import os
import chardet


def extract_text(file_path: str) -> str:
    ext = os.path.splitext(file_path)[1].lower()
    try:
        if ext == ".txt":
            return _read_txt(file_path)
        elif ext == ".pdf":
            return _read_pdf(file_path)
        elif ext == ".docx":
            return _read_docx(file_path)
        elif ext == ".epub":
            return _read_epub(file_path)
        elif ext == ".odt":
            return _read_odt(file_path)
        elif ext == ".rtf":
            return _read_rtf(file_path)
        elif ext in (".html", ".htm"):
            return _read_html(file_path)
        else:
            return f"Unsupported format: {ext}"
    except Exception as e:
        return f"Error reading file: {str(e)}"


def _read_txt(path: str) -> str:
    with open(path, "rb") as f:
        raw = f.read()
    detected = chardet.detect(raw)
    encoding = detected.get("encoding", "utf-8") or "utf-8"
    return raw.decode(encoding, errors="replace")


def _read_pdf(path: str) -> str:
    from PyPDF2 import PdfReader
    reader = PdfReader(path)
    text = []
    for page in reader.pages:
        page_text = page.extract_text()
        if page_text:
            text.append(page_text)
    return "\n\n".join(text)


def _read_docx(path: str) -> str:
    from docx import Document
    doc = Document(path)
    return "\n\n".join(p.text for p in doc.paragraphs if p.text.strip())


def _read_epub(path: str) -> str:
    import ebooklib
    from ebooklib import epub
    from bs4 import BeautifulSoup
    book = epub.read_epub(path, options={"ignore_ncx": True})
    text = []
    for item in book.get_items():
        if item.get_type() == ebooklib.ITEM_DOCUMENT:
            soup = BeautifulSoup(item.get_content(), "html.parser")
            item_text = soup.get_text(separator="\n")
            if item_text.strip():
                text.append(item_text.strip())
    return "\n\n".join(text)


def _read_odt(path: str) -> str:
    from odf.opendocument import load
    from odf.text import P
    doc = load(path)
    paragraphs = doc.getElementsByType(P)
    text = []
    for p in paragraphs:
        t = ""
        for node in p.childNodes:
            if hasattr(node, "data"):
                t += node.data
            elif hasattr(node, "__str__"):
                t += str(node)
        if t.strip():
            text.append(t.strip())
    return "\n\n".join(text)


def _read_rtf(path: str) -> str:
    from striprtf.striprtf import rtf_to_text
    with open(path, "r", errors="replace") as f:
        rtf_content = f.read()
    return rtf_to_text(rtf_content)


def _read_html(path: str) -> str:
    from bs4 import BeautifulSoup
    with open(path, "r", encoding="utf-8", errors="replace") as f:
        soup = BeautifulSoup(f.read(), "html.parser")
    for tag in soup(["script", "style", "nav", "header", "footer"]):
        tag.decompose()
    return soup.get_text(separator="\n")