Initial upload: Code Privacy Shield v0.1.0

src/code_privacy_shield/redactor.py

@@ -0,0 +1,156 @@
+import re
+from dataclasses import dataclass, field
+from typing import Dict, List, Optional, Set, Tuple
+
+from .patterns import PatternLibrary
+
+
+@dataclass
+class RedactionMatch:
+    start: int
+    end: int
+    category: str
+    name: str
+    original: str
+    replacement: str
+
+
+@dataclass
+class RedactionResult:
+    original: str
+    redacted: str
+    matches: List[RedactionMatch] = field(default_factory=list)
+    categories: Set[str] = field(default_factory=set)
+
+
+class Redactor:
+    DEFAULT_REPLACEMENT = "█" * 8
+
+    def __init__(self, pattern_library: Optional[PatternLibrary] = None):
+        self.pattern_library = pattern_library or PatternLibrary()
+        self.custom_patterns: Dict[str, List[Tuple[re.Pattern, str]]] = {}
+
+    def add_custom_pattern(self, name: str, pattern: str, category: str = "custom") -> bool:
+        try:
+            compiled = re.compile(pattern, re.IGNORECASE)
+            if category not in self.custom_patterns:
+                self.custom_patterns[category] = []
+            self.custom_patterns[category].append((compiled, name))
+            return True
+        except re.error:
+            return False
+
+    def _find_all_matches(self, content: str) -> List[RedactionMatch]:
+        matches: List[RedactionMatch] = []
+        all_patterns = self.pattern_library.get_all_patterns()
+
+        for category, patterns in all_patterns.items():
+            for pattern, name in patterns:
+                for match in pattern.finditer(content):
+                    original = match.group(0)
+                    replacement = self._generate_replacement(original)
+                    matches.append(RedactionMatch(
+                        start=match.start(),
+                        end=match.end(),
+                        category=category,
+                        name=name,
+                        original=original,
+                        replacement=replacement,
+                    ))
+
+        for category, patterns in self.custom_patterns.items():
+            for pattern, name in patterns:
+                for match in pattern.finditer(content):
+                    original = match.group(0)
+                    replacement = self._generate_replacement(original)
+                    matches.append(RedactionMatch(
+                        start=match.start(),
+                        end=match.end(),
+                        category=category,
+                        name=name,
+                        original=original,
+                        replacement=replacement,
+                    ))
+
+        return matches
+
+    def _sort_matches_by_position(self, matches: List[RedactionMatch]) -> List[RedactionMatch]:
+        return sorted(matches, key=lambda m: (m.start, m.end))
+
+    def _remove_overlapping_matches(self, matches: List[RedactionMatch]) -> List[RedactionMatch]:
+        if not matches:
+            return matches
+
+        sorted_matches = self._sort_matches_by_position(matches)
+        non_overlapping: List[RedactionMatch] = []
+        current_end = -1
+
+        for match in sorted_matches:
+            if match.start >= current_end:
+                non_overlapping.append(match)
+                current_end = match.end
+
+        return non_overlapping
+
+    def _generate_replacement(self, original: str) -> str:
+        length = len(original)
+        if length <= 4:
+            return self.DEFAULT_REPLACEMENT
+        return self.DEFAULT_REPLACEMENT + original[-4:]
+
+    def _apply_redactions(self, content: str, matches: List[RedactionMatch]) -> str:
+        if not matches:
+            return content
+
+        sorted_matches = self._sort_matches_by_position(matches)
+        non_overlapping = self._remove_overlapping_matches(sorted_matches)
+
+        result_parts = []
+        last_pos = 0
+
+        for match in non_overlapping:
+            result_parts.append(content[last_pos:match.start])
+            result_parts.append(match.replacement)
+            last_pos = match.end
+
+        result_parts.append(content[last_pos:])
+        return "".join(result_parts)
+
+    def redact(self, content: str, preserve_structure: bool = True) -> RedactionResult:
+        matches = self._find_all_matches(content)
+        redacted = self._apply_redactions(content, matches)
+        categories = set(m.category for m in matches)
+
+        return RedactionResult(
+            original=content,
+            redacted=redacted,
+            matches=matches,
+            categories=categories,
+        )
+
+    def redact_file(self, file_path: str, encoding: str = "utf-8") -> RedactionResult:
+        with open(file_path, "r", encoding=encoding) as f:
+            content = f.read()
+
+        result = self.redact(content)
+
+        return result
+
+    def redact_multiple(
+        self,
+        contents: Dict[str, str],
+        preserve_structure: bool = True
+    ) -> Dict[str, RedactionResult]:
+        return {
+            path: self.redact(content) for path, content in contents.items()
+        }
+
+    def get_match_summary(self, result: RedactionResult) -> Dict[str, int]:
+        summary: Dict[str, int] = {}
+        for match in result.matches:
+            key = f"{match.category}:{match.name}"
+            summary[key] = summary.get(key, 0) + 1
+        return summary
+
+    def filter_matches_by_category(self, result: RedactionResult, categories: Set[str]) -> List[RedactionMatch]:
+        return [m for m in result.matches if m.category in categories]