--   This file is part of Reno desktop.
--
--  Reno desktop is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
--
--  Reno desktop is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License along with Reno desktop. If not, see <https://www.gnu.org/licenses/>. 
-- Pure lua module for controlling, reading and enumerating devices through sysfs
-- Because in Linux we trust.
local syscontrol = {
    power_supply = {},
    backlight = {},
    hwmon = {}
}
syscontrol.backlight.enumerate = function()
    local lshandler = io.popen("ls -1 /sys/class/backlight","r")
    if lshandler then
        local out = lshandler:read("*a")
        lshandler:close()
        local devices = {}
        out:gsub("(%S*)\n",function(a)
            table.insert(devices,a)
        end)
        return devices
    else
        return nil, "Unable to ls /sys/class/backlight"
    end
end
syscontrol.backlight.read_attribs = function(dev_name)
    local fhandler,err = io.open("/sys/class/backlight/"..dev_name.."/brightness","r")
    if fhandler then
        local bhandler = io.open("/sys/class/backlight/"..dev_name.."/max_brightness","r")
        local device = {
            name = dev_name,
            full_path = "/sys/class/backlight/"..dev_name,
            brightness = tonumber(fhandler:read("*a")),
            max_brightness = tonumber(bhandler:read("*a")),
            writable = false
        }
        fhandler:close()
        local wfhandler = io.open("/sys/class/backlight/"..dev_name.."/brightness","w")
        if wfhandler then
            wfhandler:close()
            device.writable = true
        end
        return device
    else
        return nil, err
    end
end
syscontrol.backlight.set_brightness = function(device,brightness)
    if device.writable then
        brightness = tonumber(brightness)
        if (brightness < 0) or (brightness > device.max_brightness) then
            return nil, "Brightness exceeds given limits"
        end
        local fhandler,err = io.open(device.full_path.."/brightness","w")
        if fhandler then
            fhandler:write(tostring(brightness))
            fhandler:close()
            return true
        else
            return nil, err
        end
    else
        return nil, "Device is not writable"
    end
end
syscontrol.power_supply.enumerate = function()
    local lshandler = io.popen("ls -1 /sys/class/power_supply","r")
    if lshandler then
        local out = lshandler:read("*a")
        lshandler:close()
        local devices = {}
        out:gsub("(%S*)\n",function(a)
            table.insert(devices,a)
        end)
        return devices
    else
        return nil, "Unable to ls /sys/class/power_supply"
    end
end
syscontrol.power_supply.read_attribs = function(dev_name)
    local fhandler,err = io.open("/sys/class/power_supply/"..dev_name.."/type","r")
    if fhandler then
        local dtype = fhandler:read("*a"):match("%S*")
        fhandler:close()
        local full_path = "/sys/class/power_supply/"..dev_name
        local device = {
            type = dtype,
            full_path = full_path,
            name = dev_name
        }
        if dtype == "Mains" then
            local online_f = io.open(full_path.."/online","r")
            device.online = (online_f:read("*a"):match("%S*") == "1")
            online_f:close()
        elseif dtype == "Battery" then
            local capacity_f = io.open(full_path.."/capacity","r")
            local model_f = io.open(full_path.."/model_name","r")
            local energy_full_design_f = io.open(full_path.."/energy_full_design","r")
            local energy_full_f = io.open(full_path.."/energy_full","r")
            local charging_f = io.open(full_path.."/status","r")
            device.model = model_f:read("*a"):match("[^\n]*")
            device.energy_full_design = tonumber(energy_full_design_f:read("*a"))
            device.energy_full = tonumber(energy_full_f:read("*a"))
            device.quality = (device.energy_full/device.energy_full_design)*100
            device.capacity = tonumber(capacity_f:read("*a"))
            device.charging = (charging_f:read("*a"):match("%S*") == "Charging")
            capacity_f:close()
            model_f:close()
            energy_full_design_f:close()
            energy_full_f:close()
        end 
        return device
    else
        return nil, err
    end
end
return syscontrol