from __future__ import annotations

import json
import os
import time
from pathlib import Path
from typing import Any
from urllib.error import URLError
from urllib.parse import urlencode
from urllib.request import urlopen

from flask import Flask, jsonify, request, send_from_directory
from flask_cors import CORS
import httpx


app = Flask(__name__, static_folder="../frontend/dist", static_url_path="")
CORS(app, resources={r"/api/*": {"origins": "*"}})

MONERO_GET_INFO_URL = os.getenv("MONERO_GET_INFO_URL", "http://monerod.crypto.svc.cluster.local:18081/get_info")
VM_BASE_URL = os.getenv(
    "VM_BASE_URL",
    "http://victoria-metrics-single-server.monitoring.svc.cluster.local:8428",
).rstrip("/")
VM_QUERY_TIMEOUT_SEC = float(os.getenv("VM_QUERY_TIMEOUT_SEC", "2"))
HTTP_CHECK_TIMEOUT_SEC = float(os.getenv("HTTP_CHECK_TIMEOUT_SEC", "2"))
LAB_STATUS_CACHE_SEC = float(os.getenv("LAB_STATUS_CACHE_SEC", "30"))
GRAFANA_HEALTH_URL = os.getenv("GRAFANA_HEALTH_URL", "https://metrics.bstein.dev/api/health")
OCEANUS_NODE_EXPORTER_URL = os.getenv("OCEANUS_NODE_EXPORTER_URL", "http://192.168.22.24:9100/metrics")
AI_CHAT_API = os.getenv("AI_CHAT_API", "http://ollama.ai.svc.cluster.local:11434").rstrip("/")
AI_CHAT_MODEL = os.getenv("AI_CHAT_MODEL", "qwen2.5-coder:7b-instruct-q4_0")
AI_CHAT_SYSTEM_PROMPT = os.getenv(
    "AI_CHAT_SYSTEM_PROMPT",
    "You are the Titan Lab assistant for bstein.dev. Be concise and helpful.",
)
AI_CHAT_TIMEOUT_SEC = float(os.getenv("AI_CHAT_TIMEOUT_SEC", "20"))
AI_NODE_NAME = os.getenv("AI_CHAT_NODE_NAME") or os.getenv("AI_NODE_NAME") or "ai-cluster"
AI_GPU_DESC = os.getenv("AI_CHAT_GPU_DESC") or "local GPU (dynamic)"
AI_PUBLIC_ENDPOINT = os.getenv("AI_PUBLIC_CHAT_ENDPOINT", "https://chat.ai.bstein.dev/api/ai/chat")
AI_K8S_LABEL = os.getenv("AI_K8S_LABEL", "app=ollama")
AI_K8S_NAMESPACE = os.getenv("AI_K8S_NAMESPACE", "ai")
AI_MODEL_ANNOTATION = os.getenv("AI_MODEL_ANNOTATION", "ai.bstein.dev/model")
AI_GPU_ANNOTATION = os.getenv("AI_GPU_ANNOTATION", "ai.bstein.dev/gpu")

_LAB_STATUS_CACHE: dict[str, Any] = {"ts": 0.0, "value": None}

@app.route("/api/healthz")
def healthz() -> Any:
    return jsonify({"ok": True})


@app.route("/api/monero/get_info")
def monero_get_info() -> Any:
    try:
        with urlopen(MONERO_GET_INFO_URL, timeout=2) as resp:
            payload = json.loads(resp.read().decode("utf-8"))
        return jsonify(payload)
    except (URLError, TimeoutError, ValueError) as exc:
        return jsonify({"error": str(exc), "url": MONERO_GET_INFO_URL}), 503


def _vm_query(expr: str) -> float | None:
    url = f"{VM_BASE_URL}/api/v1/query?{urlencode({'query': expr})}"
    with urlopen(url, timeout=VM_QUERY_TIMEOUT_SEC) as resp:
        payload = json.loads(resp.read().decode("utf-8"))

    if payload.get("status") != "success":
        return None

    result = (payload.get("data") or {}).get("result") or []
    if not result:
        return None

    values: list[float] = []
    for item in result:
        try:
            values.append(float(item["value"][1]))
        except (KeyError, IndexError, TypeError, ValueError):
            continue

    if not values:
        return None

    return max(values)


def _http_ok(url: str, expect_substring: str | None = None) -> bool:
    try:
        with urlopen(url, timeout=HTTP_CHECK_TIMEOUT_SEC) as resp:
            if getattr(resp, "status", 200) != 200:
                return False
            if expect_substring:
                chunk = resp.read(4096).decode("utf-8", errors="ignore")
                return expect_substring in chunk
            return True
    except (URLError, TimeoutError, ValueError):
        return False


@app.route("/api/lab/status")
def lab_status() -> Any:
    now = time.time()
    cached = _LAB_STATUS_CACHE.get("value")
    if cached and (now - float(_LAB_STATUS_CACHE.get("ts", 0.0)) < LAB_STATUS_CACHE_SEC):
        return jsonify(cached)

    connected = False
    atlas_up = False
    atlas_known = False
    atlas_source = "unknown"
    oceanus_up = False
    oceanus_known = False
    oceanus_source = "unknown"

    try:
        atlas_value = _vm_query('max(up{job="kubernetes-apiservers"})')
        oceanus_value = _vm_query('max(up{instance=~"(titan-23|192.168.22.24)(:9100)?"})')
        connected = True
        atlas_known = atlas_value is not None
        atlas_up = bool(atlas_value and atlas_value > 0.5)
        atlas_source = "victoria-metrics"
        oceanus_known = oceanus_value is not None
        oceanus_up = bool(oceanus_value and oceanus_value > 0.5)
        oceanus_source = "victoria-metrics"
    except (URLError, TimeoutError, ValueError):
        atlas_value = None
        oceanus_value = None

    if not atlas_known:
        if _http_ok(GRAFANA_HEALTH_URL):
            connected = True
            atlas_known = True
            atlas_up = True
            atlas_source = "grafana-health"

    if not oceanus_up:
        if _http_ok(OCEANUS_NODE_EXPORTER_URL, expect_substring="node_exporter_build_info"):
            connected = True
            oceanus_known = True
            oceanus_up = True
            oceanus_source = "node-exporter"

    payload = {
        "connected": connected,
        "atlas": {"up": atlas_up, "known": atlas_known, "source": atlas_source},
        "oceanus": {"up": oceanus_up, "known": oceanus_known, "source": oceanus_source},
        "checked_at": int(now),
    }

    _LAB_STATUS_CACHE["ts"] = now
    _LAB_STATUS_CACHE["value"] = payload
    return jsonify(payload)


@app.route("/api/ai/chat", methods=["POST"])
def ai_chat() -> Any:
    payload = request.get_json(silent=True) or {}
    user_message = (payload.get("message") or "").strip()
    history = payload.get("history") or []

    if not user_message:
        return jsonify({"error": "message required"}), 400

    messages: list[dict[str, str]] = []
    if AI_CHAT_SYSTEM_PROMPT:
        messages.append({"role": "system", "content": AI_CHAT_SYSTEM_PROMPT})

    for item in history:
        role = item.get("role")
        content = (item.get("content") or "").strip()
        if role in ("user", "assistant") and content:
            messages.append({"role": role, "content": content})

    messages.append({"role": "user", "content": user_message})

    body = {"model": AI_CHAT_MODEL, "messages": messages, "stream": False}
    started = time.time()

    try:
        with httpx.Client(timeout=AI_CHAT_TIMEOUT_SEC) as client:
            resp = client.post(f"{AI_CHAT_API}/api/chat", json=body)
            resp.raise_for_status()
            data = resp.json()
            reply = (data.get("message") or {}).get("content") or ""
            elapsed_ms = int((time.time() - started) * 1000)
            return jsonify({"reply": reply, "latency_ms": elapsed_ms})
    except (httpx.RequestError, httpx.HTTPStatusError, ValueError) as exc:
        return jsonify({"error": str(exc)}), 502


@app.route("/api/ai/info", methods=["GET"])
def ai_info() -> Any:
    meta = _discover_ai_meta()
    return jsonify(meta)


def _discover_ai_meta() -> dict[str, str]:
    """
    Best-effort discovery of which node/gpu is hosting the AI service.
    Tries the Kubernetes API using the service account if available; falls back to env.
    """
    meta = {
        "node": AI_NODE_NAME,
        "gpu": AI_GPU_DESC,
        "model": AI_CHAT_MODEL,
        "endpoint": AI_PUBLIC_ENDPOINT or "/api/ai/chat",
    }

    # Only attempt k8s if we're in-cluster and credentials exist.
    sa_path = Path("/var/run/secrets/kubernetes.io/serviceaccount")
    token_path = sa_path / "token"
    ca_path = sa_path / "ca.crt"
    ns_path = sa_path / "namespace"
    if not token_path.exists() or not ca_path.exists() or not ns_path.exists():
        return meta

    try:
        token = token_path.read_text().strip()
        namespace = AI_K8S_NAMESPACE
        base_url = "https://kubernetes.default.svc"
        pod_url = f"{base_url}/api/v1/namespaces/{namespace}/pods?labelSelector={AI_K8S_LABEL}"

        with httpx.Client(verify=str(ca_path), timeout=HTTP_CHECK_TIMEOUT_SEC, headers={"Authorization": f"Bearer {token}"}) as client:
            resp = client.get(pod_url)
            resp.raise_for_status()
            data = resp.json()
            items = data.get("items") or []
            running = [p for p in items if p.get("status", {}).get("phase") == "Running"] or items
            if running:
                pod = running[0]
                node_name = pod.get("spec", {}).get("nodeName") or meta["node"]
                meta["node"] = node_name

                annotations = pod.get("metadata", {}).get("annotations") or {}
                gpu_hint = (
                    annotations.get(AI_GPU_ANNOTATION)
                    or annotations.get("ai.gpu/description")
                    or annotations.get("gpu/description")
                )
                if gpu_hint:
                    meta["gpu"] = gpu_hint

                model_hint = annotations.get(AI_MODEL_ANNOTATION)
                if not model_hint:
                    # Try to infer from container image tag.
                    containers = pod.get("spec", {}).get("containers") or []
                    if containers:
                        image = containers[0].get("image") or ""
                        model_hint = image.split(":")[-1] if ":" in image else image
                if model_hint:
                    meta["model"] = model_hint
    except Exception:
        # swallow errors; keep fallbacks
        pass

    return meta


@app.route("/", defaults={"path": ""})
@app.route("/<path:path>")
def serve_frontend(path: str) -> Any:
    dist_path = Path(app.static_folder)
    index_path = dist_path / "index.html"

    if dist_path.exists() and index_path.exists():
        target = dist_path / path
        if path and target.exists():
            return send_from_directory(app.static_folder, path)
        return send_from_directory(app.static_folder, "index.html")

    return jsonify(
        {
            "message": "Frontend not built yet. Run `npm install && npm run build` inside frontend/, then restart Flask.",
            "available_endpoints": ["/api/healthz", "/api/monero/get_info"],
        }
    )


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000, debug=True)