from stdint import *
import t, c
import asm


RTC_CMOS_ADDR: t.CUInt16T = 0x70
RTC_CMOS_DATA: t.CUInt16T = 0x71

RTC_REG_SECONDS: t.CDefine = 0x00
RTC_REG_MINUTES: t.CDefine = 0x02
RTC_REG_HOURS: t.CDefine = 0x04
RTC_REG_DAY: t.CDefine = 0x07
RTC_REG_MONTH: t.CDefine = 0x08
RTC_REG_YEAR: t.CDefine = 0x09
RTC_REG_STATUS_A: t.CDefine = 0x0A
RTC_REG_STATUS_B: t.CDefine = 0x0B

RTC_TZ_OFFSET: t.CDefine = 8

rtc_seconds: t.CStatic | t.CVolatile | t.CUInt8T = 0
rtc_minutes: t.CStatic | t.CVolatile | t.CUInt8T = 0
rtc_hours: t.CStatic | t.CVolatile | t.CUInt8T = 0
rtc_day: t.CStatic | t.CVolatile | t.CUInt8T = 0
rtc_month: t.CStatic | t.CVolatile | t.CUInt8T = 0
rtc_year: t.CStatic | t.CVolatile | t.CUInt16T = 0

def cmos_read(reg: t.CUInt8T) -> t.CUInt8T:
    asm.outb(RTC_CMOS_ADDR, reg)
    return asm.inb(RTC_CMOS_DATA)

def bcd_to_bin(bcd: t.CUInt8T) -> t.CUInt8T:
    return (bcd >> 4) * 10 + (bcd & 0x0F)

def rtc_read_time():
    while cmos_read(RTC_REG_STATUS_A) & 0x80: pass
    sec: t.CUInt8T = cmos_read(RTC_REG_SECONDS)
    min_: t.CUInt8T = cmos_read(RTC_REG_MINUTES)
    hour: t.CUInt8T = cmos_read(RTC_REG_HOURS)
    day: t.CUInt8T = cmos_read(RTC_REG_DAY)
    mon: t.CUInt8T = cmos_read(RTC_REG_MONTH)
    year: t.CUInt8T = cmos_read(RTC_REG_YEAR)
    reg_b: t.CUInt8T = cmos_read(RTC_REG_STATUS_B)
    if not (reg_b & 0x04):
        sec = bcd_to_bin(sec)
        min_ = bcd_to_bin(min_)
        hour = bcd_to_bin(hour)
        day = bcd_to_bin(day)
        mon = bcd_to_bin(mon)
        year = bcd_to_bin(year)
    if not (reg_b & 0x02) and (hour & 0x80):
        hour = ((hour & 0x7F) + 12) % 24
    hour = hour + RTC_TZ_OFFSET
    if hour >= 24:
        hour = hour - 24
        day = day + 1
        max_day: t.CUInt8T = 31
        if mon == 4 or mon == 6 or mon == 9 or mon == 11:
            max_day = 30
        elif mon == 2:
            max_day = 28
            y4: t.CUInt16T = t.CUInt16T(year) + 2000
            if (y4 % 4 == 0 and y4 % 100 != 0) or (y4 % 400 == 0):
                max_day = 29
        if day > max_day:
            day = 1
            mon = mon + 1
            if mon > 12:
                mon = 1
                year = year + 1
    global rtc_seconds, rtc_minutes, rtc_hours, rtc_day, rtc_month, rtc_year
    rtc_seconds = sec
    rtc_minutes = min_
    rtc_hours = hour
    rtc_day = day
    rtc_month = mon
    rtc_year = t.CUInt16T(year) + 2000

def rtc_init():
    rtc_read_time()

def rtc_get_hours() -> t.CUInt8T:
    return rtc_hours

def rtc_get_minutes() -> t.CUInt8T:
    return rtc_minutes

def rtc_get_seconds() -> t.CUInt8T:
    return rtc_seconds

def rtc_get_day() -> t.CUInt8T:
    return rtc_day

def rtc_get_month() -> t.CUInt8T:
    return rtc_month

def rtc_get_year() -> t.CUInt16T:
    return rtc_year