# app.py
import json
import traceback
import tempfile # Not strictly needed by process_upload anymore, but good to keep if other parts use it.
import os
import gradio as gr
from typing import Tuple, Optional, Any 

# Import config first to ensure JAVA_HOME is set early
import config 

from main_analyzer import analyze_pdf 
# language_tool_python needed for the test in __main__
import language_tool_python


def process_upload(uploaded_file_input: Optional[Any]) -> Tuple[str, Optional[str]]:
    """
    Processes the uploaded file from Gradio.
    'uploaded_file_input' is expected to be an object from gr.File(),
    which could be a path string (like gradio.utils.NamedString) or a file-like object.
    """
    if uploaded_file_input is None:
        print("App: No file uploaded.")
        return json.dumps({"error": "No file uploaded."}, indent=2), None

    try:
        # Pass the uploaded_file_input directly to analyze_pdf.
        # analyze_pdf is responsible for determining if it's a path or a stream
        # and handling it accordingly (including creating a temp file for streams if needed).
        print(f"App: Received file input of type: {type(uploaded_file_input)}. Passing to analyzer.")
        
        results_dict, _ = analyze_pdf(uploaded_file_input) 
        
        # Check if analyze_pdf returned an error (it returns a dict with "error" key in that case)
        if isinstance(results_dict, dict) and "error" in results_dict:
            print(f"App: Analysis returned an error: {results_dict['error']}")
            # Return the error JSON directly
            return json.dumps(results_dict, indent=2, ensure_ascii=False), None

        results_json = json.dumps(results_dict, indent=2, ensure_ascii=False)
        return results_json, None 

    except Exception as e:
        # This catches unexpected errors during the call to analyze_pdf or JSON dumping.
        print(f"App: Error in process_upload: {e}\n{traceback.format_exc()}")
        error_detail = str(e)
        # If the error is due to an invalid input type that analyze_pdf couldn't handle:
        if "Invalid PDF input type" in error_detail: # Check for specific error from analyze_pdf
             error_detail = f"Invalid PDF input type received from uploader: {type(uploaded_file_input)}. Details: {str(e)}"
        
        error_message = json.dumps({"error": error_detail, "traceback": traceback.format_exc()}, indent=2)
        return error_message, None
    # No explicit temp file cleanup needed here in process_upload for the Gradio-provided file object.
    # Gradio manages its own temporary files.
    # analyze_pdf manages any internal temporary files it creates.

def create_interface():
    with gr.Blocks(title="PDF Analyzer") as interface:
        gr.Markdown("# PDF Analyzer")
        gr.Markdown(
            "Upload a PDF document to analyze its structure, references, language, and more. "
            "Language issues are derived from font-filtered text. "
            "Regex issues and general document checks use unfiltered text from the original PDF. "
            "All issue coordinates (if found) are mapped back to the original PDF."
        )
        
        with gr.Row():
            file_input = gr.File(
                label="Upload PDF",
                file_types=[".pdf"]
                # Default type: Gradio provides a path-like object (e.g., NamedString)
                # or a TemporaryFileWrapper. Both should be acceptable by analyze_pdf.
            )
        
        with gr.Row():
            analyze_btn = gr.Button("Analyze PDF")
        
        with gr.Row():
            results_output = gr.JSON(
                label="Analysis Results",
                show_label=True
            )
        
        with gr.Row():
            pdf_output = gr.File( 
                label="Annotated PDF (Placeholder - View Coordinates in JSON)",
                show_label=True,
                interactive=False 
            )
        
        analyze_btn.click(
            fn=process_upload,
            inputs=[file_input],
            outputs=[results_output, pdf_output]
        )
    return interface

if __name__ == "__main__":
    print("\n--- Launching Gradio Interface ---")
    # config.set_java_home() is called when config.py is imported.

    try:
        lt_test = language_tool_python.LanguageTool('en-US')
        lt_test.close()
        print("App: LanguageTool initialized successfully for test.")
    except Exception as lt_e:
        print(f"App: Warning: Could not initialize LanguageTool for test. Language checks might fail: {lt_e}\n{traceback.format_exc(limit=1)}")
        print("Please ensure Java is installed and JAVA_HOME is correctly set (see config.py).")
    
    app_interface = create_interface()
    app_interface.launch(
        share=False,
    )