import flask
import requests
from urllib.parse import urljoin
from flask import request
from datetime import datetime
import time
from flask_babel import gettext

##
# Return a error response to the client.
#
# @param abort_status_code status code to return along the response.
# @param params _kw_ arguments to passed verbatim to the templating engine.
def err_abort(abort_status_code, **params):
    t = flask.render_template("templates/error.html", **params)
    flask.abort(flask.make_response(t, abort_status_code))

##
# POST a request to the backend, and return a error
# response if any error occurs.
#
# @param endpoint the backend endpoint where to POST
#        this request.
# @param json the POST's body.
# @return the backend response (JSON format).
def backend_post(backend_url, endpoint, json):
    headers = {"Authorization": "ApiKey sandbox"}
    final_url = urljoin(backend_url, endpoint)
    print("POSTing to: " + final_url)
    try:
        resp = requests.post(
            final_url, json=json, headers=headers
        )
    except requests.ConnectionError:
        err_abort(500, message=gettext("Could not establish connection to backend"))
    try:
        response_json = resp.json()
    except ValueError:
        err_abort(
            500,
            message=gettext("Could not parse response from backend"),
            status_code=resp.status_code
        )
    if resp.status_code != 200:
        err_abort(
            500,
            message=gettext("Backend returned error status"),
            json=response_json,
            status_code=resp.status_code
        )
    print("Backend responds to {}: {}".format(final_url, str(response_json)))
    return response_json


##
# Issue a GET request to the backend.
#
# @param endpoint the backend endpoint where to issue the request.
# @param params (dict type of) URL parameters to append to the request.
# @return the JSON response from the backend, or a error response
#         if something unexpected happens.
def backend_get(backend_url, endpoint, params):
    headers = {"Authorization": "ApiKey sandbox"}
    final_url = urljoin(backend_url, endpoint)
    print("GETting: " + final_url + " with params: " + str(params))
    try:
        resp = requests.get(
            final_url, params=params, headers=headers
        )
    except requests.ConnectionError:
        err_abort(500, message=gettext("Could not establish connection to backend"))
    try:
        response_json = resp.json()
    except ValueError:
        err_abort(500, message=gettext("Could not parse response from backend"))
    if resp.status_code != 200:
        err_abort(
            500,
            message=gettext("Backend returned error status"),
            json=response_json,
            status_code=resp.status_code
        )
    print("Backend responds to {}: {}".format(final_url, str(response_json)))
    return response_json

def get_locale():
    parts = request.path.split('/', 2)
    if (2 >= len(parts)):
        # Totally unexpected path format, do not localize
        return "en"
    lang = parts[1]
    return lang

##
# Helper function used inside Jinja2 logic to create a links
# to the current page but in a different language. Used to
# implement the "Language" menu.
#
def self_localized(lang):
    """
    Return URL for the current page in another locale.
    """
    path = request.path
    # path must have the form "/$LANG/$STUFF"
    parts = path.split('/', 2)
    if (2 >= len(parts)):
        # Totally unexpected path format, do not localize
        return path
    return "/" + lang + "/" + parts[2]


##
# Return a error response to the client.
#
# @param abort_status_code status code to return along the response.
# @param params _kw_ arguments to passed verbatim to the templating engine.
def err_abort(abort_status_code, **params):
    t = flask.render_template(
        "templates/error.html.j2",
        lang=get_locale(),
        **params
    )
    flask.abort(flask.make_response(t, abort_status_code))



def fallback_404(error):
    return "Page not found"



class Deadline:
    def __init__(self, value):
        self.value = value
    def isExpired(self):
        if self.value == "never":
            return False
        now = int(round(time.time()) * 1000)
        now_dt = datetime.fromtimestamp(now / 1000)
        deadline_dt = datetime.fromtimestamp(self.value / 1000)
        print("debug: checking refund expiration, now: {}, deadline: {}".format(
            now_dt.strftime("%c"), deadline_dt.strftime("%c")
        ))
        return now > self.value