"""
models.py – SQLAlchemy ORM models for SexyChat.

Tables
------
users    – Registered accounts
messages – Encrypted PM history (user↔user and user↔AI)
"""

from datetime import datetime
from database import db


class User(db.Model):
    __tablename__ = "users"

    id               = db.Column(db.Integer, primary_key=True)
    username         = db.Column(db.String(20), unique=True, nullable=False, index=True)
    password_hash    = db.Column(db.String(128), nullable=False)
    email            = db.Column(db.String(255), unique=True, nullable=True)
    has_ai_access    = db.Column(db.Boolean, default=False, nullable=False)
    ai_messages_used = db.Column(db.Integer, default=0, nullable=False)
    is_verified      = db.Column(db.Boolean, default=False, nullable=False)
    created_at       = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)

    sent_messages     = db.relationship(
        "Message", foreign_keys="Message.sender_id",
        backref="sender", lazy="dynamic",
    )
    received_messages = db.relationship(
        "Message", foreign_keys="Message.recipient_id",
        backref="recipient", lazy="dynamic",
    )

    # Persistent "Ignore" list
    ignoring = db.relationship(
        "User",
        secondary="user_ignores",
        primaryjoin="User.id == UserIgnore.ignorer_id",
        secondaryjoin="User.id == UserIgnore.ignored_id",
        backref=db.backref("ignored_by", lazy="dynamic"),
        lazy="dynamic"
    )

    def __repr__(self):
        return f"<User {self.username!r}>"


class UserIgnore(db.Model):
    __tablename__ = "user_ignores"

    id         = db.Column(db.Integer, primary_key=True)
    ignorer_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False)
    ignored_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)

    __table_args__ = (
        db.Index("ix_ignore_pair", "ignorer_id", "ignored_id", unique=True),
    )



class Message(db.Model):
    __tablename__ = "messages"

    id                = db.Column(db.Integer, primary_key=True)
    sender_id         = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False)
    recipient_id      = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False)
    # AES-GCM ciphertext – base64 encoded; server never stores plaintext
    encrypted_content = db.Column(db.Text, nullable=False)
    # AES-GCM nonce / IV – base64 encoded (12 bytes → 16 chars)
    nonce             = db.Column(db.String(64), nullable=False)
    timestamp         = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)

    __table_args__ = (
        # Composite indices for the two common query patterns
        db.Index("ix_msg_recipient_ts", "recipient_id", "timestamp"),
        db.Index("ix_msg_sender_ts",    "sender_id",    "timestamp"),
    )

    def __repr__(self):
        return f"<Message {self.sender_id}→{self.recipient_id} @ {self.timestamp}>"