local wibox = require("wibox")
local awful = require("awful")
local beautiful = require "beautiful"
local gears = require("gears")
local helpers = require "helpers"
local dpi = beautiful.xresources.apply_dpi

local datewidget = function(date, weekend, notIn)
  weekend = weekend or false
  if notIn then
    return wibox.widget {
      markup = helpers.colorizeText(date, beautiful.fg3),
      halign = 'center',
      font   = beautiful.sans .. " 14",
      widget = wibox.widget.textbox
    }
  else
    return wibox.widget {
      markup = weekend and helpers.colorizeText(date, beautiful.fg) or date,
      halign = 'center',
      font   = beautiful.sans .. " 14",
      widget = wibox.widget.textbox
    }
  end
end

local daywidget = function(day, weekend, notIn)
  weekend = weekend or false
  return wibox.widget {
    markup = weekend and helpers.colorizeText(day, beautiful.red) or day,
    halign = 'center',
    font   = beautiful.sans .. " 14",
    widget = wibox.widget.textbox
  }
end
local currwidget = function(day)
  return wibox.widget {
    markup = helpers.colorizeText(day, beautiful.blue),
    halign = 'center',
    font   = beautiful.sans .. " 14",
    widget = wibox.widget.textbox
  }
end

local title = wibox.widget {
  font = beautiful.sans .. " Bold 14",
  widget = wibox.widget.textbox,
  halign = 'center'
}

local theGrid = wibox.widget {
  forced_num_rows = 7,
  forced_num_cols = 7,
  vertical_spacing = dpi(10),
  horizontal_spacing = dpi(10),
  min_cols_size = dpi(30),
  min_rows_size = dpi(30),
  homogenous = true,
  layout = wibox.layout.grid,
}

local curr

local updateCalendar = function(date)
  title.text = os.date("%B %Y", os.time(date))
  theGrid:reset()
  for _, w in ipairs { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" } do
    if w == "Sun" or w == "Sat" then
      theGrid:add(daywidget(w, true, false))
    else
      theGrid:add(daywidget(w, false, false))
    end
  end
  local firstDate = os.date("*t", os.time({ day = 1, month = date.month, year = date.year }))
  local lastDate = os.date("*t", os.time({ day = 0, month = date.month + 1, year = date.year }))
  local days_to_add_at_month_start = firstDate.wday - 1
  local days_to_add_at_month_end = 42 - lastDate.day - days_to_add_at_month_start

  local previous_month_last_day = os.date("*t", os.time({ year = date.year, month = date.month, day = 0 })).day
  local row = 2
  local col = firstDate.wday

  for day = previous_month_last_day - days_to_add_at_month_start, previous_month_last_day - 1, 1 do
    theGrid:add(datewidget(day, false, true))
  end

  for day = 1, lastDate.day do
    if day == date.day then
      theGrid:add_widget_at(currwidget(day), row, col)
    elseif col == 1 or col == 7 then
      theGrid:add_widget_at(datewidget(day, true, false), row, col)
    else
      theGrid:add_widget_at(datewidget(day, false, false), row, col)
    end

    if col == 7 then
      col = 1
      row = row + 1
    else
      col = col + 1
    end
  end

  for day = 1, days_to_add_at_month_end do
    theGrid:add(datewidget(day, false, true))
  end
end

return function()
  curr = os.date("*t")
  updateCalendar(curr)
  gears.timer {
    timeout   = 60,
    call_now  = true,
    autostart = true,
    callback  = function()
      curr = os.date("*t")
      updateCalendar(curr)
    end
  }
  return wibox.widget {
    {
      {
        {
          {
            {
              text = "󰁍",
              font = beautiful.icofont,
              widget = wibox.widget.textbox,
              buttons = awful.button({}, 1, function()
                curr = os.date("*t", os.time({
                  day = curr.day,
                  month = curr.month - 1,
                  year = curr.year
                }))
                updateCalendar(curr)
              end)
            },
            widget = wibox.container.margin,
            left = 38,
          },
          title,
          {
            {
              text = "󰁔",
              font = beautiful.icofont,
              widget = wibox.widget.textbox,
              buttons = awful.button({}, 1, function()
                curr = os.date("*t", os.time({
                  day = curr.day,
                  month = curr.month + 1,
                  year = curr.year
                }))
                updateCalendar(curr)
              end)
            },
            widget = wibox.container.margin,
            right = 38,
          },
          layout = wibox.layout.align.horizontal
        },
        {
          theGrid,
          widget = wibox.container.place,
          halign = 'center',
        },
        spacing = 17,
        layout = wibox.layout.fixed.vertical
      },
      widget = wibox.container.margin,
      margins = 50
    },
    shape = helpers.rrect(10),
    widget = wibox.container.background,
    bg = beautiful.mbg
  }
end