File size: 6,022 Bytes
a6f490e
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
62a231e
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
a6f490e
 
 
62a231e
a6f490e
 
 
 
 
 
 
 
 
62a231e
 
 
a6f490e
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
from langchain_community.document_loaders import PyPDFLoader
from transformers import pipeline
import torch
from collections import defaultdict
import time


class DocumentClassifier:
    
    LABELS = [
        "lab report",
        "prescription",
        "discharge summary",
        "progress note",
        "imaging report",
        "consultation note",
        "operative report",
        "immunization record"
    ]
    
    def __init__(
        self, 
        pages_per_group=2,
        min_confidence=0.35,
        model_name="cross-encoder/nli-deberta-v3-small"
    ):
        self.pages_per_group = pages_per_group
        self.min_confidence = min_confidence
        self.model_name = model_name
        self.classifier = None
        
        print(f"[Classifier] Loading {model_name}...")
        self._load_model()
    
    def _load_model(self):
        device = 0 if torch.cuda.is_available() else -1
        self.classifier = pipeline(
            "zero-shot-classification",
            model=self.model_name,
            device=device
        )
        print(f"[Classifier] Ready (device: {'GPU' if device >= 0 else 'CPU'})")
    
    def classify_document(self, file_path):
        start_time = time.time()
        
        try:
            loader = PyPDFLoader(file_path)
            pages = loader.load()
            
            if not pages:
                return self._default_result()
            
            print(f"[Classifier] Analyzing {len(pages)} pages...")
            
            page_groups = self._create_page_groups(pages)
            print(f"[Classifier] Created {len(page_groups)} groups, classifying in parallel...")
            
            group_results = self._classify_groups_parallel(page_groups)
            page_map = self._build_page_map(group_results)
            
            all_types = [p['type'] for p in page_map.values()]
            type_counts = defaultdict(int)
            for t in all_types:
                type_counts[t] += 1
            primary_type = max(type_counts.items(), key=lambda x: x[1])[0]
            
            unique_types = sorted(set(all_types), 
                                 key=lambda t: type_counts[t], 
                                 reverse=True)
            
            result = {
                "primary_type": primary_type,
                "page_classifications": page_map,
                "all_types": unique_types,
                "processing_time": round(time.time() - start_time, 2),
                "total_pages": len(pages)
            }
            
            print(f"[Classifier] Done in {result['processing_time']}s - "
                  f"Primary: {primary_type}, Types found: {len(unique_types)}")
            
            return result
            
        except Exception as e:
            print(f"[Classifier] Error: {e}")
            import traceback
            traceback.print_exc()
            return self._default_result()
    
    def _create_page_groups(self, pages):
        groups = []
        for i in range(0, len(pages), self.pages_per_group):
            group_pages = pages[i:i + self.pages_per_group]
            page_nums = list(range(i + 1, i + len(group_pages) + 1))
            
            text = " ".join([p.page_content for p in group_pages])
            
            if len(text) > 2000:
                text = text[:1000] + " ... " + text[-1000:]
            
            groups.append({
                'text': text,
                'page_numbers': page_nums
            })
        
        return groups
    
    def _classify_groups_parallel(self, groups):
        results = []
        texts = [g['text'] for g in groups]

        # Use pipeline's native batching — faster than ThreadPoolExecutor,
        # especially on GPU, and avoids thread-safety issues with PyTorch.
        batch_results = self.classifier(texts, self.LABELS, multi_label=True, batch_size=8)

        for group, result in zip(groups, batch_results):
            primary_type = result['labels'][0]
            primary_score = result['scores'][0]

            if primary_score < self.min_confidence:
                primary_type = 'other'

            scores = {label: score for label, score in zip(result['labels'], result['scores'])}
            results.append({
                'type': primary_type,
                'confidence': primary_score,
                'scores': scores,
                'page_numbers': group['page_numbers']
            })

        return results
    
    def _classify_single_group(self, group):
        # Kept for single-group use if needed directly
        text = group['text']
        
        if not text.strip():
            return {'type': 'other', 'confidence': 0.0, 'scores': {}}
        
        result = self.classifier(text, self.LABELS, multi_label=True)
        
        primary_type = result['labels'][0]
        primary_score = result['scores'][0]

        if primary_score < self.min_confidence:
            primary_type = 'other'
        
        scores = {
            label: score 
            for label, score in zip(result['labels'], result['scores'])
        }
        
        return {
            'type': primary_type,
            'confidence': primary_score,
            'scores': scores
        }
    
    def _build_page_map(self, group_results):
        page_map = {}
        
        for group in group_results:
            page_nums = group.get('page_numbers', [])
            doc_type = group.get('type', 'other')
            confidence = group.get('confidence', 0.0)
            
            for page_num in page_nums:
                page_map[page_num] = {
                    'type': doc_type,
                    'confidence': round(confidence, 2)
                }
        
        return page_map
    
    def _default_result(self):
        return {
            "primary_type": "other",
            "page_classifications": {},
            "all_types": ["other"],
            "processing_time": 0.0,
            "total_pages": 0
        }