import os
import time
import ipaddress
import logging

import requests
from flask import Flask, render_template, request, jsonify, abort

LAPI_URL = os.environ["LAPI_URL"].rstrip("/")
MACHINE_ID = os.environ["LAPI_MACHINE_ID"]
MACHINE_PW = os.environ["LAPI_MACHINE_PASSWORD"]
BOUNCER_KEY = os.environ["LAPI_BOUNCER_KEY"]
TRUSTED_HOPS = int(os.environ.get("TRUSTED_PROXY_HOPS", "1"))
REQ_TIMEOUT = 5

# LAPI splits read vs write:
#   GET  /v1/decisions  → bouncer X-Api-Key
#   DELETE /v1/decisions → machine Bearer JWT (from /v1/watchers/login)

app = Flask(__name__)
logging.basicConfig(level=logging.INFO)
log = app.logger

_token = {"jwt": None, "exp": 0.0}


def _login():
    r = requests.post(
        f"{LAPI_URL}/v1/watchers/login",
        json={"machine_id": MACHINE_ID, "password": MACHINE_PW},
        timeout=REQ_TIMEOUT,
    )
    r.raise_for_status()
    _token["jwt"] = r.json()["token"]
    _token["exp"] = time.time() + 60 * 13
    return _token["jwt"]


def _jwt():
    if not _token["jwt"] or time.time() >= _token["exp"]:
        return _login()
    return _token["jwt"]


def _bouncer(method, path, **kw):
    headers = kw.pop("headers", {})
    headers["X-Api-Key"] = BOUNCER_KEY
    return requests.request(method, f"{LAPI_URL}{path}", headers=headers, timeout=REQ_TIMEOUT, **kw)


def _machine(method, path, **kw):
    headers = kw.pop("headers", {})
    headers["Authorization"] = f"Bearer {_jwt()}"
    r = requests.request(method, f"{LAPI_URL}{path}", headers=headers, timeout=REQ_TIMEOUT, **kw)
    if r.status_code == 401:
        _token["exp"] = 0
        headers["Authorization"] = f"Bearer {_jwt()}"
        r = requests.request(method, f"{LAPI_URL}{path}", headers=headers, timeout=REQ_TIMEOUT, **kw)
    return r


def caller_ip():
    xff = request.headers.get("X-Forwarded-For", "")
    chain = [p.strip() for p in xff.split(",") if p.strip()]
    if chain and TRUSTED_HOPS > 0:
        idx = max(0, len(chain) - TRUSTED_HOPS)
        candidate = chain[idx]
    else:
        candidate = request.remote_addr
    try:
        ipaddress.ip_address(candidate)
    except (ValueError, TypeError):
        abort(400, "could not determine caller ip")
    return candidate


def valid_ip(s):
    try:
        ipaddress.ip_address(s)
        return True
    except (ValueError, TypeError):
        return False


@app.get("/")
def index():
    return render_template("index.html", my_ip=caller_ip())


@app.get("/decisions")
def list_decisions():
    q = request.args.get("ip", "").strip()
    params = {}
    if q:
        if not valid_ip(q):
            return render_template("_decisions.html", error="invalid IP", decisions=[]), 400
        params["ip"] = q
    r = _bouncer("GET", "/v1/decisions", params=params)
    if r.status_code != 200:
        return render_template("_decisions.html", error=f"LAPI {r.status_code}: {r.text[:200]}", decisions=[]), 502
    decisions = r.json() or []
    return render_template("_decisions.html", decisions=decisions, error=None)


@app.post("/unban")
def unban():
    ip = request.form.get("ip", "").strip()
    decision_id = request.form.get("id", "").strip()
    if decision_id:
        if not decision_id.isdigit():
            return "invalid id", 400
        r = _machine("DELETE", f"/v1/decisions/{decision_id}")
    elif ip:
        if not valid_ip(ip):
            return "invalid IP", 400
        r = _machine("DELETE", "/v1/decisions", params={"ip": ip})
    else:
        return "need id or ip", 400
    if r.status_code not in (200, 204):
        return f"LAPI {r.status_code}: {r.text[:200]}", 502
    log.info("unbanned by=%s ip=%s id=%s", caller_ip(), ip, decision_id)
    return list_decisions()


@app.post("/unban-me")
def unban_me():
    ip = caller_ip()
    r = _machine("DELETE", "/v1/decisions", params={"ip": ip})
    if r.status_code not in (200, 204):
        return f"LAPI {r.status_code}: {r.text[:200]}", 502
    log.info("unban-me by=%s", ip)
    return render_template("_unban_me.html", ip=ip, result=r.json() if r.text else {})


@app.get("/healthz")
def healthz():
    try:
        r = _bouncer("GET", "/v1/decisions", params={"limit": 1})
        return jsonify(ok=r.status_code == 200, lapi_status=r.status_code), 200 if r.status_code == 200 else 503
    except Exception as e:
        return jsonify(ok=False, error=str(e)), 503