"""
Creates different AI instances, based on the given configuration.
"""

import argparse
from typing import cast
from .configuration import Config, AIConfig, OpenAIConfig
from .ai import AI, AIError
from .ais.openai import OpenAI


def create_ai(args: argparse.Namespace, config: Config) -> AI:  # noqa: 11
    """
    Creates an AI subclass instance from the given arguments
    and configuration file. If AI has not been set in the
    arguments, it searches for the ID 'default'. If that
    is not found, it uses the first AI in the list.
    """
    ai_conf: AIConfig
    if args.AI:
        try:
            ai_conf = config.ais[args.AI]
        except KeyError:
            raise AIError(f"AI ID '{args.AI}' does not exist in this configuration")
    elif 'default' in config.ais:
        ai_conf = config.ais['default']
    else:
        try:
            ai_conf = next(iter(config.ais.values()))
        except StopIteration:
            raise AIError("No AI found in this configuration")

    if ai_conf.name == 'openai':
        ai = OpenAI(cast(OpenAIConfig, ai_conf))
        if args.model:
            ai.config.model = args.model
        if args.max_tokens:
            ai.config.max_tokens = args.max_tokens
        if args.temperature:
            ai.config.temperature = args.temperature
        return ai
    else:
        raise AIError(f"AI '{args.AI}' is not supported")