"""图书元数据刮削模块。

数据源策略：
- 中文书：豆瓣网页爬取 + Goodreads 补评分
- 英文书：Goodreads 为主力
- 兜底：Google Books API / Open Library ISBN API
"""

import json
import re
import time
import random

try:
    import requests as _requests
    _HAS_REQUESTS = True
except ImportError:
    import urllib.request
    _HAS_REQUESTS = False

# ── 常量 ────────────────────────────────────────────────────────────

_UA = (
    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) "
    "AppleWebKit/537.36 (KHTML, like Gecko) "
    "Chrome/123.0.0.0 Safari/537.36"
)

DOUBAN_ISBN_URL = "https://book.douban.com/isbn/{isbn}"
DOUBAN_SUBJECT_URL = "https://book.douban.com/subject/{sid}/"
GOODREADS_BOOK_URL = "https://www.goodreads.com/book/show/{book_id}"
GOODREADS_SEARCH_URL = "https://www.goodreads.com/search?q={query}"
GOOGLE_BOOKS_URL = "https://www.googleapis.com/books/v1/volumes?q=isbn:{isbn}"
OPEN_LIBRARY_URL = (
    "https://openlibrary.org/api/books?bibkeys=ISBN:{isbn}&format=json&jscmd=data"
)
OPEN_LIBRARY_COVER = "https://covers.openlibrary.org/b/isbn/{isbn}-L.jpg"

# ── 工具函数 ─────────────────────────────────────────────────────────

def _get(url, timeout=15):
    """带 UA 的 HTTP GET，返回响应文本或 None。优先使用 requests 库。"""
    headers = {"User-Agent": _UA}
    if _HAS_REQUESTS:
        try:
            resp = _requests.get(url, headers=headers, timeout=timeout,
                                 allow_redirects=True)
            if resp.status_code == 200:
                return resp.text
            return None
        except Exception:
            return None
    else:
        import urllib.request
        req = urllib.request.Request(url, headers=headers)
        try:
            with urllib.request.urlopen(req, timeout=timeout) as resp:
                return resp.read().decode("utf-8", errors="replace")
        except Exception:
            return None


def _get_with_playwright(url, timeout=30000):
    """用 Playwright 无头浏览器获取页面 HTML（用于豆瓣等反爬严格的站点）。"""
    try:
        from playwright.sync_api import sync_playwright
    except ImportError:
        print("⚠️  需要安装 Playwright：pip install playwright && playwright install")
        return None

    html = None
    # 多种启动策略：系统 Chrome → Playwright Chromium → 不同 headless 模式
    launch_options = [
        {"channel": "chrome", "headless": True},         # 系统 Chrome
        {"channel": "chromium", "headless": True},        # 系统 Chromium
        {"headless": True,                                # Playwright 自带
         "args": ["--disable-blink-features=AutomationControlled"]},
        {"headless": False,                               # 非 headless（最后手段）
         "args": ["--headless=new"]},                     # Chrome 新 headless 模式
    ]

    try:
        with sync_playwright() as p:
            browser = None
            for opts in launch_options:
                try:
                    browser = p.chromium.launch(**opts)
                    break
                except Exception:
                    continue

            if not browser:
                print("⚠️  无法启动浏览器。请确保已安装 Chrome 或运行：playwright install")
                return None

            context = browser.new_context(
                user_agent=_UA,
                viewport={"width": 1280, "height": 800},
                locale="zh-CN",
            )
            page = context.new_page()
            page.goto(url, wait_until="domcontentloaded", timeout=timeout)
            # 等待核心内容出现
            try:
                page.wait_for_selector("#info", timeout=8000)
            except Exception:
                pass  # 即使超时也继续，页面可能已部分加载
            html = page.content()
            browser.close()
    except Exception as e:
        print(f"⚠️  Playwright 访问失败：{e}")
        return None

    return html


def _sleep():
    """礼貌延时，避免被封。"""
    time.sleep(random.uniform(1.0, 2.5))


def _is_isbn(s):
    digits = re.sub(r"[-\s]", "", s)
    return re.fullmatch(r"\d{10}|\d{13}", digits) is not None


def _clean_isbn(s):
    return re.sub(r"[-\s]", "", s)


def _is_chinese_isbn(isbn):
    """以 978-7 / 7 开头的 ISBN 通常是中文出版物。"""
    d = _clean_isbn(isbn)
    return d.startswith("9787") or d.startswith("7")


# ── 豆瓣刮削 ─────────────────────────────────────────────────────────

def _parse_douban_html(html):
    """解析豆瓣图书详情页 HTML，返回 dict。需要 beautifulsoup4。"""
    try:
        from bs4 import BeautifulSoup
    except ImportError:
        raise RuntimeError("请先安装 beautifulsoup4：pip install beautifulsoup4")

    soup = BeautifulSoup(html, "html.parser")

    result = {}

    # 书名
    title_tag = soup.find("h1")
    if title_tag:
        span = title_tag.find("span")
        result["title"] = (span or title_tag).get_text(strip=True)

    # 封面
    cover_tag = soup.find("a", attrs={"class": "nbg"})
    if cover_tag:
        img = cover_tag.find("img")
        if img:
            result["cover_url"] = img.get("src", "")

    # 豆瓣评分
    rating_tag = soup.find("strong", attrs={"class": "ll rating_num"})
    if rating_tag:
        txt = rating_tag.get_text(strip=True)
        try:
            result["douban_score"] = float(txt)
        except ValueError:
            pass

    # 作者、出版社等在 #info 块
    info = soup.find("div", id="info")
    if info:
        # 方法1：通过 <span class="pl"> 标签精确提取
        for span in info.find_all("span", class_="pl"):
            label = span.get_text(strip=True).rstrip("：: ")
            # 获取同级后续文本和链接
            values = []
            for sib in span.next_siblings:
                if hasattr(sib, 'name'):
                    if sib.name == 'br':
                        break
                    if sib.name == 'span' and 'pl' in (sib.get('class') or []):
                        break
                    if sib.name == 'a':
                        values.append(sib.get_text(strip=True))
                    elif sib.name == 'span':
                        values.append(sib.get_text(strip=True))
                else:
                    t = str(sib).strip().strip("：:/·, ")
                    if t:
                        values.append(t)
            value = " ".join(v for v in values if v).strip(" /：:")

            if not value:
                continue

            if "作者" in label:
                # 去掉 [国籍] 标注
                author_clean = re.sub(r"\[.*?\]", "", value).strip(" /")
                # 清理多余空格
                author_clean = re.sub(r"\s+", " ", author_clean).strip()
                if author_clean:
                    result["author"] = author_clean
            elif "译者" in label:
                result["translator"] = re.sub(r"\s+", " ", value).strip(" /")
            elif "出版社" in label:
                result["publisher"] = value
            elif "出版年" in label:
                result["pub_date"] = value
            elif "ISBN" in label.upper():
                result["isbn"] = value

        # 方法2：兜底 — 如果 span.pl 没有拿到，用纯文本
        if not result.get("author"):
            text = info.get_text(separator="\n")
            for line in text.splitlines():
                line = line.strip()
                if "作者" in line:
                    parts = re.split(r"[：:]", line, 1)
                    if len(parts) == 2 and parts[1].strip():
                        author = re.sub(r"\[.*?\]", "", parts[1]).strip(" /")
                        if author:
                            result["author"] = author
                    break

    # 标签
    tag_links = soup.select("a.tag")
    if tag_links:
        tags = [a.get_text(strip=True) for a in tag_links[:6]]
        result["tags"] = ",".join(tags)

    return result if result.get("title") else None


def fetch_douban(identifier: str):
    """
    从豆瓣刮削图书信息。
    identifier 可以是：
      - ISBN（10位或13位）
      - 豆瓣图书链接（含 subject/id）
      - 豆瓣 subject id（纯数字）
    """
    identifier = identifier.strip()

    if _is_isbn(identifier):
        url = DOUBAN_ISBN_URL.format(isbn=_clean_isbn(identifier))
    elif "douban.com/subject/" in identifier:
        url = identifier.split("?")[0].rstrip("/") + "/"
    elif re.fullmatch(r"\d+", identifier):
        url = DOUBAN_SUBJECT_URL.format(sid=identifier)
    else:
        return None

    _sleep()
    html = _get_with_playwright(url)
    if not html or "豆瓣" not in html:
        # Playwright 失败时尝试普通 requests（偶尔可能成功）
        html = _get(url)
        if not html or "豆瓣" not in html:
            return None

    data = _parse_douban_html(html)
    return data


# ── Goodreads 刮削 ────────────────────────────────────────────────────

def _parse_goodreads_html(html):
    """解析 Goodreads 图书详情页 HTML，返回 dict。"""
    try:
        from bs4 import BeautifulSoup
    except ImportError:
        raise RuntimeError("请先安装 beautifulsoup4：pip install beautifulsoup4")

    soup = BeautifulSoup(html, "html.parser")
    result = {}

    # 书名 — <h1 class="Text Text__title1" ...>
    title_tag = soup.find("h1", attrs={"data-testid": "bookTitle"})
    if not title_tag:
        title_tag = soup.find("h1")
    if title_tag:
        result["title"] = title_tag.get_text(strip=True)

    # 作者 — <span class="ContributorLink__name" ...>
    author_tags = soup.select("span.ContributorLink__name")
    if author_tags:
        authors = []
        for a in author_tags:
            name = a.get_text(strip=True)
            # 排除角色标注如 "(Primary Contributor)"
            if name and "Contributor" not in name:
                authors.append(name)
        if authors:
            result["author"] = " / ".join(dict.fromkeys(authors))  # 去重保序

    # 评分 — 在页面文本中匹配 "X.XX" 紧跟 ratings 数字
    # 格式通常是 "3.8015,305 ratings" 或类似
    rating_match = re.search(
        r'"ratingValue"\s*:\s*([\d.]+)', html
    )
    if rating_match:
        try:
            result["goodreads_score"] = float(rating_match.group(1))
        except ValueError:
            pass

    if not result.get("goodreads_score"):
        # 备选：从可见文本中提取
        rating_div = soup.find("div", attrs={"class": re.compile(r"RatingStatistics__rating")})
        if rating_div:
            txt = rating_div.get_text(strip=True)
            try:
                result["goodreads_score"] = float(txt)
            except ValueError:
                pass

    if not result.get("goodreads_score"):
        # 再备选：页面全文正则（"4.18" 后跟 "ratings")
        fallback = re.search(r'(\d\.\d{1,2})\s*[\d,]+\s*rating', html)
        if fallback:
            try:
                result["goodreads_score"] = float(fallback.group(1))
            except ValueError:
                pass

    # 分类标签 — genre links
    genre_links = soup.select("span.BookPageMetadataSection__genreButton a")
    if not genre_links:
        genre_links = soup.select("a[href*='/genres/']")
    if genre_links:
        tags = []
        for a in genre_links:
            tag = a.get_text(strip=True)
            if tag and tag not in tags and len(tags) < 6:
                tags.append(tag)
        if tags:
            result["tags"] = ",".join(tags)

    # 出版信息 — 在页面文本中查找
    pub_match = re.search(
        r'(?:First published|Published)\s+(\w+\s+\d{1,2},\s*\d{4}|\w+\s+\d{4}|\d{4})',
        html
    )
    if pub_match:
        result["pub_date"] = pub_match.group(1)

    # 封面
    cover_tag = soup.find("img", attrs={"class": re.compile(r"ResponsiveImage")})
    if cover_tag:
        src = cover_tag.get("src", "")
        if src and "nophoto" not in src:
            result["cover_url"] = src

    return result if result.get("title") else None


def fetch_goodreads(identifier: str):
    """
    从 Goodreads 刮削图书信息。
    identifier 可以是：
      - Goodreads 链接（含 /book/show/）
      - ISBN（会用搜索页查找）
    """
    identifier = identifier.strip()

    if "goodreads.com/book/show/" in identifier:
        url = identifier.split("?")[0].split("&")[0]
    elif _is_isbn(identifier):
        # 先通过搜索页找到书籍链接
        search_url = GOODREADS_SEARCH_URL.format(query=_clean_isbn(identifier))
        _sleep()
        search_html = _get(search_url)
        if not search_html:
            return None
        # 从搜索结果中提取第一个 /book/show/ 链接
        match = re.search(r'/book/show/(\d+[^"\s\']*)', search_html)
        if not match:
            return None
        url = f"https://www.goodreads.com/book/show/{match.group(1)}"
    else:
        return None

    _sleep()
    html = _get(url)
    if not html or "goodreads" not in html.lower():
        return None

    return _parse_goodreads_html(html)


def fetch_goodreads_score(isbn: str):
    """只获取 Goodreads 评分（用于补全其他来源的数据）。"""
    data = fetch_goodreads(isbn)
    if data and data.get("goodreads_score"):
        return data["goodreads_score"]
    return None


# ── Google Books API ──────────────────────────────────────────────────

def fetch_google_books(isbn: str):
    """通过 Google Books API 获取图书信息（无需 key）。"""
    isbn = _clean_isbn(isbn)
    url = GOOGLE_BOOKS_URL.format(isbn=isbn)
    html = _get(url)
    if not html:
        return None

    try:
        data = json.loads(html)
    except json.JSONDecodeError:
        return None

    if data.get("totalItems", 0) == 0:
        return None

    item = data["items"][0]
    vol = item.get("volumeInfo", {})

    result = {"title": vol.get("title", "")}

    authors = vol.get("authors", [])
    if authors:
        result["author"] = " / ".join(authors)

    if vol.get("publisher"):
        result["publisher"] = vol["publisher"]

    if vol.get("publishedDate"):
        result["pub_date"] = vol["publishedDate"][:7]  # YYYY-MM

    # 封面
    images = vol.get("imageLinks", {})
    cover = images.get("thumbnail") or images.get("smallThumbnail")
    if cover:
        # 换成更大图
        result["cover_url"] = cover.replace("zoom=1", "zoom=3")

    # 分类标签
    cats = vol.get("categories", [])
    if cats:
        result["tags"] = ",".join(cats[:4])

    # 评分（Google Books 有 averageRating 字段）
    if vol.get("averageRating"):
        result["goodreads_score"] = float(vol["averageRating"])

    return result if result.get("title") else None


# ── Open Library 兜底 ─────────────────────────────────────────────────

def fetch_open_library(isbn: str):
    """Open Library ISBN API 兜底。"""
    isbn = _clean_isbn(isbn)
    url = OPEN_LIBRARY_URL.format(isbn=isbn)
    html = _get(url)
    if not html:
        return None

    try:
        data = json.loads(html)
    except json.JSONDecodeError:
        return None

    key = f"ISBN:{isbn}"
    if key not in data:
        return None

    book = data[key]
    result = {"title": book.get("title", "")}

    authors = book.get("authors", [])
    if authors:
        result["author"] = " / ".join(a.get("name", "") for a in authors)

    pubs = book.get("publishers", [])
    if pubs:
        result["publisher"] = pubs[0].get("name", "")

    if book.get("publish_date"):
        result["pub_date"] = book["publish_date"]

    # 封面：直接用 covers API（即使信息里没有封面也能试）
    cover_url = f"https://covers.openlibrary.org/b/isbn/{isbn}-L.jpg"
    result["cover_url"] = cover_url

    subjects = book.get("subjects", [])
    if subjects:
        tags = [s.get("name", "") for s in subjects[:4]]
        result["tags"] = ",".join(t for t in tags if t)

    return result if result.get("title") else None


# ── 主入口 ────────────────────────────────────────────────────────────

def fetch_by_isbn(isbn: str):
    """
    根据 ISBN 自动选择数据源。
    中文 ISBN → 豆瓣 + Goodreads 补 GR 评分。
    英文 ISBN → Goodreads 为主力 → Google Books 兜底。
    """
    if _is_chinese_isbn(isbn):
        result = fetch_douban(isbn)
        if result:
            # 尝试补全 Goodreads 评分
            if not result.get("goodreads_score"):
                gr_score = fetch_goodreads_score(isbn)
                if gr_score:
                    result["goodreads_score"] = gr_score
            return result, "豆瓣"
        result = fetch_open_library(isbn)
        if result:
            return result, "Open Library"
    else:
        # 英文书：Goodreads 为主力
        result = fetch_goodreads(isbn)
        if result:
            return result, "Goodreads"
        # 兜底
        result = fetch_google_books(isbn)
        if result:
            return result, "Google Books"
        result = fetch_open_library(isbn)
        if result:
            return result, "Open Library"

    return None, None


def preview(data: dict, source: str):
    """格式化打印刮削结果预览。"""
    lines = [f"\n📖 《{data.get('title', '未知')}》  [来源: {source}]"]
    if data.get("author"):
        lines.append(f"   作者：{data['author']}")
    if data.get("translator"):
        lines.append(f"   译者：{data['translator']}")
    if data.get("publisher") or data.get("pub_date"):
        pub = " · ".join(filter(None, [data.get("publisher"), data.get("pub_date")]))
        lines.append(f"   出版：{pub}")
    if data.get("douban_score"):
        lines.append(f"   豆瓣：{data['douban_score']}")
    if data.get("goodreads_score"):
        lines.append(f"   GR：{data['goodreads_score']}")
    if data.get("tags"):
        lines.append(f"   标签：{data['tags']}")
    if data.get("cover_url"):
        lines.append(f"   封面：{data['cover_url']}")
    return "\n".join(lines)