from __future__ import annotations

from datetime import datetime
from typing import Any
import uuid

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

from govoplan_core.db.base import Base, TimestampMixin


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


class ApprovalRequestRevision(Base, TimestampMixin):
    __tablename__ = "approval_request_revisions"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "request_id", "revision", name="uq_approval_request_revision"
        ),
        Index(
            "ix_approval_request_current", "tenant_id", "request_id", "superseded_at"
        ),
        Index(
            "ix_approval_request_subject",
            "tenant_id",
            "subject_module",
            "subject_type",
            "subject_id",
            "state",
        ),
    )

    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)
    request_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    revision: Mapped[int] = mapped_column(Integer, nullable=False)
    previous_revision_id: Mapped[str | None] = mapped_column(
        ForeignKey("approval_request_revisions.id", ondelete="RESTRICT"),
        nullable=True,
        index=True,
    )
    state: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    current_step_key: Mapped[str | None] = mapped_column(
        String(120), nullable=True, index=True
    )
    subject_module: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    subject_type: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    subject_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    subject_version: Mapped[str | None] = mapped_column(
        String(120), nullable=True, index=True
    )
    subject_digest: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    recorded_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    superseded_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True), nullable=True, index=True
    )
    payload: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False)
    actor_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)


class ApprovalDecisionRecord(Base, TimestampMixin):
    __tablename__ = "approval_decision_records"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id",
            "request_id",
            "step_key",
            "effective_actor_id",
            name="uq_approval_step_actor",
        ),
        UniqueConstraint(
            "tenant_id",
            "request_id",
            "idempotency_key",
            name="uq_approval_decision_replay",
        ),
        Index("ix_approval_decision_history", "tenant_id", "request_id", "recorded_at"),
    )

    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)
    request_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    request_revision: Mapped[int] = mapped_column(Integer, nullable=False)
    step_key: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    outcome: Mapped[str] = mapped_column(String(20), nullable=False, index=True)
    reason: Mapped[str] = mapped_column(String(4000), nullable=False)
    actor_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    effective_actor_id: Mapped[str] = mapped_column(
        String(255), nullable=False, index=True
    )
    delegation_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
    authority_provenance: Mapped[dict[str, Any]] = mapped_column(
        JSON, nullable=False, default=dict
    )
    signature_ref: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    recorded_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    idempotency_key: Mapped[str] = mapped_column(String(160), nullable=False)
    receipt_sha256: Mapped[str] = mapped_column(String(64), nullable=False, index=True)


class ApprovalLifecycleEvent(Base, TimestampMixin):
    __tablename__ = "approval_lifecycle_events"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "request_id", "sequence", name="uq_approval_event_sequence"
        ),
    )

    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)
    request_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    sequence: Mapped[int] = mapped_column(Integer, nullable=False)
    event_type: Mapped[str] = mapped_column(String(60), nullable=False, index=True)
    recorded_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    actor_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
    payload: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False, default=dict)


class ApprovalReplay(Base, TimestampMixin):
    __tablename__ = "approval_replays"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "operation", "idempotency_key", name="uq_approval_replay"
        ),
    )

    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)
    operation: Mapped[str] = mapped_column(String(80), nullable=False, index=True)
    idempotency_key: Mapped[str] = mapped_column(String(160), nullable=False)
    request_sha256: Mapped[str] = mapped_column(String(64), nullable=False)
    response: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False)


class ApprovalTemplateRevision(Base, TimestampMixin):
    __tablename__ = "approval_template_revisions"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "template_id", "revision", name="uq_approval_template_revision"
        ),
        UniqueConstraint(
            "tenant_id", "key", "revision", name="uq_approval_template_key_revision"
        ),
        Index(
            "ix_approval_template_current", "tenant_id", "template_id", "superseded_at"
        ),
    )

    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)
    template_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    key: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    revision: Mapped[int] = mapped_column(Integer, nullable=False)
    previous_revision_id: Mapped[str | None] = mapped_column(
        ForeignKey("approval_template_revisions.id", ondelete="RESTRICT"),
        nullable=True,
        index=True,
    )
    state: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    content_sha256: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    recorded_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    superseded_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True), nullable=True, index=True
    )
    payload: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False)
    actor_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)


__all__ = [
    "ApprovalDecisionRecord",
    "ApprovalLifecycleEvent",
    "ApprovalReplay",
    "ApprovalRequestRevision",
    "ApprovalTemplateRevision",
]