"""Google Programmable Search Engine (Custom Search JSON API) — minimal stdlib client.

Env (see also `universal_brain_chat` / Space README):
  GOOGLE_CSE_API_KEY — required
  GOOGLE_CSE_CX — Programmable Search Engine id (required)
  GOOGLE_CSE_NUM — optional, 1–10 (default 5)
  GOOGLE_CSE_SAFE — optional, e.g. ``off`` or ``active`` (see Google ``cse.list`` reference)
"""

from __future__ import annotations

import json
import os
import re
import urllib.error
import urllib.parse
import urllib.request
from dataclasses import dataclass

_CSE_ENDPOINT = "https://www.googleapis.com/customsearch/v1"
_DEFAULT_UA = "TinyModel-UniversalBrain/1.0 (+https://github.com/HyperlinksSpace/TinyModel)"


@dataclass(frozen=True)
class CSEHit:
    title: str
    link: str
    snippet: str


def read_google_cse_settings() -> tuple[str | None, str | None, int, str | None]:
    key = (os.environ.get("GOOGLE_CSE_API_KEY") or "").strip() or None
    cx = (os.environ.get("GOOGLE_CSE_CX") or "").strip() or None
    raw_n = (os.environ.get("GOOGLE_CSE_NUM") or "5").strip()
    try:
        num = max(1, min(10, int(raw_n)))
    except ValueError:
        num = 5
    safe_raw = (os.environ.get("GOOGLE_CSE_SAFE") or "").strip()
    safe = safe_raw or None
    return key, cx, num, safe


def google_cse_search(
    query: str,
    *,
    api_key: str,
    cx: str,
    num: int = 5,
    safe: str | None = None,
    timeout_sec: float = 20.0,
) -> list[CSEHit]:
    q = (query or "").strip()
    if not q:
        return []
    n = max(1, min(10, num))
    params: dict[str, str] = {"key": api_key, "cx": cx, "q": q, "num": str(n)}
    if safe:
        params["safe"] = safe
    url = f"{_CSE_ENDPOINT}?{urllib.parse.urlencode(params)}"
    req = urllib.request.Request(url, headers={"User-Agent": _DEFAULT_UA})
    try:
        with urllib.request.urlopen(req, timeout=timeout_sec) as resp:
            raw = resp.read().decode("utf-8", errors="replace")
    except urllib.error.HTTPError as e:
        body = e.read().decode("utf-8", errors="replace") if e.fp else ""
        try:
            err = json.loads(body).get("error", {})
            msg = err.get("message", body[:500])
        except json.JSONDecodeError:
            msg = body[:500] or str(e)
        raise RuntimeError(f"Google CSE HTTP {e.code}: {msg}") from e
    except urllib.error.URLError as e:
        raise RuntimeError(f"Google CSE network error: {e}") from e

    data = json.loads(raw)
    if isinstance(data, dict) and "error" in data:
        err = data.get("error") or {}
        msg = err.get("message", str(err)) if isinstance(err, dict) else str(err)
        raise RuntimeError(f"Google CSE API error: {msg}")

    items = data.get("items") if isinstance(data, dict) else None
    if not isinstance(items, list):
        return []

    out: list[CSEHit] = []
    for it in items:
        if not isinstance(it, dict):
            continue
        title = str(it.get("title") or "").strip()
        link = str(it.get("link") or "").strip()
        snippet = str(it.get("snippet") or "").strip()
        if link:
            out.append(CSEHit(title=title or "(no title)", link=link, snippet=snippet))
    return out


def format_cse_hits_markdown(hits: list[CSEHit], *, for_chat: bool) -> str:
    """Markdown block: either standalone (/web) or system-context injection."""
    if not hits:
        return "(No web results.)"
    lines: list[str] = []
    if for_chat:
        lines.append(
            "### Web search snippets (Google Programmable Search)\n"
            "Ground factual claims that depend on current or external information in these excerpts when they "
            "apply. Cite sources as **[Web n]** and include the page URL. If snippets are insufficient, say so."
        )
    else:
        lines.append("### Google web search results\n")
    for i, h in enumerate(hits, 1):
        lines.append(
            f"**[Web {i}]** {h.title}\n"
            f"- **URL:** {h.link}\n"
            f"- **Snippet:** {h.snippet}\n"
        )
    return "\n".join(lines).strip()


def heuristic_suggests_web_search(msg: str) -> bool:
    """True if ``msg`` likely needs live web results (used when the router returns ``chat``).

    Conservative: skips code-like text, slash commands, short lines, and in-app / FAQ phrasing.
    """
    m = (msg or "").strip().lower()
    if len(m) < 12:
        return False
    if m.startswith("/"):
        return False
    if "```" in m or m.startswith("def "):
        return False
    if any(
        x in m
        for x in (
            "/retrieve",
            "faq excerpt",
            "this space",
            "this app",
            "your refund",
            "your policy",
            "your shipping",
            "your terms",
            "according to your faq",
            "in your documentation",
        )
    ):
        return False

    phrases = (
        "latest ",
        "breaking ",
        "breaking news",
        " as of ",
        "right now",
        "today ",
        "today's",
        "tonight",
        "yesterday",
        "this week",
        "this month",
        "current president",
        "current ceo",
        "current prime minister",
        "who won ",
        "who won the",
        "election results",
        "stock price",
        "share price",
        "market cap",
        "exchange rate",
        "crypto price",
        "weather in",
        "forecast for",
        "when is the next",
        "still alive",
        "world cup",
        "olympics",
        "super bowl",
        "score of",
        "official announcement",
        "press release",
        "release date",
        "when did ",
        "when does ",
        "google ",
        "search online",
        "look up online",
        "on wikipedia",
        "according to the news",
        "news about",
        "headlines",
        "rumor is",
        "rumour is",
        "is it true that",
        "fact check",
        "verify online",
    )
    if any(p in m for p in phrases):
        return True
    if re.search(r"\b20(2[4-9]|[3-9][0-9])\b", m) and re.search(
        r"\b(who|what|when|where|why|how|did|does|do|is|are|was|were|will|has|have)\b", m
    ):
        return True
    return False