-- Update an  idividual player’s timer display
--
-- When running the function the player data will be read from the player’s
-- `player` object and the output will be generated
--
-- @param player the player object to update
mtimer_update = function (player)
    -- Formatting options
    local runtime = player:get_attribute('mtimer:runtime')
    local offset = mtimer_position(player:get_attribute('mtimer:offset'))
    local ingame_time = player:get_attribute('mtimer:ingame_time')
    local current_time = player:get_attribute('mtimer:current_time')
    local font_color = player:get_attribute('mtimer:font_color')
    local start = player:get_attribute('mtimer:start')
    local show = player:get_attribute('mtimer:show')
    local locale = player:get_attribute('mtimer:locale')
    local position = mtimer_position(player:get_attribute('mtimer:position'))
    local format = player:get_attribute('mtimer:format')
    local alignment = mtimer_position(player:get_attribute('mtimer:alignment'))

    -- Settings
    local joined_timestamp = player:get_attribute('mtimer:joined_timestamp')
    local hud_id = tonumber(player:get_attribute('mtimer:hud_id'))

    -- Calculate ingame time
    local ingame_timestamp = 24*60*minetest.get_timeofday()
    local ingame_h = tostring((math.floor(ingame_timestamp/60) % 60))
    local ingame_m = tostring((math.floor(ingame_timestamp) % 60))

    -- Replace variables in output format if wanted by the user
    local rendered_output_format = ''
    if show == 'true' then
        rendered_output_format = format:gsub('+.', {
            ['+s'] = os.date(start, joined_timestamp),
            ['+c'] = os.date(current_time),
            ['+r'] = os.date('!'..runtime:gsub('(+.)', {
                ['+h'] = '%H',
                ['+m'] = '%M',
                ['+s'] = '%S'
            }), os.time() - joined_timestamp),
            ['+i'] = ingame_time:gsub('(+.)', {
                ['+h'] = string.rep('0', 2-#ingame_h)..ingame_h,
                ['+m'] = string.rep('0', 2-#ingame_m)..ingame_m
            }),
            ['+n'] = "\n"
        })
    end

    -- Render the output format as HUD element
    player:hud_change(hud_id, 'text', rendered_output_format)
    player:hud_change(hud_id, 'number', '0x'..font_color)
    player:hud_change(hud_id, 'position', position)
    player:hud_change(hud_id, 'alignment', alignment)
    player:hud_change(hud_id, 'offset', offset)
end



-- Self-calling iteration function
--
-- The function iterates of all currentlz logged on players, checks if they
-- have the custom attribute `mtimer:hud_id` set (this is the last value that
-- will be set when a player joins so the player is set up completely if
-- `mtimer:hud_id` is present in the custom player attributes) and then runs
-- the function to update the timer display. After that the function calls
-- itself again, using the set interval.
--
-- @param interval The intervall used to self-calling again after execution
mtimer_iterate = function(interval)
    for _,player in pairs(minetest.get_connected_players()) do
        if player:get_attribute('mtimer:hud_id') ~= nil then
            mtimer_update(player)
        end
    end
    minetest.after(interval, mtimer_iterate, interval)
end