# utils/export.py - Export functionality for PDF Analysis & Orchestrator
import json
import os
from pathlib import Path
from typing import Dict, Any, Optional, List
from datetime import datetime
from config import Config

class ExportManager:
    """Handle export of analysis results to various formats"""
    
    def __init__(self, export_dir: str = None):
        self.export_dir = Path(export_dir or Config.EXPORT_DIR)
        self.export_dir.mkdir(parents=True, exist_ok=True)
    
    def export_text(self, content: str, filename: str = None, 
                   metadata: Dict[str, Any] = None) -> str:
        """Export content as text file"""
        if not filename:
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            filename = f"analysis_{timestamp}.txt"
        
        if not filename.endswith('.txt'):
            filename += '.txt'
        
        filepath = self.export_dir / filename
        
        # Add metadata header if provided
        if metadata:
            header = self._format_metadata_header(metadata)
            content = f"{header}\n\n{content}"
        
        with open(filepath, 'w', encoding='utf-8') as f:
            f.write(content)
        
        return str(filepath)
    
    def export_json(self, data: Dict[str, Any], filename: str = None) -> str:
        """Export data as JSON file"""
        if not filename:
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            filename = f"analysis_{timestamp}.json"
        
        if not filename.endswith('.json'):
            filename += '.json'
        
        filepath = self.export_dir / filename
        
        # Add export metadata
        export_data = {
            "exported_at": datetime.now().isoformat(),
            "export_version": "1.0",
            "data": data
        }
        
        with open(filepath, 'w', encoding='utf-8') as f:
            json.dump(export_data, f, indent=2, ensure_ascii=False)
        
        return str(filepath)
    
    def export_pdf(self, content: str, filename: str = None, 
                   metadata: Dict[str, Any] = None, username: str = None) -> str:
        """Export content as PDF (requires reportlab)"""
        try:
            from reportlab.lib.pagesizes import letter
            from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer
            from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
            from reportlab.lib.units import inch
        except ImportError:
            raise ImportError("reportlab is required for PDF export. Install with: pip install reportlab")
        
        if not filename:
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            filename = f"analysis_{timestamp}.pdf"
        
        if not filename.endswith('.pdf'):
            filename += '.pdf'
        
        filepath = self.export_dir / filename
        
        # Create PDF
        doc = SimpleDocTemplate(str(filepath), pagesize=letter)
        styles = getSampleStyleSheet()
        
        # Custom style for content
        content_style = ParagraphStyle(
            'CustomContent',
            parent=styles['Normal'],
            fontSize=11,
            spaceAfter=12,
            leading=14
        )
        
        story = []
        
        # Add metadata header if provided
        if metadata:
            header_style = ParagraphStyle(
                'Header',
                parent=styles['Heading1'],
                fontSize=14,
                spaceAfter=20
            )
            story.append(Paragraph("Analysis Report", header_style))
            story.append(Spacer(1, 12))
            
            for key, value in metadata.items():
                story.append(Paragraph(f"<b>{key}:</b> {value}", styles['Normal']))
            story.append(Spacer(1, 20))
        
        # Add content
        paragraphs = content.split('\n\n')
        for para in paragraphs:
            if para.strip():
                story.append(Paragraph(para.strip(), content_style))
                story.append(Spacer(1, 6))
        
        doc.build(story)
        return str(filepath)
    
    def _format_metadata_header(self, metadata: Dict[str, Any]) -> str:
        """Format metadata as text header"""
        lines = ["=" * 50, "ANALYSIS REPORT", "=" * 50]
        
        for key, value in metadata.items():
            lines.append(f"{key}: {value}")
        
        lines.append("=" * 50)
        return "\n".join(lines)
    
    def get_export_history(self, limit: int = 10) -> List[Dict[str, Any]]:
        """Get recent export history"""
        files = []
        for filepath in self.export_dir.glob("*"):
            if filepath.is_file():
                stat = filepath.stat()
                files.append({
                    "filename": filepath.name,
                    "filepath": str(filepath),
                    "size": stat.st_size,
                    "created": datetime.fromtimestamp(stat.st_ctime).isoformat(),
                    "format": filepath.suffix[1:] if filepath.suffix else "unknown"
                })
        
        # Sort by creation time, newest first
        files.sort(key=lambda x: x["created"], reverse=True)
        return files[:limit]
    
    def cleanup_old_exports(self, days: int = 7) -> int:
        """Clean up exports older than specified days"""
        cutoff_time = datetime.now().timestamp() - (days * 24 * 60 * 60)
        deleted_count = 0
        
        for filepath in self.export_dir.glob("*"):
            if filepath.is_file() and filepath.stat().st_ctime < cutoff_time:
                try:
                    filepath.unlink()
                    deleted_count += 1
                except Exception:
                    pass
        
        return deleted_count