#!/usr/bin/env/python

import math
import random

class sources:
    def __init__(self):
        self.available_sources = ['file', 'sine', 'cosine', 'random', 'zeros']
        self.corresponding_methods = ['read_file','gen_sine', 'gen_cosine', 'gen_random_data', 'gen_zeros']


    def get_sources_list(self):
        return self.available_sources


    def read_file(self, file_name, delimiter):

        try:
            my_file = open(file_name, 'r')
        except IOError:
            print "no file named " + file_name
            return []  #return an empty packet

        data_from_file = my_file.read()   #read the file as a big string
        my_file.close()   #done reading the file.  process the string from now on

        data_from_file.strip('\n')  #\n's will not be tollerated
        data_from_file.strip('[')   #['s will not be tollerated
        data_from_file.strip(']')   #]'s will not be tollerated

        data_from_file = data_from_file.split(delimiter)  #break string into a list

        return data_from_file


    def gen_sine(self, freq, len):
        '''freq is frequency in cycles per packet.  len is the length of the packet.  type is the data type to return (e.g., "float", "short", "int")'''

        count = 0
        sine = []
        while count < len:
            sine.append(math.sin(freq*2*math.pi*count/len))
            count = count + 1

        return sine


    def gen_cosine(self, freq, len):
        '''freq is frequency in cycles per packet.  len is the length of the packet.  type is the data type to return (e.g., "float", "short", "int")'''

        count = 0
        cosine = []
        while count < len:
            cosine.append(math.cos(freq*2*math.pi*count/len))
            count = count + 1

        return cosine



    def gen_random_data(self, len, rand_type):
        '''the rand_type variable defines which function call to use in the random module'''

        data = []
        rand_type = rand_type.lower()  #makes comparison case insensitive
        if rand_type == 'random':
            count = 0
            while count < len:
                data.append(random.random())
                count = count + 1
        elif rand_type == 'uniform':
            count = 0
            while count < len:
                data.append(random.uniform())
                count = count + 1
        else:
            print "random methods other than random and uniform are not supported in sources.random_data"

        return data
		
    def gen_zeros(self, len):
        '''returns a list of zeros'''
        data = []
        for n in range(len):
            data.append(0)
        return data