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

from sqlalchemy import JSON, Column, UniqueConstraint
from sqlmodel import Field, Relationship, SQLModel


class RecurringItemType(str, enum.Enum):
    INCOME = "INCOME"
    EXPENSE = "EXPENSE"
    SAVINGS = "SAVINGS"


class RecurringFrequency(str, enum.Enum):
    WEEKLY = "WEEKLY"
    MONTHLY = "MONTHLY"
    QUARTERLY = "QUARTERLY"
    BIANNUAL = "BIANNUAL"
    YEARLY = "YEARLY"


class TransactionType(str, enum.Enum):
    COMPRA = "COMPRA"
    DEVOLUCION = "DEVOLUCION"
    DEPOSITO = "DEPOSITO"


class TransactionSource(str, enum.Enum):
    CREDIT_CARD = "CREDIT_CARD"
    CASH = "CASH"
    TRANSFER = "TRANSFER"


class Currency(str, enum.Enum):
    CRC = "CRC"
    USD = "USD"
    BTC = "BTC"
    XMR = "XMR"


class Bank(str, enum.Enum):
    BAC = "BAC"
    BCR = "BCR"
    DAVIVIENDA = "DAVIVIENDA"
    FCL = "FCL"
    ROP = "ROP"
    VOL = "VOL"
    MEMP = "MEMP"
    MPAT = "MPAT"
    MORTGAGE = "MORTGAGE"


class AccountType(str, enum.Enum):
    BANK = "BANK"
    PENSION = "PENSION"
    CRYPTO = "CRYPTO"
    SAVINGS = "SAVINGS"
    LIABILITY = "LIABILITY"


# --- Category ---


class CategoryBase(SQLModel):
    name: str = Field(index=True, unique=True)
    icon: str = "tag"
    auto_match_patterns: Optional[str] = Field(
        default=None,
        description="Comma-separated merchant substrings for auto-matching",
    )


class Category(CategoryBase, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    transactions: list["Transaction"] = Relationship(back_populates="category")


class CategoryCreate(CategoryBase):
    pass


class CategoryRead(CategoryBase):
    id: int


class CategoryUpdate(SQLModel):
    name: Optional[str] = None
    icon: Optional[str] = None
    auto_match_patterns: Optional[str] = None


# --- Account ---


class AccountBase(SQLModel):
    bank: Bank
    currency: Currency
    label: str
    balance: float = 0.0
    account_type: AccountType = AccountType.BANK
    next_payment: Optional[float] = None


class Account(AccountBase, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    updated_at: datetime = Field(default_factory=datetime.utcnow)


class AccountCreate(AccountBase):
    pass


class AccountRead(AccountBase):
    id: int
    updated_at: datetime


class AccountUpdate(SQLModel):
    balance: Optional[float] = None
    label: Optional[str] = None
    next_payment: Optional[float] = None


# --- Transaction ---


class TransactionBase(SQLModel):
    amount: float
    currency: Currency = Currency.CRC
    merchant: str
    city: Optional[str] = None
    date: datetime
    card_type: Optional[str] = None
    card_last4: Optional[str] = None
    authorization_code: Optional[str] = None
    reference: Optional[str] = Field(default=None, index=True)
    transaction_type: TransactionType = TransactionType.COMPRA
    source: TransactionSource = TransactionSource.CREDIT_CARD
    bank: Bank = Bank.BAC
    notes: Optional[str] = None
    category_id: Optional[int] = Field(default=None, foreign_key="category.id")


class Transaction(TransactionBase, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    category: Optional[Category] = Relationship(back_populates="transactions")


class TransactionCreate(TransactionBase):
    pass


class TransactionRead(TransactionBase):
    id: int
    created_at: datetime
    category: Optional[CategoryRead] = None


class TransactionUpdate(SQLModel):
    amount: Optional[float] = None
    currency: Optional[Currency] = None
    merchant: Optional[str] = None
    city: Optional[str] = None
    date: Optional[datetime] = None
    transaction_type: Optional[TransactionType] = None
    source: Optional[TransactionSource] = None
    notes: Optional[str] = None
    category_id: Optional[int] = None


# --- Exchange Rate ---


class ExchangeRate(SQLModel, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    date: datetime
    buy_rate: float
    sell_rate: float
    fetched_at: datetime = Field(default_factory=datetime.utcnow)


class ExchangeRateRead(SQLModel):
    buy_rate: float
    sell_rate: float
    date: datetime
    fetched_at: datetime


# --- API Token ---


class APIToken(SQLModel, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    name: str
    token_hash: str = Field(index=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    expires_at: Optional[datetime] = None
    is_active: bool = True


class APITokenCreate(SQLModel):
    name: str
    expires_days: Optional[int] = None


class APITokenRead(SQLModel):
    id: int
    name: str
    created_at: datetime
    expires_at: Optional[datetime]
    is_active: bool


# --- User Settings ---


class UserSettings(SQLModel, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    key: str = Field(index=True, unique=True, default="default")
    data: dict = Field(
        default_factory=dict,
        sa_column=Column(JSON, nullable=False, server_default="{}"),
    )
    updated_at: datetime = Field(default_factory=datetime.utcnow)


class UserSettingsRead(SQLModel):
    key: str
    data: dict
    updated_at: datetime


class UserSettingsUpdate(SQLModel):
    data: dict


# --- Recurring Item ---


class RecurringItemBase(SQLModel):
    name: str
    amount: float
    currency: Currency = Currency.CRC
    item_type: RecurringItemType
    frequency: RecurringFrequency = RecurringFrequency.MONTHLY
    day_of_month: Optional[int] = None
    month_of_year: Optional[int] = None
    override_amounts: Optional[dict] = Field(
        default=None,
        sa_column=Column(JSON, nullable=True),
    )
    category_id: Optional[int] = Field(default=None, foreign_key="category.id")
    is_active: bool = True
    notes: Optional[str] = None


class RecurringItem(RecurringItemBase, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    category: Optional[Category] = Relationship()


class RecurringItemCreate(RecurringItemBase):
    pass


class RecurringItemRead(RecurringItemBase):
    id: int
    created_at: datetime
    category: Optional[CategoryRead] = None


class RecurringItemUpdate(SQLModel):
    name: Optional[str] = None
    amount: Optional[float] = None
    currency: Optional[Currency] = None
    item_type: Optional[RecurringItemType] = None
    frequency: Optional[RecurringFrequency] = None
    day_of_month: Optional[int] = None
    month_of_year: Optional[int] = None
    override_amounts: Optional[dict] = None
    category_id: Optional[int] = None
    is_active: Optional[bool] = None
    notes: Optional[str] = None


# --- Push Subscription ---


class PushSubscription(SQLModel, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    endpoint: str = Field(unique=True)
    p256dh: str
    auth: str
    created_at: datetime = Field(default_factory=datetime.utcnow)


class PushSubscriptionCreate(SQLModel):
    endpoint: str
    keys: dict  # {"p256dh": "...", "auth": "..."}


# --- Pension Snapshot ---


class PensionSnapshotBase(SQLModel):
    fund: Bank
    contract_number: str
    period_start: date
    period_end: date
    saldo_anterior: float
    aportes: float
    rendimientos: float
    retiros: float
    traslados: float
    comision: float
    correccion: float
    bonificacion: float
    saldo_final: float
    source_filename: str


class PensionSnapshot(PensionSnapshotBase, table=True):
    __table_args__ = (
        UniqueConstraint("fund", "period_start", "period_end"),
    )
    id: Optional[int] = Field(default=None, primary_key=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class PensionSnapshotRead(PensionSnapshotBase):
    id: int
    created_at: datetime