"""SQLModel table definitions for Ten31Portal."""

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

from sqlmodel import Field, SQLModel, Column, String, JSON, UniqueConstraint


# --- Enums ---

class UserRole(str, enum.Enum):
    # Internal staff
    approver = "approver"        # "Managing Partner" — full access incl. valuation sign-off
    operations = "operations"    # full access except final sign-off
    cfo = "cfo"
    fund_admin = "fund_admin"
    viewer = "viewer"
    # External accounts (entity-scoped via EntityAccess)
    investor = "investor"
    fund_administrator = "fund_administrator"


# External roles see only the entities granted to them.
EXTERNAL_ROLES = (UserRole.investor, UserRole.fund_administrator)


class DocumentCategory(str, enum.Enum):
    capital_account = "capital_account"
    k1 = "k1"
    statement = "statement"
    tax = "tax"
    other = "other"


class EntityType(str, enum.Enum):
    fund = "fund"
    spv = "spv"
    gp = "gp"
    mgmt_co = "mgmt_co"
    carry = "carry"


class EntityStatus(str, enum.Enum):
    active = "active"
    closed = "closed"


class RoundStatus(str, enum.Enum):
    draft = "draft"
    submitted = "submitted"
    approved = "approved"
    returned = "returned"


# --- Tables ---

class User(SQLModel, table=True):
    __tablename__ = "users"

    id: int | None = Field(default=None, primary_key=True)
    name: str
    username: str = Field(sa_column=Column(String, unique=True, nullable=False))
    email: str | None = Field(default=None, sa_column=Column(String, unique=True, nullable=True))
    password_hash: str
    role: UserRole
    is_active: bool = Field(default=True)
    # The built-in Service Admin (bootstrap account). Can be reset but never deleted.
    is_service_admin: bool = Field(default=False)
    # False for members imported without a password; set True when an admin sets one.
    login_enabled: bool = Field(default=True)
    # When an investor invests under several legal names (one per Partner/vehicle), each name
    # is its own account. Linking the secondary accounts to one "primary" lets that person sign
    # in once and see every name's investments. Null = this account logs in on its own.
    primary_account_id: int | None = Field(default=None, foreign_key="users.id", index=True)
    # Fund-administrator investor ID (from the eNAV ALLOC SI tab) for idempotent re-import.
    external_investor_id: str | None = Field(default=None, sa_column=Column(String, nullable=True))
    # When this investor last loaded their documents list — docs newer than this get a "New"
    # badge in the portal. Null until their first visit (nothing badged for brand-new logins).
    docs_seen_at: datetime | None = Field(default=None)
    # Two-factor auth (optional, per-user opt-in). The secret is set at setup time but only
    # counts once totp_enabled is True (enrollment is confirmed with a first valid code).
    totp_secret: str | None = Field(default=None)
    totp_enabled: bool = Field(default=False)
    # JSON list of sha256 hex digests of unused one-time recovery codes.
    totp_recovery_codes: str | None = Field(default=None)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class Entity(SQLModel, table=True):
    __tablename__ = "entities"

    id: int | None = Field(default=None, primary_key=True)
    name: str
    type: EntityType
    vintage_year: int | None = None
    fund_size_cents: int | None = None
    status: EntityStatus = Field(default=EntityStatus.active)
    # For a GP/mgmt entity that is also an LP with capital accounts (e.g. Ten31 LLC), link to
    # its investor account so its Assets view can pull real per-fund balances from the eNAV.
    linked_user_id: int | None = Field(default=None, foreign_key="users.id", index=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class Holding(SQLModel, table=True):
    __tablename__ = "holdings"

    id: int | None = Field(default=None, primary_key=True)
    entity_id: int = Field(foreign_key="entities.id", index=True)
    company_name: str
    created_at: datetime = Field(default_factory=datetime.utcnow)


class Position(SQLModel, table=True):
    __tablename__ = "positions"

    id: int | None = Field(default=None, primary_key=True)
    holding_id: int = Field(foreign_key="holdings.id", index=True)
    security_name: str
    investment_date: date
    shares: str | None = None  # Decimal stored as string
    cost_cents: int
    created_at: datetime = Field(default_factory=datetime.utcnow)


class ValuationRound(SQLModel, table=True):
    __tablename__ = "valuation_rounds"
    __table_args__ = (
        UniqueConstraint("entity_id", "quarter_end", name="uq_round_entity_quarter"),
    )

    id: int | None = Field(default=None, primary_key=True)
    entity_id: int = Field(foreign_key="entities.id")
    quarter_end: date
    status: RoundStatus = Field(default=RoundStatus.draft)
    submitted_by: int | None = Field(default=None, foreign_key="users.id", index=True)
    submitted_at: datetime | None = None
    approved_by: int | None = Field(default=None, foreign_key="users.id", index=True)
    approved_at: datetime | None = None
    return_note: str | None = None
    is_seed: bool = Field(default=False)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class Valuation(SQLModel, table=True):
    __tablename__ = "valuations"
    __table_args__ = (
        UniqueConstraint("round_id", "position_id", name="uq_valuation_round_position"),
    )

    id: int | None = Field(default=None, primary_key=True)
    round_id: int = Field(foreign_key="valuation_rounds.id")
    position_id: int = Field(foreign_key="positions.id", index=True)
    value_cents: int
    created_at: datetime = Field(default_factory=datetime.utcnow)


class AuditLog(SQLModel, table=True):
    __tablename__ = "audit_log"

    id: int | None = Field(default=None, primary_key=True)
    actor_user_id: int | None = Field(default=None, foreign_key="users.id", index=True)
    action: str
    object_type: str
    object_id: int | None = None
    # An action-specific JSON payload describing the change (stored in a JSON column). Most
    # callers pass a dict of changed fields (e.g. an entity update); some pass an identifying
    # field on delete, and some pass None. Matches AuditLogResponse.detail in schemas.py.
    detail: dict | list | str | None = Field(default=None, sa_column=Column(JSON, nullable=True))
    created_at: datetime = Field(default_factory=datetime.utcnow)


class EntityAccess(SQLModel, table=True):
    """Which entities an external account may view."""
    __tablename__ = "entity_access"
    __table_args__ = (
        UniqueConstraint("user_id", "entity_id", name="uq_access_user_entity"),
    )

    id: int | None = Field(default=None, primary_key=True)
    user_id: int = Field(foreign_key="users.id")
    entity_id: int = Field(foreign_key="entities.id", index=True)
    # Set when this member sold/transferred their stake (e.g. a secondary sale): the fund's
    # books show a $0 balance with no distribution, which is NOT a loss. An exited position
    # shows a badge instead of gain/loss, keeps its documents, and drops out of totals.
    exited_on: date | None = Field(default=None)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class Document(SQLModel, table=True):
    """An uploaded file. Shared to a fund (investor_user_id null) or private to one investor."""
    __tablename__ = "documents"

    id: int | None = Field(default=None, primary_key=True)
    entity_id: int = Field(foreign_key="entities.id", index=True)
    investor_user_id: int | None = Field(default=None, foreign_key="users.id", index=True)
    category: DocumentCategory = Field(default=DocumentCategory.other)
    title: str
    original_filename: str
    content_type: str
    size_bytes: int
    storage_path: str  # opaque filename on the data volume, relative to DOCS_DIR
    uploaded_by: int | None = Field(default=None, foreign_key="users.id", index=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class CapitalAccountStatement(SQLModel, table=True):
    """An investor's capital-account figures for one fund as of a date."""
    __tablename__ = "capital_account_statements"
    __table_args__ = (
        UniqueConstraint("entity_id", "investor_user_id", "as_of_date",
                         name="uq_capacct_entity_investor_date"),
    )

    id: int | None = Field(default=None, primary_key=True)
    entity_id: int = Field(foreign_key="entities.id")
    investor_user_id: int = Field(foreign_key="users.id", index=True)
    as_of_date: date
    commitment_cents: int = 0          # initial capital commitment
    beginning_balance_cents: int = 0
    contributions_cents: int = 0       # paid-in capital
    distributions_cents: int = 0       # capital returned (for DPI)
    ending_balance_cents: int = 0      # current capital value
    document_id: int | None = Field(default=None, foreign_key="documents.id", index=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)


class EntityStake(SQLModel, table=True):
    """A holder entity's ownership stake in a fund/SPV it manages.

    Models the assets of a GP or management company: its interest in each fund it manages,
    which are entities in their own right rather than portfolio-company holdings.
    """
    __tablename__ = "entity_stakes"
    __table_args__ = (
        UniqueConstraint("holder_entity_id", "fund_entity_id", name="uq_stake_holder_fund"),
    )

    id: int | None = Field(default=None, primary_key=True)
    holder_entity_id: int = Field(foreign_key="entities.id", index=True)  # the GP / mgmt co
    fund_entity_id: int = Field(foreign_key="entities.id", index=True)    # the fund/SPV held
    ownership_pct: float | None = None   # e.g. 20.0 for a 20% interest
    value_cents: int | None = None       # optional current value of the stake
    note: str | None = None
    created_at: datetime = Field(default_factory=datetime.utcnow)