from datetime import date, datetime
from enum import Enum
from typing import Optional

from sqlmodel import (
    Column,
    Date,
    DateTime,
    Field,
    ForeignKey,
    Integer,
    Relationship,
    SQLModel,
    Text,
    UniqueConstraint,
)


class TradeType(str, Enum):
    SELL_PUT = "SELL_PUT"
    CLOSE_SELL_PUT = "CLOSE_SELL_PUT"
    ASSIGNMENT = "ASSIGNMENT"
    SELL_CALL = "SELL_CALL"
    CLOSE_SELL_CALL = "CLOSE_SELL_CALL"
    EXERCISE_CALL = "EXERCISE_CALL"
    LONG_SPOT = "LONG_SPOT"
    CLOSE_LONG_SPOT = "CLOSE_LONG_SPOT"
    SHORT_SPOT = "SHORT_SPOT"
    CLOSE_SHORT_SPOT = "CLOSE_SHORT_SPOT"
    LONG_CFD = "LONG_CFD"
    CLOSE_LONG_CFD = "CLOSE_LONG_CFD"
    SHORT_CFD = "SHORT_CFD"
    CLOSE_SHORT_CFD = "CLOSE_SHORT_CFD"
    LONG_OTHER = "LONG_OTHER"
    CLOSE_LONG_OTHER = "CLOSE_LONG_OTHER"
    SHORT_OTHER = "SHORT_OTHER"
    CLOSE_SHORT_OTHER = "CLOSE_SHORT_OTHER"


class TradeStrategy(str, Enum):
    WHEEL = "WHEEL"
    FX = "FX"
    SPOT = "SPOT"
    OTHER = "OTHER"


class CycleStatus(str, Enum):
    OPEN = "OPEN"
    CLOSED = "CLOSED"


class UnderlyingCurrency(str, Enum):
    EUR = "EUR"
    USD = "USD"
    GBP = "GBP"
    JPY = "JPY"
    AUD = "AUD"
    CAD = "CAD"
    CHF = "CHF"
    NZD = "NZD"
    CNY = "CNY"


class FundingSource(str, Enum):
    CASH = "CASH"
    MARGIN = "MARGIN"
    MIXED = "MIXED"


class Trades(SQLModel, table=True):
    __tablename__ = "trades"  # type: ignore[attr-defined]
    __table_args__ = (
        UniqueConstraint(
            "user_id", "friendly_name", name="uq_trades_user_friendly_name"
        ),
    )

    id: int | None = Field(default=None, primary_key=True)
    user_id: int = Field(foreign_key="users.id", nullable=False, index=True)
    # allow null while user may omit friendly_name; uniqueness enforced per-user by constraint
    friendly_name: str | None = Field(
        default=None, sa_column=Column(Text, nullable=True)
    )
    symbol: str = Field(sa_column=Column(Text, nullable=False))
    exchange_id: int = Field(foreign_key="exchanges.id", nullable=False, index=True)
    exchange: "Exchanges" = Relationship(back_populates="trades")
    underlying_currency: UnderlyingCurrency = Field(
        sa_column=Column(Text, nullable=False)
    )
    trade_type: TradeType = Field(sa_column=Column(Text, nullable=False))
    trade_strategy: TradeStrategy = Field(sa_column=Column(Text, nullable=False))
    trade_date: date = Field(sa_column=Column(Date, nullable=False))
    trade_time_utc: datetime = Field(
        sa_column=Column(DateTime(timezone=True), nullable=False)
    )
    expiry_date: date | None = Field(default=None, nullable=True)
    strike_price_cents: int | None = Field(default=None, nullable=True)
    quantity: int = Field(sa_column=Column(Integer, nullable=False))
    quantity_multiplier: int = Field(
        sa_column=Column(Integer, nullable=False), default=1
    )
    price_cents: int = Field(sa_column=Column(Integer, nullable=False))
    gross_cash_flow_cents: int = Field(sa_column=Column(Integer, nullable=False))
    commission_cents: int = Field(sa_column=Column(Integer, nullable=False))
    net_cash_flow_cents: int = Field(sa_column=Column(Integer, nullable=False))
    is_invalidated: bool = Field(default=False, nullable=False)
    invalidated_at: datetime | None = Field(
        default=None, sa_column=Column(DateTime(timezone=True), nullable=True)
    )
    replaced_by_trade_id: int | None = Field(
        default=None, foreign_key="trades.id", nullable=True
    )
    notes: str | None = Field(default=None, sa_column=Column(Text, nullable=True))
    cycle_id: int | None = Field(
        default=None, foreign_key="cycles.id", nullable=True, index=True
    )

    cycle: "Cycles" = Relationship(back_populates="trades")

    related_loan_change_event: Optional["CycleLoanChangeEvents"] = Relationship(
        back_populates="trade",
        sa_relationship_kwargs={"uselist": False},
    )


class Cycles(SQLModel, table=True):
    __tablename__ = "cycles"  # type: ignore[attr-defined]
    __table_args__ = (
        UniqueConstraint(
            "user_id", "friendly_name", name="uq_cycles_user_friendly_name"
        ),
    )

    id: int | None = Field(default=None, primary_key=True)
    user_id: int = Field(foreign_key="users.id", nullable=False, index=True)
    friendly_name: str | None = Field(
        default=None, sa_column=Column(Text, nullable=True)
    )
    symbol: str = Field(sa_column=Column(Text, nullable=False))
    exchange_id: int = Field(foreign_key="exchanges.id", nullable=False, index=True)
    exchange: "Exchanges" = Relationship(back_populates="cycles")
    underlying_currency: UnderlyingCurrency = Field(
        sa_column=Column(Text, nullable=False)
    )
    status: CycleStatus = Field(sa_column=Column(Text, nullable=False))
    funding_source: FundingSource = Field(sa_column=Column(Text, nullable=True))
    capital_exposure_cents: int | None = Field(default=None, nullable=True)
    start_date: date = Field(sa_column=Column(Date, nullable=False))
    end_date: date | None = Field(default=None, sa_column=Column(Date, nullable=True))

    trades: list["Trades"] = Relationship(back_populates="cycle")

    loan_amount_cents: int | None = Field(default=None, nullable=True)
    loan_interest_rate_tenth_bps: int | None = Field(default=None, nullable=True)

    latest_interest_accrued_date: date | None = Field(
        default=None, sa_column=Column(Date, nullable=True)
    )
    total_accrued_amount_cents: int = Field(
        default=0, sa_column=Column(Integer, nullable=False)
    )

    loan_change_events: list["CycleLoanChangeEvents"] = Relationship(
        back_populates="cycle"
    )
    daily_accruals: list["CycleDailyAccrual"] = Relationship(back_populates="cycle")


class CycleLoanChangeEvents(SQLModel, table=True):
    __tablename__ = "cycle_loan_change_events"  # type: ignore[attr-defined]
    __table_args__ = (
        UniqueConstraint(
            "cycle_id", "effective_date", name="uq_cycle_loan_change_cycle_date"
        ),
    )

    id: int | None = Field(default=None, primary_key=True)
    cycle_id: int = Field(
        sa_column=Column(
            Integer,
            ForeignKey("cycles.id", ondelete="CASCADE"),
            nullable=False,
            index=True,
        )
    )
    effective_date: date = Field(sa_column=Column(Date, nullable=False))
    loan_amount_cents: int | None = Field(
        default=None, sa_column=Column(Integer, nullable=True)
    )
    loan_interest_rate_tenth_bps: int | None = Field(
        default=None, sa_column=Column(Integer, nullable=True)
    )
    related_trade_id: int | None = Field(
        default=None,
        sa_column=Column(Integer, ForeignKey("trades.id"), nullable=True, unique=True),
    )  # Not used for now.
    notes: str | None = Field(default=None, sa_column=Column(Text, nullable=True))
    created_at: datetime = Field(
        sa_column=Column(DateTime(timezone=True), nullable=False)
    )

    cycle: "Cycles" = Relationship(back_populates="loan_change_events")
    trade: Optional["Trades"] = Relationship(back_populates="related_loan_change_event")


class CycleDailyAccrual(SQLModel, table=True):
    __tablename__ = "cycle_daily_accrual"  # type: ignore[attr-defined]
    __table_args__ = (
        UniqueConstraint(
            "cycle_id", "accrual_date", name="uq_cycle_daily_accruals_cycle_date"
        ),
    )

    id: int | None = Field(default=None, primary_key=True)
    cycle_id: int = Field(
        sa_column=Column(
            Integer,
            ForeignKey("cycles.id", ondelete="CASCADE"),
            nullable=False,
            index=True,
        )
    )
    accrual_date: date = Field(sa_column=Column(Date, nullable=False))
    accrual_amount_cents: int = Field(sa_column=Column(Integer, nullable=False))
    created_at: datetime = Field(
        sa_column=Column(DateTime(timezone=True), nullable=False)
    )

    cycle: "Cycles" = Relationship(back_populates="daily_accruals")


class Exchanges(SQLModel, table=True):
    __tablename__ = "exchanges"  # type: ignore[attr-defined]
    __table_args__ = (
        UniqueConstraint("user_id", "name", name="uq_exchanges_user_name"),
    )
    id: int | None = Field(default=None, primary_key=True)
    user_id: int = Field(foreign_key="users.id", nullable=False, index=True)
    name: str = Field(sa_column=Column(Text, nullable=False))
    notes: str | None = Field(default=None, sa_column=Column(Text, nullable=True))
    trades: list["Trades"] = Relationship(back_populates="exchange")
    cycles: list["Cycles"] = Relationship(back_populates="exchange")
    user: "Users" = Relationship(back_populates="exchanges")


class Users(SQLModel, table=True):
    __tablename__ = "users"  # type: ignore[attr-defined]
    id: int | None = Field(default=None, primary_key=True)
    # unique=True already creates an index; no need to also set index=True
    username: str = Field(sa_column=Column(Text, nullable=False, unique=True))
    password_hash: str = Field(sa_column=Column(Text, nullable=False))
    is_active: bool = Field(default=True, nullable=False)
    sessions: list["Sessions"] = Relationship(back_populates="user")
    exchanges: list["Exchanges"] = Relationship(back_populates="user")


class Sessions(SQLModel, table=True):
    __tablename__ = "sessions"  # type: ignore[attr-defined]
    id: int | None = Field(default=None, primary_key=True)
    user_id: int = Field(foreign_key="users.id", nullable=False, index=True)
    session_token_hash: str = Field(sa_column=Column(Text, nullable=False, unique=True))
    created_at: datetime = Field(
        sa_column=Column(DateTime(timezone=True), nullable=False)
    )
    expires_at: datetime = Field(
        sa_column=Column(DateTime(timezone=True), nullable=False, index=True)
    )
    last_seen_at: datetime | None = Field(
        sa_column=Column(DateTime(timezone=True), nullable=True)
    )
    last_used_ip: str | None = Field(
        default=None, sa_column=Column(Text, nullable=True)
    )
    user_agent: str | None = Field(default=None, sa_column=Column(Text, nullable=True))
    device_name: str | None = Field(default=None, sa_column=Column(Text, nullable=True))
    user: "Users" = Relationship(back_populates="sessions")