"""FileUploadConfig Model."""

from typing import TYPE_CHECKING, Optional

from abacus_common_logic.connectors.database import db
from abacus_common_logic.models import BaseSoftDeleteModel
from sqlalchemy import JSON, BigInteger, Column, Enum, Integer, String
from sqlalchemy.orm import Mapped
from sqlalchemy.sql.elements import UnaryExpression

from abacus_file_upload.constants import UPLOAD_TYPES

if TYPE_CHECKING:
    from abacus_file_upload.models.file_upload import FileUpload


class FileUploadConfig(BaseSoftDeleteModel):
    """FileUploadConfig Model."""

    __tablename__ = 'file_upload_config'

    file_upload_config_id: Mapped[int] = Column(
        Integer, primary_key=True, autoincrement=True, comment='Primary key.'
    )
    upload_type: Mapped[str] = Column(
        Enum(*UPLOAD_TYPES, name='upload_type', create_type=False),
        comment='Type identifier for the upload. Defines which upload configuration to use. Must be unique.',
    )
    s3_key_template: Mapped[str] = Column(
        String(255),
        default='{file_key}.{ext}',
        server_default='{file_key}.{ext}',
        comment='S3 path/key template',
    )
    allowed_file_types: Mapped[Optional[dict]] = Column(
        JSON,
        comment='Array of allowed file extensions, without leading dot and lowercase (e.g., ["csv", "pdf", "xlsx"]). NULL = allow all extensions.',
    )
    max_file_size_bytes: Mapped[int] = Column(
        BigInteger,
        default=10485760,
        server_default='10485760',
        comment='Maximum file size in bytes. Defaults to 10MB, S3 maximum is 5TB.',
    )
    multipart_threshold_bytes: Mapped[Optional[int]] = Column(
        BigInteger,
        default=104857600,
        server_default='104857600',
        comment='File size threshold for multipart upload. Defaults to 100MB, S3 maximum is 5GB.',
    )
    min_multipart_chunk_size_bytes: Mapped[Optional[int]] = Column(
        BigInteger,
        default=10485760,
        server_default='10485760',
        comment='Minimum chunk size for multipart uploads. Defaults to 10MB, S3 range is [5MB, 5GB]. Calculated chunk size should be >= this value and stay within the S3 part limit (10,000).',
    )
    description: Mapped[Optional[str]] = Column(
        String(255), comment='Description of what this upload config is for.'
    )
    event_name: Mapped[Optional[str]] = Column(
        String(32),
        nullable=True,
        comment='An event that can be configured to trigger a lambda or an Airflow DAG',
    )

    # Relationship to file_upload
    file_uploads: Mapped[list['FileUpload']] = db.relationship(
        'FileUpload', back_populates='file_upload_config', lazy='dynamic'
    )

    @classmethod
    def default_order(cls) -> UnaryExpression:
        """Override to customize default ordering."""
        return cls.upload_type.asc()

    @classmethod
    def find_by_upload_type(cls, upload_type: str) -> Optional['FileUploadConfig']:
        """Find active config by upload_type."""
        return cls.query.filter(
            cls.upload_type == upload_type, cls.deleted_at.is_(None)
        ).first()