import os
import sys
import tempfile
import gradio as gr

# Add backend directory to sys.path so internal imports work seamlessly
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), 'backend')))

from backend.pdf_processor import convert_pdf_to_images
from backend.services.export_service import ExportService

def process_pdf(pdf_file, mineru_api_base, mineru_token, baidu_api_key, baidu_secret_key, max_workers, progress=gr.Progress()):
    if not pdf_file:
        return None, "Error: No file uploaded."
    if not mineru_token:
        # Fallback to HF Secrets using exact screenshot names or defaults
        mineru_token = os.environ.get("MinerU_Token", os.environ.get("MINERU_TOKEN", ""))
        if not mineru_token:
            return None, "Error: MinerU Token is required."
            
    if not baidu_api_key:
        baidu_api_key = os.environ.get("Baidu_API_Key", os.environ.get("BAIDU_API_KEY", ""))
    if not baidu_secret_key:
        baidu_secret_key = os.environ.get("Baidu_Secret_Key", os.environ.get("BAIDU_SECRET_KEY", ""))
        
    if not mineru_api_base:
        mineru_api_base = os.environ.get("MinerU_API_Base", os.environ.get("MINERU_API_BASE", "https://asemxin2000-mineru.hf.space"))

    # Set up environment variables that the backend relies on
    os.environ['MINERU_TOKEN'] = mineru_token
    os.environ['MINERU_API_BASE'] = mineru_api_base
    os.environ['BAIDU_API_KEY'] = baidu_api_key
    os.environ['BAIDU_SECRET_KEY'] = baidu_secret_key
    
    # We'll use a local temp upload folder
    upload_dir = tempfile.mkdtemp()
    os.environ['UPLOAD_FOLDER'] = upload_dir

    try:
        progress(0, desc="Converting PDF to images...")
        # 1. Convert PDF to high-res images
        image_paths = convert_pdf_to_images(pdf_file.name, output_dir=upload_dir, dpi=300)
        
        if not image_paths:
            return None, "Error: Failed to extract images from PDF."
            
        progress(0.1, desc=f"Extracted {len(image_paths)} pages.")

        # Progress callback adapter
        def progress_adapter(step: str, message: str, percent: int):
            # Gradio progress takes float [0, 1]
            # Since pdf to image took 10%, we map the remaining 90% (percent / 100 * 0.9 + 0.1)
            mapped_progress = (percent / 100.0) * 0.9 + 0.1
            progress(mapped_progress, desc=f"[{step}] {message}")

        # 2. Run the main PPTX conversion pipeline exactly as designed in banana-slides
        # Defaulting export strategies to hybrid which combines MinerU and Baidu OCR
        pptx_bytes, warnings = ExportService.create_editable_pptx_with_recursive_analysis(
            image_paths=image_paths,
            output_file=None, # Return bytes
            slide_width_pixels=1920,
            slide_height_pixels=1080,
            max_depth=1, # Depth 1 is generally enough for presentations
            max_workers=int(max_workers),
            progress_callback=progress_adapter,
            export_extractor_method='hybrid' if baidu_api_key else 'mineru',
            export_inpaint_method='baidu' if baidu_api_key else 'generative', # generative requires AI model, let's just stick to baidu if we have it
            fail_fast=False # tolerate warnings
        )
        
        if not pptx_bytes:
            return None, "Error: PPTX generation returned empty bytes."

        # Save to a temporary file
        output_pptx_path = os.path.join(upload_dir, "output_presentation.pptx")
        with open(output_pptx_path, "wb") as f:
            f.write(pptx_bytes)
            
        warning_msg = f"Done! {len(warnings.to_summary())} warnings encountered." if warnings.has_warnings() else "Done successfully!"
        return output_pptx_path, warning_msg

    except Exception as e:
        import traceback
        traceback.print_exc()
        return None, f"An error occurred: {str(e)}"

# Define the Gradio Interface
with gr.Blocks(title="PDF to Editable PPTX") as demo:
    gr.Markdown("# 🍌📄 PDF to Editable PPTX Converter")
    gr.Markdown("Convert your PDF slides into high-fidelity editable PowerPoint files using OpenXLab MinerU and Baidu OCR APIs.")
    
    with gr.Row():
        with gr.Column(scale=1):
            pdf_input = gr.File(label="Upload PDF", file_types=[".pdf"])
            max_workers = gr.Slider(minimum=1, maximum=16, value=2, step=1, label="Max Workers (Parallel Processing)")
            
            with gr.Accordion("API Keys (Optional if set in Space Secrets)", open=False):
                mineru_api_base = gr.Textbox(label="MinerU API Base", value=os.environ.get("MinerU_API_Base", os.environ.get("MINERU_API_BASE", "https://asemxin2000-mineru.hf.space")), placeholder="https://asemxin2000-mineru.hf.space", info="MinerU 服务地址（HF Space 或 mineru.net）")
                mineru_token = gr.Textbox(label="MinerU Token", type="password", value=os.environ.get("MinerU_Token", os.environ.get("MINERU_TOKEN", "")))
                baidu_api_key = gr.Textbox(label="Baidu API Key", type="password", value=os.environ.get("Baidu_API_Key", os.environ.get("BAIDU_API_KEY", "")))
                baidu_secret = gr.Textbox(label="Baidu Secret Key", type="password", value=os.environ.get("Baidu_Secret_Key", os.environ.get("BAIDU_SECRET_KEY", "")))
                
            convert_btn = gr.Button("Convert to PPTX", variant="primary")
            
        with gr.Column(scale=1):
            status_box = gr.Textbox(label="Status", interactive=False)
            pptx_output = gr.File(label="Download PPTX")
            
    convert_btn.click(
        fn=process_pdf,
        inputs=[pdf_input, mineru_api_base, mineru_token, baidu_api_key, baidu_secret, max_workers],
        outputs=[pptx_output, status_box]
    )

if __name__ == "__main__":
    demo.launch()