import json
import os
from datetime import datetime


class VocabularyManager:
    def __init__(self, data_file="vocabulary_data.json"):
        """
        初始化词汇管理器
        :param data_file: 词汇数据存储文件
        """
        self.data_file = data_file
        self.vocabulary = {}
        self._load_data()

    def _load_data(self):
        """从文件加载词汇数据"""
        if os.path.exists(self.data_file):
            try:
                with open(self.data_file, 'r', encoding='utf-8') as f:
                    self.vocabulary = json.load(f)
            except (json.JSONDecodeError, FileNotFoundError):
                self.vocabulary = {}

    def _save_data(self):
        """保存词汇数据到文件"""
        with open(self.data_file, 'w', encoding='utf-8') as f:
            json.dump(self.vocabulary, f, ensure_ascii=False, indent=2)

    def add_word(self, word, definition, example=None, tags=None):
        """
        添加新单词
        :param word: 单词
        :param definition: 释义
        :param example: 例句（可选）
        :param tags: 标签列表（可选）
        :return: 添加结果消息
        """
        if word.lower() in self.vocabulary:
            return f"'{word}' already exists in vocabulary"

        word_data = {
            'definition': definition,
            'example': example,
            'tags': tags if tags else [],
            'date_added': datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
            'review_count': 0,
            'last_reviewed': None
        }
        self.vocabulary[word.lower()] = word_data
        self._save_data()
        return f"'{word}' added successfully"

    def get_word(self, word):
        """
        获取单词详情
        :param word: 要查询的单词
        :return: 单词数据字典（不存在则返回None）
        """
        return self.vocabulary.get(word.lower())

    def update_word(self, word, definition=None, example=None, tags=None):
        """
        更新单词信息
        :param word: 要更新的单词
        :param definition: 新释义（可选）
        :param example: 新例句（可选）
        :param tags: 新标签列表（可选）
        :return: 更新结果消息
        """
        word_key = word.lower()
        if word_key not in self.vocabulary:
            return f"'{word}' not found in vocabulary"

        if definition:
            self.vocabulary[word_key]['definition'] = definition
        if example is not None:  # 允许空字符串
            self.vocabulary[word_key]['example'] = example
        if tags is not None:  # 允许空列表
            self.vocabulary[word_key]['tags'] = tags

        self._save_data()
        return f"'{word}' updated successfully"

    def delete_word(self, word):
        """
        删除单词
        :param word: 要删除的单词
        :return: 删除结果消息
        """
        word_key = word.lower()
        if word_key in self.vocabulary:
            del self.vocabulary[word_key]
            self._save_data()
            return f"'{word}' deleted successfully"
        return f"'{word}' not found in vocabulary"

    def list_all_words(self):
        """
        获取所有单词列表
        :return: 按添加时间排序的单词列表
        """
        return sorted(
            self.vocabulary.keys(),
            key=lambda w: self.vocabulary[w]['date_added'],
            reverse=True
        )

    def record_review(self, word):
        """
        记录单词复习
        :param word: 复习的单词
        :return: 复习记录结果
        """
        word_key = word.lower()
        if word_key in self.vocabulary:
            self.vocabulary[word_key]['review_count'] += 1
            self.vocabulary[word_key]['last_reviewed'] = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
            self._save_data()
            return f"Review recorded for '{word}'"
        return f"'{word}' not found in vocabulary"

    def search_words(self, keyword):
        """
        搜索包含关键字的单词
        :param keyword: 搜索关键字
        :return: 匹配的单词列表
        """
        keyword = keyword.lower()
        return [
            word for word, data in self.vocabulary.items()
            if keyword in word or
               keyword in data['definition'].lower() or
               (data['example'] and keyword in data['example'].lower())
        ]


# 示例用法
if __name__ == "__main__":
    vm = VocabularyManager()

    # 添加单词
    print(vm.add_word("ephemeral", "短暂的，瞬息的",
                      "Beauty is ephemeral, lasting only a few moments.",
                      ["adjective", "literary"]))

    # 获取单词详情
    print("\nWord details:")
    print(vm.get_word("ephemeral"))

    # 更新单词
    print(vm.update_word("ephemeral", tags=["adjective", "poetic"]))

    # 记录复习
    print(vm.record_review("ephemeral"))

    # 列出所有单词
    print("\nAll words:")
    print(vm.list_all_words())

    # 搜索单词
    print("\nSearch results:")
    print(vm.search_words("brief"))