#!/usr/bin/env python3
"""
Standalone PDF Export Script

This script processes export requests from the gallery and creates merged PDFs.
Usage: python export_plots.py [request_file.json]
"""

import sys
import json
import argparse
from pathlib import Path
from orchestration.pdf_export import PDFExporter, check_dependencies


def main():
    parser = argparse.ArgumentParser(description='Export gallery plots to merged PDF')
    parser.add_argument('request_file', nargs='?', default='export_request.json',
                       help='JSON file containing export request')
    parser.add_argument('--output', '-o', help='Output PDF file path')
    parser.add_argument('--check-deps', action='store_true',
                       help='Check available dependencies')
    
    args = parser.parse_args()
    
    if args.check_deps:
        deps = check_dependencies()
        print("Available dependencies:")
        for dep, available in deps.items():
            status = "✓" if available else "✗"
            print(f"  {status} {dep}")
        
        if not any(deps.values()):
            print("\nNo PDF merging tools available!")
            print("Install one of the following:")
            print("  - PyPDF2 and reportlab: pip install PyPDF2 reportlab")
            print("  - pdfjam: apt-get install texlive-extra-utils (on Ubuntu/Debian)")
        return
    
    request_file = Path(args.request_file)
    if not request_file.exists():
        print(f"Error: Request file '{request_file}' not found")
        print("Create a JSON file with the following structure:")
        print(json.dumps({
            "plots": ["/path/to/plot1.pdf", "/path/to/plot2.pdf"],
            "layout": {"rows": 1, "cols": 2},
            "output_name": "merged_plots.pdf"
        }, indent=2))
        return 1
    
    try:
        with open(request_file, 'r') as f:
            request_data = json.load(f)
    except json.JSONDecodeError as e:
        print(f"Error: Invalid JSON in '{request_file}': {e}")
        return 1
    
    # Validate request data
    if 'plots' not in request_data:
        print("Error: Missing 'plots' field in request")
        return 1
    
    plot_paths = request_data['plots']
    layout = request_data.get('layout', {'rows': 2, 'cols': 2})
    output_name = args.output or request_data.get('output_name', 'merged_plots.pdf')
    
    # Validate plot files exist
    missing_files = []
    for plot_path in plot_paths:
        if not Path(plot_path).exists():
            missing_files.append(plot_path)
    
    if missing_files:
        print("Error: The following plot files were not found:")
        for missing in missing_files:
            print(f"  - {missing}")
        return 1
    
    print(f"Exporting {len(plot_paths)} plots to '{output_name}'...")
    print(f"Layout: {layout['rows']}x{layout['cols']}")
    
    # Create exporter and merge plots
    exporter = PDFExporter()
    
    try:
        pdf_bytes = exporter.merge_plots(plot_paths, layout, output_name)
        
        if not args.output and 'output_name' not in request_data:
            # Write to file if not already done by exporter
            with open(output_name, 'wb') as f:
                f.write(pdf_bytes)
        
        print(f"✓ Successfully created '{output_name}'")
        print(f"  File size: {len(pdf_bytes) / 1024:.1f} KB")
        
        # Clean up request file if export was successful
        request_file.unlink(missing_ok=True)
        
    except Exception as e:
        print(f"Error during export: {e}")
        return 1
    
    return 0


if __name__ == '__main__':
    sys.exit(main())