"""SQLAlchemy models for chat room management

Tables:
- incident_rooms: Stores room metadata and configuration
- room_members: User-room associations with roles
- room_templates: Predefined templates for common incident types
"""
from sqlalchemy import Column, Integer, String, Text, DateTime, Enum, ForeignKey, UniqueConstraint, Index
from sqlalchemy.orm import relationship
from datetime import datetime
import enum
import uuid
from app.core.database import Base


class IncidentType(str, enum.Enum):
    """Types of production incidents"""
    EQUIPMENT_FAILURE = "equipment_failure"
    MATERIAL_SHORTAGE = "material_shortage"
    QUALITY_ISSUE = "quality_issue"
    OTHER = "other"


class SeverityLevel(str, enum.Enum):
    """Incident severity levels"""
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    CRITICAL = "critical"


class RoomStatus(str, enum.Enum):
    """Room lifecycle status"""
    ACTIVE = "active"
    RESOLVED = "resolved"
    ARCHIVED = "archived"


class MemberRole(str, enum.Enum):
    """Room member roles"""
    OWNER = "owner"
    EDITOR = "editor"
    VIEWER = "viewer"


class IncidentRoom(Base):
    """Incident room model for production incidents"""

    __tablename__ = "incident_rooms"

    room_id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    title = Column(String(255), nullable=False)
    incident_type = Column(Enum(IncidentType), nullable=False)
    severity = Column(Enum(SeverityLevel), nullable=False)
    status = Column(Enum(RoomStatus), default=RoomStatus.ACTIVE, nullable=False)
    location = Column(String(255))
    description = Column(Text)
    resolution_notes = Column(Text)

    # User tracking
    created_by = Column(String(255), nullable=False)  # User email/ID who created the room

    # Timestamps
    created_at = Column(DateTime, default=datetime.utcnow, nullable=False)
    resolved_at = Column(DateTime)
    archived_at = Column(DateTime)
    last_activity_at = Column(DateTime, default=datetime.utcnow, nullable=False)
    last_updated_at = Column(DateTime, default=datetime.utcnow, nullable=False)

    # Ownership transfer tracking
    ownership_transferred_at = Column(DateTime)
    ownership_transferred_by = Column(String(255))

    # Denormalized count for performance
    member_count = Column(Integer, default=0, nullable=False)

    # Relationships
    members = relationship("RoomMember", back_populates="room", cascade="all, delete-orphan")
    files = relationship("RoomFile", back_populates="room", cascade="all, delete-orphan")

    # Indexes for common queries
    __table_args__ = (
        Index("ix_incident_rooms_status_created", "status", "created_at"),
        Index("ix_incident_rooms_created_by", "created_by"),
    )


class RoomMember(Base):
    """Room membership model"""

    __tablename__ = "room_members"

    id = Column(Integer, primary_key=True, autoincrement=True)
    room_id = Column(String(36), ForeignKey("incident_rooms.room_id", ondelete="CASCADE"), nullable=False)
    user_id = Column(String(255), nullable=False)  # User email/ID
    role = Column(Enum(MemberRole), nullable=False)

    # Tracking
    added_by = Column(String(255), nullable=False)  # Who added this member
    added_at = Column(DateTime, default=datetime.utcnow, nullable=False)
    removed_at = Column(DateTime)  # Soft delete timestamp

    # Relationships
    room = relationship("IncidentRoom", back_populates="members")

    # Constraints and indexes
    __table_args__ = (
        # Ensure unique active membership (where removed_at IS NULL)
        UniqueConstraint("room_id", "user_id", "removed_at", name="uq_room_member_active"),
        Index("ix_room_members_room_user", "room_id", "user_id"),
        Index("ix_room_members_user", "user_id"),
    )


class RoomTemplate(Base):
    """Predefined templates for common incident types"""

    __tablename__ = "room_templates"

    template_id = Column(Integer, primary_key=True, autoincrement=True)
    name = Column(String(100), unique=True, nullable=False)
    description = Column(Text)
    incident_type = Column(Enum(IncidentType), nullable=False)
    default_severity = Column(Enum(SeverityLevel), nullable=False)
    default_members = Column(Text)  # JSON array of user roles
    metadata_fields = Column(Text)  # JSON schema for additional fields