from datetime import datetime, timezone

from sqlalchemy import BigInteger, ForeignKey, String, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column

from app.db.base import Base


def utcnow() -> datetime:
    return datetime.now(timezone.utc)


class User(Base):
    __tablename__ = "users"

    id: Mapped[int] = mapped_column(primary_key=True)
    username: Mapped[str] = mapped_column(String(64), unique=True, index=True)
    password_hash: Mapped[str] = mapped_column(String(256))
    derivation_index: Mapped[int] = mapped_column(unique=True)
    address: Mapped[str] = mapped_column(String(128), unique=True)
    # Read cache only; must always be written in the same transaction as the
    # utxo_events rows it summarizes. Source of truth is utxo_events.
    cached_balance_sats: Mapped[int] = mapped_column(BigInteger, default=0)
    created_at: Mapped[datetime] = mapped_column(default=utcnow)


class UtxoEvent(Base):
    __tablename__ = "utxo_events"
    __table_args__ = (UniqueConstraint("txid", "vout"),)

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    txid: Mapped[str] = mapped_column(String(64))
    vout: Mapped[int]
    amount_sats: Mapped[int] = mapped_column(BigInteger)
    confirmed_height: Mapped[int]
    confirmed_at: Mapped[datetime] = mapped_column(default=utcnow)
    # Set once this UTXO is consumed by an outgoing bet/withdrawal build.
    spent_txid: Mapped[str | None] = mapped_column(String(64), default=None)


class Round(Base):
    __tablename__ = "rounds"

    id: Mapped[int] = mapped_column(primary_key=True)
    status: Mapped[str] = mapped_column(String(16), default="open")
    opened_at: Mapped[datetime] = mapped_column(default=utcnow)
    closed_at: Mapped[datetime | None] = mapped_column(default=None)
    draw_block_height: Mapped[int | None] = mapped_column(default=None)
    draw_block_hash: Mapped[str | None] = mapped_column(String(64), default=None)
    seed_int: Mapped[str | None] = mapped_column(String(128), default=None)
    winner_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id"), default=None)
    pool_amount_sats: Mapped[int | None] = mapped_column(BigInteger, default=None)
    winner_amount_sats: Mapped[int | None] = mapped_column(BigInteger, default=None)
    fee_amount_sats: Mapped[int | None] = mapped_column(BigInteger, default=None)
    payout_txid: Mapped[str | None] = mapped_column(String(64), default=None)


class RoundParticipant(Base):
    __tablename__ = "round_participants"
    __table_args__ = (UniqueConstraint("round_id", "user_id"),)

    id: Mapped[int] = mapped_column(primary_key=True)
    round_id: Mapped[int] = mapped_column(ForeignKey("rounds.id"), index=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    bet_amount_sats: Mapped[int] = mapped_column(BigInteger)
    bet_txid: Mapped[str] = mapped_column(String(64))
    # Ordering / tie-break field per spec: broadcast time, not confirmation time.
    broadcast_at: Mapped[datetime] = mapped_column(default=utcnow)
    confirmed_at: Mapped[datetime | None] = mapped_column(default=None)
    status: Mapped[str] = mapped_column(String(16), default="broadcast")


class RoundConfig(Base):
    """Single-row operational config, DB-backed so it's editable without a redeploy.

    round_duration is intentionally NOT here: it stays env-var-driven per spec.
    Don't move it here without an explicit decision to change that.
    """

    __tablename__ = "round_config"

    id: Mapped[int] = mapped_column(primary_key=True)
    fee_address: Mapped[str] = mapped_column(String(128))
    bet_amount_sats: Mapped[int] = mapped_column(BigInteger)
    updated_at: Mapped[datetime] = mapped_column(default=utcnow, onupdate=utcnow)


class PendingTransaction(Base):
    """Single source of truth for the RBF timeout->bump->rebroadcast loop."""

    __tablename__ = "pending_transactions"

    id: Mapped[int] = mapped_column(primary_key=True)
    kind: Mapped[str] = mapped_column(String(16))  # bet | payout | withdrawal
    round_id: Mapped[int | None] = mapped_column(ForeignKey("rounds.id"), default=None)
    withdrawal_id: Mapped[int | None] = mapped_column(ForeignKey("withdrawals.id"), default=None)
    user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id"), default=None)
    current_txid: Mapped[str] = mapped_column(String(64))
    fee_rate_sat_vb: Mapped[int]
    raw_tx_hex: Mapped[str] = mapped_column(String)
    broadcast_at: Mapped[datetime] = mapped_column(default=utcnow)
    status: Mapped[str] = mapped_column(String(16), default="pending")
    replaced_by_txid: Mapped[str | None] = mapped_column(String(64), default=None)
    attempt_count: Mapped[int] = mapped_column(default=1)
    updated_at: Mapped[datetime] = mapped_column(default=utcnow, onupdate=utcnow)


class Withdrawal(Base):
    __tablename__ = "withdrawals"

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    external_address: Mapped[str] = mapped_column(String(128))
    amount_requested_sats: Mapped[int] = mapped_column(BigInteger)
    amount_sent_sats: Mapped[int | None] = mapped_column(BigInteger, default=None)
    txid: Mapped[str | None] = mapped_column(String(64), default=None)
    status: Mapped[str] = mapped_column(String(16), default="pending")
    created_at: Mapped[datetime] = mapped_column(default=utcnow)
    confirmed_at: Mapped[datetime | None] = mapped_column(default=None)


class AuditLog(Base):
    __tablename__ = "audit_log"

    id: Mapped[int] = mapped_column(primary_key=True)
    event_type: Mapped[str] = mapped_column(String(32))
    payload_json: Mapped[str] = mapped_column(String)
    user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id"), default=None)
    round_id: Mapped[int | None] = mapped_column(ForeignKey("rounds.id"), default=None)
    created_at: Mapped[datetime] = mapped_column(default=utcnow)