-------------------------------------------------
-- Battery Arc Widget for Awesome Window Manager
-- Shows the battery level of the laptop
-- More details could be found here:
-- https://github.com/streetturtle/awesome-wm-widgets/tree/master/batteryarc-widget

-- @author Pavel Makhov
-- @copyright 2019 Pavel Makhov
-------------------------------------------------

local awful = require("awful")
local beautiful = require("beautiful")
local naughty = require("naughty")
local wibox = require("wibox")
local watch = require("awful.widget.watch")

local HOME = os.getenv("HOME")

local widget = {}

local function worker(args)

    local args = args or {}

    local font = args.font or 'Play 6'
    local arc_thickness = args.thickness or 2

    local text_color = args.text_color or beautiful.fg_color
    local low_level_color = args.low_level_color or '#e53935'
    local medium_level_color = args.medium_level_color or '#c0ca33'
    local full_level_color = args.full_level_color or beautiful.fg_color

    local warning_msg_title = args.warning_msg_title or 'Huston, we have a problem'
    local warning_msg_text = args.warning_msg_text or 'Battery is dying'
    local warning_msg_position = args.warning_msg_position or 'bottom_right'
    local warning_msg_icon = args.warning_msg_icon or HOME .. '/.config/awesome/awesome-wm-widgets/batteryarc-widget/spaceman.jpg'

    local text = wibox.widget {
        id = "txt",
        font = font,
        align = 'center', -- align the text
        valign = 'center',
        widget = wibox.widget.textbox
    }

    local text_with_background = wibox.container.background(text)

    widget = wibox.widget {
        text_with_background,
        max_value = 1,
        rounded_edge = true,
        thickness = arc_thickness,
        start_angle = 4.71238898, -- 2pi*3/4
        forced_height = 18,
        forced_width = 18,
        bg = "#ffffff11",
        paddings = 2,
        widget = wibox.container.arcchart,
        set_value = function(self, value)
            self.value = value
        end,
    }

    local last_battery_check = os.time()

    watch("acpi -i", 10,
            function(widget, stdout)
                local batteryType

                local battery_info = {}
                local capacities = {}
                for s in stdout:gmatch("[^\r\n]+") do
                    local status, charge_str, time = string.match(s, '.+: (%a+), (%d?%d?%d)%%,?.*')
                    if string.match(s, 'rate information') then
                        -- ignore such line
                    elseif status ~= nil then
                        table.insert(battery_info, { status = status, charge = tonumber(charge_str) })
                    else
                        local cap_str = string.match(s, '.+:.+last full capacity (%d+)')
                        table.insert(capacities, tonumber(cap_str))
                    end
                end

                local capacity = 0
                for i, cap in ipairs(capacities) do
                    capacity = capacity + cap
                end

                local charge = 0
                local status
                for i, batt in ipairs(battery_info) do
                    if batt.charge >= charge then
                        -- use most charged battery status. This is arbitrary, and maybe another metric should be used
                        status = batt.status
                    end

                    charge = charge + batt.charge * capacities[i]
                end

                local charge_percentage
                if capacity > 5 then
                    charge = charge / capacity
                    charge_percentage = charge / 100
                else
                    -- when widget.value is < 0.04, the widget shows a full circle (as widget.value=1)
                    charge_percentage = 0.05
                end

                widget.value = charge / 100

                if status == 'Charging' then
                    text_with_background.bg = full_level_color
                    text_with_background.fg = '#000000'
                else
                    text_with_background.bg = '#00000000'
                    text_with_background.fg = text_color
                end

                --- if battery is fully charged (100) there is not enough place for three digits, so we don't show any text
                text.text = charge == 100
                        and ''
                        or string.format('%d', charge)

                if charge < 15 then
                    widget.colors = { low_level_color }
                    if status ~= 'Charging' and os.difftime(os.time(), last_battery_check) > 300 then
                        -- if 5 minutes have elapsed since the last warning
                        last_battery_check = os.time()

                        show_battery_warning()
                    end
                elseif charge > 15 and charge < 40 then
                    widget.colors = { medium_level_color }
                else
                    widget.colors = { full_level_color }
                end
            end,
            widget)

    -- Popup with battery info
    -- One way of creating a pop-up notification - naughty.notify
    local notification
    function show_battery_status()
        awful.spawn.easy_async([[bash -c 'acpi']],
                function(stdout, _, _, _)
                    naughty.destroy(notification)
                    notification = naughty.notify {
                        text = stdout,
                        title = "Battery status",
                        timeout = 5,
                        hover_timeout = 0.5,
                        width = 200,
                    }
                end)
    end

    widget:connect_signal("mouse::enter", function()
        show_battery_status()
    end)
    widget:connect_signal("mouse::leave", function()
        naughty.destroy(notification)
    end)

    -- Alternative to naughty.notify - tooltip. You can compare both and choose the preferred one

    --battery_popup = awful.tooltip({objects = {battery_widget}})

    -- To use colors from beautiful theme put
    -- following lines in rc.lua before require("battery"):
    -- beautiful.tooltip_fg = beautiful.fg_normal
    -- beautiful.tooltip_bg = beautiful.bg_normal

    --[[ Show warning notification ]]
    function show_battery_warning()
        naughty.notify {
            icon = warning_msg_icon,
            icon_size = 100,
            text = warning_msg_text,
            title = warning_msg_title,
            timeout = 25, -- show the warning for a longer time
            hover_timeout = 0.5,
            position = warning_msg_position,
            bg = "#F06060",
            fg = "#EEE9EF",
            width = 300,
        }
    end

    return widget

end

return setmetatable(widget, { __call = function(_, ...)
    return worker(...)
end })