import subprocess
import tempfile
import pdfplumber
import json
from pathlib import Path
import os
import logging

# Set up logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

TEMP_DIR = Path("/tmp/ocr_processing")
TEMP_DIR.mkdir(exist_ok=True)
output_folder = TEMP_DIR / "output"
log_folder = TEMP_DIR / "logs"
output_folder.mkdir(exist_ok=True)
log_folder.mkdir(exist_ok=True)


def pdf_to_json(pdf_input):
    try:
        if hasattr(pdf_input, "read"):
            pdf_input.seek(0)

            with pdfplumber.open(pdf_input) as pdf:
                pages = [
                    {"page": i + 1, "text": (page.extract_text() or "").strip()}
                    for i, page in enumerate(pdf.pages)
                ]

            return {"pages": pages}

        elif isinstance(pdf_input, (str, Path)):
            pdf_path = Path(pdf_input)
            with pdfplumber.open(pdf_path) as pdf:
                pages = [
                    {"page": i + 1, "text": (page.extract_text() or "").strip()}
                    for i, page in enumerate(pdf.pages)
                ]

            return {"pages": pages}

        else:
            raise ValueError("Invalid file type provided")

    except Exception as e:
        logger.error(f"Failed to extract text from PDF: {str(e)}")
        raise Exception(f"Failed to extract text from PDF: {str(e)}")


def ocr_pdf(input_file_path: Path):
    try:
        input_path = Path(input_file_path)
        output_file = output_folder / f"{input_path.stem}-OCR.pdf"
        log_file = log_folder / f"{input_path.stem}.log"
        sidecar_txt = output_folder / f"{input_path.stem}.txt"

        if not input_path.exists():
            logger.error(f"Input file does not exist: {input_path}")
            return None

        try:
            subprocess.run(["ocrmypdf", "--version"], capture_output=True, check=True)
        except (subprocess.CalledProcessError, FileNotFoundError):
            logger.error("ocrmypdf is not installed or not in PATH")
            return None

        cmd = [
            "ocrmypdf",
            "--force-ocr",
            "--output-type",
            "pdfa",
            "--language",
            "deu+eng",
            "--sidecar",
            str(sidecar_txt),
            str(input_path),
            str(output_file),
        ]

        with open(log_file, "w") as log:
            result = subprocess.run(cmd, stdout=log, stderr=log, timeout=600)

        if result.returncode == 0:
            if output_file.exists():
                logger.info(
                    f"OCR successful, output file size: {output_file.stat().st_size} bytes"
                )
                return output_file
            else:
                logger.error(f"OCR completed but output file not found: {output_file}")
                return None
        else:
            logger.error(f"OCR failed with return code: {result.returncode}")
            return None

    except subprocess.TimeoutExpired:
        logger.error("OCR timed out after 600 seconds")
        return None
    except FileNotFoundError as e:
        logger.error(f"File not found error: {e}")
        return None
    except Exception as e:
        logger.error(f"Unexpected error in OCR: {e}", exc_info=True)
        return None


def extract_text_to_json(pdf_path: Path):
    try:
        json_path = output_folder / f"{pdf_path.stem}.json"

        with pdfplumber.open(pdf_path) as pdf:
            pages = [
                {"page": i + 1, "text": (page.extract_text() or "").strip()}
                for i, page in enumerate(pdf.pages)
            ]

        with open(json_path, "w", encoding="utf-8") as f:
            json.dump(pages, f, indent=2, ensure_ascii=False)
        return json_path

    except Exception as e:
        logger.error(f"Failed to extract text to JSON: {e}")
        return None