from __future__ import annotations

from datetime import datetime
from typing import Any
import uuid

from sqlalchemy import DateTime, ForeignKey, Index, Integer, JSON, String, Text, 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 Ticket(Base, TimestampMixin):
    __tablename__ = "tickets"
    __table_args__ = (
        UniqueConstraint("tenant_id", "ticket_number", name="uq_ticket_number"),
        Index("ix_ticket_queue", "tenant_id", "queue_ref", "status", "priority"),
        Index("ix_ticket_catalog", "tenant_id", "status", "updated_at"),
        Index("ix_ticket_service_target", "tenant_id", "service_target_at", "status"),
    )

    id: Mapped[str] = mapped_column(String(255), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    ticket_number: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    revision: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
    ticket_type: Mapped[str] = mapped_column(String(80), nullable=False, index=True)
    priority: Mapped[str] = mapped_column(String(40), nullable=False, index=True)
    status: Mapped[str] = mapped_column(String(40), nullable=False, index=True)
    title: Mapped[str] = mapped_column(String(500), nullable=False)
    description: Mapped[str] = mapped_column(Text, nullable=False)
    visibility: Mapped[str] = mapped_column(String(40), nullable=False, index=True)
    queue_ref: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    assignee: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    reporter: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    requester: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    participants: Mapped[list[dict[str, Any]]] = mapped_column(JSON, nullable=False, default=list)
    links: Mapped[list[dict[str, Any]]] = mapped_column(JSON, nullable=False, default=list)
    metadata_payload: Mapped[dict[str, Any]] = mapped_column("metadata", JSON, nullable=False, default=dict)
    search_text: Mapped[str] = mapped_column(Text, nullable=False)
    received_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, index=True)
    recorded_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, index=True)
    change_reason: Mapped[str] = mapped_column(String(1_000), nullable=False)
    service_target_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    resolved_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    resolution_summary: Mapped[str | None] = mapped_column(Text, nullable=True)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), 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)


class TicketHistory(Base, TimestampMixin):
    __tablename__ = "ticket_history"
    __table_args__ = (
        UniqueConstraint("tenant_id", "ticket_id", "revision", name="uq_ticket_history_revision"),
        UniqueConstraint("tenant_id", "idempotency_key", name="uq_ticket_history_idempotency"),
        Index("ix_ticket_history_timeline", "tenant_id", "ticket_id", "occurred_at"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    ticket_id: Mapped[str] = mapped_column(
        ForeignKey("tickets.id", ondelete="RESTRICT"), nullable=False, index=True
    )
    revision: Mapped[int] = mapped_column(Integer, nullable=False)
    event_type: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    occurred_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, index=True)
    actor_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    reason: Mapped[str] = mapped_column(String(1_000), nullable=False)
    idempotency_key: Mapped[str] = mapped_column(String(255), nullable=False)
    request_sha256: Mapped[str] = mapped_column(String(64), nullable=False)
    snapshot: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False)
    details: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False, default=dict)


class TicketComment(Base, TimestampMixin):
    __tablename__ = "ticket_comments"
    __table_args__ = (
        UniqueConstraint("tenant_id", "comment_id", name="uq_ticket_comment"),
        Index("ix_ticket_comment_timeline", "tenant_id", "ticket_id", "created_at"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    ticket_id: Mapped[str] = mapped_column(
        ForeignKey("tickets.id", ondelete="RESTRICT"), nullable=False, index=True
    )
    comment_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    ticket_revision: Mapped[int] = mapped_column(Integer, nullable=False)
    visibility: Mapped[str] = mapped_column(String(40), nullable=False, index=True)
    body: Mapped[str] = mapped_column(Text, nullable=False)
    created_by: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)


class TicketEscalation(Base, TimestampMixin):
    __tablename__ = "ticket_escalations"
    __table_args__ = (
        UniqueConstraint("tenant_id", "ticket_id", "idempotency_key", name="uq_ticket_escalation_replay"),
        UniqueConstraint("tenant_id", "provider_id", "case_id", name="uq_ticket_case_link"),
        Index("ix_ticket_escalation_timeline", "tenant_id", "ticket_id", "occurred_at"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    ticket_id: Mapped[str] = mapped_column(
        ForeignKey("tickets.id", ondelete="RESTRICT"), nullable=False, index=True
    )
    provider_id: Mapped[str] = mapped_column(String(200), nullable=False, index=True)
    idempotency_key: Mapped[str] = mapped_column(String(255), nullable=False)
    request_sha256: Mapped[str] = mapped_column(String(64), nullable=False)
    occurred_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, index=True)
    actor_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    case_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    case_number: Mapped[str] = mapped_column(String(255), nullable=False)
    case_url: Mapped[str] = mapped_column(String(1_500), nullable=False)
    handoff_note: Mapped[str | None] = mapped_column(Text, nullable=True)
    outcome: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False, default=dict)


__all__ = ["Ticket", "TicketComment", "TicketEscalation", "TicketHistory"]