-- 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 x = o:gsub(',[^,]+$', '')
    local y = o:gsub('^[^,]+,', '')
    return {x=x, y=y}
end


local _mtimer_get_options = function ()
    local path = minetest.get_modpath(minetest.get_current_modname())
    local file = io.open(path..DIR_DELIM..'settingtypes.txt', 'rb')
    local result = {}

    for line in file:lines() do
        if line:match("^([a-zA-Z])") then
            local name = line:gsub(' .+', '')
            local default_value = line:gsub('^[^ ]+ %b() %a+ ', '')
            local set_value = minetest.setting_get(name)
            result[name] = set_value or default_value
        end
    end

    return result
end

local _options = _mtimer_get_options()

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 playerData = {}


minetest.register_on_joinplayer(function(player)
    minetest.after(1, function(player)
        local playerName = player:get_player_name()
        local _hudID = player:hud_add({
            hud_elem_type = 'text',
            position = location.position,
            alignment = location.alignment,
            offset = location.offset,
            text = placeholder,
            number = '0x'..font_color
        })
        playerData[playerName] = {
            startTime = os.time(),
            hudID = _hudID
        }
        minetest.after(5, _mtimer_changeText, player)
    end, player)
end)


minetest.register_on_leaveplayer(function(player)
    local playerName = player:get_player_name()
    playerData[playerName] = nil
end)


function _mtimer_changeText(player)
    local playerName = player:get_player_name()
    if playerName == '' 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 currentLocale = os.setlocale(nil)
    os.setlocale(format.locale)

    local startTime = playerData[playerName].startTime
    local hudID = playerData[playerName].hudID

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

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

    player:hud_change(hudID, 'text', res)
    minetest.after(interval, _mtimer_changeText, player)
end