget(caption)
	end

	dcp[s].y = dcp[s].y + args.labelsize.height + args.margin.y

	desktop.current_pos = dcp

	return dcp
end

-- Adds base icons (This PC, Trash, etc) to desktop
-- @param args settings from desktop.add_icons
function desktop.add_base_icons(args)
	for _, base in ipairs(args.baseicons) do
		desktop.add_single_icon(args, base.label, utils.lookup_icon(base.icon), function()
			awful.spawn(string.format("%s '%s'", args.open_with, base.onclick))
		end)
	end
end

-- Looks up a suitable icon for filename
-- @param filename string file name
-- @return icon file path (string)
function desktop.lookup_file_icon(filename)
	-- load system MIME types
	if #mime_types == 0 then
		for line in io.lines('/etc/mime.types') do
			if not line:find('^#') then
				local parsed = {}
				for w in line:gmatch('[^%s]+') do
					table.insert(parsed, w)
				end
				if #parsed > 1 then
					for i = 2, #parsed do
						mime_types[parsed[i]] = parsed[1]:gsub('/', '-')
					end
				end
			end
		end
	end

	-- try to search a possible icon among standards
	local extension = filename:match('%a+$')
	local mime = mime_types[extension] or ''
	local mime_family = mime:match('^%a+') or ''

	local possible_filenames = {
		mime,
		'gnome-mime-' .. mime,
		mime_family,
		'gnome-mime-' .. mime_family,
		extension,
	}

	for i, filename in ipairs(possible_filenames) do
		local icon = utils.lookup_icon(filename)
		if icon then
			return icon
		end
	end

	-- if we don"t find ad icon, then pretend is a plain text file
	return utils.lookup_icon('text-x-generic')
end

-- Parse subdirectories and files list from input directory
-- @input dir directory to parse (string)
-- @return files table with found entries
function desktop.parse_dirs_and_files(dir)
	local files = {}
	local paths = pipelines('find ' .. dir .. ' -maxdepth 1 -type d |sort|tail -n +1')
	for path in paths do
		if path:match('[^/]+$') then
			local file = {}
			file.filename = path:match('[^/]+$')
			file.path = path
			file.show = true
			file.icon = utils.lookup_icon('folder')
			table.insert(files, file)
		end
	end
	local paths = pipelines('find ' .. dir .. ' -maxdepth 1 -type f')
	for path in paths do
		if not path:find('%.desktop$') then
			local file = {}
			file.filename = path:match('[^/]+$')
			file.path = path
			file.show = true
			file.icon = desktop.lookup_file_icon(file.filename)
			table.insert(files, file)
		end
	end
	return files
end

-- Adds subdirectories and files icons from args.dir
-- @param args settings from desktop.add_icons
function desktop.add_dirs_and_files_icons(args)
	for _, file in ipairs(desktop.parse_dirs_and_files(args.dir)) do
		if file.show then
			local label = args.showlabels and file.filename or nil
			local onclick = function()
				awful.spawn(string.format("%s '%s'", args.open_with, file.path))
			end
			desktop.add_single_icon(args, label, file.icon, onclick)
		end
	end
end

-- Main function, adds base, directory and files icons
-- @param args user defined settings, with fallback on defaults
function desktop.add_icons(args)
	args = args or {}
	args.screen = args.screen or mouse.screen
	args.dir = args.dir or os.getenv('HOME') .. '/Desktop'
	args.showlabels = args.showlabel or true
	args.open_with = args.open_with or 'xdg_open'
	args.baseicons = args.baseicons or desktop.baseicons
	args.iconsize = args.iconsize or desktop.iconsize
	args.labelsize = args.labelsize or desktop.labelsize
	args.margin = args.margin or desktop.margin

	-- trying to fallback on Adwaita if theme.icon_theme is not defined
	-- if Adwaita is missing too, no icons will be shown
	if not theme.icon_theme then
		theme.icon_theme = args.icon_theme or 'Adwaita'
	end

	desktop.add_base_icons(args)
	desktop.add_dirs_and_files_icons(args)
end

return desktop