--[[

     Lain
     Layouts, widgets and utilities for Awesome WM

     Utilities section

     Licensed under GNU General Public License v2
      * (c) 2013,      Luca CPZ
      * (c) 2010-2012, Peter Hofmann

--]]

local awful = require('awful')
local sqrt = math.sqrt
local pairs = pairs
local client = client
local tonumber = tonumber
local wrequire = require('lain.helpers').wrequire
local setmetatable = setmetatable

-- Lain utilities submodule
-- lain.util
local util = { _NAME = 'lain.util' }

-- Like awful.menu.clients, but only show clients of currently selected tags
function util.menu_clients_current_tags(menu, args)
	-- List of currently selected tags.
	local cls_tags = awful.screen.focused().selected_tags

	if cls_tags == nil then
		return nil
	end

	-- Final list of menu items.
	local cls_t = {}

	-- For each selected tag get all clients of that tag and add them to
	-- the menu. A click on a menu item will raise that client.
	for i = 1, #cls_tags do
		local t = cls_tags[i]
		local cls = t:clients()

		for _, c in pairs(cls) do
			cls_t[#cls_t + 1] = {
				awful.util.escape(c.name) or '',
				function()
					c.minimized = false
					client.focus = c
					c:raise()
				end,
				c.icon,
			}
		end
	end

	-- No clients? Then quit.
	if #cls_t <= 0 then
		return nil
	end

	-- menu may contain some predefined values, otherwise start with a
	-- fresh menu.
	if not menu then
		menu = {}
	end

	-- Set the list of items and show the menu.
	menu.items = cls_t
	local m = awful.menu(menu)
	m:show(args)

	return m
end

-- Magnify a client: set it to "float" and resize it.
function util.magnify_client(c, width_f, height_f)
	if c and not c.floating then
		util.magnified_client = c
		util.mc(c, width_f, height_f)
	else
		util.magnified_client = nil
		c.floating = false
	end
end

-- https://github.com/lcpz/lain/issues/195
function util.mc(c, width_f, height_f)
	c = c or util.magnified_client
	if not c then
		return
	end

	c.floating = true
	local s = awful.screen.focused()
	local mg = s.workarea
	local g = {}
	local mwfact = width_f or s.selected_tag.master_width_factor or 0.5
	g.width = sqrt(mwfact) * mg.width
	g.height = sqrt(height_f or mwfact) * mg.height
	g.x = mg.x + (mg.width - g.width) / 2
	g.y = mg.y + (mg.height - g.height) / 2

	if c then
		c:geometry(g)
	end -- if c is still a valid object
end

-- Non-empty tag browsing
-- direction in {-1, 1} <-> {previous, next} non-empty tag
function util.tag_view_nonempty(direction, sc)
	direction = direction or 1
	local s = sc or awful.screen.focused()
	local tags = s.tags
	local sel = s.selected_tag

	local i = sel.index
	repeat
		i = i + direction

		-- Wrap around when we reach one of the bounds
		if i > #tags then
			i = i - #tags
		end
		if i < 1 then
			i = i + #tags
		end

		local t = tags[i]

		-- Stop when we get back to where we started
		if t == sel then
			break
		end

		-- If it's The One, view it.
		if #t:clients() > 0 then
			t:view_only()
			return
		end
	until false
end

-- {{{ Dynamic tagging

-- Add a new tag
function util.add_tag(layout)
	awful.prompt.run({
		prompt = 'New tag name: ',
		textbox = awful.screen.focused().mypromptbox.widget,
		exe_callback = function(name)
			if not name or #name == 0 then
				return
			end
			awful.tag
				.add(name, { screen = awful.screen.focused(), layout = layout or awful.layout.suit.tile })
				:view_only()
		end,
	})
end

-- Rename current tag
function util.rename_tag()
	awful.prompt.run({
		prompt = 'Rename tag: ',
		textbox = awful.screen.focused().mypromptbox.widget,
		exe_callback = function(new_name)
			if not new_name or #new_name == 0 then
				return
			end
			local t = awful.screen.focused().selected_tag
			if t then
				t.name = new_name
			end
		end,
	})
end

-- Move current tag
-- pos in {-1, 1} <-> {previous, next} tag position
function util.move_tag(pos)
	local tag = awful.screen.focused().selected_tag
	if tonumber(pos) <= -1 then
		awful.tag.move(tag.index - 1, tag)
	else
		awful.tag.move(tag.index + 1, tag)
	end
end

-- Delete current tag
-- Any rule set on the tag shall be broken
function util.delete_tag()
	local t = awful.screen.focused().selected_tag
	if not t then
		return
	end
	t:delete()
end

-- }}}

-- On the fly useless gaps change
function util.useless_gaps_resize(thatmuch, s, t)
	local scr = s or awful.screen.focused()
	local tag = t or scr.selected_tag
	tag.gap = tag.gap + tonumber(thatmuch)
	awful.layout.arrange(scr)
end

return setmetatable(util, { __index = wrequire })