import os
import errno
import requests
import json
import datetime
import time
import tempfile
import pytz

import config
import blizzard
import spec


def log(*data):
    print(datetime.datetime.now(), '|', *data)


class Updater(object):

    RFC2616 = '%a, %d %b %Y %H:%M:%S %Z'

    def __init__(self, region: str):
        self.region = region
        self.http = requests.Session()
        self.credentials = blizzard.get_credentials(config.pwd)
        self.last_modified = {}
        self.oauth = None


    def get_oauth(self) -> dict:
        if self.oauth is not None:
            return self.oauth

        api = self.http.post(f"{blizzard.get_bnet_host(self.region)}/oauth/token", data={'grant_type': 'client_credentials'}, auth=self.credentials)
        oauth = api.json()
        #log(region, oauth)
        api.raise_for_status()

        self.oauth = oauth
        return oauth


    def api_call(self, path: str, namespace: str, access_token: str, headers=None) -> requests.Response:
        url = f"{blizzard.get_api_host(self.region)}{path}"
        qs = {'namespace': f"{namespace}-{self.region}", 'access_token': access_token}

        api = self.http.get(url, params=qs, headers=headers) #, headers={'Authorization': f"Authorization: Token {access_token}"})
        api.raise_for_status()
        return api


    def create_dst(self, dst: str):
        try:
            os.makedirs(os.path.dirname(dst))
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise


    def save_raw(self, path: str, raw: requests.Response):
        dst = f"{config.raw}/{path.replace('/', '_')}.json"

        self.create_dst(dst)

        # safe write: tmp write and then mv
        fd, tmp_path = tempfile.mkstemp(dir=config.pwd)
        try:
            with os.fdopen(fd, 'w') as tmp:
                json.dump(raw.json(), tmp, indent=2)
        finally:
            os.replace(tmp_path, dst)


    def get_last_modified(self, path: str):
        # cached!
        if path in self.last_modified:
            return self.last_modified[path]

        dst = f"{config.raw}/{path.replace('/', '_')}.json"

        try:
            # mtime to datetime from timestamp, default tz, replace to GMT, format
            modified = datetime.datetime.fromtimestamp(os.path.getmtime(dst)).astimezone().replace(tzinfo=pytz.timezone('GMT')).strftime(self.RFC2616)
            self.last_modified[path] = modified
            return self.last_modified[path]
        except FileNotFoundError:
            return None


    def set_last_modified(self, path: str, modified: str):
        dst = f"{config.raw}/{path.replace('/', '_')}.json"
        self.last_modified[path] = modified

        # same Last-Modified for raw file
        epoch = time.mktime(time.strptime(modified, self.RFC2616)) # Tue, 11 May 2021 14:06:37 GMT
        os.utime(dst, (epoch, epoch))


    def iterate_index(self):
        try:
            oauth = self.get_oauth()
            access_token = oauth['access_token']
        except (requests.exceptions.HTTPError, KeyError) as e:
            log(type(e), e)
            return

        for api in spec.apis:
            # only indexes
            if not 'index' in api or not api['index']:
                continue

            try:
                last_modified = self.get_last_modified(api['path'])
                headers = {'If-Modified-Since': last_modified} if last_modified is not None else None

                response = self.api_call(api['path'], api['namespace'], access_token, headers=headers)

                if response.status_code == 200:
                    self.save_raw(api['path'], response)
                    self.set_last_modified(api['path'], response.headers['Last-Modified'])

            except requests.exceptions.HTTPError as e:
                log(e)
                continue


    def iterate_links(self):
        try:
            oauth = self.get_oauth()
            access_token = oauth['access_token']
        except (requests.exceptions.HTTPError, KeyError) as e:
            log(type(e), e)
            return

        for api in spec.apis:
            # no indexes
            if 'index' in api and api['index']:
                continue

            log(api)
            continue
            try:
                last_modified = self.get_last_modified(api['path'])
                headers = {'If-Modified-Since': last_modified} if last_modified is not None else None

                response = self.api_call(api['path'], api['namespace'], access_token, headers=headers)

                log(response.status_code, api)
                if response.status_code == 200:
                    self.save_last_modified(api['path'], response.headers['Last-Modified'])
                    self.save_raw(api['path'], response)

            except requests.exceptions.HTTPError as e:
                log(e)
                continue


if __name__ == "__main__":
    region = blizzard.get_by_key(spec.regions, 'code', 'us')['code']

    updater = Updater(region)
    updater.iterate_index()
    #updater.iterate_links()