-- Convert a given x,y string into a table {x=given_x, y=given_y} and return
-- it to be used of the screen location parameters in the HUD definition
local mtimer_location_value = function (o)
    local given_x = o:gsub(',[^,]+$', '')
    local given_y = o:gsub('^[^,]+,', '')
    return {x=given_x, y=given_y}
end

local modpath = minetest.get_modpath(minetest.get_current_modname())..DIR_DELIM
local options = dofile(modpath..'system'..DIR_DELIM..'get_options.lua')

local interval = options['mtimer_update_interval']
local placeholder = options['mtimer_placeholder']
local font_color = options['mtimer_font_color']

local format = {
    locale = options['mtimer_locale'],
    start = options['mtimer_session_start'],
    runtime = options['mtimer_session_runtime'],
    current = options['mtimer_current_time'],
    ingame = options['mtimer_ingame_time'],
    output = options['mtimer_output_format']
}

local location = {
    position = mtimer_location_value(options['mtimer_position']),
    alignment = mtimer_location_value(options['mtimer_alignment']),
    offset = mtimer_location_value(options['mtimer_offset'])
}

local player_data = {}


minetest.register_on_joinplayer(function(player)
    minetest.after(1, function(player)
        local player_name = player:get_player_name()
        local _hud_id = player:hud_add({
            hud_elem_type = 'text',
            position = location.position,
            alignment = location.alignment,
            offset = location.offset,
            text = placeholder,
            number = '0x'..font_color
        })
        player_data[player_name] = {
            start_time = os.time(),
            hud_id = _hud_id
        }
        minetest.after(5, change_text, player)
    end, player)
end)


minetest.register_on_leaveplayer(function(player)
    local player_name = player:get_player_name()
    player_data[player_name] = nil
end)


function change_text(player)
    local player_name = player:get_player_name()
    if player_name == '' then return end

    -- Save the game-detected locale. Fun fact: changing the locale on runtime
    -- from within a mod causes the UI to glitch out completely.
    local current_locale = os.setlocale(nil)
    os.setlocale(format.locale)

    local start_time = player_data[player_name].start_time
    local hud_id = player_data[player_name].hud_id

    local time = 24*60*minetest.get_timeofday()
    local h = tostring((math.floor(time/60) % 60))
    local m = tostring((math.floor(time) % 60))

    local res = format.output:gsub('(+.)', {
        ['+s'] = os.date(format.start, start_time),
        ['+c'] = os.date(format.current),
        ['+r'] = os.date('!'..format.runtime:gsub('(+.)', {
            ['+h'] = '%H',
            ['+m'] = '%M',
            ['+s'] = '%S'
        }), os.time() - start_time),
        ['+i'] = format.ingame:gsub('(+.)', {
            ['+h'] = string.rep('0', 2-#h)..h,
            ['+m'] = string.rep('0', 2-#m)..m
        }),
        ['+n'] = "\n"
    })

    os.setlocale(current_locale) -- Restore game-detected locale

    player:hud_change(hud_id, 'text', res)
    minetest.after(interval, change_text, player)
end