Source code for cloup.constraints.exceptions

from collections.abc import Iterable, Sequence
from typing import TYPE_CHECKING

import click
from click import Context, Parameter

from .common import join_param_labels

if TYPE_CHECKING:
    from ._core import Constraint




def default_constraint_error(params: Iterable[Parameter], desc: str) -> str:
    return f"the following constraint on parameters [{join_param_labels(params)}] was not satisfied: {desc}"





class ConstraintViolated(click.UsageError):
    def __init__(
        self,
        message: str,
        ctx: Context,
        constraint: "Constraint",
        params: Sequence[click.Parameter],
    ):
        super().__init__(message, ctx=ctx)
        self.ctx = ctx
        self.constraint = constraint
        self.params = params



    @classmethod
    def default(
        cls,
        desc: str,
        ctx: Context,
        constraint: "Constraint",
        params: Sequence[Parameter],
    ) -> "ConstraintViolated":
        return ConstraintViolated(
            default_constraint_error(params, desc),
            ctx=ctx,
            constraint=constraint,
            params=params,
        )






class UnsatisfiableConstraint(Exception):
    """Raised if a constraint cannot be satisfied by a group of parameters
    independently from their values at runtime; e.g. ``mutually_exclusive`` cannot
    be satisfied if multiple of the parameters are required."""

    def __init__(
        self, constraint: "Constraint", params: Iterable[Parameter], reason: str
    ):
        self.constraint = constraint
        self.params = params
        self.reason = reason
        param_names = join_param_labels(params)
        message = (
            f"\nthe constraint {constraint}\n"
            f"defined on parameters [{param_names}]\n"
            f"cannot be satisfied because {reason}"
        )
        super().__init__(message)