Add initial project structure with OCR functionality and dependencies

- Create .gitignore to exclude Python-generated files and virtual environments
- Add .python-version for Python version management
- Implement main OCR script (main.py) to process PDF files and extract text
- Add PDF processing functions in pdf_ocr.py
- Update README.md with project description, requirements, and usage instructions
- Include pyproject.toml for project metadata and dependencies
- Add uv.lock for dependency resolution

main.py

@@ -0,0 +1,121 @@
+from __future__ import annotations
+
+import argparse
+import shutil
+import sys
+from pathlib import Path
+
+import pytesseract
+
+from pdf_ocr import get_total_pages, ocr_pdf_range
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        description="Recognize text from selected PDF pages and save to a text file.",
+    )
+    parser.add_argument("--input", required=True, type=Path, help="Path to source PDF file.")
+    parser.add_argument("--start", required=True, type=int, help="Start page (1-based, inclusive).")
+    parser.add_argument("--end", required=True, type=int, help="End page (1-based, inclusive).")
+    parser.add_argument("--output", required=True, type=Path, help="Path to output TXT file.")
+    parser.add_argument("--lang", default="rus+eng", help="Tesseract language(s), example: rus+eng.")
+    parser.add_argument("--dpi", default=300, type=int, help="Render DPI before OCR. Default: 300.")
+    parser.add_argument(
+        "--rotate",
+        default=0,
+        type=int,
+        help="Rotate page image before OCR. Allowed: 0, 90, 180, 270, -90, -180, -270.",
+    )
+    return parser
+
+
+def validate_args(args: argparse.Namespace) -> int:
+    input_path: Path = args.input
+    if not input_path.exists() or not input_path.is_file():
+        raise ValueError(f"Input file not found: {input_path}")
+
+    if input_path.suffix.lower() != ".pdf":
+        raise ValueError(f"Input file must have .pdf extension: {input_path}")
+
+    if args.start < 1:
+        raise ValueError("--start must be >= 1.")
+
+    if args.end < args.start:
+        raise ValueError("--end must be >= --start.")
+
+    if args.dpi < 72:
+        raise ValueError("--dpi must be >= 72.")
+
+    allowed_rotations = {-270, -180, -90, 0, 90, 180, 270}
+    if args.rotate not in allowed_rotations:
+        raise ValueError("--rotate must be one of: 0, 90, 180, 270, -90, -180, -270.")
+
+    total_pages = get_total_pages(input_path)
+    if args.end > total_pages:
+        raise ValueError(
+            f"--end ({args.end}) is out of range. Document has {total_pages} pages.",
+        )
+
+    return total_pages
+
+
+def ensure_tesseract_available() -> None:
+    if shutil.which("tesseract") is None:
+        raise RuntimeError(
+            "Tesseract is not installed or not in PATH. Install it, for example: sudo apt-get install tesseract-ocr",
+        )
+
+    try:
+        _ = pytesseract.get_tesseract_version()
+    except Exception as exc:
+        raise RuntimeError("Cannot use Tesseract binary from current environment.") from exc
+
+
+def write_output(output_path: Path, pages: list[tuple[int, str]]) -> None:
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    with output_path.open("w", encoding="utf-8") as output_file:
+        for page_number, text in pages:
+            output_file.write(f"=== Page {page_number} ===\n")
+            output_file.write(text.rstrip())
+            output_file.write("\n\n")
+
+
+def main() -> int:
+    parser = build_parser()
+    args = parser.parse_args()
+
+    try:
+        total_pages = validate_args(args)
+        ensure_tesseract_available()
+
+        print(
+            (
+                f"Running OCR for pages {args.start}-{args.end} of {total_pages} "
+                f"from {args.input} with rotate={args.rotate}..."
+            ),
+            flush=True,
+        )
+
+        pages = ocr_pdf_range(
+            args.input,
+            args.start,
+            args.end,
+            lang=args.lang,
+            dpi=args.dpi,
+            rotate=args.rotate,
+            on_progress=lambda index, total, page: print(
+                f"[{index}/{total}] OCR page {page}",
+                flush=True,
+            ),
+        )
+        write_output(args.output, pages)
+    except (ValueError, RuntimeError) as exc:
+        print(f"Error: {exc}", file=sys.stderr)
+        return 1
+
+    print(f"Saved OCR text to: {args.output}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())