from . import db

# tag to object relationship table
image_tags = db.Table(
    "image_tags",
    db.Column(
        "image_id", db.Integer,
        db.ForeignKey("image_record.id", ondelete="CASCADE"),
        primary_key=True,
    ),
    db.Column(
        "tag_id", db.Integer,
        db.ForeignKey("tag.id", ondelete="CASCADE"),
        primary_key=True,
    ),
    db.UniqueConstraint("image_id", "tag_id", name="uq_image_tag"),
)

class ImageRecord(db.Model):
    __tablename__ = "image_record"
    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(64), nullable=True)  # hex of 256-bit hash
    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",
        passive_deletes=True,
    )

class Tag(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(255), unique=True, nullable=False)
    kind = db.Column(db.String(64), nullable=True)
    images = db.relationship(
        "ImageRecord",
        secondary=image_tags,
        back_populates="tags",
        passive_deletes=True,
    )

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.
    """
    __tablename__ = "archive_record"
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(512), nullable=False)
    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())
    artist = db.Column(db.String(255), nullable=True)
    tag_id = db.Column(db.Integer, db.ForeignKey("tag.id", ondelete="SET NULL"), nullable=True)
    tag = db.relationship("Tag")


class AppSettings(db.Model):
    """
    Key-value store for application settings and version tracking.
    Used to persist configuration and trigger data migrations on version changes.
    """
    __tablename__ = "app_settings"
    id = db.Column(db.Integer, primary_key=True)
    key = db.Column(db.String(64), unique=True, nullable=False)
    value = db.Column(db.Text, nullable=True)
    updated_at = db.Column(db.DateTime, default=db.func.now(), onupdate=db.func.now())