from typing import Dict, Any
import json
from docx import Document
from openpyxl import load_workbook


async def fill_form(template_path: str, data: Dict[str, Any]) -> dict:
    """
    Auto-fill form template with extracted data
    
    Args:
        template_path: Path to form template (DOCX or XLSX)
        data: Dictionary of field values
        
    Returns:
        Dict with filled form path and fields filled
    """
    try:
        file_ext = Path(template_path).suffix.lower()
        output_path = template_path.replace(file_ext, f'_filled{file_ext}')
        
        if file_ext == '.docx':
            return await fill_docx_form(template_path, data, output_path)
        elif file_ext in ['.xlsx', '.xls']:
            return await fill_excel_form(template_path, data, output_path)
        else:
            # Generic text replacement
            return await fill_text_form(template_path, data, output_path)
            
    except Exception as e:
        return {'error': str(e), 'success': False}


async def fill_docx_form(template_path: str, data: Dict[str, Any], output_path: str) -> dict:
    """Fill DOCX form template"""
    try:
        doc = Document(template_path)
        fields_filled = []
        
        # Replace in paragraphs
        for paragraph in doc.paragraphs:
            for key, value in data.items():
                placeholder = f"{{{{{key}}}}}"  # {{field_name}}
                if placeholder in paragraph.text:
                    paragraph.text = paragraph.text.replace(placeholder, str(value))
                    fields_filled.append(key)
        
        # Replace in tables
        for table in doc.tables:
            for row in table.rows:
                for cell in row.cells:
                    for key, value in data.items():
                        placeholder = f"{{{{{key}}}}}"
                        if placeholder in cell.text:
                            cell.text = cell.text.replace(placeholder, str(value))
                            if key not in fields_filled:
                                fields_filled.append(key)
        
        doc.save(output_path)
        
        return {
            'success': True,
            'output_path': output_path,
            'fields_filled': fields_filled,
            'total_fields': len(fields_filled)
        }
        
    except Exception as e:
        return {'error': str(e), 'success': False}


async def fill_excel_form(template_path: str, data: Dict[str, Any], output_path: str) -> dict:
    """Fill Excel form template"""
    try:
        wb = load_workbook(template_path)
        ws = wb.active
        fields_filled = []
        
        # Search for placeholders and replace
        for row in ws.iter_rows():
            for cell in row:
                if cell.value and isinstance(cell.value, str):
                    for key, value in data.items():
                        placeholder = f"{{{{{key}}}}}"
                        if placeholder in cell.value:
                            cell.value = cell.value.replace(placeholder, str(value))
                            fields_filled.append(key)
        
        wb.save(output_path)
        
        return {
            'success': True,
            'output_path': output_path,
            'fields_filled': list(set(fields_filled)),
            'total_fields': len(set(fields_filled))
        }
        
    except Exception as e:
        return {'error': str(e), 'success': False}


async def fill_text_form(template_path: str, data: Dict[str, Any], output_path: str) -> dict:
    """Fill text-based form"""
    try:
        with open(template_path, 'r', encoding='utf-8') as f:
            content = f.read()
        
        fields_filled = []
        for key, value in data.items():
            placeholder = f"{{{{{key}}}}}"
            if placeholder in content:
                content = content.replace(placeholder, str(value))
                fields_filled.append(key)
        
        with open(output_path, 'w', encoding='utf-8') as f:
            f.write(content)
        
        return {
            'success': True,
            'output_path': output_path,
            'fields_filled': fields_filled,
            'total_fields': len(fields_filled)
        }
        
    except Exception as e:
        return {'error': str(e), 'success': False}


async def generate_form_template(fields: list) -> dict:
    """Generate a blank form template with specified fields"""
    try:
        doc = Document()
        doc.add_heading('Form Template', 0)
        
        for field in fields:
            p = doc.add_paragraph()
            p.add_run(f"{field}: ").bold = True
            p.add_run(f"{{{{{field}}}}}")
        
        output_path = "data/outputs/form_template.docx"
        doc.save(output_path)
        
        return {
            'success': True,
            'output_path': output_path,
            'fields': fields
        }
        
    except Exception as e:
        return {'error': str(e), 'success': False}