from typing import List, Optional
from dataclasses import dataclass


@dataclass
class Template:

    name: str

    def __post_init__(self):

        if self.name == "vanilla":
            r"""
            Supports language model inference without histories.
            """
            self._register_template(
                prefix="",
                prompt="{query}",
                sep="",
                use_history=False
            )

        elif self.name == "alpaca":
            r"""
            Supports: https://huggingface.co/tatsu-lab/alpaca-7b-wdiff
                      https://github.com/ymcui/Chinese-LLaMA-Alpaca
            """
            self._register_template(
                prefix="Below is an instruction that describes a task. "
                       "Write a response that appropriately completes the request.\n\n",
                prompt="### Instruction:\n{query}\n\n### Response:\n",
                sep="\n\n",
                use_history=True
            )

        elif self.name == "vicuna":
            r"""
            Supports: https://huggingface.co/lmsys/vicuna-7b-delta-v1.1
                      https://huggingface.co/lmsys/vicuna-13b-delta-v1.1
            """
            self._register_template(
                prefix="A chat between a curious user and an artificial intelligence assistant. "
                       "The assistant gives helpful, detailed, and polite answers to the user's questions.",
                prompt="USER: {query} ASSISTANT: ",
                sep="</s>",
                use_history=True
            )

        elif self.name == "belle":
            r"""
            Supports: https://huggingface.co/BelleGroup/BELLE-LLaMA-EXT-13B
            """
            self._register_template(
                prefix="",
                prompt="Human: {query}\n\nBelle: ",
                sep="\n\n",
                use_history=True
            )

        elif self.name == "linly":
            r"""
            Supports: https://github.com/CVI-SZU/Linly
            """
            self._register_template(
                prefix="",
                prompt="User: {query}\nBot: ",
                sep="\n",
                use_history=True
            )

        elif self.name == "billa":
            r"""
            Supports: https://github.com/Neutralzz/BiLLa
            """
            self._register_template(
                prefix="",
                prompt="Human: {query}\nAssistant: ",
                sep="\n",
                use_history=True
            )

        elif self.name == "ziya":
            r"""
            Supports: https://huggingface.co/IDEA-CCNL/Ziya-LLaMA-13B-v1
            """
            self._register_template(
                prefix="",
                prompt="<human>:{query}\n<bot>:",
                sep="\n",
                use_history=True
            )

        elif self.name == "aquila":
            r"""
            Supports: https://huggingface.co/qhduan/aquilachat-7b
            """
            self._register_template(
                prefix="A chat between a curious human and an artificial intelligence assistant. "
                       "The assistant gives helpful, detailed, and polite answers to the human's questions.",
                prompt="Human: {query}\nAssistant: ",
                sep="###",
                use_history=True
            )

        else:
            raise ValueError("Template {} does not exist.".format(self.name))

    def get_prompt(self, query: str, history: Optional[list] = None, prefix: Optional[str] = "") -> str:
        r"""
        Returns a string containing prompt without response.
        """
        return "".join(self._format_example(query, history, prefix))

    def get_dialog(self, query: str, resp: str, history: Optional[list] = None, prefix: Optional[str] = "") -> List[str]:
        r"""
        Returns a list containing 2 * n elements where the 2k-th is a query and the (2k+1)-th is a response.
        """
        return self._format_example(query, history, prefix) + [resp]

    def _register_template(self, prefix: str, prompt: str, sep: str, use_history: Optional[bool] = True) -> None:
        self.prefix = prefix
        self.prompt = prompt
        self.sep = sep
        self.use_history = use_history

    def _format_example(self, query: str, history: Optional[list] = None, prefix: Optional[str] = "") -> List[str]:
        prefix = prefix if prefix else self.prefix
        history = history if (history and self.use_history) else []
        history = history + [(query, "<dummy>")]
        convs = []
        for turn_idx, (user_query, bot_resp) in enumerate(history):
            if turn_idx == 0:
                convs.append(prefix + self.prompt.format(query=user_query))
                convs.append(bot_resp)
            else:
                convs.append(self.sep + self.prompt.format(query=user_query))
                convs.append(bot_resp)
        return convs[:-1] # drop last