"""
app.py — B24 Browser AI backend.

Accounts are NOT owned here. Signup/login are proxied to the messenger
backend (Messenger_back_database) so B24 Meet and B24 Browser share one
account system. Every other route verifies the JWT locally using the
shared JWT_SECRET (see auth.py) — no network round-trip needed.
"""

import os
import time
from functools import wraps
from concurrent.futures import ThreadPoolExecutor, as_completed

import requests
from flask import Flask, request, jsonify, Response, send_from_directory
from flask_cors import CORS

import auth
import search
import ai
import scraper
import video
import keepalive
import ota
import ota_db

app = Flask(__name__)
CORS(app)

ota_db.init_db()

ADMIN_PASSKEY = os.environ.get("ADMIN_PASSKEY")

MESSENGER_BACKEND_URL = os.environ.get(
    "MESSENGER_BACKEND_URL", "https://brighton233j-messenger-back-database.hf.space"
)

GNEWS_API_KEY = os.environ.get("GNEWS_API_KEY")
_news_cache = {"data": None, "fetched_at": 0}
NEWS_CACHE_SECONDS = 1200  # 20 minutes


def get_auth_user():
    header = request.headers.get("Authorization", "")
    token = header.replace("Bearer ", "").strip()
    if not token:
        return None
    return auth.verify_token(token)


def require_auth(fn):
    @wraps(fn)
    def wrapper(*args, **kwargs):
        payload = get_auth_user()
        if not payload:
            return jsonify({"error": "Unauthorized"}), 401
        request.user = payload
        return fn(*args, **kwargs)

    return wrapper


def require_admin(fn):
    @wraps(fn)
    def wrapper(*args, **kwargs):
        key = request.headers.get("X-Admin-Key")
        if not ADMIN_PASSKEY or key != ADMIN_PASSKEY:
            return jsonify({"error": "Forbidden"}), 403
        return fn(*args, **kwargs)

    return wrapper


def get_identity():
    """Auth'd users are identified by their account id; guests are scoped by
    IP so per-identity limits (e.g. keep-alive session caps) still apply
    without requiring login."""
    payload = get_auth_user()
    if payload:
        return payload["sub"]
    return f"guest:{request.remote_addr}"


# ---------------------------------------------------------------------------
# Auth — proxied to messenger backend, accounts live there only
# ---------------------------------------------------------------------------

@app.route("/auth/signup", methods=["POST"])
def signup():
    try:
        resp = requests.post(
            f"{MESSENGER_BACKEND_URL}/auth/signup",
            json=request.get_json(silent=True) or {},
            timeout=10,
        )
    except requests.RequestException:
        return jsonify({"error": "Could not reach account server"}), 502
    return (resp.text, resp.status_code, {"Content-Type": "application/json"})


@app.route("/auth/login", methods=["POST"])
def login():
    try:
        resp = requests.post(
            f"{MESSENGER_BACKEND_URL}/auth/login",
            json=request.get_json(silent=True) or {},
            timeout=10,
        )
    except requests.RequestException:
        return jsonify({"error": "Could not reach account server"}), 502
    return (resp.text, resp.status_code, {"Content-Type": "application/json"})


@app.route("/login")
def login_page():
    return send_from_directory(".", "login.html")


# ---------------------------------------------------------------------------
# AI features
# ---------------------------------------------------------------------------

@app.route("/summarize", methods=["POST"])
@require_auth
def summarize():
    data = request.get_json(silent=True) or {}
    url = data.get("url", "")
    text = data.get("text", "")
    if not text:
        return jsonify({"error": "text is required"}), 400
    summary = ai.summarize_page(url, text)
    return jsonify({"summary": summary})


@app.route("/smart-search", methods=["POST"])
@require_auth
def smart_search():
    data = request.get_json(silent=True) or {}
    query = data.get("query", "").strip()
    if not query:
        return jsonify({"error": "query is required"}), 400

    results = search.ddg_search(query)
    if isinstance(results, dict) and "error" in results:
        return jsonify(results), 502

    answer = ai.synthesize_search(query, results)
    return jsonify({"answer": answer, "results": results})


@app.route("/related", methods=["POST"])
@require_auth
def related():
    data = request.get_json(silent=True) or {}
    url = data.get("url", "")
    text = data.get("text", "")
    if not text:
        return jsonify({"error": "text is required"}), 400

    queries = ai.suggest_related(url, text)

    def _search_one(q):
        results = search.ddg_search(q, max_results=1)
        if isinstance(results, list) and results:
            return {"query": q, **results[0]}
        return {"query": q, "title": q, "url": "", "snippet": ""}

    links = []
    with ThreadPoolExecutor(max_workers=5) as pool:
        futures = {pool.submit(_search_one, q): q for q in queries}
        for fut in as_completed(futures):
            links.append(fut.result())

    return jsonify({"related": links})


@app.route("/scrape", methods=["POST"])
@require_auth
def scrape():
    data = request.get_json(silent=True) or {}
    url = data.get("url", "")
    if not url:
        return jsonify({"error": "url is required"}), 400

    result = scraper.fetch_page(url)
    if "error" in result:
        return jsonify(result), 502
    return jsonify(result)


# ---------------------------------------------------------------------------
# Video (yt-dlp)
# ---------------------------------------------------------------------------

@app.route("/video/info", methods=["POST"])
@require_auth
def video_info():
    data = request.get_json(silent=True) or {}
    url = data.get("url", "")
    if not url:
        return jsonify({"error": "url is required"}), 400

    result = video.get_video_info(url)
    if "error" in result:
        return jsonify(result), 502
    return jsonify(result)


@app.route("/video/download", methods=["GET"])
@require_auth
def video_download():
    url = request.args.get("url", "")
    format_id = request.args.get("format_id")
    if not url:
        return jsonify({"error": "url is required"}), 400

    return Response(
        video.stream_download(url, format_id),
        mimetype="video/x-matroska",
        headers={"Content-Disposition": "attachment; filename=video.mkv"},
    )


# ---------------------------------------------------------------------------
# Keep Alive — open to guests (scoped by IP instead of account when signed out)
# ---------------------------------------------------------------------------

@app.route("/keepalive/start", methods=["POST"])
def keepalive_start():
    data = request.get_json(silent=True) or {}
    url = data.get("url", "")
    interval = data.get("interval", 60)
    if not url:
        return jsonify({"error": "url is required"}), 400
    result = keepalive.start(get_identity(), url, interval)
    if "error" in result:
        return jsonify(result), 429
    return jsonify(result)


@app.route("/keepalive/stop", methods=["POST"])
def keepalive_stop():
    data = request.get_json(silent=True) or {}
    session_id = data.get("session_id", "")
    result = keepalive.stop(get_identity(), session_id)
    if "error" in result:
        return jsonify(result), 404
    return jsonify(result)


@app.route("/keepalive/status", methods=["GET"])
def keepalive_status():
    return jsonify({"sessions": keepalive.status(get_identity())})


# ---------------------------------------------------------------------------
# News (GNews.io, cached)
# ---------------------------------------------------------------------------

def fetch_news(query="Uganda technology"):
    if not GNEWS_API_KEY:
        return []
    try:
        resp = requests.get(
            "https://gnews.io/api/v4/search",
            params={"q": query, "lang": "en", "max": 10, "token": GNEWS_API_KEY},
            timeout=10,
        )
        data = resp.json()
    except Exception:
        return []

    items = []
    for a in data.get("articles", []):
        items.append({
            "title": a.get("title", ""),
            "link": a.get("url", ""),
            "source": (a.get("source") or {}).get("name", ""),
            "published": a.get("publishedAt", ""),
            "image": a.get("image"),
        })
    return items


@app.route("/news", methods=["GET"])
def get_news():
    query = request.args.get("q", "Uganda technology")
    now = time.time()
    if _news_cache["data"] and (now - _news_cache["fetched_at"] < NEWS_CACHE_SECONDS):
        return jsonify({"cached": True, "articles": _news_cache["data"]})

    articles = fetch_news(query)
    _news_cache["data"] = articles
    _news_cache["fetched_at"] = now
    return jsonify({"cached": False, "articles": articles})


# ---------------------------------------------------------------------------
# Admin / OTA
# ---------------------------------------------------------------------------

@app.route("/admin/upload-ota", methods=["POST"])
@require_admin
def admin_upload_ota():
    """Admin uploads a zip of the dist/ folder from
    `npx expo export --platform android --output-dir dist` (multipart
    'file' + form fields 'runtime_version', optional 'notes')."""
    if "file" not in request.files:
        return jsonify({"error": "No file provided"}), 400

    file = request.files["file"]
    runtime_version = (request.form.get("runtime_version") or "").strip()
    notes = request.form.get("notes")

    if not runtime_version:
        return jsonify({"error": "runtime_version is required"}), 400

    result, error = ota.process_upload(file, runtime_version, notes)
    if error:
        body, status = error
        return jsonify(body), status
    return jsonify(result)


@app.route("/api/manifest", methods=["GET"])
def api_manifest():
    """The endpoint expo-updates itself calls (set as `updates.url` in
    app.json). Implements the Expo Updates protocol's plain-JSON response
    path (no code signing; protocol version 1's 'no update' case is a 406,
    per spec)."""
    protocol_version = request.headers.get("expo-protocol-version", "0")
    platform = request.headers.get("expo-platform") or request.args.get("platform")
    runtime_version = request.headers.get("expo-runtime-version") or request.args.get("runtime-version")
    current_update_id = request.headers.get("expo-current-update-id")

    manifest, error = ota.build_manifest(protocol_version, platform, runtime_version, current_update_id)
    if error:
        body, status = error
        return jsonify(body), status

    resp = jsonify(manifest)
    resp.headers["expo-protocol-version"] = protocol_version
    resp.headers["expo-sfv-version"] = "0"
    resp.headers["cache-control"] = "private, max-age=0"
    return resp


@app.route("/health", methods=["GET"])
def health():
    return jsonify({"status": "ok"})


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=7860)