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

local ret = {}
ret.widget = wibox.widget.textbox()
ret.widget:set_align("right")
ret.widget.font = "Ubuntu Mono"

local total_text = ""
local position = 1
local width = 30
local dots = 3

local last_notification = nil

local function string_starts_with(String,Start)
   return string.sub(String,1,string.len(Start))==Start
end

local function string_split(str, delimiter)
    if str == nil then
        return {}
    end
    local ret = {''}
    count = 1
    for i = 1, string.len(str) do
        local c = str:sub(i,i)
        if c == delimiter then
            count = count + 1
            ret[count] = ''
        else
            ret[count] = ret[count] .. c
        end
    end
    return ret
end

local function pad(str, len, char)
    if char == nil then char = ' ' end
    return str .. string.rep(char, len - #str)
end

local function set_text(text)

    total_text = text[1]

    if last_notification ~= nil then
        naughty.destroy(last_notification)
    end

    if text[2] == nil then
        return
    end

    elts = string_split(text[1], '-')
    artist = string.sub(elts[1], 1, -1)
    album = string.sub(elts[2], 2, -1)
    song = string.sub(elts[3], 2)
    notification_text = '\n' .. album .. '\n' .. song .. '\n'

    if string.len(total_text) >= width then
        position = math.floor((width - string.len(total_text)) / 2)
    end

    update_widget()
end

ret.execute_command = function(command)
    local fd = io.popen('music-client ' .. command)
    local text = string_split(fd:read('*all'), '\n')
    local rc = {fd:close()}
    if rc[3] == 0 then
        if string_starts_with(command, 'file') or string_starts_with(command, 'next') or string_starts_with(command, 'previous') then
            set_text(text)
        elseif string_starts_with(command, 'noop') then
            total_text = text[1]
            position = math.floor((width - string.len(total_text)) / 2)
        end
    else
        set_text({'music-server not running'})
    end
end

function update_widget()
    if string.len(total_text) < width then
        ret.widget:set_text(pad(total_text, width, ' '))
    else
        local pos = math.min(position, string.len(total_text) - width)
        pos = math.max(1, pos)
        ret.widget:set_text(string.sub(total_text, pos, pos + width))
        position = position + 1
        if position > string.len(total_text) then
            position = math.floor((width - string.len(total_text)) / 2)
        end
    end
end

ret.execute_command('noop')

ret.widget.timer = timer({timeout=0.2})
ret.widget.timer:connect_signal("timeout", update_widget)
ret.widget.timer:start()

ret.widget = ret.widget

return ret