import enum
import uuid
from datetime import datetime

from sqlalchemy import ForeignKey, Index, Integer, String, Text, func
from sqlalchemy.dialects.postgresql import ENUM
from sqlalchemy.orm import Mapped, mapped_column, relationship

from proxy_pool.db.base import Base, TimestampMixin, UUIDPrimaryKeyMixin


class CreditTxType(str, enum.StrEnum):
    PURCHASE = "purchase"
    ACQUIRE = "acquire"
    REFUND = "refund"
    ADMIN_ADJUST = "admin_adjust"


class User(UUIDPrimaryKeyMixin, TimestampMixin, Base):
    __tablename__ = "users"

    email: Mapped[str] = mapped_column(String(320), unique=True)
    display_name: Mapped[str | None] = mapped_column(String(128))
    is_active: Mapped[bool] = mapped_column(default=True)

    api_keys: Mapped[list["ApiKey"]] = relationship(back_populates="user")
    credit_entries: Mapped[list["CreditLedger"]] = relationship(back_populates="user")


class ApiKey(UUIDPrimaryKeyMixin, TimestampMixin, Base):
    __tablename__ = "api_keys"
    __table_args__ = (
        Index("ix_api_keys_hash", "key_hash", unique=True),
        Index("ix_api_keys_prefix", "prefix"),
    )

    user_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("users.id", ondelete="CASCADE"),
    )
    key_hash: Mapped[str] = mapped_column(String(128))
    prefix: Mapped[str] = mapped_column(String(8))
    label: Mapped[str | None] = mapped_column(String(128))
    is_active: Mapped[bool] = mapped_column(default=True)
    last_used_at: Mapped[datetime | None] = mapped_column()
    expires_at: Mapped[datetime | None] = mapped_column()

    user: Mapped["User"] = relationship(back_populates="api_keys")


class CreditLedger(UUIDPrimaryKeyMixin, TimestampMixin, Base):
    __tablename__ = "credit_ledger"
    __table_args__ = (Index("ix_ledger_user_created", "user_id", "created_at"),)

    user_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("users.id", ondelete="CASCADE"),
    )
    amount: Mapped[int] = mapped_column(Integer)
    tx_type: Mapped[CreditTxType] = mapped_column(
        ENUM(CreditTxType, name="credit_tx_type"),
    )
    description: Mapped[str | None] = mapped_column(Text)
    reference_id: Mapped[uuid.UUID | None] = mapped_column()

    user: Mapped["User"] = relationship(back_populates="credit_entries")


class ProxyLease(UUIDPrimaryKeyMixin, Base):
    __tablename__ = "proxy_leases"
    __table_args__ = (
        Index("ix_leases_user", "user_id"),
        Index("ix_leases_proxy_active", "proxy_id", "is_released"),
    )

    user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"))
    proxy_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("proxies.id"))
    acquired_at: Mapped[datetime] = mapped_column(server_default=func.now())
    expires_at: Mapped[datetime] = mapped_column()
    is_released: Mapped[bool] = mapped_column(default=False)