import uuid

from decouple import config
from django.contrib.auth.models import User
from django.core.validators import MaxValueValidator, MinValueValidator
from django.db import models
from django.db.models.signals import pre_delete
from django.dispatch import receiver
from django.utils import timezone

MIN_TRADE = config("MIN_TRADE", cast=int, default=20_000)
MAX_TRADE = config("MAX_TRADE", cast=int, default=1_000_000)
FIAT_EXCHANGE_DURATION = config("FIAT_EXCHANGE_DURATION", cast=int, default=24)


class Order(models.Model):
    class Types(models.IntegerChoices):
        BUY = 0, "BUY"
        SELL = 1, "SELL"

    class Status(models.IntegerChoices):
        WFB = 0, "Waiting for maker bond"
        PUB = 1, "Public"
        PAU = 2, "Paused"
        TAK = 3, "Waiting for taker bond"
        UCA = 4, "Cancelled"
        EXP = 5, "Expired"
        WF2 = 6, "Waiting for trade collateral and buyer invoice"
        WFE = 7, "Waiting only for seller trade collateral"
        WFI = 8, "Waiting only for buyer invoice"
        CHA = 9, "Sending fiat - In chatroom"
        FSE = 10, "Fiat sent - In chatroom"
        DIS = 11, "In dispute"
        CCA = 12, "Collaboratively cancelled"
        PAY = 13, "Sending satoshis to buyer"
        SUC = 14, "Sucessful trade"
        FAI = 15, "Failed lightning network routing"
        WFR = 16, "Wait for dispute resolution"
        MLD = 17, "Maker lost dispute"
        TLD = 18, "Taker lost dispute"

    class ExpiryReasons(models.IntegerChoices):
        NTAKEN = 0, "Expired not taken"
        NMBOND = 1, "Maker bond not locked"
        NESCRO = 2, "Escrow not locked"
        NINVOI = 3, "Invoice not submitted"
        NESINV = 4, "Neither escrow locked or invoice submitted"

    # order info
    reference = models.UUIDField(default=uuid.uuid4, editable=False)
    status = models.PositiveSmallIntegerField(
        choices=Status.choices, null=False, default=Status.WFB
    )
    created_at = models.DateTimeField(default=timezone.now)
    expires_at = models.DateTimeField()
    expiry_reason = models.PositiveSmallIntegerField(
        choices=ExpiryReasons.choices, null=True, blank=True, default=None
    )

    # order details
    type = models.PositiveSmallIntegerField(choices=Types.choices, null=False)
    currency = models.ForeignKey("api.Currency", null=True, on_delete=models.SET_NULL)
    amount = models.DecimalField(max_digits=18, decimal_places=8, null=True, blank=True)
    has_range = models.BooleanField(default=False, null=False, blank=False)
    min_amount = models.DecimalField(
        max_digits=18, decimal_places=8, null=True, blank=True
    )
    max_amount = models.DecimalField(
        max_digits=18, decimal_places=8, null=True, blank=True
    )
    payment_method = models.CharField(
        max_length=70, null=False, default="not specified", blank=True
    )
    # order pricing method. A explicit amount of sats, or a relative premium above/below market.
    is_explicit = models.BooleanField(default=False, null=False)
    # marked to market
    premium = models.DecimalField(
        max_digits=5,
        decimal_places=2,
        default=0,
        null=True,
        validators=[MinValueValidator(-100), MaxValueValidator(999)],
        blank=True,
    )
    # explicit
    satoshis = models.PositiveBigIntegerField(
        null=True,
        validators=[MinValueValidator(MIN_TRADE), MaxValueValidator(MAX_TRADE)],
        blank=True,
    )
    # optionally makers can choose the public order duration length (seconds)
    public_duration = models.PositiveBigIntegerField(
        default=60 * 60 * config("DEFAULT_PUBLIC_ORDER_DURATION", cast=int, default=24)
        - 1,
        null=False,
        validators=[
            MinValueValidator(
                60 * 60 * config("MIN_PUBLIC_ORDER_DURATION", cast=float, default=0.166)
            ),  # Min is 10 minutes
            MaxValueValidator(
                60 * 60 * config("MAX_PUBLIC_ORDER_DURATION", cast=float, default=24)
            ),  # Max is 24 Hours
        ],
        blank=False,
    )

    # optionally makers can choose the escrow lock / invoice submission step length (seconds)
    escrow_duration = models.PositiveBigIntegerField(
        default=60 * int(config("INVOICE_AND_ESCROW_DURATION")) - 1,
        null=False,
        validators=[
            MinValueValidator(60 * 30),  # Min is 30 minutes
            MaxValueValidator(60 * 60 * 8),  # Max is 8 Hours
        ],
        blank=False,
    )

    # optionally makers can choose the fidelity bond size of the maker and taker (%)
    bond_size = models.DecimalField(
        max_digits=4,
        decimal_places=2,
        default=config("DEFAULT_BOND_SIZE", cast=float, default=3),
        null=False,
        validators=[
            MinValueValidator(config("MIN_BOND_SIZE", cast=float, default=1)),  # 1  %
            MaxValueValidator(config("MAX_BOND_SIZE", cast=float, default=1)),  # 15 %
        ],
        blank=False,
    )

    # how many sats at creation and at last check (relevant for marked to market)
    t0_satoshis = models.PositiveBigIntegerField(
        null=True,
        validators=[MinValueValidator(MIN_TRADE), MaxValueValidator(MAX_TRADE)],
        blank=True,
    )  # sats at creation
    last_satoshis = models.PositiveBigIntegerField(
        null=True,
        validators=[MinValueValidator(0), MaxValueValidator(MAX_TRADE * 2)],
        blank=True,
    )  # sats last time checked. Weird if 2* trade max...
    # timestamp of last_satoshis
    last_satoshis_time = models.DateTimeField(null=True, default=None, blank=True)
    # time the fiat exchange is confirmed and Sats released to buyer
    contract_finalization_time = models.DateTimeField(
        null=True, default=None, blank=True
    )
    # order participants
    maker = models.ForeignKey(
        User, related_name="maker", on_delete=models.SET_NULL, null=True, default=None
    )  # unique = True, a maker can only make one order
    taker = models.ForeignKey(
        User,
        related_name="taker",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
        blank=True,
    )  # unique = True, a taker can only take one order

    # When collaborative cancel is needed and one partner has cancelled.
    maker_asked_cancel = models.BooleanField(default=False, null=False)
    taker_asked_cancel = models.BooleanField(default=False, null=False)

    is_fiat_sent = models.BooleanField(default=False, null=False)
    reverted_fiat_sent = models.BooleanField(default=False, null=False)

    # in dispute
    is_disputed = models.BooleanField(default=False, null=False)
    maker_statement = models.TextField(
        max_length=50_000, null=True, default=None, blank=True
    )
    taker_statement = models.TextField(
        max_length=50_000, null=True, default=None, blank=True
    )

    # LNpayments
    # Order collateral
    maker_bond = models.OneToOneField(
        "api.LNPayment",
        related_name="order_made",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
        blank=True,
    )
    taker_bond = models.OneToOneField(
        "api.LNPayment",
        related_name="order_taken",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
        blank=True,
    )
    trade_escrow = models.OneToOneField(
        "api.LNPayment",
        related_name="order_escrow",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
        blank=True,
    )
    # is buyer payout a LN invoice (false) or on chain address (true)
    is_swap = models.BooleanField(default=False, null=False)
    # buyer payment LN invoice
    payout = models.OneToOneField(
        "api.LNPayment",
        related_name="order_paid_LN",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
        blank=True,
    )
    # buyer payment address
    payout_tx = models.OneToOneField(
        "api.OnchainPayment",
        related_name="order_paid_TX",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
        blank=True,
    )

    # coordinator proceeds (sats revenue for this order)
    proceeds = models.PositiveBigIntegerField(
        default=0,
        null=True,
        validators=[MinValueValidator(0)],
        blank=True,
    )

    # ratings
    maker_rated = models.BooleanField(default=False, null=False)
    taker_rated = models.BooleanField(default=False, null=False)
    maker_platform_rated = models.BooleanField(default=False, null=False)
    taker_platform_rated = models.BooleanField(default=False, null=False)

    logs = models.TextField(
        max_length=80_000,
        null=True,
        default="<thead><tr><b><th>Timestamp</th><th>Level</th><th>Event</th></b></tr></thead>",
        blank=True,
        editable=False,
    )

    def __str__(self):
        if self.has_range and self.amount is None:
            amt = str(float(self.min_amount)) + "-" + str(float(self.max_amount))
        else:
            amt = float(self.amount)
        return f"Order {self.id}: {self.Types(self.type).label} BTC for {amt} {self.currency}"

    def t_to_expire(self, status):
        t_to_expire = {
            0: config(
                "EXP_MAKER_BOND_INVOICE", cast=int, default=300
            ),  # 'Waiting for maker bond'
            1: self.public_duration,  # 'Public'
            2: 0,  # 'Deleted'
            3: config(
                "EXP_TAKER_BOND_INVOICE", cast=int, default=150
            ),  # 'Waiting for taker bond'
            4: 0,  # 'Cancelled'
            5: 0,  # 'Expired'
            6: int(
                self.escrow_duration
            ),  # 'Waiting for trade collateral and buyer invoice'
            7: int(self.escrow_duration),  # 'Waiting only for seller trade collateral'
            8: int(self.escrow_duration),  # 'Waiting only for buyer invoice'
            9: 60 * 60 * FIAT_EXCHANGE_DURATION,  # 'Sending fiat - In chatroom'
            10: 60 * 60 * FIAT_EXCHANGE_DURATION,  # 'Fiat sent - In chatroom'
            11: 1 * 24 * 60 * 60,  # 'In dispute'
            12: 0,  # 'Collaboratively cancelled'
            13: 100 * 24 * 60 * 60,  # 'Sending satoshis to buyer'
            14: 100 * 24 * 60 * 60,  # 'Successful trade'
            15: 100 * 24 * 60 * 60,  # 'Failed lightning network routing'
            16: 100 * 24 * 60 * 60,  # 'Wait for dispute resolution'
            17: 100 * 24 * 60 * 60,  # 'Maker lost dispute'
            18: 100 * 24 * 60 * 60,  # 'Taker lost dispute'
        }

        return t_to_expire[status]

    def log(self, event="empty event", level="INFO"):
        """
        log() adds a new line to the Order.log field. We wrap it all in a
        try/catch block since this function is called inside the main request->response
        pipe and any error here would lead to a 500 response.
        """
        if config("DISABLE_ORDER_LOGS", cast=bool, default=True):
            return
        try:
            timestamp = timezone.now().replace(microsecond=0).isoformat()
            level_in_tag = "" if level == "INFO" else "<b>"
            level_out_tag = "" if level == "INFO" else "</b>"
            self.logs = (
                self.logs
                + f"<tr><td>{timestamp}</td><td>{level_in_tag}{level}{level_out_tag}</td><td>{event}</td></tr>"
            )
            self.save(update_fields=["logs"])
        except Exception:
            pass

    def update_status(self, new_status):
        old_status = self.status
        self.status = new_status
        self.save(update_fields=["status"])
        self.log(
            f"Order state went from {old_status}: <i>{Order.Status(old_status).label}</i> to {new_status}: <i>{Order.Status(new_status).label}</i>"
        )


@receiver(pre_delete, sender=Order)
def delete_lnpayment_at_order_deletion(sender, instance, **kwargs):
    to_delete = (
        instance.maker_bond,
        instance.payout,
        instance.taker_bond,
        instance.trade_escrow,
    )

    for lnpayment in to_delete:
        try:
            lnpayment.delete()
        except Exception:
            pass