import uuid
from datetime import datetime, timezone

from flask_login import UserMixin
from werkzeug.security import check_password_hash, generate_password_hash

from app import db


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

    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False, index=True)
    email = db.Column(db.String(120), unique=True, nullable=False, index=True)
    password_hash = db.Column(db.String(256), nullable=False)
    is_admin = db.Column(db.Boolean, nullable=False, default=False)
    is_active = db.Column(db.Boolean, nullable=False, default=True)
    created_at = db.Column(
        db.DateTime,
        nullable=False,
        default=lambda: datetime.now(timezone.utc),
    )

    photos = db.relationship("Photo", backref="owner", lazy="dynamic")
    folders = db.relationship("Folder", backref="owner", lazy="dynamic")

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        return check_password_hash(self.password_hash, password)

    @property
    def photo_count(self):
        return self.photos.count()

    @property
    def total_size(self):
        from sqlalchemy import func

        result = db.session.query(func.coalesce(func.sum(Photo.file_size), 0)).filter(
            Photo.user_id == self.id
        ).scalar()
        return int(result or 0)


class Folder(db.Model):
    __tablename__ = "folders"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(120), nullable=False)
    owner_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False, index=True)
    share_token = db.Column(db.String(64), unique=True, nullable=False, index=True)
    is_private = db.Column(db.Boolean, nullable=False, default=True)
    password_hash = db.Column(db.String(256), nullable=True)
    created_at = db.Column(
        db.DateTime,
        nullable=False,
        default=lambda: datetime.now(timezone.utc),
    )

    photos = db.relationship("Photo", backref="folder", lazy="dynamic")
    members = db.relationship("FolderMember", backref="folder", lazy="dynamic", cascade="all, delete-orphan")
    invites = db.relationship("FolderInvite", backref="folder", lazy="dynamic", cascade="all, delete-orphan")

    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        if not self.share_token:
            self.share_token = uuid.uuid4().hex

    def set_access_password(self, password):
        if password:
            self.password_hash = generate_password_hash(password)
        else:
            self.password_hash = None

    def check_access_password(self, password):
        if not self.password_hash:
            return True
        return check_password_hash(self.password_hash, password)

    @property
    def has_password(self):
        return bool(self.password_hash)

    @property
    def photo_count(self):
        return self.photos.count()

    def regenerate_share_token(self):
        self.share_token = uuid.uuid4().hex


class FolderMember(db.Model):
    __tablename__ = "folder_members"

    id = db.Column(db.Integer, primary_key=True)
    folder_id = db.Column(db.Integer, db.ForeignKey("folders.id"), nullable=False, index=True)
    user_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False, index=True)
    role = db.Column(db.String(20), nullable=False, default="viewer")
    added_at = db.Column(
        db.DateTime,
        nullable=False,
        default=lambda: datetime.now(timezone.utc),
    )
    added_by_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=True)

    user = db.relationship("User", foreign_keys=[user_id])
    added_by = db.relationship("User", foreign_keys=[added_by_id])

    __table_args__ = (db.UniqueConstraint("folder_id", "user_id", name="uq_folder_member"),)


class FolderInvite(db.Model):
    __tablename__ = "folder_invites"

    id = db.Column(db.Integer, primary_key=True)
    folder_id = db.Column(db.Integer, db.ForeignKey("folders.id"), nullable=False, index=True)
    email = db.Column(db.String(120), nullable=False, index=True)
    role = db.Column(db.String(20), nullable=False, default="viewer")
    invited_by_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=False)
    created_at = db.Column(
        db.DateTime,
        nullable=False,
        default=lambda: datetime.now(timezone.utc),
    )

    invited_by = db.relationship("User", foreign_keys=[invited_by_id])

    __table_args__ = (db.UniqueConstraint("folder_id", "email", name="uq_folder_invite"),)


class Photo(db.Model):
    __tablename__ = "photos"

    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), nullable=False)
    original_name = db.Column(db.String(255), nullable=False)
    file_size = db.Column(db.Integer, nullable=False, default=0)
    mime_type = db.Column(db.String(100), nullable=False, default="image/jpeg")
    user_id = db.Column(db.Integer, db.ForeignKey("users.id"), nullable=True, index=True)
    folder_id = db.Column(db.Integer, db.ForeignKey("folders.id"), nullable=True, index=True)
    created_at = db.Column(
        db.DateTime,
        nullable=False,
        default=lambda: datetime.now(timezone.utc),
    )

    @property
    def url(self):
        return f"/uploads/{self.filename}"

    @property
    def size_human(self):
        size = self.file_size
        for unit in ("Б", "КБ", "МБ", "ГБ"):
            if size < 1024:
                return f"{size:.0f} {unit}" if unit == "Б" else f"{size:.1f} {unit}"
            size /= 1024
        return f"{size:.1f} ТБ"