# -*- coding: utf-8 -*-
"""Toutiao (今日头条) — search articles and trending content."""

import json
import re
import urllib.parse
import urllib.request
from typing import List, Tuple

from .base import Channel

_UA = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36"
_TIMEOUT = 15
_SEARCH_URL = (
    "https://so.toutiao.com/search"
    "?dvpf=pc&source=input&keyword={keyword}&enable_druid_v2=1"
)

_SKIP_TEMPLATES = ("Search", "Bottom", "76-", "20-", "26-", "67-baike")


def _fetch_html(url: str) -> str:
    """Fetch URL and return HTML string."""
    req = urllib.request.Request(url, headers={"User-Agent": _UA})
    with urllib.request.urlopen(req, timeout=_TIMEOUT) as resp:
        return resp.read().decode("utf-8")


def _parse_search_results(html: str) -> list:
    """Extract article results from Toutiao search page HTML.

    The page embeds each search result as a JSON object inside a <script> tag.
    """
    scripts = re.findall(r"<script[^>]*>(.*?)</script>", html, re.DOTALL)
    articles = []
    for s in scripts:
        if len(s) < 1000:
            continue
        if not s.strip().startswith("{"):
            continue
        try:
            data = json.loads(s).get("data", {})
        except (json.JSONDecodeError, ValueError):
            continue
        if not isinstance(data, dict):
            continue

        title = data.get("title", "")
        tpl = data.get("template_key", "")
        if not title:
            continue
        if any(tpl.startswith(p) for p in _SKIP_TEMPLATES):
            continue

        # article_url is the primary field; display paths are fallbacks
        article_url = (
            data.get("article_url", "")
            or data.get("source_url", "")
            or (data.get("display") or {}).get("info", {}).get("url", "")
        )

        if not article_url:
            continue

        articles.append({
            "title": title,
            "url": article_url,
            "source": data.get("media_name", "") or data.get("source", ""),
            "abstract": (data.get("abstract", "") or "")[:300],
            "publish_time": data.get("publish_time"),
            "read_count": data.get("read_count"),
            "comment_count": data.get("comment_count"),
        })
    return articles


class ToutiaoChannel(Channel):
    name = "toutiao"
    description = "今日头条搜索与资讯"
    backends = ["Toutiao Web (public)"]
    tier = 0

    def can_handle(self, url: str) -> bool:
        from urllib.parse import urlparse
        d = urlparse(url).netloc.lower()
        return "toutiao.com" in d

    def check(self, config=None) -> Tuple[str, str]:
        try:
            test_url = _SEARCH_URL.format(keyword="test")
            req = urllib.request.Request(test_url, headers={"User-Agent": _UA})
            with urllib.request.urlopen(req, timeout=_TIMEOUT) as resp:
                if resp.status == 200:
                    content = resp.read().decode("utf-8")
                    if "data" in content or "title" in content:
                        return "ok", "头条搜索可用（搜索文章、视频、资讯）"
                    return "warn", "头条搜索返回非预期内容"
            return "warn", "头条搜索返回非 200 状态"
        except Exception as e:
            return "warn", f"头条搜索连接失败（可能需要代理）：{e}"

    def read(self, url: str) -> str:
        """通过 Jina Reader 读取头条文章正文。"""
        if not url.startswith(("http://", "https://")):
            url = "https://" + url
        jina_url = f"https://r.jina.ai/{url}"
        req = urllib.request.Request(
            jina_url,
            headers={"User-Agent": _UA, "Accept": "text/plain"},
        )
        with urllib.request.urlopen(req, timeout=_TIMEOUT) as resp:
            return resp.read().decode("utf-8")

    def search(self, keyword: str, limit: int = 10) -> list:
        """搜索头条文章。

        Args:
            keyword: 搜索关键词
            limit:   最多返回条数

        Returns:
            list of dicts with keys:
              title, url, source, abstract, publish_time, read_count, comment_count
        """
        encoded = urllib.parse.quote(keyword)
        url = _SEARCH_URL.format(keyword=encoded)
        html = _fetch_html(url)
        return _parse_search_results(html)[:limit]