from __future__ import annotations

from typing import TYPE_CHECKING, Optional

import attrs

from ...pipeline import Step
from ...platform import platform

if TYPE_CHECKING:
    from ...resource import Resource


@attrs.define(kw_only=True, repr=False)
class row_search(Step):
    """Search rows.

    This step can be added using the `steps` parameter
    for the `transform` function.

    """

    type = "row-search"

    regex: str
    """
    Regex pattern to search for rows. If field_name is set it
    will only be applied to the specified field. For example, regex=r"^e.*".
    """

    field_name: Optional[str] = None
    """
    Field name in which to search for.
    """

    negate: bool = False
    """
    Whether to revert the result. If True, all the rows that does
    not match the pattern will be returned.
    """

    # Transform

    def transform_resource(self, resource: Resource):
        table = resource.to_petl()  # type: ignore
        search = platform.petl.searchcomplement if self.negate else platform.petl.search  # type: ignore
        if self.field_name:
            resource.data = search(table, self.field_name, self.regex)  # type: ignore
        else:
            resource.data = search(table, self.regex)  # type: ignore

    # Metadata

    metadata_profile_patch = {
        "required": ["regex"],
        "properties": {
            "regex": {},
            "fieldName": {"type": "string"},
            "negate": {},
        },
    }