--[[

     Licensed under GNU General Public License v2
      * (c) 2014-, Samir Benmendil
      * (c) -2013, Luke Bonham (lain)

--]]

local awful        = require("awful")
local beautiful    = require("beautiful")
local naughty      = require("naughty")
local wibox        = require("wibox")

local io           = { popen = io.popen }
local os           = { date = os.date }
local tonumber     = tonumber

local calendar = {}
calendar.cal       = "/usr/bin/cal --color=always"
calendar.font      = "monospace 10"
calendar.fg        = beautiful.fg_normal or "#FFFFFF"
calendar.bg        = beautiful.bg_normal or "#FFFFFF"
calendar.position  = "top_right"
calendar.offset = 0

local calwidget = wibox.widget.textclock(" %a %b %d, %H:%M ", 10)

calwidget:connect_signal("mouse::enter", function () calendar:show(0) end)
calwidget:connect_signal("mouse::leave", function () calendar:hide() end)
calwidget:buttons(awful.util.table.join(
    awful.button({ }, 1, function () calendar:show(-1) end),
    awful.button({ }, 3, function () calendar:show( 1) end),
    awful.button({ }, 4, function () calendar:show(-1) end),
    awful.button({ }, 5, function () calendar:show( 1) end)))

-- Calendar notification
local cal_notification = nil

function calendar:hide()
    if cal_notification ~= nil then
        naughty.destroy(cal_notification)
        cal_notification = nil
    end
end

function calendar:show(inc_offset)
    calendar:hide()

    local offs = inc_offset or 0

    calendar.offset = calendar.offset + offs

    local today = tonumber(os.date('%d'))
    local month = tonumber(os.date('%m'))
    local year  = tonumber(os.date('%Y'))

    if offs ~= 0 or calendar.offset ~= 0
    then -- no current month showing, no day to highlight
        month = month + calendar.offset

        if month > 12 then
            month = month % 12
            year = year + 1
            if month <= 0 then
                month = 12
            end
        elseif month < 1 then
            month = month + 12
            year = year - 1
            if month <= 0 then
                month = 1
            end
        end
    end

    local f = io.popen(calendar.cal .. ' ' .. month .. ' ' .. year)

    local text = string.format("<span font='%s'><b>%s</b>\n%s</span>",
        calendar.font,
        f:read(),
        f:read("*a"):gsub("%s\n","\n"):gsub("%s+$", ""))
    f:close()

    text = text:gsub("%[7m","<b><span "
        .. "foreground='"..calendar.bg .. "' "
        .. "background='"..calendar.fg .. "'>")
    text = text:gsub("%[27m", "</span></b>")

    cal_notification = naughty.notify({
        text = text,
        position = calendar.position,
        fg = calendar.fg,
        bg = calendar.bg,
        screen = mouse.screen
    })
end

return calwidget