from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Enum, UniqueConstraint
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from app.core.config import Base
import enum

class MeetingStatus(str, enum.Enum):
    SCHEDULED = "scheduled"
    IN_PROGRESS = "in_progress"
    COMPLETED = "completed"
    CANCELLED = "cancelled"

class MeetingPriority(str, enum.Enum):
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    CRITICAL = "critical"

class Meeting(Base):
    __tablename__ = "meetings"
    
    id = Column(Integer, primary_key=True, index=True)
    title = Column(String(255), nullable=False)
    description = Column(Text, nullable=True)
    status = Column(Enum(MeetingStatus, values_callable=lambda x: [e.value for e in x]), default=MeetingStatus.SCHEDULED)
    priority = Column(Enum(MeetingPriority, values_callable=lambda x: [e.value for e in x]), default=MeetingPriority.MEDIUM)
    meeting_code = Column(String(64), nullable=True, unique=True, index=True)
    
    project_id = Column(Integer, ForeignKey("projects.id"), nullable=False)
    milestone_id = Column(Integer, ForeignKey("milestones.id"), nullable=False)
    reporter_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    
    scheduled_at = Column(DateTime(timezone=True), nullable=True)
    duration_minutes = Column(Integer, nullable=True)
    
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

    participants = relationship("MeetingParticipant", back_populates="meeting", cascade="all, delete-orphan")


class MeetingParticipant(Base):
    __tablename__ = "meeting_participants"
    __table_args__ = (
        UniqueConstraint("meeting_id", "user_id", name="uq_meeting_participant"),
    )

    id = Column(Integer, primary_key=True, index=True)
    meeting_id = Column(Integer, ForeignKey("meetings.id", ondelete="CASCADE"), nullable=False)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    joined_at = Column(DateTime(timezone=True), server_default=func.now())

    meeting = relationship("Meeting", back_populates="participants")