# ============================================================
# File: scraper/sites/piaotian.py
# Purpose:
#   Concrete SiteScraper implementation for ptwxz.com (Piaotian).
#   Moves all parsing logic out of BookScraper.
# ============================================================

from scraper.sites.base import SiteScraper
from bs4 import BeautifulSoup
from urllib.parse import urljoin
import re
from typing import Optional


class PiaotianScraper(SiteScraper):
    root = "https://www.ptwxz.com"
    encoding = "GB18030"
    chapter_list_selector = "div.centent"

    # ------------------------------------------------------------
    # METADATA PARSING
    # ------------------------------------------------------------
    def parse_title(self, soup: BeautifulSoup) -> str:
        h1 = soup.find("h1")
        return h1.get_text(strip=True) if h1 else "UnknownBook"

    def parse_author(self, soup: BeautifulSoup) -> str:
        td = soup.find("td", string=lambda t: t and "作" in t)
        raw = td.get_text(strip=True) if td else ""
        return raw.split("：")[1] if "：" in raw else "UnknownAuthor"

    def parse_description(self, soup: BeautifulSoup) -> str:
        span = soup.find("span", string=lambda t: t and "内容简介" in t)
        if not span:
            return ""

        parts = []
        for sib in span.next_siblings:
            # stop when next <span> reappears
            if getattr(sib, "name", None) == "span":
                break

            text = (
                sib.get_text(strip=True)
                if hasattr(sib, "get_text")
                else str(sib).strip()
            )
            if text:
                parts.append(text)

        return "\n".join(parts)

    # ------------------------------------------------------------
    # COVER PARSING
    # (exactly your BookScraper._parse_cover logic)
    # ------------------------------------------------------------
    def parse_cover(self, soup: BeautifulSoup, url: str) -> Optional[str]:
        # Extract book_id from URL
        m = re.search(r"/(\d+)\.html$", url)
        if not m:
            return None

        book_id = m.group(1)

        # Extract vol (bookinfo/<vol>/<id>.html)
        m2 = re.search(r"/bookinfo/(\d+)/", url)
        volume = m2.group(1) if m2 else None

        imgs = soup.find_all("img", src=True)
        chosen = None

        # Priority 1: match "/files/article/image/{vol}/{book_id}/"
        if volume:
            target_path = f"/files/article/image/{volume}/{book_id}/"
            for img in imgs:
                src = img["src"]
                if target_path in src:
                    chosen = src
                    break

        # Priority 2: endswith "/{book_id}s.jpg"
        if not chosen:
            target_suffix = f"/{book_id}s.jpg"
            for img in imgs:
                src = img["src"]
                if src.endswith(target_suffix):
                    chosen = src
                    break

        if not chosen:
            return None

        return urljoin(self.root, chosen)

    # ------------------------------------------------------------
    # CHAPTER EXTRACTION
    # ------------------------------------------------------------
    def extract_chapter_page_url(self, soup: BeautifulSoup) -> str:
        node = soup.select_one(
            "html > body > div:nth-of-type(6) > div:nth-of-type(2) > div > table"
        )
        href = node.select_one("a").get("href")
        return urljoin(self.root, href)

    def parse_chapter_list(self, soup: BeautifulSoup) -> list:
        cont = soup.select_one(self.chapter_list_selector)
        items = cont.select("ul li a[href]") if cont else []

        chapters = []
        idx = 1

        for a in items:
            href = a.get("href")
            if not href.endswith(".html"):
                continue
            title = a.get_text(strip=True)
            full_url = urljoin(self.root, href)
            chapters.append({"num": idx, "title": title, "url": full_url})
            idx += 1

        return chapters