from django.db import models
from django.db.models import ExpressionWrapper, F, Func, Q
from django.db.models.functions import Mod


class Door(models.Model):
    name = models.CharField(max_length=64, unique=True)

    def __str__(self):
        return self.name


class HIDEventQuerySet(models.QuerySet):
    def with_is_red(self):
        """Based on `function isRedEvent` from /html/hid-global.js on a HID EDGE EVO Solo"""
        return self.annotate(
            is_red=ExpressionWrapper(
                Q(
                    event_type__in=[
                        HIDEvent.EventType.DENIED_ACCESS_CARD_NOT_FOUND,
                        HIDEvent.EventType.DENIED_ACCESS_ACCESS_PIN_NOT_FOUND,
                        HIDEvent.EventType.DENIED_ACCESS_SCHEDULE,
                        HIDEvent.EventType.DENIED_ACCESS_WRONG_PIN,
                        HIDEvent.EventType.DENIED_ACCESS_CARD_EXPIRED,
                        HIDEvent.EventType.DENIED_ACCESS_PIN_LOCKOUT,
                        HIDEvent.EventType.DENIED_ACCESS_UNASSIGNED_CARD,
                        HIDEvent.EventType.DENIED_ACCESS_PIN_EXPIRED,
                        HIDEvent.EventType.DOOR_FORCED_ALARM,
                        HIDEvent.EventType.DOOR_HELD_ALARM,
                        HIDEvent.EventType.TAMPER_SWITCH_ALARM,
                        HIDEvent.EventType.AC_FAILURE,
                        HIDEvent.EventType.BATTERY_FAILURE,
                    ]
                ),
                output_field=models.BooleanField(),
            )
        )

    def with_decoded_card_number(self):
        # TODO: CONV and BIT_COUNT are MySQL/MariaDB specific
        class Conv(Func):
            function = "CONV"
            arity = 3
            # This is technically not true, but fine for my purposes
            output_field = models.IntegerField()

        class BitCount(Func):
            function = "BIT_COUNT"
            arity = 1

        return (
            self.alias(card_number=Conv(F("raw_card_number"), 16, 10))
            .alias(more_than_26_bits=F("card_number").bitrightshift(26))
            .annotate(card_is_26_bit=Q(more_than_26_bits=0))
            .alias(
                parity_a=Mod(
                    BitCount(F("card_number").bitrightshift(1).bitand(0xFFF)), 2
                ),
                parity_b=Mod(
                    BitCount(F("card_number").bitrightshift(13).bitand(0xFFF)), 2
                ),
            )
            .annotate(
                card_is_valid_26_bit=~Q(parity_a=F("card_number").bitand(1))
                & Q(parity_b=F("card_number").bitrightshift(25).bitand(1))
            )
            .annotate(
                card_number_26_bit=F("card_number").bitrightshift(1).bitand(0xFFFF),
                card_facility_code_26_bit=F("card_number")
                .bitrightshift(17)
                .bitand(0xFF),
            )
        )


class HIDEvent(models.Model):
    objects = HIDEventQuerySet.as_manager()

    class EventType(models.IntegerChoices):
        DENIED_ACCESS_CARD_NOT_FOUND = 1022, "Denied Access: Card Not Found"
        DENIED_ACCESS_ACCESS_PIN_NOT_FOUND = 1023, "Denied Access Access: PIN Not Found"
        GRANTED_ACCESS = 2020, "Granted Access"
        GRANTED_ACCESS_EXTENDED_TIME = 2021, "Granted Access: Extended Time"
        DENIED_ACCESS_SCHEDULE = 2024, "Denied Access: Schedule"
        DENIED_ACCESS_WRONG_PIN = 2029, "Denied Access: Wrong PIN"
        DENIED_ACCESS_CARD_EXPIRED = 2036, "Denied Access: Card Expired"
        DENIED_ACCESS_PIN_LOCKOUT = 2042, "Denied Access: PIN Lockout"
        DENIED_ACCESS_UNASSIGNED_CARD = 2043, "Denied Access: Unassigned Card"
        DENIED_ACCESS_UNASSIGNED_ACCESS_PIN = (
            2044,
            "Denied Access: Unassigned Access PIN",
        )
        DENIED_ACCESS_PIN_EXPIRED = 2046, "Denied Access: PIN Expired"
        ALARM_ACKNOWLEDGED = 4034, "Alarm Acknowledged"
        DOOR_LOCKED_SCHEDULED = 4035, "Door Locked: Scheduled"
        DOOR_UNLOCKED_SCHEDULED = 4036, "Door Unlocked: Scheduled"
        DOOR_FORCED_ALARM = 4041, "Door Forced Alarm"
        DOOR_HELD_ALARM = 4042, "Door Held Alarm"
        TAMPER_SWITCH_ALARM = 4043, "Tamper Switch Alarm"
        AC_FAILURE = 4044, "AC Failure"
        BATTERY_FAILURE = 4045, "Battery Failure"
        REX_SWITCH_ALARM = 4051, "REX Switch Alarm"
        TIME_SET_TO = 7020, "Time Set To"
        GRANTED_ACCESS_MANUAL = 12031, "Granted Access: Manual"
        DOOR_UNLOCKED = 12032, "Door Unlocked"
        DOOR_LOCKED = 12033, "Door Locked"

    door = models.ForeignKey(Door, on_delete=models.CASCADE)
    timestamp = models.DateTimeField()
    event_type = models.IntegerField(db_column="eventType", choices=EventType.choices)
    reader_address = models.IntegerField(db_column="readerAddress")
    cardholder_id = models.IntegerField(blank=True, null=True, db_column="cardholderID")
    command_status = models.BooleanField(
        blank=True, null=True, db_column="commandStatus"
    )
    forename = models.TextField(blank=True, null=True)
    surname = models.TextField(blank=True, null=True)
    io_state = models.BooleanField(blank=True, null=True, db_column="ioState")
    new_time = models.DateTimeField(blank=True, null=True, db_column="newTime")
    old_time = models.DateTimeField(blank=True, null=True, db_column="oldTime")
    raw_card_number = models.CharField(
        max_length=8, blank=True, null=True, db_column="rawCardNumber"
    )

    @property
    def description(self):
        """
        Based on `Global.localeStrings` from /html/en_EN/en_EN.js
        and `function eventDataHandler` from /html/modules/hid-dashboard.js
        on a HID EDGE EVO Solo
        """

        name = f"{self.forename} {self.surname}"
        direction = "IN" if self.reader_address == 0 else "OUT"

        event_types = {
            1022: f"Denied Access, {direction} Card Not Found {self.raw_card_number}",
            1023: f"Denied Access, {direction} Access PIN Not Found {self.raw_card_number}",
            2020: f"Granted Access, {direction} {name}",
            2021: f"Granted Access, {direction} Extended Time {name}",
            2024: f"Denied Access, {direction} Schedule {name}",
            2029: f"Denied Access, {direction} Wrong PIN {name}",
            2036: f"Denied Access, {direction} Card Expired {name}",
            2042: f"Denied Access, {direction} PIN Lockout {name}",
            2043: f"Denied Access, {direction} Unassigned Card {self.raw_card_number}",
            2044: f"Denied Access, {direction} Unassigned Access PIN {self.raw_card_number}",
            2046: f"Denied Access - PIN Expired {name}",
            4034: "Alarm Acknowledged",
            4035: "Door Locked-Scheduled",
            4036: "Door Unlocked-Scheduled",
            4041: "Door Forced Alarm",
            4042: "Door Held Alarm",
            4043: "Tamper Switch Alarm",
            4044: "AC Failure",
            4045: "Battery Failure",
            4051: "REX Switch Alarm",
            7020: f"Time Set to: {self.new_time}",
            12031: f"Granted Access, {direction} Manual",
            12032: "Door Unlocked",
            12033: "Door Locked",
        }

        return event_types.get(self.event_type, f"Unknown Event Type {self.event_type}")

    def __str__(self):
        return f"{self.door.name} {self.timestamp} - {self.description}"

    def decoded_card_number(self) -> str:
        """Requires annotations from `with_decoded_card_number`"""
        if self.raw_card_number is None:
            return None
        elif self.card_is_26_bit:
            if self.card_is_valid_26_bit:
                return f"{self.card_facility_code_26_bit} - {self.card_number_26_bit}"
            else:
                return "Invalid"
        else:
            return "Not 26 bit card"

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=["door", "timestamp", "event_type"], name="unique_hidevent"
            )
        ]
        db_table = "hidevent"
        ordering = ("-timestamp",)