Initial commit: Document Translation API with Excel, Word, PowerPoint support

translators/excel_translator.py

@@ -0,0 +1,161 @@
+"""
+Excel Translation Module
+Translates Excel files while preserving all formatting, formulas, images, and layout
+"""
+import re
+from pathlib import Path
+from typing import Dict, Set
+from openpyxl import load_workbook
+from openpyxl.worksheet.worksheet import Worksheet
+from openpyxl.cell.cell import Cell
+from openpyxl.utils import get_column_letter
+from services.translation_service import translation_service
+
+
+class ExcelTranslator:
+    """Handles translation of Excel files with strict formatting preservation"""
+    
+    def __init__(self):
+        self.translation_service = translation_service
+        self.formula_pattern = re.compile(r'=.*')
+    
+    def translate_file(self, input_path: Path, output_path: Path, target_language: str) -> Path:
+        """
+        Translate an Excel file while preserving all formatting and structure
+        
+        Args:
+            input_path: Path to input Excel file
+            output_path: Path to save translated Excel file
+            target_language: Target language code
+        
+        Returns:
+            Path to the translated file
+        """
+        # Load workbook with data_only=False to preserve formulas
+        workbook = load_workbook(input_path, data_only=False)
+        
+        # First, translate all worksheet content
+        sheet_name_mapping = {}
+        for sheet_name in workbook.sheetnames:
+            worksheet = workbook[sheet_name]
+            self._translate_worksheet(worksheet, target_language)
+            
+            # Prepare translated sheet name (but don't rename yet)
+            translated_sheet_name = self.translation_service.translate_text(
+                sheet_name, target_language
+            )
+            if translated_sheet_name and translated_sheet_name != sheet_name:
+                # Truncate to Excel's 31 character limit and ensure uniqueness
+                new_name = translated_sheet_name[:31]
+                counter = 1
+                base_name = new_name[:28] if len(new_name) > 28 else new_name
+                while new_name in sheet_name_mapping.values() or new_name in workbook.sheetnames:
+                    new_name = f"{base_name}_{counter}"
+                    counter += 1
+                sheet_name_mapping[sheet_name] = new_name
+        
+        # Now rename sheets (after all content is translated)
+        for original_name, new_name in sheet_name_mapping.items():
+            workbook[original_name].title = new_name
+        
+        # Save the translated workbook
+        workbook.save(output_path)
+        workbook.close()
+        
+        return output_path
+    
+    def _translate_worksheet(self, worksheet: Worksheet, target_language: str):
+        """
+        Translate all cells in a worksheet while preserving formatting
+        
+        Args:
+            worksheet: Worksheet to translate
+            target_language: Target language code
+        """
+        # Iterate through all cells that have values
+        for row in worksheet.iter_rows():
+            for cell in row:
+                if cell.value is not None:
+                    self._translate_cell(cell, target_language)
+    
+    def _translate_cell(self, cell: Cell, target_language: str):
+        """
+        Translate a single cell while preserving its formula and formatting
+        
+        Args:
+            cell: Cell to translate
+            target_language: Target language code
+        """
+        original_value = cell.value
+        
+        # Skip if cell is empty
+        if original_value is None:
+            return
+        
+        # Handle formulas
+        if isinstance(original_value, str) and original_value.startswith('='):
+            self._translate_formula(cell, original_value, target_language)
+        # Handle regular text
+        elif isinstance(original_value, str):
+            translated_text = self.translation_service.translate_text(
+                original_value, target_language
+            )
+            cell.value = translated_text
+        # Numbers, dates, booleans remain unchanged
+    
+    def _translate_formula(self, cell: Cell, formula: str, target_language: str):
+        """
+        Translate text within a formula while preserving the formula structure
+        
+        Args:
+            cell: Cell containing the formula
+            formula: Formula string
+            target_language: Target language code
+        """
+        # Extract text strings from formula (text within quotes)
+        string_pattern = re.compile(r'"([^"]*)"')
+        strings = string_pattern.findall(formula)
+        
+        if not strings:
+            return
+        
+        # Translate each string and replace in formula
+        translated_formula = formula
+        for original_string in strings:
+            if original_string.strip():  # Only translate non-empty strings
+                translated_string = self.translation_service.translate_text(
+                    original_string, target_language
+                )
+                # Replace in formula, being careful with special regex characters
+                translated_formula = translated_formula.replace(
+                    f'"{original_string}"', f'"{translated_string}"'
+                )
+        
+        cell.value = translated_formula
+    
+    def _should_translate(self, text: str) -> bool:
+        """
+        Determine if text should be translated
+        
+        Args:
+            text: Text to check
+        
+        Returns:
+            True if text should be translated, False otherwise
+        """
+        if not text or not isinstance(text, str):
+            return False
+        
+        # Don't translate if it's only numbers, special characters, or very short
+        if len(text.strip()) < 2:
+            return False
+        
+        # Check if it's a formula (handled separately)
+        if text.startswith('='):
+            return False
+        
+        return True
+
+
+# Global translator instance
+excel_translator = ExcelTranslator()