#!/usr/bin/env python
#_*_coding:utf-8_*_

import re
import math

def DDE(fastas, **kw):
    AA = kw['order'] if kw['order'] != None else 'ACDEFGHIKLMNPQRSTVWY'

    myCodons = {
        'A': 4,
        'C': 2,
        'D': 2,
        'E': 2,
        'F': 2,
        'G': 4,
        'H': 2,
        'I': 3,
        'K': 2,
        'L': 6,
        'M': 1,
        'N': 2,
        'P': 4,
        'Q': 2,
        'R': 6,
        'S': 6,
        'T': 4,
        'V': 4,
        'W': 1,
        'Y': 2
    }

    encodings = []
    diPeptides = [aa1 + aa2 for aa1 in AA for aa2 in AA]
    header = ['#', 'label'] + diPeptides
    encodings.append(header)

    myTM = []
    for pair in diPeptides:
        myTM.append((myCodons[pair[0]] / 61) * (myCodons[pair[1]] / 61))

    AADict = {}
    for i in range(len(AA)):
        AADict[AA[i]] = i

    for i in fastas:
        name, sequence, label = i[0], re.sub('-', '', i[1]), i[2]
        code = [name, label]
        tmpCode = [0] * 400
        for j in range(len(sequence) - 2 + 1):
            tmpCode[AADict[sequence[j]] * 20 + AADict[sequence[j+1]]] = tmpCode[AADict[sequence[j]] * 20 + AADict[sequence[j+1]]] +1
        if sum(tmpCode) != 0:
            tmpCode = [i/sum(tmpCode) for i in tmpCode]

        myTV = []
        for j in range(len(myTM)):
            myTV.append(myTM[j] * (1-myTM[j]) / (len(sequence) - 1))

        for j in range(len(tmpCode)):
            tmpCode[j] = (tmpCode[j] - myTM[j]) / math.sqrt(myTV[j])

        code = code + tmpCode
        encodings.append(code)
    return encodings