from . import db
from flask_login import UserMixin
from . import login_manager
from datetime import datetime

# tag to object relationship table
image_tags = db.Table(
    'image_tags',
    db.Column('image_id', db.Integer, db.ForeignKey('image_record.id'), primary_key=True),
    db.Column('tag_id', db.Integer, db.ForeignKey('tag.id'), primary_key=True),
    db.UniqueConstraint('image_id', 'tag_id', name='uq_image_tag')  # prevent duplicate tags per image
)

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password_hash = db.Column(db.String(256), nullable=False)
    is_admin = db.Column(db.Boolean, default=False)

class ImageRecord(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), nullable=False)
    filepath = db.Column(db.String(512), nullable=False)
    thumb_path = db.Column(db.String(512))
    hash = db.Column(db.String(64), unique=True, nullable=False)  # SHA256
    perceptual_hash = db.Column(db.String(16), nullable=True)  # hex of 64-bit hash
    artist = db.Column(db.String(255), nullable=True)
    file_size = db.Column(db.Integer, nullable=True)
    width = db.Column(db.Integer, nullable=True)
    height = db.Column(db.Integer, nullable=True)
    format = db.Column(db.String(10), nullable=True)
    camera_model = db.Column(db.String(255), nullable=True)
    taken_at = db.Column(db.DateTime, nullable=True)
    imported_at = db.Column(db.DateTime, default=db.func.now())
    is_thumbnail = db.Column(db.Boolean, default=False)
    tags = db.relationship('Tag', secondary=image_tags, back_populates='images')

class Tag(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    # Tag names are unique so we can upsert quickly (e.g. "zip:Artist/ArchiveName.zip")
    name = db.Column(db.String(255), unique=True, nullable=False)
    # Optional “kind” if you want to filter by tag type later ("zip", "import-source", etc.)
    kind = db.Column(db.String(64), nullable=True)

    images = db.relationship('ImageRecord', secondary=image_tags, back_populates='tags')

class ArchiveRecord(db.Model):
    """
    Tracks archives we've processed so we can skip re-importing the same large file.
    Also holds a Tag that marks images that came from this archive.
    """
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(512), nullable=False)  # full path or logical name
    file_size = db.Column(db.BigInteger, nullable=False)
    hash = db.Column(db.String(64), unique=True, nullable=False)  # SHA256 of the archive file
    imported_at = db.Column(db.DateTime, default=db.func.now())

    # optional: where this archive lived in the source tree (e.g., artist dir)
    artist = db.Column(db.String(255), nullable=True)

    # Link to the tag we created for this archive so we can reuse it if the same archive returns
    tag_id = db.Column(db.Integer, db.ForeignKey('tag.id'), nullable=False)
    tag = db.relationship('Tag', backref=db.backref('archives', lazy='dynamic'))

@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))