import sys
import re
import jieba
import numpy as np
from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout,
                             QHBoxLayout, QTextEdit, QPushButton, QLabel,
                             QMessageBox, QSpinBox, QFileDialog, QComboBox)
from PyQt5.QtCore import Qt
 
 
class TextRankSummarizer:
    def __init__(self, language='chinese'):
        self.language = language
        self.stopwords = self.load_stopwords()
 
        # 初始化jieba中文分詞器
        if language == 'chinese':
            jieba.initialize()
 
    def load_stopwords(self):
        """內(nèi)置停用詞表"""
        if self.language == 'chinese':
            return {'的', '了', '在', '是', '我', '有', '和', '就', '不', '人', '都', '一', '一個', '也', '要'}
        else:  # 英文停用詞
            return {'a', 'an', 'the', 'and', 'or', 'but', 'if', 'is', 'are', 'of', 'to', 'in', 'on'}
 
    def preprocess_text(self, text):
        """文本預處理"""
        # 清洗特殊字符
        text = re.sub(r'[^\w\s。，.?！]', '', text)
 
        # 分句處理
        if self.language == 'chinese':
            sentences = re.split(r'[。??？]', text)
        else:
            sentences = re.split(r'[.!?]', text)
 
        return [s.strip() for s in sentences if len(s) > 2]
 
    def calculate_similarity(self, sentence, other_sentence):
        """計算句子相似度"""
        words1 = [w for w in (jieba.cut(sentence) if self.language == 'chinese' else sentence.lower().split())
                  if w not in self.stopwords]
        words2 = [w for w in
                  (jieba.cut(other_sentence) if self.language == 'chinese' else other_sentence.lower().split())
                  if w not in self.stopwords]
 
        # 使用Jaccard相似度
        intersection = len(set(words1) & set(words2))
        union = len(set(words1) | set(words2))
        return intersection / union if union != 0 else 0
 
    def textrank(self, sentences, top_n=5, damping_factor=0.85, max_iter=100):
        """TextRank算法實現(xiàn)"""
        similarity_matrix = np.zeros((len(sentences), len(sentences)))
 
        # 構(gòu)建相似度矩陣
        for i in range(len(sentences)):
            for j in range(len(sentences)):
                if i != j:
                    similarity_matrix[i][j] = self.calculate_similarity(sentences[i], sentences[j])
 
        # 歸一化矩陣
        row_sum = similarity_matrix.sum(axis=1)
        normalized_matrix = similarity_matrix / row_sum[:, np.newaxis]
 
        # 初始化得分
        scores = np.ones(len(sentences))
 
        # 迭代計算
        for _ in range(max_iter):
            prev_scores = np.copy(scores)
            for i in range(len(sentences)):
                scores[i] = (1 - damping_factor) + damping_factor * np.sum(normalized_matrix[i, :] * prev_scores)
 
            if np.linalg.norm(scores - prev_scores) < 1e-5:
                break
 
        # 獲取重要句子索引
        ranked_indices = np.argsort(scores)[::-1][:top_n]
        return sorted(ranked_indices)
 
    def summarize(self, text, ratio=0.2):
        """生成摘要"""
        sentences = self.preprocess_text(text)
        if len(sentences) < 3:
            return "文本過短，無法生成有效摘要"
 
        top_n = max(1, int(len(sentences) * ratio))
        important_indices = self.textrank(sentences, top_n=top_n)
 
        # 按原文順序排列
        selected_sentences = [sentences[i] for i in sorted(important_indices)]
 
        # 中文使用句號連接，英文使用.連接
        separator = '。' if self.language == 'chinese' else '. '
        return separator.join(selected_sentences) + ('。' if self.language == 'chinese' else '.')
 
 
class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
 
        # 初始化摘要器
        self.summarizer = TextRankSummarizer()
 
        # 界面設(shè)置
        self.setup_ui()
 
    def setup_ui(self):
        self.setWindowTitle("TextRank文本摘要工具")
        self.setGeometry(100, 100, 1000, 800)
 
        main_widget = QWidget()
        layout = QVBoxLayout()
 
        # 輸入?yún)^(qū)
        self.input_text = QTextEdit()
        self.input_text.setPlaceholderText("在此粘貼需要摘要的文本（建議500字以上）...")
 
        # 控制區(qū)
        control_layout = QHBoxLayout()
        self.ratio_spin = QSpinBox()
        self.ratio_spin.setRange(5, 50)
        self.ratio_spin.setValue(20)
        self.ratio_spin.setSuffix("%")
 
        self.lang_combo = QComboBox()
        self.lang_combo.addItems(["中文", "英文"])
 
        self.summarize_btn = QPushButton("生成摘要")
        self.import_btn = QPushButton("導入文件")
        self.clear_btn = QPushButton("清空")
 
        control_layout.addWidget(QLabel("摘要比例："))
        control_layout.addWidget(self.ratio_spin)
        control_layout.addWidget(QLabel("語言："))
        control_layout.addWidget(self.lang_combo)
        control_layout.addWidget(self.import_btn)
        control_layout.addWidget(self.summarize_btn)
        control_layout.addWidget(self.clear_btn)
 
        # 輸出區(qū)
        self.output_text = QTextEdit()
        self.output_text.setReadOnly(True)
 
        # 布局組合
        layout.addWidget(QLabel("輸入文本："))
        layout.addWidget(self.input_text)
        layout.addLayout(control_layout)
        layout.addWidget(QLabel("摘要結(jié)果："))
        layout.addWidget(self.output_text)
 
        main_widget.setLayout(layout)
        self.setCentralWidget(main_widget)
 
        # 信號連接
        self.summarize_btn.clicked.connect(self.generate_summary)
        self.import_btn.clicked.connect(self.import_file)
        self.clear_btn.clicked.connect(self.clear_content)
        self.lang_combo.currentTextChanged.connect(self.change_language)
 
    def change_language(self, lang):
        self.summarizer = TextRankSummarizer('chinese' if lang == "中文" else 'english')
 
    def generate_summary(self):
        text = self.input_text.toPlainText().strip()
        if not text:
            QMessageBox.warning(self, "輸入錯誤", "請輸入需要摘要的文本")
            return
 
        ratio = self.ratio_spin.value() / 100
        summary = self.summarizer.summarize(text, ratio)
        self.output_text.setPlainText(summary)
 
    def import_file(self):
        path, _ = QFileDialog.getOpenFileName(
            self, "打開文本文件", "",
            "文本文件 (*.txt);;所有文件 (*.*)"
        )
        if path:
            try:
                with open(path, 'r', encoding='utf-8') as f:
                    self.input_text.setPlainText(f.read())
            except Exception as e:
                QMessageBox.critical(self, "錯誤", f"文件讀取失?。篭n{str(e)}")
 
    def clear_content(self):
        self.input_text.clear()
        self.output_text.clear()
 
 
if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())