local M = {}

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

-- mapping from logical screen indices to indices corresponding to their
-- physical layout
function M.screen_physical(n)
    local function screen_cmp(s1, s2)
        return s1.geometry.x < s2.geometry.x
    end

    local screens = {}
    for s in screen do
        screens[s.index] = s
    end

    table.sort(screens, screen_cmp)

    if screens[n] ~= nil then
        return screens[n]
    end
    return nil
end

function M.screen_focus_physical(n)
    local s = M.screen_physical(n)
    if s then
        awful.screen.focus(s)
    end
end

-- audio control functions
function M.vol_control(n)
    local cmd = string.format("amixer -q set Master %d%%", math.abs(n)) .. (n < 0 and "-" or "+")
    awful.spawn(cmd)
end

function M.vol_mute_toggle()
    awful.spawn("amixer -q set Master toggle")
end

function M.spawn_current(command)
    awful.spawn(command, {tag = mouse.screen.selected_tag})
end

function M.screen_lock()
    awful.spawn.easy_async("xscreensaver-command -lock",
        function(stdout, stderr, exitreason, exitcode)
            if exitcode ~= 0 then
                naughty.notify({ preset = naughty.config.presets.critical,
                                 title = "Error locking the screen",
                                 text  = table.concat({stdout, stderr}, "\n") })

            end
        end)

end

return M