# -*- coding: utf8 -*- 
'''
Created on Jul 10, 2016

@author: Dayo
'''
from math import ceil


class SMSCounter():
    
    GSM_7BIT = 'GSM_7BIT'
    GSM_7BIT_EX = 'GSM_7BIT_EX'
    UTF16 = 'UTF16'
    GSM_7BIT_LEN = GSM_7BIT_EX_LEN = 160
    UTF16_LEN = 70
    GSM_7BIT_LEN_MULTIPART = GSM_7BIT_EX_LEN_MULTIPART = 153
    UTF16_LEN_MULTIPART = 67

    
    def get_gsm_7bit_map(self):
        
        return(
               [10,13,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,
      51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,
      71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,
      92,95,97,98,99,100,101,102,103,104,105,106,107,108,109,110,
      111,112,113,114,115,116,117,118,119,120,121,122,
      161,163,164,165,191,196,197,198,199,201,209,214,
      216,220,223,224,228,229,230,232,233,236,241,242,
      246,248,249,252,915,916,920,923,926,928,931,934,
      936,937]
               )
        
    def get_added_gsm_7bit_ex_map(self):
        
        return [91,92,93,94,123,124,125,126,8364]
    
    def get_gsm_7bit_ex_map(self):
        
        return(self.get_added_gsm_7bit_ex_map()+self.get_gsm_7bit_map())
    
    
    def text_to_unicode_pointcode_list(self, plaintext):
        
        textlist = []
        for stg in plaintext:
            textlist.append(ord(stg))            
        return textlist
    
    def unicode_pointcode_list_to_text(self, strlist):
        
        text = ''
        for stc in strlist:
            text.join(chr(stc))            
        return text
    
    
    def detect_encoding(self, plaintext):
        
        rf = self.text_to_unicode_pointcode_list(plaintext)

        utf16chars = set(rf).difference(set(self.get_gsm_7bit_map()))

        if len(utf16chars):
            return self.UTF16
        
        exchars = set(rf).intersection(set(self.get_added_gsm_7bit_ex_map()))

        if len(exchars):
            return self.GSM_7BIT_EX
        
        return self.GSM_7BIT
        
        
        
    
    def count(self, plaintext):
        
        textlist = self.text_to_unicode_pointcode_list(plaintext)
        
        exchars = []
        encoding = self.detect_encoding(plaintext)
        length = len(textlist)
        
        if encoding == self.GSM_7BIT_EX:
            lengthexchars = len(exchars)
            length+=lengthexchars
            
        if encoding == self.GSM_7BIT:
            permessage = self.GSM_7BIT_LEN
            if length > self.GSM_7BIT_LEN:
                permessage = self.GSM_7BIT_LEN_MULTIPART
                
        
        elif encoding == self.GSM_7BIT_EX:
            permessage = self.GSM_7BIT_EX_LEN
            if length > self.GSM_7BIT_EX_LEN:
                permessage = self.GSM_7BIT_EX_LEN_MULTIPART
                
        
        else:
            permessage = self.UTF16_LEN
            if length > self.UTF16_LEN:
                permessage = self.UTF16_LEN_MULTIPART
                
        
        messages = ceil(length/permessage)
        remaining = (permessage * messages) - length
        
        returnset = {
            'encoding' : encoding,
            'length' : length,
            'per_message' : permessage,
            'remaining' : remaining,
            'messages' : messages
                     }
        
        return returnset
    
    
    def truncate(self, plaintext, limitsms):
        
        count = self.count(plaintext)
        
        if count.mesages <= limitsms:
            return plaintext
        
        
        if count.encoding == 'UTF16':
            limit = self.UTF16_LEN
            
            if limitsms > 2:
                limit = self.UTF16_LEN_MULTIPART
                
        if count.encoding != 'UTF16':
            limit = self.GSM_7BIT_LEN
            
            if limitsms > 2:
                limit = self.GSM_7BIT_LEN_MULTIPART
    
            
        while True:
            text = plaintext[0:limit*limitsms]
            count = self.count(plaintext)
            
            limit = limit - 1
            
            if count.messages < limitsms:
                break
            
        return text