src/core/semantic_encoder.py

"""
语义编码器 — vecs75字符级语义编码
替代brain.py中的hash编码，让输入向量具有语义信息

原理:
  "你好" → 查表"你"vec + "好"vec → 取平均 → 归一化 → 75维语义向量
  语义相近的文字编码后余弦相似度高，hash编码做不到
"""
import numpy as np
import pickle
import os
from typing import Optional


class SemanticEncoder:
    """vecs75语义编码器"""
    
    def __init__(self, model_dir: str = None):
        self.words = []
        self.vecs75 = None
        self.vecs_n = None  # 归一化版本
        self.w2i = {}
        self.dim = 75
        self._loaded = False
        self._clean_loaded = False  # 干净解码词表
        
        # 尝试加载(支持pkl和npz+json格式)
        paths = []
        if model_dir:
            paths.append(os.path.join(model_dir, 'vocab75_index.pkl'))
            paths.append(os.path.join(model_dir, 'vocab75_index.npz'))  # npz格式
        paths.append(os.path.expanduser('~/.swarm/models/vocab75_index.pkl'))
        paths.append(os.path.expanduser('~/.swarm/models/vocab75_index.npz'))
        paths.append(os.path.expanduser('~/swarm_product/models/vocab75_index.pkl'))
        paths.append(os.path.expanduser('~/swarm_product/models/vocab75_index.npz'))
        
        for p in paths:
            if os.path.exists(p):
                self._load(p)
                break
        
        if not self._loaded:
            # 硬编码路径 (HF Space + 本地)
            check_paths = [
                '/home/admin/swarm_product/models/vocab75_index.pkl',
                '/home/admin/swarm_product/models/vocab75_index.npz',
                '/app/models/vocab75_index.pkl',
                '/app/models/vocab75_index.npz',
                'models/vocab75_index.pkl',  # 相对路径
                'models/vocab75_index.npz',
            ]
            import sys
            print(f'[Encoder] 检查路径: {check_paths}', file=sys.stderr)
            for p in check_paths:
                print(f'[Encoder] 检查 {p}, exists={os.path.exists(p)}', file=sys.stderr)
                if os.path.exists(p):
                    self._load(p)
                    break
    
    def _load(self, path: str):
        """加载vecs75词表(支持pkl和npz+json格式)"""
        try:
            # 确定npz和json路径
            if path.endswith('.npz'):
                npz_path = path
                json_path = path.replace('.npz', '_words.json')
            else:
                npz_path = path.replace('.pkl', '.npz')
                json_path = path.replace('.pkl', '_words.json')
            if os.path.exists(npz_path) and os.path.exists(json_path):
                import json as _json
                with open(json_path, 'r', encoding='utf-8') as f:
                    self.words = _json.load(f)
                data = np.load(npz_path)
                self.vecs75 = data['vecs75']
                if 'vecs75_normed' in data:
                    norms = np.linalg.norm(self.vecs75, axis=1, keepdims=True)
                    norms[norms < 1e-8] = 1
                    self.vecs_n = self.vecs75 / norms
                else:
                    self.vecs_n = data['vecs75_normed']
            elif os.path.exists(path):
                # 回退pkl格式
                with open(path, 'rb') as f:
                    data = pickle.load(f)
                self.words = data['words']
                self.vecs75 = data['vecs75']
                norms = np.linalg.norm(self.vecs75, axis=1, keepdims=True)
                norms[norms < 1e-8] = 1
                self.vecs_n = self.vecs75 / norms
            else:
                return
            self.w2i = {w: i for i, w in enumerate(self.words)}
            self._loaded = True
            print(f'[SemanticEncoder] 加载: {len(self.words)}词, {self.vecs75.shape}')
            # 加载干净解码词表
            self._load_clean(path)
        except Exception as e:
            print(f'[SemanticEncoder] 加载失败: {e}')
    
    def _load_clean(self, orig_path: str):
        """加载干净解码词表(支持pkl和npz+json格式)"""
        # 尝试npz+json格式(优先)
        npz_path = orig_path.replace('vocab75_index.pkl', 'vocab75_clean.npz')
        json_path = orig_path.replace('vocab75_index.pkl', 'vocab75_clean_words.json')
        if os.path.exists(npz_path) and os.path.exists(json_path):
            try:
                import json as _json
                with open(json_path, 'r', encoding='utf-8') as f:
                    self._clean_words = _json.load(f)
                data = np.load(npz_path)
                self._clean_vecs_n = data['vecs75_normed']
                self._clean_loaded = True
                print(f'[SemanticEncoder] 干净词表: {len(self._clean_words)}词')
                return
            except Exception as e:
                print(f'[SemanticEncoder] 干净词表(npz)加载失败: {e}')
        
        # 回退pkl格式
        clean_path = orig_path.replace('vocab75_index.pkl', 'vocab75_clean.pkl')
        if not os.path.exists(clean_path):
            clean_path = '/home/admin/swarm_product/models/vocab75_clean.pkl'
        if os.path.exists(clean_path):
            try:
                with open(clean_path, 'rb') as f:
                    data = pickle.load(f)
                self._clean_words = data['words']
                self._clean_vecs_n = data['vecs75_normed']
                self._clean_loaded = True
                print(f'[SemanticEncoder] 干净词表: {len(self._clean_words)}词')
            except Exception as e:
                print(f'[SemanticEncoder] 干净词表加载失败: {e}')
    
    def encode(self, text: str) -> np.ndarray:
        """
        文本→75维语义向量
        
        策略: 字符级查表+加权平均
        - 前面的字权重高（注意力衰减）
        - 取平均后归一化
        - 无匹配字符时回退到hash编码
        """
        if not self._loaded or not text:
            return self._hash_encode(text or '')
        
        # 字符级查表
        char_vecs = []
        weights = []
        for i, ch in enumerate(text[:20]):
            if ch in self.w2i:
                idx = self.w2i[ch]
                char_vecs.append(self.vecs75[idx])
                weights.append(1.0 / (i + 1))  # 前面的字更重要
        
        if not char_vecs:
            # 全部字符不在词表中，回退hash
            return self._hash_encode(text)
        
        # 加权平均
        char_vecs = np.array(char_vecs)
        weights = np.array(weights).reshape(-1, 1)
        vec = (char_vecs * weights).sum(axis=0) / weights.sum()
        
        # 归一化
        norm = np.linalg.norm(vec)
        if norm > 1e-8:
            vec = vec / norm
        
        return vec.astype(np.float32)
    
    def _hash_encode(self, text: str) -> np.ndarray:
        """回退: hash编码（旧逻辑）"""
        vec = np.zeros(self.dim, dtype=np.float32)
        for i, ch in enumerate(text[:20]):
            idx = hash(ch) % self.dim
            vec[idx] += 1.0 / (i + 1)
        if vec.max() > 0:
            vec = vec / vec.max()
        return vec
    
    def decode_nearest(self, vec: np.ndarray, top_k: int = 5, 
                        prefer_chinese: bool = True, max_word_len: int = 4) -> list:
        """
        向量→最近邻词汇（输出解码器用）
        
        Args:
            vec: 75维向量
            top_k: 返回前k个
            prefer_chinese: 优先返回中文词(过滤英文/长短语)
            max_word_len: 最大词长度(过滤长短语)
            
        Returns:
            [(词, 相似度), ...]
        """
        if not self._loaded:
            return []
        
        vec = np.asarray(vec, dtype=np.float32).ravel()[:self.dim]
        if len(vec) < self.dim:
            vec = np.pad(vec, (0, self.dim - len(vec)))
        
        norm = np.linalg.norm(vec)
        if norm < 1e-8:
            return []
        vec_n = vec / norm
        
        # 余弦相似度
        # 优先用干净词表解码
        if self._clean_loaded:
            sims = self._clean_vecs_n @ vec_n
            # 先取较多候选
            n_cand = min(top_k * 5, len(sims))
            top_indices = np.argsort(sims)[-n_cand:][::-1]
            results = []
            # 优先中文词
            for i in top_indices:
                w = self._clean_words[i]
                if '\u4e00' <= w[0] <= '\u9fff':  # 首字是中文
                    results.append((w, float(sims[i])))
                if len(results) >= top_k:
                    break
            # 不够再补英文
            if len(results) < top_k:
                for i in top_indices:
                    w = self._clean_words[i]
                    if not any(r[0] == w for r in results):
                        results.append((w, float(sims[i])))
                    if len(results) >= top_k:
                        break
            return results
        
        sims = self.vecs_n @ vec_n
        
        if prefer_chinese:
            # 先取top_k*3候选，再过滤
            n_cand = min(top_k * 5, len(sims))
            top_indices = np.argsort(sims)[-n_cand:][::-1]
            results = []
            for i in top_indices:
                w = self.words[i]
                # 过滤: 只要中文词且长度<=max_word_len, 排除脏数据(以n开头的中英混合)
                if len(w) <= max_word_len and any('\u4e00' <= c <= '\u9fff' for c in w):
                    # 排除vecs75脏数据: 以非中文字符开头但含中文的混合词
                    first_char = w[0]
                    if '\u4e00' <= first_char <= '\u9fff':
                        results.append((w, float(sims[i])))
                    elif first_char.isalpha() and len(w) > 1 and '\u4e00' <= w[1] <= '\u9fff':
                        continue  # 跳过"n这个"类脏数据
                    else:
                        results.append((w, float(sims[i])))
                if len(results) >= top_k:
                    break
            # 如果过滤后不够，补回英文/长词
            if len(results) < top_k:
                for i in top_indices:
                    w = self.words[i]
                    if not any(r[0] == w for r in results):
                        results.append((w, float(sims[i])))
                    if len(results) >= top_k:
                        break
            return results
        else:
            top_indices = np.argsort(sims)[-top_k:][::-1]
            return [(self.words[i], float(sims[i])) for i in top_indices]
    
    def encode_sentence(self, text: str) -> np.ndarray:
        """
        句子级编码 — 分词后词向量平均（比字符级更精准）
        
        简单分词: 连续中文字符/连续英文/数字各为一段
        """
        if not self._loaded or not text:
            return self.encode(text or '')
        
        # 简单分词: 2-gram + 1-gram
        tokens = set()
        # 1-gram
        for ch in text:
            if ch in self.w2i:
                tokens.add(ch)
        # 2-gram (相邻字组合)
        for i in range(len(text) - 1):
            bigram = text[i:i+2]
            if bigram in self.w2i:
                tokens.add(bigram)
        
        if not tokens:
            return self.encode(text)
        
        # 取平均
        idxs = [self.w2i[t] for t in tokens]
        vec = self.vecs75[idxs].mean(axis=0)
        norm = np.linalg.norm(vec)
        if norm > 1e-8:
            vec = vec / norm
        
        return vec.astype(np.float32)


# 全局单例（延迟加载）
_encoder = None

def get_encoder() -> SemanticEncoder:
    """获取全局编码器实例"""
    global _encoder
    if _encoder is None:
        _encoder = SemanticEncoder()
    return _encoder