# Copyright (c) Alibaba Cloud.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.

"""A simple command-line interactive chat demo."""

import argparse
import os
import platform
import shutil
from copy import deepcopy

from transformers import AutoModelForCausalLM, AutoTokenizer
from transformers.generation import GenerationConfig
from transformers.trainer_utils import set_seed

DEFAULT_CKPT_PATH = 'QWen/QWen-7B-Chat'

_WELCOME_MSG = '''\
Welcome to use Qwen-7B-Chat model, type text to start chat, type :h to show command help
欢迎使用 Qwen-7B 模型，输入内容即可进行对话，:h 显示命令帮助
'''
_HELP_MSG = '''\
Commands:
    :help / :h          Show this help message              显示帮助信息
    :exit / :quit / :q  Exit the demo                       退出Demo
    :clear / :cl        Clear screen                        清屏
    :clear-his / :clh   Clear history                       清除对话历史
    :history / :his     Show history                        显示对话历史
    :seed               Show current random seed            显示当前随机种子
    :seed <N>           Set random seed to <N>              设置随机种子
    :conf               Show current generation config      显示生成配置
    :conf <key>=<value> Change generation config            修改生成配置
    :reset-conf         Reset generation config             重置生成配置
'''


def _load_model_tokenizer(args):
    tokenizer = AutoTokenizer.from_pretrained(
        args.checkpoint_path, trust_remote_code=True, resume_download=True,
    )

    if args.cpu_only:
        device_map = "cpu"
    else:
        device_map = "auto"

    model = AutoModelForCausalLM.from_pretrained(
        args.checkpoint_path,
        device_map=device_map,
        trust_remote_code=True,
        resume_download=True,
    ).eval()
    model.generation_config = GenerationConfig.from_pretrained(
        args.checkpoint_path, trust_remote_code=True, resume_download=True,
    )
    return model, tokenizer


def _clear_screen():
    if platform.system() == "Windows":
        os.system("cls")
    else:
        os.system("clear")


def _print_history(history):
    terminal_width = shutil.get_terminal_size()[0]
    print(f'History ({len(history)})'.center(terminal_width, '='))
    for index, (query, response) in enumerate(history):
        print(f'User[{index}]: {query}')
        print(f'QWen[{index}]: {response}')
    print('=' * terminal_width)


def _get_input() -> str:
    while True:
        try:
            message = input('User> ').strip()
        except UnicodeDecodeError:
            print('[ERROR] Encoding error in input')
            continue
        except KeyboardInterrupt:
            exit(1)
        if message:
            return message
        print('[ERROR] Query is empty')


def main():
    parser = argparse.ArgumentParser(
        description='QWen-7B-Chat command-line interactive chat demo.')
    parser.add_argument("-c", "--checkpoint-path", type=str, default=DEFAULT_CKPT_PATH,
                        help="Checkpoint name or path, default to %(default)r")
    parser.add_argument("-s", "--seed", type=int, default=1234, help="Random seed")
    parser.add_argument("--cpu-only", action="store_true", help="Run demo with CPU only")
    args = parser.parse_args()

    history, response = [], ''

    model, tokenizer = _load_model_tokenizer(args)
    orig_gen_config = deepcopy(model.generation_config)

    _clear_screen()
    print(_WELCOME_MSG)

    seed = args.seed

    while True:
        query = _get_input()

        # Process commands.
        if query.startswith(':'):
            command_words = query[1:].strip().split()
            if not command_words:
                command = ''
            else:
                command = command_words[0]

            if command in ['exit', 'quit', 'q']:
                break
            elif command in ['clear', 'cl']:
                _clear_screen()
                print(_WELCOME_MSG)
                continue
            elif command in ['clear-history', 'clh']:
                print(f'[INFO] All {len(history)} history cleared')
                history.clear()
                continue
            elif command in ['help', 'h']:
                print(_HELP_MSG)
                continue
            elif command in ['history', 'his']:
                _print_history(history)
                continue
            elif command in ['seed']:
                if len(command_words) == 1:
                    print(f'[INFO] Current random seed: {seed}')
                    continue
                else:
                    new_seed_s = command_words[1]
                    try:
                        new_seed = int(new_seed_s)
                    except ValueError:
                        print(f'[WARNING] Fail to change random seed: {new_seed_s!r} is not a valid number')
                    else:
                        print(f'[INFO] Random seed changed to {new_seed}')
                        seed = new_seed
                    continue
            elif command in ['conf']:
                if len(command_words) == 1:
                    print(model.generation_config)
                else:
                    for key_value_pairs_str in command_words[1:]:
                        eq_idx = key_value_pairs_str.find('=')
                        if eq_idx == -1:
                            print('[WARNING] format: <key>=<value>')
                            continue
                        conf_key, conf_value_str = key_value_pairs_str[:eq_idx], key_value_pairs_str[eq_idx + 1:]
                        try:
                            conf_value = eval(conf_value_str)
                        except Exception as e:
                            print(e)
                            continue
                        else:
                            print(f'[INFO] Change config: model.generation_config.{conf_key} = {conf_value}')
                            setattr(model.generation_config, conf_key, conf_value)
                continue
            elif command in ['reset-conf']:
                print('[INFO] Reset generation config')
                model.generation_config = deepcopy(orig_gen_config)
                print(model.generation_config)
                continue
            else:
                # As normal query.
                pass

        # Run chat.
        set_seed(seed)
        try:
            for response in model.chat_stream(tokenizer, query, history=history):
                _clear_screen()
                print(f"\nUser: {query}")
                print(f"\nQwen-7B: {response}")
        except KeyboardInterrupt:
            print('[WARNING] Generation interrupted')
            continue

        history.append((query, response))


if __name__ == "__main__":
    main()