import math
import sys


def HypoThe(Theta,xi):
    if(len(Theta)==len(xi)):
        sum=0
        for i in range(len(xi)):
            sum+=(Theta[i]*xi[i])
        return sum
    else:
        return False

def RegCostFunc(Theta,X,Y,lamb):
    sum1=0
    for i in range(len(X)):
        sum1+=((HypoThe(Theta, X[i])-Y[i])**2)
    J=sum1
    sum1=0
    for i in range(1,len(Theta)):
        sum1+=(Theta[i]**2)
    J+=lamb*sum1
    return J/(2*len(X))



def GradTerm(X,Y,Theta,i):
    sum1=0
    for j in range(len(X)):
        sum1+=((HypoThe(Theta,X[j])-Y[j])*X[j][i])
    return sum1

def GradDesc(Theta,alpha,Xfeature,Ylabels):
    Theta_=[]
    for i in range(0,len(Theta)):
        Theta_.append(Theta(i)-(alpha* GradTerm(Xfeature,Ylabels,Theta,i)/len(Xfeature)))
    return Theta_


def LinearRegression(Xfeature,Ylabels,alpha,iterations):
  if len(Xfeature)!=len(Ylabels):
        print("Missing Data");
        return False
    else:
        for i in range(len(Xfeature)):
            Xfeature[i].insert(0,1)
        Theta=[0]*len(Xfeature[0])
        for i in range(iterations):
            print("\nIteration Number ",i)
            print(Theta)
            Theta=GradDesc(Theta, alpha, Xfeature, Ylabels)
        print(Theta)
        return Theta

Xfeature=[]
Ylabels=[]
f1=open("LinearRegression.txt")
z=f1.readline()
print("Fetching Data")
while z:
    print(".",end=".")
    temp=z.split(",")
    temp1=[]
    for i in range(len(temp)-1):
        temp1.append(float((temp[i])))
    Xfeature.append(temp1)
    Ylabels.append(float(temp[-1]))
    z=f1.readline()
f1.flush()
print("")
iterations=int(input("Enter the Number of Iterations"))
alpha=float(input("Enter the learning rate"))
m=round(len(Xfeature)/5)
print(Xfeature[0]," ", Ylabels[0]," ", alpha," ", iterations )


Theta=LinearRegression(Xfeature, Ylabels, alpha, iterations)

print("\n========================================================================================")

print("Saving Model......")
f2=open("Models.txt","w")
f2.write(str(Theta)+"\n")
f2.close
print("========================================================================================\n")
while True:
    print("Enter ",len(Xfeature[0])," features to predict value for")
    Pred=[1];
    sys.stdout.flush()
    for i in range(len(Xfeature[0])-1):
        temp=float(input("Enter feature number "))
        Pred.append(temp)
    print(HypoThe(Theta,Pred))