from collections import Iterable


class Checks:
    """Class of predicates for waiting events

    This class requires you to pass ctx so that the person who
    invocated the command can be determined.

    You may pass an optional iterable in custom to check if the
    content is a member of it."""

    def __init__(self, ctx, custom: Iterable = None):
        self.ctx = ctx
        self.custom = custom

    def confirm(self, m):
        return self.ctx.author == m.author and m.content.lower() in ('yes', 'no')

    def valid_int(self, m):
        return self.ctx.author == m.author and m.content.isdigit()

    def positive(self, m):
        return self.ctx.author == m.author and m.content.isdigit() and int(m.content) > 0

    def role(self, m):
        roles = [r.name for r in self.ctx.guild.roles if r.name != "Bot"]
        return self.ctx.author == m.author and m.content in roles

    def member(self, m):
        return self.ctx.author == m.author and m.content in [x.name for x in self.ctx.guild.members]

    def content(self, m):
        if self.content is not None:
            return self.ctx.author == m.author and m.content in self.custom
        else:
            raise ValueError("Custom must be set for this check.")