-- incomplete, will add as needed

java()
local Luan = require "luan:Luan.luan"
local error = Luan.error
local ipairs = Luan.ipairs or error()
local Math = require "luan:Math.luan"
local floor = Math.floor or error()
local Number = require "luan:Number.luan"
local long = Number.long or error()
local Table = require "luan:Table.luan"
local System = require "java:java.lang.System"
local Calendar = require "java:java.util.Calendar"
local Date = require "java:java.util.Date"
local TimeZone = require "java:java.util.TimeZone"
local SimpleDateFormat = require "java:java.text.SimpleDateFormat"

local Time = {}

function Time.now()
	return System.currentTimeMillis()
end

-- add more as needed
local fields = {
	year = Calendar.YEAR;
	month = Calendar.MONTH;
	day_of_month = Calendar.DAY_OF_MONTH;
}

function Time.get( time, ... )
	local cal = Calendar.getInstance()
	cal.setTimeInMillis(time)
	local rtn = {}
	for i, v in ipairs{...} do
		local fld = fields[v]
		fld or error("invalid field: "..v)
		local n = cal.get(fld)
		if v == "month" then
			n = n + 1
		end
		rtn[i] = n
	end
	return Table.unpack(rtn)
end

-- Time.time_zone      set for other than default

function Time.get_time_zone()
	local tz = Time.time_zone and TimeZone.getTimeZone(Time.time_zone) or TimeZone.getDefault()
	return tz.getID().." - "..tz.getDisplayName()
end

local function set_time_zone(fmt)
	Time.time_zone and fmt.setTimeZone( TimeZone.getTimeZone(Time.time_zone) )
end

function Time.format(time,pattern)
	time = long(time)
	pattern = pattern or "yyyy-MM-dd HH:mm:ss"
	local fmt = SimpleDateFormat.new(pattern)
	set_time_zone(fmt)
	return fmt.format(Date.new(time))
end

function Time.on( year, month, day, hour, minute, second, millis )
	month = month - 1
	local cal = Calendar.getInstance()
--	cal.setLenient(false)
	cal.set( year, month, day, hour or 0, minute or 0, second or 0 )
	cal.set( Calendar.MILLISECOND, millis or 0 )
	return cal.getTimeInMillis()
end

function Time.period( t )
	local cal = Calendar.getInstance()
	cal.setTimeZone(TimeZone.getTimeZone("GMT"))
	local days = t.days or 0
	days = days + 1
	cal.set( 1970, 0, days, t.hours or 0, t.minutes or 0, t.seconds or 0 )
	cal.set( Calendar.MILLISECOND, t.millis or 0 )
	return cal.getTimeInMillis()
end

function Time.parse( pattern, source )
	local fmt = SimpleDateFormat.new(pattern)
	set_time_zone(fmt)
	return fmt.parse(source).getTime()
end


local count_times = {
	days = Time.period{days=1}
	hours = Time.period{hours=1}
	minutes = Time.period{minutes=1}
	seconds = Time.period{seconds=1}
}

function Time.count( time, ... )
	local cal = Calendar.getInstance()
	cal.setTimeInMillis(time)
	local rtn = {}
	for i, v in ipairs{...} do
		local t = count_times[v]
		t or error("invalid field: "..v)
		rtn[#rtn+1] = floor(time/t)
		time = time%t
	end
	rtn[#rtn+1] = time
	return Table.unpack(rtn)
end


return Time