local m = mtimer
local S = m.translator


local get_date_names = function (dates)
    -- %w -> weekday [0-6 = Sunday-Saturday]
    local weekdays = {
        S('Sunday'), S('Monday'), S('Tuesday'), S('Wednesday'), S('Thursday'),
        S('Friday'), S('Saturday')
    }
    -- %m -> month [01-12 = January-December]
    local months = {
        S('January'), S('February'), S('March'), S('April'), S('May'),
        S('June'), S('July'), S('August'), S('September'), S('Oktober'),
        S('November'), S('December')
    }
    return {
        day = weekdays[tonumber(dates.day)],
        month = months[tonumber(dates.month)]
    }
end


local get_real_time_universal = function (player_name, time_type)
    local player = minetest.get_player_by_name(player_name)
    local player_meta = player:get_meta()
    local m_meta = m.meta
    local timezone_offset = player_meta:get_string(m_meta.timezone_offset.key)
    local server_timestamp = ''
    local local_timestamp = ''
    local format = ''

    if time_type == 'real' then
        server_timestamp = os.time()
        local_timestamp = server_timestamp + ((timezone_offset*60)*60)
        format = player_meta:get_string(m_meta.real_time.key)
    elseif time_type == 'session' then
        server_timestamp = player_meta:get('mtimer:session_start')
        local_timestamp = server_timestamp + ((timezone_offset*60)*60)
        format = player_meta:get_string(m_meta.session_start_time.key)
    end

    local date_names = get_date_names({
        day = os.date('!%w', local_timestamp),
        month = os.date('!%m', local_timestamp)
    })

    local values = {
        times = {
            server_time = os.date('%Y-%m-%dT%T', server_timestamp),
            local_time = os.date('!%Y-%m-%dT%T', local_timestamp),
            offset = timezone_offset,
        },
        variables = {
            hours_24 = os.date('!%H', local_timestamp),
            hours_12 = os.date('!%I', local_timestamp),
            minutes = os.date('!%M', local_timestamp),
            seconds = os.date('!%S', local_timestamp),
            dayname = date_names.day,
            monthname = date_names.month,
            year = os.date('!%Y', local_timestamp),
            month = os.date('!%m', local_timestamp),
            day = os.date('!%d', local_timestamp),
            iso8601_date = os.date('!%Y-%m-%d', local_timestamp),
            iso8601_time = os.date('!%H:%M:%S', local_timestamp),
            timestamp = local_timestamp
        },
        format = format
    }

    values['formatted'] = format:gsub('{[a-z0-9]+}', {
        ['{24h}'] = values.variables.hours_24,
        ['{12h}'] = values.variables.hours_12,
        ['{min}'] = values.variables.minutes,
        ['{sec}'] = values.variables.seconds,
        ['{dname}'] = values.variables.dayname,
        ['{mname}'] = values.variables.monthname,
        ['{year}'] = values.variables.year,
        ['{month}'] = values.variables.month,
        ['{day}'] = values.variables.day,
        ['{isodate}'] = values.variables.iso8601_date,
        ['{isotime}'] = values.variables.iso8601_time,
        ['{timestamp}'] = values.variables.timestamp
    })

    return values
end


local get_ingame_time = function (player_name)
    local player = minetest.get_player_by_name(player_name)
    local format = player:get_meta():get_string(m.meta.ingame_time.key)
    local time_of_day = tostring((minetest.get_timeofday() * 24000) * 3.6)
    local ingame_timestamp = tonumber(string.format('%.0f', time_of_day))

    local values = {
        hours_24 = os.date('!%H', ingame_timestamp),
        hours_12 = os.date('!%I', ingame_timestamp),
        minutes = os.date('!%M', ingame_timestamp),
        ingame_timestamp = ingame_timestamp,
        format = format
    }

    values['formatted'] = format:gsub('{[a-z0-9]+}', {
        ['{24h}'] = values.hours_24,
        ['{12h}'] = values.hours_12,
        ['{min}'] = values.minutes,
        ['{its}'] = values.ingame_timestamp
    })

    return values
end


local get_session_duration = function (player_name)
    local player = minetest.get_player_by_name(player_name)
    local player_meta = player:get_meta()
    local format = player_meta:get_string(m.meta.session_duration.key)
    local start_timestamp = player_meta:get_string('mtimer:session_start')
    local current_timestamp = os.time()
    local difference = current_timestamp - start_timestamp

    local values = {
        format = format,
        difference = difference,
        days = string.format('%02d', math.floor(difference/86400)),
        hours = string.format('%02d', math.floor((difference % 86400)/3600)),
        minutes = string.format('%02d', math.floor((difference % 3600)/60)),
        seconds = string.format('%02d', math.floor((difference % 60)))
    }

    values['formatted'] = format:gsub('{[a-z0-9]+}', {
        ['{days}'] = values.days,
        ['{hours}'] = values.hours,
        ['{minutes}'] = values.minutes,
        ['{seconds}'] = values.seconds
    })

    return values
end


mtimer.get_times = function (player_name)
    return {
        session_start_time = get_real_time_universal(player_name, 'session'),
        session_duration = get_session_duration(player_name),
        real_time = get_real_time_universal(player_name, 'real'),
        ingame_time = get_ingame_time(player_name)
    }
end