# /// script
# requires-python = ">=3.11"
# dependencies = [
#     "datasets",
#     "huggingface-hub[hf_transfer]",
#     "pillow",
#     "vllm",
#     "transformers>=4.45.0",
#     "qwen-vl-utils",
#     "tqdm",
#     "toolz",
#     "torch",
#     "flash-attn",
# ]
#
# ///

"""
Document layout analysis and OCR using dots.ocr with vLLM.

This script processes document images through the dots.ocr model to extract
layout information, text content, or both. Supports multiple output formats
including JSON, structured columns, and markdown.

Features:
- Layout detection with bounding boxes and categories
- Text extraction with reading order preservation
- Multiple prompt modes for different tasks
- Flexible output formats
- Multilingual document support
"""

import argparse
import base64
import io
import json
import logging
import os
import sys
from typing import Any, Dict, List, Optional, Union

import torch
from datasets import load_dataset
from huggingface_hub import login
from PIL import Image
from toolz import partition_all
from tqdm.auto import tqdm

# Import both vLLM and transformers - we'll use based on flag
try:
    from vllm import LLM, SamplingParams
    VLLM_AVAILABLE = True
except ImportError:
    VLLM_AVAILABLE = False
    
from transformers import AutoModelForCausalLM, AutoProcessor

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Try to import qwen_vl_utils for transformers backend
try:
    from qwen_vl_utils import process_vision_info
    QWEN_VL_AVAILABLE = True
except ImportError:
    QWEN_VL_AVAILABLE = False
    logger.warning("qwen_vl_utils not available, transformers backend may not work properly")

# Prompt definitions from dots.ocr's dict_promptmode_to_prompt
PROMPT_MODES = {
    "layout-all": """Please output the layout information from the PDF image, including each layout element's bbox, its category, and the corresponding text content within the bbox.

1. Bbox format: [x1, y1, x2, y2]

2. Layout Categories: The possible categories are ['Caption', 'Footnote', 'Formula', 'List-item', 'Page-footer', 'Page-header', 'Picture', 'Section-header', 'Table', 'Text', 'Title'].

3. Text Extraction & Formatting Rules:
    - Picture: For the 'Picture' category, the text field should be omitted.
    - Formula: Format its text as LaTeX.
    - Table: Format its text as HTML.
    - All Others (Text, Title, etc.): Format their text as Markdown.

4. Constraints:
    - The output text must be the original text from the image, with no translation.
    - All layout elements must be sorted according to human reading order.

5. Final Output: The entire output must be a single JSON object.
""",
    
    "layout-only": """Please output the layout information from this PDF image, including each layout's bbox and its category. The bbox should be in the format [x1, y1, x2, y2]. The layout categories for the PDF document include ['Caption', 'Footnote', 'Formula', 'List-item', 'Page-footer', 'Page-header', 'Picture', 'Section-header', 'Table', 'Text', 'Title']. Do not output the corresponding text. The layout result should be in JSON format.""",
    
    "ocr": """Extract the text content from this image.""",
    
    "grounding-ocr": """Extract text from the given bounding box on the image (format: [x1, y1, x2, y2]).\nBounding Box:\n"""
}


def check_cuda_availability():
    """Check if CUDA is available and exit if not."""
    if not torch.cuda.is_available():
        logger.error("CUDA is not available. This script requires a GPU.")
        logger.error("Please run on a machine with a CUDA-capable GPU.")
        sys.exit(1)
    else:
        logger.info(f"CUDA is available. GPU: {torch.cuda.get_device_name(0)}")


def make_dots_message(
    image: Union[Image.Image, Dict[str, Any], str],
    mode: str = "layout-all",
    bbox: Optional[List[int]] = None,
) -> List[Dict]:
    """Create chat message for dots.ocr processing."""
    # Convert to PIL Image if needed
    if isinstance(image, Image.Image):
        pil_img = image
    elif isinstance(image, dict) and "bytes" in image:
        pil_img = Image.open(io.BytesIO(image["bytes"]))
    elif isinstance(image, str):
        pil_img = Image.open(image)
    else:
        raise ValueError(f"Unsupported image type: {type(image)}")

    # Convert to base64 data URI
    buf = io.BytesIO()
    pil_img.save(buf, format="PNG")
    data_uri = f"data:image/png;base64,{base64.b64encode(buf.getvalue()).decode()}"

    # Get prompt for the specified mode
    prompt = PROMPT_MODES.get(mode, PROMPT_MODES["layout-all"])
    
    # Add bbox for grounding-ocr mode
    if mode == "grounding-ocr" and bbox:
        prompt = prompt + str(bbox)
    
    # Return message in vLLM format
    return [
        {
            "role": "user",
            "content": [
                {"type": "image_url", "image_url": {"url": data_uri}},
                {"type": "text", "text": prompt},
            ],
        }
    ]


def parse_dots_output(
    output: str,
    output_format: str = "json",
    filter_category: Optional[str] = None,
    mode: str = "layout-all",
) -> Union[str, Dict[str, List]]:
    """Parse dots.ocr output and convert to requested format."""
    
    # For simple OCR mode, return text directly
    if mode == "ocr":
        return output.strip()
    
    try:
        # Parse JSON output
        data = json.loads(output.strip())
        
        # Filter by category if requested
        if filter_category and "categories" in data:
            indices = [i for i, cat in enumerate(data["categories"]) if cat == filter_category]
            filtered_data = {
                "bboxes": [data["bboxes"][i] for i in indices],
                "categories": [data["categories"][i] for i in indices],
            }
            
            # Only include texts if present (layout-all mode)
            if "texts" in data:
                filtered_data["texts"] = [data["texts"][i] for i in indices]
            
            # Include reading_order if present
            if "reading_order" in data:
                # Filter reading order to only include indices that are in our filtered set
                filtered_reading_order = []
                for group in data.get("reading_order", []):
                    filtered_group = [idx for idx in group if idx in indices]
                    if filtered_group:
                        # Remap indices to new positions
                        remapped_group = [indices.index(idx) for idx in filtered_group]
                        filtered_reading_order.append(remapped_group)
                if filtered_reading_order:
                    filtered_data["reading_order"] = filtered_reading_order
            
            data = filtered_data
        
        if output_format == "json":
            return json.dumps(data, ensure_ascii=False)
        
        elif output_format == "structured":
            # Return structured data for column creation
            result = {
                "bboxes": data.get("bboxes", []),
                "categories": data.get("categories", []),
            }
            
            # Only include texts for layout-all mode
            if mode == "layout-all":
                result["texts"] = data.get("texts", [])
            else:
                result["texts"] = []
            
            return result
        
        elif output_format == "markdown":
            # Convert to markdown format
            # Only works well with layout-all mode
            if mode != "layout-all" or "texts" not in data:
                logger.warning("Markdown format works best with layout-all mode")
                return json.dumps(data, ensure_ascii=False)
            
            md_lines = []
            texts = data.get("texts", [])
            categories = data.get("categories", [])
            reading_order = data.get("reading_order", [])
            
            # If reading order is provided, use it
            if reading_order:
                for group in reading_order:
                    for idx in group:
                        if idx < len(texts) and idx < len(categories):
                            text = texts[idx]
                            category = categories[idx]
                            md_lines.append(format_markdown_text(text, category))
            else:
                # Fall back to sequential order
                for text, category in zip(texts, categories):
                    md_lines.append(format_markdown_text(text, category))
            
            return "\n".join(md_lines)
            
    except json.JSONDecodeError as e:
        logger.warning(f"Failed to parse JSON output: {e}")
        return output.strip()
    except Exception as e:
        logger.error(f"Error parsing output: {e}")
        return output.strip()


def format_markdown_text(text: str, category: str) -> str:
    """Format text based on its category for markdown output."""
    if category == "Title":
        return f"# {text}\n"
    elif category == "Section-header":
        return f"## {text}\n"
    elif category == "List-item":
        return f"- {text}"
    elif category == "Page-header" or category == "Page-footer":
        return f"_{text}_\n"
    elif category == "Caption":
        return f"**{text}**\n"
    elif category == "Footnote":
        return f"[^{text}]\n"
    elif category == "Table":
        # Tables are already in HTML format from dots.ocr
        return f"\n{text}\n"
    elif category == "Formula":
        # Formulas are already in LaTeX format
        return f"\n${text}$\n"
    elif category == "Picture":
        # Pictures don't have text in dots.ocr output
        return "\n![Image]()\n"
    else:  # Text and any other categories
        return f"{text}\n"


def process_with_transformers(
    images: List[Union[Image.Image, Dict[str, Any], str]],
    model,
    processor,
    mode: str = "layout-all",
    max_new_tokens: int = 16384,
) -> List[str]:
    """Process images using transformers instead of vLLM."""
    outputs = []
    
    for image in tqdm(images, desc="Processing with transformers"):
        # Convert to PIL Image if needed
        if isinstance(image, dict) and "bytes" in image:
            pil_image = Image.open(io.BytesIO(image["bytes"]))
        elif isinstance(image, str):
            pil_image = Image.open(image)
        else:
            pil_image = image
            
        # Get prompt for the mode
        prompt = PROMPT_MODES.get(mode, PROMPT_MODES["layout-all"])
        
        # Create messages in the format expected by dots.ocr
        messages = [
            {
                "role": "user",
                "content": [
                    {"type": "image", "image": pil_image},
                    {"type": "text", "text": prompt}
                ]
            }
        ]
        
        # Preparation for inference (following demo code)
        text = processor.apply_chat_template(
            messages, 
            tokenize=False, 
            add_generation_prompt=True
        )
        
        if QWEN_VL_AVAILABLE:
            # Use process_vision_info as shown in demo
            image_inputs, video_inputs = process_vision_info(messages)
            inputs = processor(
                text=[text],
                images=image_inputs,
                videos=video_inputs,
                padding=True,
                return_tensors="pt",
            )
        else:
            # Fallback approach without qwen_vl_utils
            inputs = processor(
                text=text,
                images=[pil_image],
                return_tensors="pt",
            )
        
        inputs = inputs.to(model.device)
        
        # Generate
        with torch.no_grad():
            generated_ids = model.generate(
                **inputs,
                max_new_tokens=max_new_tokens,
                temperature=0.0,
                do_sample=False,
            )
        
        # Decode output (following demo code)
        generated_ids_trimmed = [
            out_ids[len(in_ids):] for in_ids, out_ids in zip(inputs.input_ids, generated_ids)
        ]
        output_text = processor.batch_decode(
            generated_ids_trimmed, 
            skip_special_tokens=True, 
            clean_up_tokenization_spaces=False
        )[0]
        
        outputs.append(output_text.strip())
    
    return outputs


def main(
    input_dataset: str,
    output_dataset: str,
    image_column: str = "image",
    mode: str = "layout-all",
    output_format: str = "json",
    filter_category: Optional[str] = None,
    batch_size: int = 32,
    model: str = "rednote-hilab/dots.ocr",
    max_model_len: int = 24000,
    max_tokens: int = 16384,
    gpu_memory_utilization: float = 0.8,
    hf_token: Optional[str] = None,
    split: str = "train",
    max_samples: Optional[int] = None,
    private: bool = False,
    use_transformers: bool = False,
    # Column name parameters
    output_column: str = "dots_ocr_output",
    bbox_column: str = "layout_bboxes",
    category_column: str = "layout_categories",
    text_column: str = "layout_texts",
    markdown_column: str = "markdown",
):
    """Process images from HF dataset through dots.ocr model."""

    # Check CUDA availability first
    check_cuda_availability()

    # Enable HF_TRANSFER for faster downloads
    os.environ["HF_HUB_ENABLE_HF_TRANSFER"] = "1"

    # Login to HF if token provided
    HF_TOKEN = hf_token or os.environ.get("HF_TOKEN")
    if HF_TOKEN:
        login(token=HF_TOKEN)

    # Load dataset
    logger.info(f"Loading dataset: {input_dataset}")
    dataset = load_dataset(input_dataset, split=split)

    # Validate image column
    if image_column not in dataset.column_names:
        raise ValueError(
            f"Column '{image_column}' not found. Available: {dataset.column_names}"
        )

    # Limit samples if requested
    if max_samples:
        dataset = dataset.select(range(min(max_samples, len(dataset))))
        logger.info(f"Limited to {len(dataset)} samples")

    # Process images in batches
    all_outputs = []
    
    if use_transformers or not VLLM_AVAILABLE:
        # Use transformers
        if not use_transformers and not VLLM_AVAILABLE:
            logger.warning("vLLM not available, falling back to transformers")
            
        logger.info(f"Initializing transformers with model: {model}")
        hf_model = AutoModelForCausalLM.from_pretrained(
            model,
            torch_dtype=torch.bfloat16,
            device_map="auto",
            trust_remote_code=True,
        )
        processor = AutoProcessor.from_pretrained(model, trust_remote_code=True)
        
        logger.info(f"Processing {len(dataset)} images with transformers")
        logger.info(f"Mode: {mode}, Output format: {output_format}")
        
        # Process all images
        all_images = [dataset[i][image_column] for i in range(len(dataset))]
        raw_outputs = process_with_transformers(
            all_images, 
            hf_model, 
            processor, 
            mode=mode,
            max_new_tokens=max_tokens
        )
        
        # Parse outputs
        for raw_text in raw_outputs:
            parsed = parse_dots_output(raw_text, output_format, filter_category, mode)
            all_outputs.append(parsed)
            
    else:
        # Use vLLM
        logger.info(f"Initializing vLLM with model: {model}")
        llm = LLM(
            model=model,
            trust_remote_code=True,
            max_model_len=max_model_len,
            gpu_memory_utilization=gpu_memory_utilization,
        )

        sampling_params = SamplingParams(
            temperature=0.0,  # Deterministic for OCR
            max_tokens=max_tokens,
        )

        logger.info(f"Processing {len(dataset)} images in batches of {batch_size}")
        logger.info(f"Mode: {mode}, Output format: {output_format}")

        # Process in batches to avoid memory issues
        for batch_indices in tqdm(
            partition_all(batch_size, range(len(dataset))),
            total=(len(dataset) + batch_size - 1) // batch_size,
            desc="dots.ocr processing",
        ):
            batch_indices = list(batch_indices)
            batch_images = [dataset[i][image_column] for i in batch_indices]

            try:
                # Create messages for batch
                batch_messages = [make_dots_message(img, mode=mode) for img in batch_images]

                # Process with vLLM
                outputs = llm.chat(batch_messages, sampling_params)

                # Extract and parse outputs
                for output in outputs:
                    raw_text = output.outputs[0].text.strip()
                    parsed = parse_dots_output(raw_text, output_format, filter_category, mode)
                    all_outputs.append(parsed)

            except Exception as e:
                logger.error(f"Error processing batch: {e}")
                # Add error placeholders for failed batch
                all_outputs.extend([{"error": str(e)}] * len(batch_images))

    # Add columns to dataset based on output format
    logger.info("Adding output columns to dataset")
    
    if output_format == "json":
        dataset = dataset.add_column(output_column, all_outputs)
        
    elif output_format == "structured":
        # Extract lists from structured outputs
        bboxes = []
        categories = []
        texts = []
        
        for output in all_outputs:
            if isinstance(output, dict) and "error" not in output:
                bboxes.append(output.get("bboxes", []))
                categories.append(output.get("categories", []))
                texts.append(output.get("texts", []))
            else:
                bboxes.append([])
                categories.append([])
                texts.append([])
        
        dataset = dataset.add_column(bbox_column, bboxes)
        dataset = dataset.add_column(category_column, categories)
        dataset = dataset.add_column(text_column, texts)
        
    elif output_format == "markdown":
        dataset = dataset.add_column(markdown_column, all_outputs)
    
    else:  # ocr mode
        dataset = dataset.add_column(output_column, all_outputs)

    # Push to hub
    logger.info(f"Pushing to {output_dataset}")
    dataset.push_to_hub(output_dataset, private=private, token=HF_TOKEN)

    logger.info("✅ dots.ocr processing complete!")
    logger.info(
        f"Dataset available at: https://huggingface.co/datasets/{output_dataset}"
    )


if __name__ == "__main__":
    # Show example usage if no arguments
    if len(sys.argv) == 1:
        print("=" * 80)
        print("dots.ocr Document Layout Analysis and OCR")
        print("=" * 80)
        print("\nThis script processes document images using the dots.ocr model to")
        print("extract layout information, text content, or both.")
        print("\nFeatures:")
        print("- Layout detection with bounding boxes and categories")
        print("- Text extraction with reading order preservation")
        print("- Multiple output formats (JSON, structured, markdown)")
        print("- Multilingual document support")
        print("\nExample usage:")
        print("\n1. Full layout analysis + OCR (default):")
        print("   uv run dots-ocr.py document-images analyzed-docs")
        print("\n2. Layout detection only:")
        print("   uv run dots-ocr.py scanned-pdfs layout-analysis --mode layout-only")
        print("\n3. Simple OCR (text only):")
        print("   uv run dots-ocr.py documents extracted-text --mode ocr")
        print("\n4. Convert to markdown:")
        print("   uv run dots-ocr.py papers papers-markdown --output-format markdown")
        print("\n5. Extract only tables:")
        print("   uv run dots-ocr.py reports table-data --filter-category Table")
        print("\n6. Structured output with custom columns:")
        print("   uv run dots-ocr.py docs analyzed \\")
        print("       --output-format structured \\")
        print("       --bbox-column boxes \\")
        print("       --category-column types \\")
        print("       --text-column content")
        print("\n7. Process a subset for testing:")
        print("   uv run dots-ocr.py large-dataset test-output --max-samples 10")
        print("\n8. Use transformers backend (more compatible):")
        print("   uv run dots-ocr.py documents analyzed --use-transformers")
        print("\n9. Running on HF Jobs:")
        print("   hf jobs run --gpu l4x1 \\")
        print("     -e HF_TOKEN=$(python3 -c \"from huggingface_hub import get_token; print(get_token())\") \\")
        print(
            "     uv run https://huggingface.co/datasets/uv-scripts/ocr/raw/main/dots-ocr.py \\"
        )
        print("       your-document-dataset \\")
        print("       your-analyzed-output \\")
        print("       --use-transformers")
        print("\n" + "=" * 80)
        print("\nFor full help, run: uv run dots-ocr.py --help")
        sys.exit(0)

    parser = argparse.ArgumentParser(
        description="Document layout analysis and OCR using dots.ocr",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Modes:
  layout-all   - Extract layout + text content (default)
  layout-only  - Extract only layout information (bbox + category)
  ocr          - Extract only text content
  grounding-ocr - Extract text from specific bbox (requires --bbox)

Output Formats:
  json        - Raw JSON output from model (default)
  structured  - Separate columns for bboxes, categories, texts
  markdown    - Convert to markdown format

Examples:
  # Basic layout + OCR
  uv run dots-ocr.py my-docs analyzed-docs

  # Layout detection only
  uv run dots-ocr.py papers layouts --mode layout-only

  # Convert to markdown
  uv run dots-ocr.py scans readable --output-format markdown

  # Extract only formulas
  uv run dots-ocr.py math-docs formulas --filter-category Formula
        """,
    )

    parser.add_argument("input_dataset", help="Input dataset ID from Hugging Face Hub")
    parser.add_argument("output_dataset", help="Output dataset ID for Hugging Face Hub")
    parser.add_argument(
        "--image-column",
        default="image",
        help="Column containing images (default: image)",
    )
    parser.add_argument(
        "--mode",
        choices=["layout-all", "layout-only", "ocr", "grounding-ocr"],
        default="layout-all",
        help="Processing mode (default: layout-all)",
    )
    parser.add_argument(
        "--output-format",
        choices=["json", "structured", "markdown"],
        default="json",
        help="Output format (default: json)",
    )
    parser.add_argument(
        "--filter-category",
        choices=['Caption', 'Footnote', 'Formula', 'List-item', 'Page-footer', 
                 'Page-header', 'Picture', 'Section-header', 'Table', 'Text', 'Title'],
        help="Filter results by layout category",
    )
    parser.add_argument(
        "--batch-size",
        type=int,
        default=32,
        help="Batch size for processing (default: 32)",
    )
    parser.add_argument(
        "--model",
        default="rednote-hilab/dots.ocr",
        help="Model to use (default: rednote-hilab/dots.ocr)",
    )
    parser.add_argument(
        "--max-model-len",
        type=int,
        default=24000,
        help="Maximum model context length (default: 24000)",
    )
    parser.add_argument(
        "--max-tokens",
        type=int,
        default=16384,
        help="Maximum tokens to generate (default: 16384)",
    )
    parser.add_argument(
        "--gpu-memory-utilization",
        type=float,
        default=0.8,
        help="GPU memory utilization (default: 0.8)",
    )
    parser.add_argument("--hf-token", help="Hugging Face API token")
    parser.add_argument(
        "--split", default="train", help="Dataset split to use (default: train)"
    )
    parser.add_argument(
        "--max-samples",
        type=int,
        help="Maximum number of samples to process (for testing)",
    )
    parser.add_argument(
        "--private", action="store_true", help="Make output dataset private"
    )
    parser.add_argument(
        "--use-transformers",
        action="store_true",
        help="Use transformers instead of vLLM (more compatible but slower)",
    )
    
    # Column name customization
    parser.add_argument(
        "--output-column",
        default="dots_ocr_output",
        help="Column name for JSON output (default: dots_ocr_output)",
    )
    parser.add_argument(
        "--bbox-column",
        default="layout_bboxes",
        help="Column name for bboxes in structured mode (default: layout_bboxes)",
    )
    parser.add_argument(
        "--category-column",
        default="layout_categories",
        help="Column name for categories in structured mode (default: layout_categories)",
    )
    parser.add_argument(
        "--text-column",
        default="layout_texts",
        help="Column name for texts in structured mode (default: layout_texts)",
    )
    parser.add_argument(
        "--markdown-column",
        default="markdown",
        help="Column name for markdown output (default: markdown)",
    )

    args = parser.parse_args()

    main(
        input_dataset=args.input_dataset,
        output_dataset=args.output_dataset,
        image_column=args.image_column,
        mode=args.mode,
        output_format=args.output_format,
        filter_category=args.filter_category,
        batch_size=args.batch_size,
        model=args.model,
        max_model_len=args.max_model_len,
        max_tokens=args.max_tokens,
        gpu_memory_utilization=args.gpu_memory_utilization,
        hf_token=args.hf_token,
        split=args.split,
        max_samples=args.max_samples,
        private=args.private,
        use_transformers=args.use_transformers,
        output_column=args.output_column,
        bbox_column=args.bbox_column,
        category_column=args.category_column,
        text_column=args.text_column,
        markdown_column=args.markdown_column,
    )