from datetime import datetime, timedelta
import os.path
from pathlib import Path
import time
import json

from models.location import JsonEncoder
from utils.helperutils import log

cache = {}

class Cache():
    def get(key, notOlderThanHours = 24):
       #print('get key ' + key)
       if key in cache:
           cacheobj = cache[key] 
           if(not cache):
               return None
           if(cacheobj.isOlderThanHours(notOlderThanHours)):
               log('removing cacheobject ' + key)
               del cache[key]
               return None
           # log( 'returning cacheobject ' + key)
           return cacheobj.obj

    def add(key, obj):
        log('adding cacheobject ' + key)
        cacheobj = CacheObj(key, obj)
        cache[key] = cacheobj


class CacheObj:
    def __init__(self, key, obj):
        self.key = key
        self.obj = obj
        self.time=datetime.now()
    
    def isOlderThanHours(self, hours):
        # log('checking time cacheobject ' + self.key + ': ' + str(self.time) + " < " + str(datetime.now() - timedelta(hours=hours)))
        return self.time < datetime.now() - timedelta(hours=hours)
  
      
class FileCache():
  def get(key, notOlderThanHours = None):
      
      filepath = "./filecache/" + key + ".json"
      cachefile = Path(filepath)
      if cachefile.is_file():
        ti_m = os.path.getmtime(filepath)

        if(notOlderThanHours is not None):
            #checks last modified age of file, and removes it if it is too old
            log('checking time cachefile ' + filepath + ': ' + str(ti_m) + " < " + str(time.time() - (3600 * notOlderThanHours)))

            if( ti_m < time.time() - (3600 * notOlderThanHours)):
                log('removing old filecache')
                os.remove(filepath)
                return None
        
        with open(filepath) as json_file:
          json_data = json.load(json_file)
          log('returning json data from cachefile: ' + key)
          return json_data
        
      return None

  def add(key, obj):
        log('adding filecacheobject ' + key)
        json_data = JsonEncoder().encode(obj)
        with open("./filecache/" + key + ".json", 'w+') as f:
          f.write(json_data)