from sqlalchemy import Boolean, Column, DateTime, Integer, String, Text, UniqueConstraint

from app import db
from .base import SoftDeleteMixin, TimestampMixin, default_uuid


class SyncMetadata(db.Model, TimestampMixin, SoftDeleteMixin):
    """Метаданные синхронизации (паспорт узла)."""

    __tablename__ = "sync_metadata"

    id = Column(String(36), primary_key=True, default=default_uuid)
    node_id = Column(String(36), nullable=False, unique=True)
    node_type = Column(String(20), nullable=False)  # 'server' | 'client'
    node_name = Column(String(100), nullable=True)
    node_status = Column(String(20), default="active")
    last_heartbeat = Column(DateTime, nullable=True)
    last_sync = Column(DateTime, nullable=True)
    sync_status = Column(String(20), default="idle")
    is_enabled = Column(Boolean, default=True)


class SyncClient(db.Model, TimestampMixin, SoftDeleteMixin):
    """Реестр клиентов синхронизации."""

    __tablename__ = "sync_clients"

    id = Column(String(36), primary_key=True, default=default_uuid)
    node_id = Column(String(36), nullable=False, unique=True)
    client_name = Column(String(100), nullable=False)
    ip_address = Column(String(45), nullable=True)
    port = Column(Integer, default=80)
    status = Column(String(20), default="active")
    last_seen = Column(DateTime, nullable=True)
    total_syncs = Column(Integer, default=0)
    last_error = Column(Text, nullable=True)
    is_enabled = Column(Boolean, default=True)
    personal_snapshot_completed_at = Column(DateTime, nullable=True)
    personal_snapshot_cursor = Column(Integer, nullable=False, default=0)


class SyncEngineState(db.Model, TimestampMixin, SoftDeleteMixin):
    """Durable flags/cursors for sync engine bootstrap."""

    __tablename__ = "sync_engine_state"

    id = Column(Integer, primary_key=True, default=1)
    universal_bootstrap_completed_at = Column(DateTime, nullable=True)
    universal_bootstrap_cursor = Column(Integer, nullable=False, default=0)
    universal_bootstrap_last_error = Column(Text, nullable=True)


class SyncClientDisplayName(db.Model):
    """Привязка клиента к отображаемому имени (для UI)."""

    __tablename__ = "sync_client_display_name"

    node_id = Column(String(36), primary_key=True)
    display_name = Column(String(100), nullable=False)
    updated_at = Column(DateTime, nullable=False)


class SyncQueue(db.Model, TimestampMixin, SoftDeleteMixin):
    """Очередь задач синхронизации."""

    __tablename__ = "sync_queue"
    __table_args__ = (
        UniqueConstraint(
            "table_name",
            "record_id",
            "action",
            "target_node_id",
            name="uq_sync_queue_task",
        ),
    )

    id = Column(String(36), primary_key=True, default=default_uuid)
    table_name = Column(String(50), nullable=False)
    record_id = Column(String(36), nullable=False)
    action = Column(String(20), nullable=False)  # 'create' | 'update' | 'delete'
    status = Column(String(20), default="pending")  # pending|processing|completed|failed
    target_node_id = Column(String(36), nullable=True)
    source_node_id = Column(String(36), nullable=True)
    priority = Column(Integer, default=1)
    retry_count = Column(Integer, default=0)
    max_retries = Column(Integer, default=3)
    error_message = Column(Text, nullable=True)
    created_at = Column(DateTime, nullable=False)
    processed_at = Column(DateTime, nullable=True)
    completed_at = Column(DateTime, nullable=True)


class SyncDelivery(db.Model, TimestampMixin, SoftDeleteMixin):
    """Фиксация доставки универсальных задач до клиентов."""

    __tablename__ = "sync_delivery"

    id = Column(String(36), primary_key=True, default=default_uuid)
    client_id = Column(String(36), nullable=False, index=True)
    task_id = Column(String(36), nullable=False, index=True)
    delivered_at = Column(DateTime, nullable=False)


class SyncConflict(db.Model, TimestampMixin, SoftDeleteMixin):
    """Конфликты синхронизации."""

    __tablename__ = "sync_conflicts"

    id = Column(String(36), primary_key=True, default=default_uuid)
    table_name = Column(String(50), nullable=False)
    record_id = Column(String(36), nullable=False)
    conflict_type = Column(String(20), nullable=False)
    local_data = Column(Text, nullable=True)
    remote_data = Column(Text, nullable=True)
    resolution = Column(String(20), nullable=True)
    resolved_by = Column(String(50), nullable=True)
    resolved_at = Column(DateTime, nullable=True)