--[[

     Licensed under GNU General Public License v2
      * (c) 2016, Luca CPZ
      * (c) 2015, unknown

--]]

local awful = require('awful')
local capi = { client = client }
local math = math
local string = string
local pairs = pairs
local screen = screen
local setmetatable = setmetatable

-- Quake-like Dropdown application spawn
local quake = {}

-- If you have a rule like "awful.client.setslave" for your terminals,
-- ensure you use an exception for QuakeDD. Otherwise, you may
-- run into problems with focus.

function quake:display()
	if self.followtag then
		self.screen = awful.screen.focused()
	end

	-- First, we locate the client
	local client = nil
	local i = 0
	for c in
		awful.client.iterate(function(c)
			-- c.name may be changed!
			return c.instance == self.name
		end)
	do
		i = i + 1
		if i == 1 then
			client = c
		else
			-- Additional matching clients, let's remove the sticky bit
			-- which may persist between awesome restarts. We don't close
			-- them as they may be valuable. They will just turn into
			-- normal clients.
			c.sticky = false
			c.ontop = false
			c.above = false
		end
	end

	if not client and not self.visible then
		return
	end

	if not client then
		-- The client does not exist, we spawn it
		local cmd = string.format('%s %s %s', self.app, string.format(self.argname, self.name), self.extra)
		awful.spawn(cmd, { tag = self.screen.selected_tag })
		return
	end

	-- Set geometry
	client.floating = true
	client.border_width = self.border
	client.size_hints_honor = false
	local maximized = client.maximized
	local fullscreen = client.fullscreen
	client:geometry(self.geometry[self.screen.index] or self:compute_size())

	-- Set not sticky and on top
	client.sticky = false
	client.ontop = true
	client.above = true
	client.skip_taskbar = true

	-- Additional user settings
	if self.settings then
		self.settings(client)
	end

	-- Toggle display
	if self.visible then
		client.hidden = false
		client.maximized = self.maximized
		client.fullscreen = self.fullscreen
		client:raise()
		self.last_tag = self.screen.selected_tag
		client:tags({ self.screen.selected_tag })
		capi.client.focus = client
	else
		self.maximized = maximized
		self.fullscreen = fullscreen
		client.maximized = false
		client.fullscreen = false
		client.hidden = true
		local ctags = client:tags()
		for j, _ in pairs(ctags) do
			ctags[j] = nil
		end
		client:tags(ctags)
	end

	return client
end

function quake:compute_size()
	-- skip if we already have a geometry for this screen
	if not self.geometry[self.screen.index] then
		local geom
		if not self.overlap then
			geom = screen[self.screen.index].workarea
		else
			geom = screen[self.screen.index].geometry
		end
		local width, height = self.width, self.height
		if width <= 1 then
			width = math.floor(geom.width * width) - 2 * self.border
		end
		if height <= 1 then
			height = math.floor(geom.height * height)
		end
		local x, y
		if self.horiz == 'left' then
			x = geom.x
		elseif self.horiz == 'right' then
			x = geom.width + geom.x - width
		else
			x = geom.x + (geom.width - width) / 2
		end
		if self.vert == 'top' then
			y = geom.y
		elseif self.vert == 'bottom' then
			y = geom.height + geom.y - height
		else
			y = geom.y + (geom.height - height) / 2
		end
		self.geometry[self.screen.index] = { x = x, y = y, width = width, height = height }
	end
	return self.geometry[self.screen.index]
end

function quake:toggle()
	if self.followtag then
		self.screen = awful.screen.focused()
	end
	local current_tag = self.screen.selected_tag
	if current_tag and self.last_tag ~= current_tag and self.visible then
		local c = self:display()
		if c then
			c:move_to_tag(current_tag)
		end
	else
		self.visible = not self.visible
		self:display()
	end
end

function quake.new(conf)
	conf = conf or {}

	conf.app = conf.app or 'xterm' -- application to spawn
	conf.name = conf.name or 'QuakeDD' -- window name
	conf.argname = conf.argname or '-name %s' -- how to specify window name
	conf.extra = conf.extra or '' -- extra arguments
	conf.border = conf.border or 1 -- client border width
	conf.visible = conf.visible or false -- initially not visible
	conf.followtag = conf.followtag or false -- spawn on currently focused screen
	conf.overlap = conf.overlap or false -- overlap wibox
	conf.screen = conf.screen or awful.screen.focused()
	conf.settings = conf.settings

	-- If width or height <= 1 this is a proportion of the workspace
	conf.height = conf.height or 0.25 -- height
	conf.width = conf.width or 1 -- width
	conf.vert = conf.vert or 'top' -- top, bottom or center
	conf.horiz = conf.horiz or 'left' -- left, right or center
	conf.geometry = {} -- internal use

	conf.maximized = false
	conf.fullscreen = false

	local dropdown = setmetatable(conf, { __index = quake })

	capi.client.connect_signal('manage', function(c)
		if c.instance == dropdown.name and c.screen == dropdown.screen then
			dropdown:display()
		end
	end)
	capi.client.connect_signal('unmanage', function(c)
		if c.instance == dropdown.name and c.screen == dropdown.screen then
			dropdown.visible = false
		end
	end)

	return dropdown
end

return setmetatable(quake, {
	__call = function(_, ...)
		return quake.new(...)
	end,
})