"""
PDF Text Extractor - Extracts text from PDF documents.
Handles scanned PDFs, multi-column layouts, and tables.
"""
import os
import json
import time
import logging
from typing import Optional

import pdfplumber

from scraper.config import RAW_SUBDIRS

logger = logging.getLogger("PDFExtractor")


class PDFExtractor:
    """Extracts text from PDF files using pdfplumber."""

    def __init__(self, output_dir: Optional[str] = None):
        self.pdf_dir = RAW_SUBDIRS["pdfs"]
        self.output_dir = output_dir or RAW_SUBDIRS["pdfs"]
        self.results = []
        os.makedirs(self.output_dir, exist_ok=True)

    def extract_from_file(self, filepath: str) -> dict:
        """Extract text from a single PDF file."""
        logger.info(f"📄 Extracting: {os.path.basename(filepath)}")

        try:
            text_parts = []
            metadata = {}

            with pdfplumber.open(filepath) as pdf:
                metadata = {
                    "num_pages": len(pdf.pages),
                    "pdf_info": pdf.metadata or {},
                }

                for i, page in enumerate(pdf.pages):
                    page_text = page.extract_text()
                    if page_text:
                        text_parts.append(page_text)

                    # Also try to extract tables
                    tables = page.extract_tables()
                    for table in tables:
                        if table:
                            table_text = "\n".join(
                                " | ".join(str(cell or "") for cell in row)
                                for row in table
                            )
                            text_parts.append(f"\n[Tabela]:\n{table_text}\n")

            full_text = "\n\n".join(text_parts)

            result = {
                "url": f"file://{filepath}",
                "title": os.path.basename(filepath).replace(".pdf", ""),
                "text": full_text,
                "text_length": len(full_text),
                "source": "PDF Document",
                "num_pages": metadata.get("num_pages", 0),
                "pdf_metadata": metadata.get("pdf_info", {}),
                "crawled_at": time.strftime("%Y-%m-%dT%H:%M:%S"),
            }

            return result

        except Exception as e:
            logger.error(f"Error extracting {filepath}: {e}")
            return {}

    def extract_all(self) -> list:
        """Extract text from all PDFs in the pdfs directory."""
        logger.info(f"🚀 Extracting all PDFs from: {self.pdf_dir}")

        pdf_files = [
            os.path.join(self.pdf_dir, f)
            for f in os.listdir(self.pdf_dir)
            if f.lower().endswith(".pdf")
        ]

        if not pdf_files:
            logger.info("No PDF files found.")
            return []

        for filepath in pdf_files:
            result = self.extract_from_file(filepath)
            if result and result.get("text_length", 0) > 50:
                # Save JSON alongside PDF
                json_path = filepath.replace(".pdf", ".json")
                with open(json_path, "w", encoding="utf-8") as f:
                    json.dump(result, f, ensure_ascii=False, indent=2)

                self.results.append(result)
                logger.info(f"   ✅ {result['title']} ({result['num_pages']} pages, {result['text_length']} chars)")
            else:
                logger.info(f"   ⏭️ Skipped (no text): {os.path.basename(filepath)}")

        logger.info(f"✅ PDF extraction complete: {len(self.results)} documents")
        return self.results

    def get_stats(self) -> dict:
        return {
            "source": "PDFs",
            "documents": len(self.results),
            "total_pages": sum(r.get("num_pages", 0) for r in self.results),
            "total_chars": sum(r.get("text_length", 0) for r in self.results),
        }