from sqlalchemy import Column, Integer, String, Text, DateTime, Boolean, ForeignKey, Enum
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from database import Base
import enum

class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True, index=True)
    username = Column(String(50), unique=True, index=True, nullable=False)
    display_name = Column(String(100), nullable=False)
    email = Column(String(255), unique=True, index=True, nullable=True)
    hashed_password = Column(String, nullable=True)
    google_id = Column(String, unique=True, nullable=True)
    avatar_color = Column(String(7), default="#6366f1")
    public_key = Column(Text, nullable=True)  # RSA public key for E2EE
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    is_online = Column(Boolean, default=False)
    last_seen = Column(DateTime(timezone=True), nullable=True)

    sent_messages = relationship("Message", foreign_keys="Message.sender_id", back_populates="sender")
    conversations = relationship("ConversationMember", back_populates="user")
    group_memberships = relationship("GroupMember", back_populates="user")

class Conversation(Base):
    __tablename__ = "conversations"

    id = Column(Integer, primary_key=True, index=True)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    members = relationship("ConversationMember", back_populates="conversation")
    messages = relationship("Message", back_populates="conversation", order_by="Message.created_at")

class ConversationMember(Base):
    __tablename__ = "conversation_members"

    id = Column(Integer, primary_key=True)
    conversation_id = Column(Integer, ForeignKey("conversations.id"))
    user_id = Column(Integer, ForeignKey("users.id"))

    conversation = relationship("Conversation", back_populates="members")
    user = relationship("User", back_populates="conversations")

class Message(Base):
    __tablename__ = "messages"

    id = Column(Integer, primary_key=True, index=True)
    conversation_id = Column(Integer, ForeignKey("conversations.id"))
    sender_id = Column(Integer, ForeignKey("users.id"))
    # Encrypted ciphertext (base64 encoded, encrypted with recipient's public key)
    ciphertext_for_recipient = Column(Text, nullable=False)
    # Also store for sender so they can read their own messages
    ciphertext_for_sender = Column(Text, nullable=True)
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    is_read = Column(Boolean, default=False)

    sender = relationship("User", foreign_keys=[sender_id], back_populates="sent_messages")
    conversation = relationship("Conversation", back_populates="messages")

class Group(Base):
    __tablename__ = "groups"

    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(100), nullable=False)
    description = Column(String(255), nullable=True)
    created_by = Column(Integer, ForeignKey("users.id"))
    avatar_color = Column(String(7), default="#8b5cf6")
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    members = relationship("GroupMember", back_populates="group")
    messages = relationship("GroupMessage", back_populates="group", order_by="GroupMessage.created_at")
    creator = relationship("User", foreign_keys=[created_by])

class GroupMember(Base):
    __tablename__ = "group_members"

    id = Column(Integer, primary_key=True)
    group_id = Column(Integer, ForeignKey("groups.id"))
    user_id = Column(Integer, ForeignKey("users.id"))
    role = Column(String(20), default="member")  # admin, member
    joined_at = Column(DateTime(timezone=True), server_default=func.now())

    group = relationship("Group", back_populates="members")
    user = relationship("User", back_populates="group_memberships")

class GroupMessage(Base):
    __tablename__ = "group_messages"

    id = Column(Integer, primary_key=True, index=True)
    group_id = Column(Integer, ForeignKey("groups.id"))
    sender_id = Column(Integer, ForeignKey("users.id"))
    # For group chats: AES key encrypted per-member (stored as JSON), message encrypted with AES
    encrypted_aes_keys = Column(Text, nullable=False)  # JSON: {user_id: encrypted_aes_key}
    ciphertext = Column(Text, nullable=False)  # AES-GCM encrypted message
    iv = Column(String(100), nullable=False)  # AES-GCM IV
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    sender = relationship("User", foreign_keys=[sender_id])
    group = relationship("Group", back_populates="messages")