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

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


def create_ai(args: argparse.Namespace, config: Config,  # noqa: 11
              def_ai: Optional[str] = None,
              def_model: Optional[str] = None) -> AI:
    """
    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. It's also possible to
    specify a default AI and model using 'def_ai' and 'def_model'.
    """
    ai_conf: AIConfig
    if hasattr(args, 'AI') and 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 def_ai:
        ai_conf = config.ais[def_ai]
    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 hasattr(args, 'model') and args.model:
            ai.config.model = args.model
        elif def_model:
            ai.config.model = def_model
        if hasattr(args, 'max_tokens') and args.max_tokens:
            ai.config.max_tokens = args.max_tokens
        if hasattr(args, 'temperature') and args.temperature:
            ai.config.temperature = args.temperature
        return ai
    else:
        raise AIError(f"AI '{args.AI}' is not supported")