-------------------------------------------------
-- CPU Widget for Awesome Window Manager
-- Shows the current CPU utilization
-- More details could be found here:
-- https://github.com/streetturtle/awesome-wm-widgets/tree/master/cpu-widget

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

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

local widget = {}

local function worker(args)

    local args = args or {}

    local width = args.width or 50
    local step_width = args.step_width or 2
    local step_spacing = args.step_spacing or 1
    local color= args.color or beautiful.fg_normal

    local cpugraph_widget = wibox.widget {
        max_value = 100,
        background_color = "#00000000",
        forced_width = width,
        step_width = step_width,
        step_spacing = step_spacing,
        widget = wibox.widget.graph,
        color = "linear:0,0:0,20:0,#FF0000:0.3,#FFFF00:0.6," .. color
    }

    --- By default graph widget goes from left to right, so we mirror it and push up a bit
    local cpu_widget = wibox.container.margin(wibox.container.mirror(cpugraph_widget, { horizontal = true }), 0, 0, 0, 2)

    local total_prev = 0
    local idle_prev = 0

    watch([[bash -c "cat /proc/stat | grep '^cpu '"]], 1,
            function(widget, stdout)
                local user, nice, system, idle, iowait, irq, softirq, steal, guest, guest_nice =
                        stdout:match('(%d+)%s(%d+)%s(%d+)%s(%d+)%s(%d+)%s(%d+)%s(%d+)%s(%d+)%s(%d+)%s(%d+)%s')

                local total = user + nice + system + idle + iowait + irq + softirq + steal

                local diff_idle = idle - idle_prev
                local diff_total = total - total_prev
                local diff_usage = (1000 * (diff_total - diff_idle) / diff_total + 5) / 10

                widget:add_value(diff_usage)

                total_prev = total
                idle_prev = idle
            end,
            cpugraph_widget
    )

    return cpu_widget

end

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