import hmac
import json
import logging
import os

from flask import (Flask, request, jsonify, abort)

from ltsdb_json import LTS

logging.basicConfig(level=logging.DEBUG)

app = Flask(__name__)

log = logging.getLogger()

@app.route("/")
def home():
    return jsonify({ "success": None })


@app.route("/report", methods=["POST"])
def report():
    data = request.get_json()
    n_ts = 0
    n_dp = 0
    for d in data:
        d["description"]["remote_addr"] = request.remote_addr
        d["description"]["node"] = verify_node(d)

        log.info("received %s", json.dumps(d))
        ts = LTS(d["description"])
        for dp in d["data"]:
            ts.add(*dp)
            ts.save()
            n_dp += 1
        n_ts += 1
    return jsonify({ "success": True, "timeseries": n_ts, "datapoints": n_dp })

def verify_node(d):
    node = d["auth"]["node"]
    timestamp = d["auth"]["timestamp"]
    digest1 = d["auth"]["hmac"]
    if "/" in node:
        raise ValueError("invalid node name %s", node)
    try:
        log.info("gettingg client config from %s", "config/" + node)
        with open("config/" + node) as fh:
            node_conf = json.load(fh)
    except Exception as e:
        log.warning("got %s opening %s", e, "config/" + node)
        abort(401, "unknown client")
    last = node_conf["last"]
    for key in node_conf["keys"]:
        msg = (node + " " + str(timestamp)).encode("UTF-8")
        hmac2 = hmac.new(key.encode("UTF-8"), msg, "SHA-256")
        digest2 = hmac2.hexdigest()
        if hmac.compare_digest(digest1, digest2):
            if timestamp > node_conf["last"]:
                node_conf["last"] = timestamp
                os.replace("config/" + node, "config/" + node + ".old")
                with open("config/" + node, "w") as fh:
                    json.dump(node_conf, fh) # XXX
                return node
            else:
                abort(409, "timestamp out of sync")
    abort(401, "auth failed")