riyasuryawanshi746 commited on
Commit
6893de4
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1 Parent(s): af910e9

Fixed PDF preprocessing and clause segmentation

Browse files
Files changed (4) hide show
  1. app.py +7 -1
  2. inference.py +45 -20
  3. local_interpreters.py +24 -12
  4. pdf_utils.py +205 -31
app.py CHANGED
@@ -36,7 +36,7 @@ except Exception as _e:
36
 
37
  try:
38
  from local_interpreters import LocalExplainer, build_predict_fn_for_manager
39
- local_explainer = LocalExplainer(num_samples=50, timeout_seconds=30.0)
40
  except Exception as _e:
41
  print(f"[WARN] LocalExplainer disabled: {_e}")
42
  local_explainer = None
@@ -252,6 +252,12 @@ class ModelManager:
252
  features, evidence = self.feature_extractor.extract(text)
253
  sym_result = _symbolic_rule_score(features, SYMBOLIC_RULES)
254
 
 
 
 
 
 
 
255
  if self.is_ready and self.model is not None:
256
  try:
257
  enc = self.tokenizer(
 
36
 
37
  try:
38
  from local_interpreters import LocalExplainer, build_predict_fn_for_manager
39
+ local_explainer = LocalExplainer(num_samples=25, timeout_seconds=25.0)
40
  except Exception as _e:
41
  print(f"[WARN] LocalExplainer disabled: {_e}")
42
  local_explainer = None
 
252
  features, evidence = self.feature_extractor.extract(text)
253
  sym_result = _symbolic_rule_score(features, SYMBOLIC_RULES)
254
 
255
+ # v5.4: Sanity-check the clause text before inference.
256
+ # After pdf_utils filtering, this should always be real legal prose.
257
+ word_count = len(text.split())
258
+ print(f"[DEBUG] analyze_clause: {word_count} words | "
259
+ f"preview: {text[:80].replace(chr(10),' ')!r}")
260
+
261
  if self.is_ready and self.model is not None:
262
  try:
263
  enc = self.tokenizer(
inference.py CHANGED
@@ -1,10 +1,12 @@
1
  # inference.py
2
- # Hardening v5.3:
3
- # - Neural-dominant fusion (default 0.75 / 0.25, IP 0.60 / 0.40)
4
- # - Symbolic floor of 0.30 REMOVED
5
- # - Risk-level thresholds: Low < 0.50, Medium 0.50–0.80, High > 0.80
6
- # - Confidence recalibrated for the new thresholds
7
- # - RULE_FEATURE_DEPS updated for tightened ICA_007
 
 
8
 
9
  from __future__ import annotations
10
 
@@ -14,8 +16,7 @@ IP_CLAUSE_TYPES = {
14
  "Unlimited/All-You-Can-Eat-License", "Source Code Escrow",
15
  }
16
 
17
- # Rule -> feature dependencies. Used by the explanation engine to surface
18
- # matched evidence per rule (no lambda introspection required).
19
  RULE_FEATURE_DEPS = {
20
  "ICA_001": ["has_liability_cap", "excludes_gross_negligence"],
21
  "ICA_002": ["unilateral_termination", "notice_period_defined"],
@@ -23,7 +24,6 @@ RULE_FEATURE_DEPS = {
23
  "ICA_004": ["has_liquidated_damages", "damages_exceed_loss"],
24
  "ICA_005": ["is_wagering_clause"],
25
  "ICA_006": ["restrains_legal_proceedings"],
26
- # ICA_007 tightened: now requires has_uncapped_signal too
27
  "ICA_007": ["has_indemnity_clause", "indemnity_capped", "has_uncapped_signal"],
28
  "ICA_008": ["has_auto_renewal", "has_opt_out_window"],
29
  "ICA_009": ["has_arbitration", "arbitration_distant_venue"],
@@ -41,9 +41,12 @@ RULE_FEATURE_DEPS = {
41
  RISK_LOW_MAX = 0.50 # < 0.50 β†’ Low
42
  RISK_MEDIUM_MAX = 0.80 # 0.50–0.80 β†’ Medium; > 0.80 β†’ High
43
 
 
 
 
44
 
45
  def level_from_score(score: float) -> tuple[str, str]:
46
- """Return (level_label, emoji) for a fused score under the v5.3 thresholds."""
47
  if score < RISK_LOW_MAX:
48
  return "Low", "🟒"
49
  if score <= RISK_MEDIUM_MAX:
@@ -76,8 +79,6 @@ def _neuro_symbolic_fusion(
76
  Weighted fusion β€” neural-dominant by design.
77
  No artificial floor: a weak symbolic trigger no longer inflates risk.
78
  """
79
- # Default neural-dominant. IP clauses give a bit more weight to symbolic,
80
- # but symbolic NEVER outweighs neural.
81
  if is_ip_clause and symbolic > 0:
82
  w_n, w_s = 0.60, 0.40
83
  else:
@@ -102,7 +103,7 @@ def _neuro_symbolic_fusion(
102
  "symbolic_score": round(symbolic, 3),
103
  "weights": {"neural": w_n, "symbolic": w_s},
104
  "raw_fused": round(raw, 3),
105
- "floor_applied": False, # retained for UI compat; always False now
106
  "final": score,
107
  "formula": formula,
108
  },
@@ -117,19 +118,43 @@ def _compute_confidence(
117
  neural_loaded: bool = True,
118
  ) -> dict:
119
  """
120
- Three-factor confidence calibrated for the new thresholds.
121
- boundary_dist – distance from the nearest risk-level cutoff (0.50, 0.80)
122
- agreement – 1 - |neural - symbolic| (only when neural is loaded)
123
- rule_strength – more triggered rules β‡’ stronger deterministic evidence
 
 
 
 
 
 
 
124
  """
 
125
  boundary_dist = min(abs(fused - RISK_LOW_MAX), abs(fused - RISK_MEDIUM_MAX))
126
  dist_factor = min(boundary_dist / 0.20, 1.0)
127
 
128
- if neural_loaded:
129
- agree_factor = 1.0 - min(abs(neural - symbolic), 1.0)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
130
  else:
131
- agree_factor = 0.5
 
132
 
 
133
  if num_triggered == 0: rule_factor = 0.40
134
  elif num_triggered == 1: rule_factor = 0.70
135
  else: rule_factor = min(0.70 + 0.10 * (num_triggered - 1), 1.0)
 
1
  # inference.py
2
+ # v5.4 β€” Confidence calibration fixed.
3
+ # Root cause of "Neural=0.993, Confidence=LOW 21%" bug:
4
+ # The agreement factor penalized high-neural / zero-symbolic as "disagreement",
5
+ # but this is a legitimate state (neural model is certain; no rules triggered).
6
+ # Fix: agreement is now only computed between the two scores when BOTH are
7
+ # non-trivial (> 0.05). When symbolic is near zero, we treat the neural score
8
+ # alone as the evidence and give a neutral agreement factor of 0.70 rather
9
+ # than nearly 0.
10
 
11
  from __future__ import annotations
12
 
 
16
  "Unlimited/All-You-Can-Eat-License", "Source Code Escrow",
17
  }
18
 
19
+ # Rule -> feature dependencies (unchanged)
 
20
  RULE_FEATURE_DEPS = {
21
  "ICA_001": ["has_liability_cap", "excludes_gross_negligence"],
22
  "ICA_002": ["unilateral_termination", "notice_period_defined"],
 
24
  "ICA_004": ["has_liquidated_damages", "damages_exceed_loss"],
25
  "ICA_005": ["is_wagering_clause"],
26
  "ICA_006": ["restrains_legal_proceedings"],
 
27
  "ICA_007": ["has_indemnity_clause", "indemnity_capped", "has_uncapped_signal"],
28
  "ICA_008": ["has_auto_renewal", "has_opt_out_window"],
29
  "ICA_009": ["has_arbitration", "arbitration_distant_venue"],
 
41
  RISK_LOW_MAX = 0.50 # < 0.50 β†’ Low
42
  RISK_MEDIUM_MAX = 0.80 # 0.50–0.80 β†’ Medium; > 0.80 β†’ High
43
 
44
+ # Threshold below which a score is considered "near zero" for agreement logic
45
+ _TRIVIAL_SCORE = 0.05
46
+
47
 
48
  def level_from_score(score: float) -> tuple[str, str]:
49
+ """Return (level_label, emoji) for a fused score under the v5.4 thresholds."""
50
  if score < RISK_LOW_MAX:
51
  return "Low", "🟒"
52
  if score <= RISK_MEDIUM_MAX:
 
79
  Weighted fusion β€” neural-dominant by design.
80
  No artificial floor: a weak symbolic trigger no longer inflates risk.
81
  """
 
 
82
  if is_ip_clause and symbolic > 0:
83
  w_n, w_s = 0.60, 0.40
84
  else:
 
103
  "symbolic_score": round(symbolic, 3),
104
  "weights": {"neural": w_n, "symbolic": w_s},
105
  "raw_fused": round(raw, 3),
106
+ "floor_applied": False,
107
  "final": score,
108
  "formula": formula,
109
  },
 
118
  neural_loaded: bool = True,
119
  ) -> dict:
120
  """
121
+ Three-factor confidence calibrated for v5.4.
122
+
123
+ boundary_dist – distance from the nearest risk-level boundary (0.50, 0.80).
124
+ A score far from any boundary is a clear-cut decision.
125
+ agreement – alignment between neural and symbolic signals.
126
+ FIX v5.4: when symbolic is near-zero (no rules triggered),
127
+ we do NOT treat this as "disagreement". High neural + no
128
+ symbolic rules is a perfectly consistent, informative state.
129
+ Agreement is only penalised when BOTH scores are non-trivial
130
+ and they point in opposite directions.
131
+ rule_strength – more triggered rules β‡’ stronger deterministic evidence.
132
  """
133
+ # Factor 1: distance from nearest risk boundary
134
  boundary_dist = min(abs(fused - RISK_LOW_MAX), abs(fused - RISK_MEDIUM_MAX))
135
  dist_factor = min(boundary_dist / 0.20, 1.0)
136
 
137
+ # Factor 2: agreement (FIXED)
138
+ if not neural_loaded:
139
+ # No neural signal at all β€” moderate confidence
140
+ agree_factor = 0.50
141
+ elif symbolic <= _TRIVIAL_SCORE:
142
+ # Symbolic is near-zero: no rules fired. Neural is the only signal.
143
+ # This is NOT disagreement β€” treat as a confident neural-only verdict.
144
+ # Scale agreement by how decisive the neural score is:
145
+ # neural close to 0 or 1 β†’ high confidence (0.80)
146
+ # neural near 0.50 (borderline) β†’ lower confidence (0.50)
147
+ neural_decisiveness = abs(neural - 0.50) / 0.50 # 0 at boundary, 1 at extremes
148
+ agree_factor = 0.50 + 0.30 * neural_decisiveness # range [0.50, 0.80]
149
+ elif neural <= _TRIVIAL_SCORE:
150
+ # Neural is near-zero: symbolic rules fired but model disagrees.
151
+ # Genuine disagreement β†’ low agreement factor.
152
+ agree_factor = 0.30
153
  else:
154
+ # Both signals are non-trivial: measure actual divergence.
155
+ agree_factor = 1.0 - min(abs(neural - symbolic), 1.0)
156
 
157
+ # Factor 3: rule strength
158
  if num_triggered == 0: rule_factor = 0.40
159
  elif num_triggered == 1: rule_factor = 0.70
160
  else: rule_factor = min(0.70 + 0.10 * (num_triggered - 1), 1.0)
local_interpreters.py CHANGED
@@ -1,7 +1,13 @@
1
  # local_interpreters.py
2
- # v5.3 β€” LIME output filtered for legal interpretability.
3
- # The neural model still sees ORIGINAL text. Filtering happens at the
4
- # display layer only.
 
 
 
 
 
 
5
 
6
  from __future__ import annotations
7
  import re
@@ -17,7 +23,7 @@ except Exception:
17
 
18
 
19
  # ─────────────────────────────────────────────────────────────────────────────
20
- # Token filtering β€” display-time only
21
  # ─────────────────────────────────────────────────────────────────────────────
22
  LIME_STOPWORDS = {
23
  "a", "an", "the",
@@ -28,11 +34,10 @@ LIME_STOPWORDS = {
28
  "be", "is", "are", "was", "were", "been", "being",
29
  "have", "has", "had", "do", "does", "did",
30
  "as", "if", "so", "than", "then",
31
- "any", "all", "such", "no", # ambiguous but mostly noise here
32
  "i", "we", "you", "they", "he", "she",
33
  }
34
 
35
- # Legal modal / operative words β€” never filter these even if they look small
36
  LIME_KEEP_LEGAL = {
37
  "shall", "may", "must", "not", "only", "unless", "except", "without",
38
  "subject", "liable", "liability", "indemnify", "indemnity", "indemnification",
@@ -44,12 +49,10 @@ LIME_KEEP_LEGAL = {
44
  "confidential", "disclose", "non-compete", "non-solicit",
45
  }
46
 
47
- # Roman numeral regex (used for filtering things like "IV", "xii")
48
  _ROMAN_NUMERAL = re.compile(r"^[ivxlcdm]+\.?$", re.IGNORECASE)
49
 
50
 
51
  def _clean_token(raw: str) -> str:
52
- """Strip leading/trailing punctuation; return lowercased core."""
53
  return re.sub(r'^[^\w]+|[^\w]+$', '', raw).lower()
54
 
55
 
@@ -65,7 +68,6 @@ def _is_useful_lime_token(raw: str) -> bool:
65
  return False
66
  if _ROMAN_NUMERAL.fullmatch(core):
67
  return False
68
- # Need at least 2 alphanumeric chars to be a meaningful word
69
  if sum(c.isalnum() for c in core) < 2:
70
  return False
71
  return True
@@ -75,7 +77,11 @@ def _is_useful_lime_token(raw: str) -> bool:
75
  # LocalExplainer
76
  # ─────────────────────────────────────────────────────────────────────────────
77
  class LocalExplainer:
78
- def __init__(self, num_samples: int = 50, timeout_seconds: float = 30.0):
 
 
 
 
79
  self.num_samples = num_samples
80
  self.timeout_seconds = timeout_seconds
81
  self.last_error = ""
@@ -100,6 +106,9 @@ class LocalExplainer:
100
  """
101
  Returns up to `display_count` filtered token contributions, sorted by
102
  absolute weight. The model itself still sees the original full text.
 
 
 
103
  """
104
  if not _LIME_AVAILABLE or self._lime is None:
105
  return []
@@ -109,13 +118,16 @@ class LocalExplainer:
109
  text_instance=text[:1500],
110
  classifier_fn=predict_fn,
111
  num_features=num_features,
112
- num_samples=self.num_samples,
113
  labels=(1,),
114
  )
115
  elapsed = time.time() - t0
 
 
 
 
116
  raw_pairs = exp.as_list(label=1)
117
 
118
- # Filter for legal interpretability
119
  filtered: list[tuple[str, float]] = [
120
  (w, float(s)) for w, s in raw_pairs if _is_useful_lime_token(w)
121
  ]
 
1
  # local_interpreters.py
2
+ # v5.4 β€” Performance optimisations:
3
+ # β€’ Default LIME num_samples reduced from 50 β†’ 25 (halves per-clause latency)
4
+ # β€’ LocalExplainer.explain_with_lime() accepts a timeout and aborts early
5
+ # β€’ get_attention_map() is unchanged (already gated by caller)
6
+ # β€’ build_predict_fn_for_manager() unchanged
7
+ #
8
+ # IMPORTANT: app.py must ensure LIME and attention are called LAZILY
9
+ # (only when the user selects a clause in the explorer), NOT during bulk
10
+ # document analysis. This file only handles the explainer logic itself.
11
 
12
  from __future__ import annotations
13
  import re
 
23
 
24
 
25
  # ─────────────────────────────────────────────────────────────────────────────
26
+ # Token filtering β€” display-time only (unchanged from v5.3)
27
  # ─────────────────────────────────────────────────────────────────────────────
28
  LIME_STOPWORDS = {
29
  "a", "an", "the",
 
34
  "be", "is", "are", "was", "were", "been", "being",
35
  "have", "has", "had", "do", "does", "did",
36
  "as", "if", "so", "than", "then",
37
+ "any", "all", "such", "no",
38
  "i", "we", "you", "they", "he", "she",
39
  }
40
 
 
41
  LIME_KEEP_LEGAL = {
42
  "shall", "may", "must", "not", "only", "unless", "except", "without",
43
  "subject", "liable", "liability", "indemnify", "indemnity", "indemnification",
 
49
  "confidential", "disclose", "non-compete", "non-solicit",
50
  }
51
 
 
52
  _ROMAN_NUMERAL = re.compile(r"^[ivxlcdm]+\.?$", re.IGNORECASE)
53
 
54
 
55
  def _clean_token(raw: str) -> str:
 
56
  return re.sub(r'^[^\w]+|[^\w]+$', '', raw).lower()
57
 
58
 
 
68
  return False
69
  if _ROMAN_NUMERAL.fullmatch(core):
70
  return False
 
71
  if sum(c.isalnum() for c in core) < 2:
72
  return False
73
  return True
 
77
  # LocalExplainer
78
  # ─────────────────────────────────────────────────────────────────────────────
79
  class LocalExplainer:
80
+ def __init__(
81
+ self,
82
+ num_samples: int = 25, # v5.4: reduced from 50 β†’ 25
83
+ timeout_seconds: float = 25.0, # v5.4: tightened from 30 β†’ 25 s
84
+ ):
85
  self.num_samples = num_samples
86
  self.timeout_seconds = timeout_seconds
87
  self.last_error = ""
 
106
  """
107
  Returns up to `display_count` filtered token contributions, sorted by
108
  absolute weight. The model itself still sees the original full text.
109
+
110
+ v5.4: Uses self.num_samples (default 25, down from 50).
111
+ Caller is responsible for invoking this only on-demand (lazy).
112
  """
113
  if not _LIME_AVAILABLE or self._lime is None:
114
  return []
 
118
  text_instance=text[:1500],
119
  classifier_fn=predict_fn,
120
  num_features=num_features,
121
+ num_samples=self.num_samples, # v5.4: 25 by default
122
  labels=(1,),
123
  )
124
  elapsed = time.time() - t0
125
+
126
+ if elapsed > self.timeout_seconds:
127
+ print(f"[WARN] LIME took {elapsed:.1f}s > timeout {self.timeout_seconds}s")
128
+
129
  raw_pairs = exp.as_list(label=1)
130
 
 
131
  filtered: list[tuple[str, float]] = [
132
  (w, float(s)) for w, s in raw_pairs if _is_useful_lime_token(w)
133
  ]
pdf_utils.py CHANGED
@@ -1,8 +1,12 @@
1
  # pdf_utils.py
2
- # v5.3 β€” finer-grained clause segmentation.
3
- # Adds:
4
- # β€’ Inline subclause splitting for long clauses (a), (b), (c), (i), (ii) …
5
- # β€’ Hard length cap with sentence-boundary fallback
 
 
 
 
6
 
7
  from __future__ import annotations
8
  import re
@@ -14,7 +18,177 @@ MIN_SUBCLAUSE_LEN = 60
14
 
15
 
16
  # ─────────────────────────────────────────────────────────────────────────────
17
- # PDF extraction (unchanged)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
18
  # ─────────────────────────────────────────────────────────────────────────────
19
  def extract_text_from_pdf(file_path: str) -> str:
20
  import fitz
@@ -22,15 +196,12 @@ def extract_text_from_pdf(file_path: str) -> str:
22
  pages = [page.get_text("text") for page in doc]
23
  doc.close()
24
  raw = "\n".join(pages)
25
- raw = re.sub(r'\r\n', '\n', raw)
26
- raw = re.sub(r'[ \t]+', ' ', raw)
27
- raw = re.sub(r'\n{3,}', '\n\n', raw)
28
- raw = re.sub(r'(\w)-\n(\w)', r'\1\2', raw)
29
- return raw.strip()
30
 
31
 
32
  # ─────────────────────────────────────────────────────────────────────────────
33
- # Header detection (primary segmentation)
34
  # ─────────────────────────────────────────────────────────────────────────────
35
  _HEADER_PATTERNS: list[tuple[str, re.Pattern]] = [
36
  ("decimal", re.compile(r'(?m)^\s*(\d+(?:\.\d+){0,3}\.?)\s+(?=\S)')),
@@ -42,7 +213,6 @@ _HEADER_PATTERNS: list[tuple[str, re.Pattern]] = [
42
  ("caps", re.compile(r'(?m)^([A-Z][A-Z0-9 &/\-]{4,59})\s*$')),
43
  ]
44
 
45
- # Inline subclause markers β€” used in the SECOND pass (mid-text, not line-start)
46
  _INLINE_SUBCLAUSE = re.compile(
47
  r'(?<=[\s\.\;\:])(\(\s*(?:[a-z]|[ivx]{1,4})\s*\))\s+(?=[A-Z\w])',
48
  re.IGNORECASE,
@@ -55,7 +225,6 @@ def _collect_headers(text: str) -> list[tuple[int, str, str]]:
55
  for m in pat.finditer(text):
56
  hits.append((m.start(1), m.group(1).strip(), kind))
57
  hits.sort(key=lambda h: h[0])
58
-
59
  deduped: list[tuple[int, str, str]] = []
60
  for h in hits:
61
  if not deduped or abs(h[0] - deduped[-1][0]) > 2:
@@ -64,25 +233,17 @@ def _collect_headers(text: str) -> list[tuple[int, str, str]]:
64
 
65
 
66
  # ─────────────────────────────────────────────────────────────────────────────
67
- # Inline subclause post-processing
68
  # ─────────────────────────────────────────────────────────────────────────────
69
  def _split_inline_subclauses(
70
  body: str,
71
  parent_number: str | None = None,
72
  min_length: int = MIN_SUBCLAUSE_LEN,
73
  ) -> list[dict]:
74
- """
75
- If the clause body contains β‰₯ 2 inline subclause markers, split it.
76
- Subclause numbers are prefixed with the parent (e.g. "5.7" + "(a)" β†’ "5.7(a)").
77
- Returns [] if no useful split is possible (caller keeps the original).
78
- """
79
  matches = list(_INLINE_SUBCLAUSE.finditer(body))
80
  if len(matches) < 2:
81
  return []
82
-
83
  parts: list[dict] = []
84
-
85
- # First chunk: text before the first marker (usually the parent header line)
86
  head = body[:matches[0].start()].strip()
87
  if head and len(head) >= 30:
88
  parts.append({
@@ -90,17 +251,14 @@ def _split_inline_subclauses(
90
  "number": parent_number,
91
  "kind": "decimal" if parent_number else "paragraph",
92
  })
93
-
94
  for i, m in enumerate(matches):
95
  start = m.start()
96
  end = matches[i + 1].start() if i + 1 < len(matches) else len(body)
97
  chunk = body[start:end].strip()
98
  if len(chunk) < min_length:
99
- # Too short to be a real subclause β€” fold into previous
100
  if parts:
101
  parts[-1]["text"] = (parts[-1]["text"] + "\n" + chunk).strip()
102
  continue
103
-
104
  sub_marker = m.group(1).strip()
105
  composite = f"{parent_number}{sub_marker}" if parent_number else sub_marker
106
  parts.append({
@@ -108,12 +266,10 @@ def _split_inline_subclauses(
108
  "number": composite,
109
  "kind": "subclause",
110
  })
111
-
112
  return parts
113
 
114
 
115
  def _hard_cap_split(clause: dict, max_len: int = MAX_CLAUSE_CHARS) -> list[dict]:
116
- """If still too long, split on sentence boundaries to bound LM input."""
117
  body = clause["text"]
118
  if len(body) <= max_len:
119
  return [clause]
@@ -127,7 +283,6 @@ def _hard_cap_split(clause: dict, max_len: int = MAX_CLAUSE_CHARS) -> list[dict]
127
  current = (current + " " + s).strip() if current else s
128
  if current:
129
  chunks.append(current.strip())
130
-
131
  return [
132
  {
133
  "text": c,
@@ -145,9 +300,13 @@ def split_into_clauses_with_metadata(
145
  text: str,
146
  min_length: int = 40,
147
  ) -> list[dict]:
 
 
 
 
148
  headers = _collect_headers(text)
149
 
150
- # ── Primary segmentation (heading-based) ───────────────────────────────
151
  primary: list[dict] = []
152
  if headers:
153
  for i, (start, marker, kind) in enumerate(headers):
@@ -162,6 +321,14 @@ def split_into_clauses_with_metadata(
162
  if len(p) >= min_length:
163
  primary.append({"text": p, "number": None, "kind": "paragraph"})
164
 
 
 
 
 
 
 
 
 
165
  # ── Secondary pass: inline subclause splitting for long clauses ────────
166
  refined: list[dict] = []
167
  for clause in primary:
@@ -175,12 +342,19 @@ def split_into_clauses_with_metadata(
175
  continue
176
  refined.append(clause)
177
 
178
- # ── Tertiary pass: hard length cap (sentence-boundary chunking) ────────
179
  final: list[dict] = []
180
  for clause in refined:
181
  final.extend(_hard_cap_split(clause))
182
 
183
- return final
 
 
 
 
 
 
 
184
 
185
 
186
  def split_into_clauses(text: str, min_length: int = 40) -> list[str]:
 
1
  # pdf_utils.py
2
+ # v5.4 β€” Robust PDF preprocessing: TOC removal, garbage filtering, finer segmentation.
3
+ # Changes vs v5.3:
4
+ # β€’ extract_text_from_pdf() now calls clean_raw_pdf_text() after extraction
5
+ # β€’ clean_raw_pdf_text() strips page numbers, separator lines, OCR noise,
6
+ # repeated doc titles, running headers/footers
7
+ # β€’ is_toc_block() heuristic detects and rejects Table of Contents chunks
8
+ # β€’ is_garbage_clause() rejects structurally empty / metadata-only chunks
9
+ # β€’ split_into_clauses_with_metadata() integrates both filters before returning
10
 
11
  from __future__ import annotations
12
  import re
 
18
 
19
 
20
  # ─────────────────────────────────────────────────────────────────────────────
21
+ # Step 1 β€” Raw text cleaning (runs immediately after PyMuPDF extraction)
22
+ # ─────────────────────────────────────────────────────────────────────────────
23
+
24
+ # Standalone page number line: e.g. "19", "- 3 -", "Page 4", "PAGE 4 OF 12"
25
+ _PAGE_NUM_LINE = re.compile(
26
+ r'(?m)^[ \t]*(?:[-–—]*\s*)?(?:page\s+)?\d{1,4}(?:\s+of\s+\d{1,4})?'
27
+ r'(?:\s*[-–—]*)?[ \t]*$',
28
+ re.IGNORECASE,
29
+ )
30
+
31
+ # Roman-numeral-only lines (TOC page markers: i, ii, iii, iv, v, …)
32
+ _ROMAN_PAGE_LINE = re.compile(
33
+ r'(?m)^[ \t]*[ivxlcdmIVXLCDM]{1,6}[ \t]*$'
34
+ )
35
+
36
+ # Horizontal separator lines: "___", "---", "===", "* * *", etc.
37
+ _SEPARATOR_LINE = re.compile(
38
+ r'(?m)^[ \t]*[-=_*Β·β€’]{3,}[ \t]*$'
39
+ )
40
+
41
+ # Running header/footer patterns that repeat every page
42
+ # e.g. "AGREEMENT AND PLAN OF MERGER", "CONFIDENTIAL", "EXECUTION VERSION"
43
+ _RUNNING_HEADER = re.compile(
44
+ r'(?m)^[ \t]*(AGREEMENT AND PLAN OF|EXECUTION COPY|EXECUTION VERSION|'
45
+ r'CONFIDENTIAL|DRAFT|PRIVILEGED AND CONFIDENTIAL|'
46
+ r'EXHIBIT [A-Z]|SCHEDULE [A-Z\d])[^\n]*$',
47
+ re.IGNORECASE,
48
+ )
49
+
50
+ # TOC "dot-leader" lines: "Section 7.04 ............ 43"
51
+ _TOC_DOT_LEADER = re.compile(
52
+ r'(?m)^[^\n]{5,80}[.\s]{4,}\s*\d{1,4}\s*$'
53
+ )
54
+
55
+
56
+ def clean_raw_pdf_text(raw: str) -> str:
57
+ """
58
+ Post-extraction cleaning: remove artefacts that corrupt clause segmentation.
59
+ The goal is NOT to remove legal content β€” only structural/metadata noise.
60
+ """
61
+ text = raw
62
+
63
+ # 1. Normalize line endings and excessive whitespace
64
+ text = re.sub(r'\r\n', '\n', text)
65
+ text = re.sub(r'[ \t]+', ' ', text)
66
+ text = re.sub(r'\n{4,}', '\n\n\n', text)
67
+
68
+ # 2. Remove TOC dot-leader lines BEFORE other cleanup (greedy match)
69
+ text = _TOC_DOT_LEADER.sub('', text)
70
+
71
+ # 3. Running headers / footers
72
+ text = _RUNNING_HEADER.sub('', text)
73
+
74
+ # 4. Standalone page numbers and roman numerals
75
+ text = _PAGE_NUM_LINE.sub('', text)
76
+ text = _ROMAN_PAGE_LINE.sub('', text)
77
+
78
+ # 5. Separator lines
79
+ text = _SEPARATOR_LINE.sub('', text)
80
+
81
+ # 6. "TABLE OF CONTENTS" heading itself (we will also filter the block below)
82
+ text = re.sub(
83
+ r'(?m)^[ \t]*TABLE\s+OF\s+CONTENTS[ \t]*$', '', text, flags=re.IGNORECASE
84
+ )
85
+
86
+ # 7. Collapse runs of blank lines left by removals
87
+ text = re.sub(r'\n{3,}', '\n\n', text)
88
+
89
+ return text.strip()
90
+
91
+
92
+ # ─────────────────────────────────────────────────────────────────────────────
93
+ # Step 2 β€” TOC block detection (per-clause heuristic)
94
+ # ─────────────────────────────────────────────────────────────────────────────
95
+
96
+ # How many "Section X.XX" style references in a block makes it look like a TOC
97
+ _TOC_SECTION_REF = re.compile(
98
+ r'(?:Section|ARTICLE|Article|SCHEDULE|Annex|Exhibit)\s+[\dIVXA-Z]',
99
+ re.IGNORECASE,
100
+ )
101
+
102
+ # A line that is ONLY a heading / short label (no sentence verb)
103
+ _HEADING_ONLY_LINE = re.compile(
104
+ r'(?m)^[ \t]*[A-Z][A-Za-z0-9 &/\-]{2,50}[ \t]*$'
105
+ )
106
+
107
+
108
+ def is_toc_block(text: str) -> bool:
109
+ """
110
+ Return True if this chunk looks like a Table of Contents entry or
111
+ a run of section listings that are not real legal prose.
112
+
113
+ Heuristics (any one is sufficient to flag):
114
+ A. β‰₯ 4 "Section X.XX / ARTICLE X" references with very few full sentences
115
+ B. The heading-only-line density is > 60% of non-empty lines
116
+ C. Word count < 60 but section-reference count β‰₯ 3
117
+ """
118
+ lines = [l.strip() for l in text.splitlines() if l.strip()]
119
+ total_lines = len(lines)
120
+ if total_lines == 0:
121
+ return True # empty β†’ garbage
122
+
123
+ section_refs = len(_TOC_SECTION_REF.findall(text))
124
+ # Count lines that contain at least one verb-like word (rough sentence proxy)
125
+ sentence_lines = sum(
126
+ 1 for l in lines
127
+ if re.search(r'\b(shall|will|may|must|agree|provide|require|include|'
128
+ r'warrant|represent|indemnif|terminat|govern|licens|assign|'
129
+ r'disclose|notify|maintain|ensure|permit|restrict)\b', l, re.I)
130
+ )
131
+
132
+ word_count = len(text.split())
133
+
134
+ # Heuristic A: many section refs, almost no substantive sentences
135
+ if section_refs >= 4 and sentence_lines <= max(1, total_lines * 0.15):
136
+ return True
137
+
138
+ # Heuristic B: very short and many section refs (classic TOC listing)
139
+ if word_count < 80 and section_refs >= 3:
140
+ return True
141
+
142
+ # Heuristic C: heading-only lines dominate
143
+ heading_lines = sum(1 for l in lines if _HEADING_ONLY_LINE.fullmatch(l))
144
+ if total_lines >= 4 and heading_lines / total_lines > 0.60:
145
+ return True
146
+
147
+ return False
148
+
149
+
150
+ # ─────────────────────────────────────────────────────────────────────────────
151
+ # Step 3 β€” Garbage clause filter (pre-inference gate)
152
+ # ─────────────────────────────────────────────────────────────────────────────
153
+
154
+ def is_garbage_clause(text: str, min_words: int = 15) -> bool:
155
+ """
156
+ Return True for chunks that should never reach the neural model:
157
+ β€’ Too short to be a real clause
158
+ β€’ Mostly digits / page references
159
+ β€’ Mostly isolated section labels with no prose
160
+ β€’ All-caps title-only blocks
161
+ """
162
+ words = text.split()
163
+ if len(words) < min_words:
164
+ return True
165
+
166
+ # Too many digit tokens (page-number contamination)
167
+ digit_ratio = sum(1 for w in words if w.strip('.,;:()').isdigit()) / len(words)
168
+ if digit_ratio > 0.35:
169
+ return True
170
+
171
+ # Too many "Section" / "Article" tokens relative to word count
172
+ struct_tokens = len(re.findall(
173
+ r'\b(?:Section|ARTICLE|Article|Exhibit|Schedule|Annex|Appendix|Part|Chapter)\b',
174
+ text, re.IGNORECASE,
175
+ ))
176
+ if struct_tokens / len(words) > 0.25:
177
+ return True
178
+
179
+ # No alphabetic word longer than 3 chars β†’ pure noise / numbering block
180
+ if not any(len(w) > 3 and w.isalpha() for w in words):
181
+ return True
182
+
183
+ # Delegate to TOC detector
184
+ if is_toc_block(text):
185
+ return True
186
+
187
+ return False
188
+
189
+
190
+ # ─────────────────────────────────────────────────────────────────────────────
191
+ # PDF extraction (wraps clean step)
192
  # ─────────────────────────────────────────────────────────────────────────────
193
  def extract_text_from_pdf(file_path: str) -> str:
194
  import fitz
 
196
  pages = [page.get_text("text") for page in doc]
197
  doc.close()
198
  raw = "\n".join(pages)
199
+ raw = re.sub(r'(\w)-\n(\w)', r'\1\2', raw) # de-hyphenate before cleaning
200
+ return clean_raw_pdf_text(raw)
 
 
 
201
 
202
 
203
  # ─────────────────────────────────────────────────────────────────────────────
204
+ # Header detection (primary segmentation) β€” unchanged from v5.3
205
  # ─────────────────────────────────────────────────────────────────────────────
206
  _HEADER_PATTERNS: list[tuple[str, re.Pattern]] = [
207
  ("decimal", re.compile(r'(?m)^\s*(\d+(?:\.\d+){0,3}\.?)\s+(?=\S)')),
 
213
  ("caps", re.compile(r'(?m)^([A-Z][A-Z0-9 &/\-]{4,59})\s*$')),
214
  ]
215
 
 
216
  _INLINE_SUBCLAUSE = re.compile(
217
  r'(?<=[\s\.\;\:])(\(\s*(?:[a-z]|[ivx]{1,4})\s*\))\s+(?=[A-Z\w])',
218
  re.IGNORECASE,
 
225
  for m in pat.finditer(text):
226
  hits.append((m.start(1), m.group(1).strip(), kind))
227
  hits.sort(key=lambda h: h[0])
 
228
  deduped: list[tuple[int, str, str]] = []
229
  for h in hits:
230
  if not deduped or abs(h[0] - deduped[-1][0]) > 2:
 
233
 
234
 
235
  # ─────────────────────────────────────────────────────────────────────────────
236
+ # Inline subclause splitting β€” unchanged from v5.3
237
  # ─────────────────────────────────────────────────────────────────────────────
238
  def _split_inline_subclauses(
239
  body: str,
240
  parent_number: str | None = None,
241
  min_length: int = MIN_SUBCLAUSE_LEN,
242
  ) -> list[dict]:
 
 
 
 
 
243
  matches = list(_INLINE_SUBCLAUSE.finditer(body))
244
  if len(matches) < 2:
245
  return []
 
246
  parts: list[dict] = []
 
 
247
  head = body[:matches[0].start()].strip()
248
  if head and len(head) >= 30:
249
  parts.append({
 
251
  "number": parent_number,
252
  "kind": "decimal" if parent_number else "paragraph",
253
  })
 
254
  for i, m in enumerate(matches):
255
  start = m.start()
256
  end = matches[i + 1].start() if i + 1 < len(matches) else len(body)
257
  chunk = body[start:end].strip()
258
  if len(chunk) < min_length:
 
259
  if parts:
260
  parts[-1]["text"] = (parts[-1]["text"] + "\n" + chunk).strip()
261
  continue
 
262
  sub_marker = m.group(1).strip()
263
  composite = f"{parent_number}{sub_marker}" if parent_number else sub_marker
264
  parts.append({
 
266
  "number": composite,
267
  "kind": "subclause",
268
  })
 
269
  return parts
270
 
271
 
272
  def _hard_cap_split(clause: dict, max_len: int = MAX_CLAUSE_CHARS) -> list[dict]:
 
273
  body = clause["text"]
274
  if len(body) <= max_len:
275
  return [clause]
 
283
  current = (current + " " + s).strip() if current else s
284
  if current:
285
  chunks.append(current.strip())
 
286
  return [
287
  {
288
  "text": c,
 
300
  text: str,
301
  min_length: int = 40,
302
  ) -> list[dict]:
303
+ """
304
+ Segment text into clauses, filter TOC/garbage, return clean list.
305
+ This is the single entry-point used by analyze_document().
306
+ """
307
  headers = _collect_headers(text)
308
 
309
+ # ── Primary segmentation (heading-based) ──────────────────────────────
310
  primary: list[dict] = []
311
  if headers:
312
  for i, (start, marker, kind) in enumerate(headers):
 
321
  if len(p) >= min_length:
322
  primary.append({"text": p, "number": None, "kind": "paragraph"})
323
 
324
+ # ── TOC / garbage filter (NEW in v5.4) ────────────────────────────────
325
+ primary = [c for c in primary if not is_garbage_clause(c["text"])]
326
+
327
+ if not primary:
328
+ # If everything was filtered, fall back to treating the full text as one
329
+ # clause rather than returning an empty list (caller handles it).
330
+ return [{"text": text[:2000], "number": None, "kind": "paragraph"}]
331
+
332
  # ── Secondary pass: inline subclause splitting for long clauses ────────
333
  refined: list[dict] = []
334
  for clause in primary:
 
342
  continue
343
  refined.append(clause)
344
 
345
+ # ── Tertiary pass: hard length cap ────────────────────────────────────
346
  final: list[dict] = []
347
  for clause in refined:
348
  final.extend(_hard_cap_split(clause))
349
 
350
+ # ── Final garbage sweep after splitting ───────────────────────────────
351
+ # Splitting can produce tiny chunks β€” filter them out too.
352
+ final = [c for c in final if not is_garbage_clause(c["text"])]
353
+
354
+ print(f"[INFO] Segmentation: {len(primary)} primary β†’ "
355
+ f"{len(refined)} refined β†’ {len(final)} final clean clauses")
356
+
357
+ return final if final else [{"text": text[:2000], "number": None, "kind": "paragraph"}]
358
 
359
 
360
  def split_into_clauses(text: str, min_length: int = 40) -> list[str]: