from __future__ import annotations

import uuid
from datetime import datetime
from typing import Any

from sqlalchemy import (
    Boolean,
    DateTime,
    ForeignKey,
    Index,
    Integer,
    JSON,
    String,
    Text,
    UniqueConstraint,
)
from sqlalchemy.orm import Mapped, mapped_column, relationship

from govoplan_core.db.base import Base, TimestampMixin


def new_uuid() -> str:
    return str(uuid.uuid4())


class ViewDefinition(Base, TimestampMixin):
    __tablename__ = "view_definitions"
    __table_args__ = (
        UniqueConstraint(
            "scope_key",
            "definition_key",
            name="uq_view_definition_scope_key",
        ),
        Index("ix_view_definitions_tenant_status", "tenant_id", "status"),
        Index("ix_view_definitions_scope", "scope_type", "scope_id"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True)
    scope_type: Mapped[str] = mapped_column(String(20), nullable=False, index=True)
    scope_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    scope_key: Mapped[str] = mapped_column(String(300), nullable=False, index=True)
    definition_key: Mapped[str] = mapped_column(String(120), nullable=False)
    name: Mapped[str] = mapped_column(String(200), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)
    status: Mapped[str] = mapped_column(
        String(24), default="draft", nullable=False, index=True
    )
    current_revision: Mapped[int] = mapped_column(Integer, default=1, nullable=False)
    published_revision_id: Mapped[str | None] = mapped_column(
        String(36),
        nullable=True,
        index=True,
    )
    created_by: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )
    updated_by: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )
    deleted_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True),
        nullable=True,
        index=True,
    )

    revisions: Mapped[list["ViewRevision"]] = relationship(
        back_populates="definition",
        cascade="all, delete-orphan",
        order_by="ViewRevision.revision",
    )
    assignments: Mapped[list["ViewAssignment"]] = relationship(
        back_populates="definition",
        cascade="all, delete-orphan",
    )


class ViewRevision(Base, TimestampMixin):
    __tablename__ = "view_revisions"
    __table_args__ = (
        UniqueConstraint(
            "definition_id",
            "revision",
            name="uq_view_revision_number",
        ),
        Index("ix_view_revisions_definition", "definition_id", "revision"),
        Index("ix_view_revisions_contract", "surface_contract_version"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True)
    definition_id: Mapped[str] = mapped_column(
        ForeignKey("view_definitions.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    revision: Mapped[int] = mapped_column(Integer, nullable=False)
    surface_contract_version: Mapped[str] = mapped_column(String(20), nullable=False)
    visible_surface_ids: Mapped[list[str]] = mapped_column(
        JSON, default=list, nullable=False
    )
    presentation: Mapped[dict[str, Any]] = mapped_column(
        JSON, default=dict, nullable=False
    )
    content_hash: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    created_by: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )

    definition: Mapped[ViewDefinition] = relationship(back_populates="revisions")


class ViewAssignment(Base, TimestampMixin):
    __tablename__ = "view_assignments"
    __table_args__ = (
        UniqueConstraint(
            "target_key",
            "definition_id",
            "mode",
            name="uq_view_assignment_target_definition_mode",
        ),
        Index("ix_view_assignments_tenant_active", "tenant_id", "is_active"),
        Index("ix_view_assignments_target", "scope_type", "scope_id"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True)
    scope_type: Mapped[str] = mapped_column(String(20), nullable=False, index=True)
    scope_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    target_key: Mapped[str] = mapped_column(String(320), nullable=False, index=True)
    definition_id: Mapped[str] = mapped_column(
        ForeignKey("view_definitions.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    revision_id: Mapped[str | None] = mapped_column(
        ForeignKey("view_revisions.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    mode: Mapped[str] = mapped_column(
        String(20), default="available", nullable=False, index=True
    )
    priority: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    is_active: Mapped[bool] = mapped_column(
        Boolean, default=True, nullable=False, index=True
    )
    metadata_: Mapped[dict[str, Any]] = mapped_column(
        "metadata",
        JSON,
        default=dict,
        nullable=False,
    )
    created_by: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )
    updated_by: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )

    definition: Mapped[ViewDefinition] = relationship(back_populates="assignments")
    revision: Mapped[ViewRevision | None] = relationship()


class ViewPreference(Base, TimestampMixin):
    __tablename__ = "view_preferences"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id",
            "account_id",
            name="uq_view_preference_tenant_account",
        ),
        Index("ix_view_preferences_tenant_account", "tenant_id", "account_id"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    account_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    selection_kind: Mapped[str] = mapped_column(
        String(20),
        default="auto",
        nullable=False,
        index=True,
    )
    view_id: Mapped[str | None] = mapped_column(
        ForeignKey("view_definitions.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )


__all__ = [
    "ViewAssignment",
    "ViewDefinition",
    "ViewPreference",
    "ViewRevision",
    "new_uuid",
]