################################################################################
#Michael Guerzhoy, 2016
#AlexNet implementation in TensorFlow, with weights
#Details:
#http://www.cs.toronto.edu/~guerzhoy/tf_alexnet/
#
#With code from https://github.com/ethereon/caffe-tensorflow
#Model from  https://github.com/BVLC/caffe/tree/master/models/bvlc_alexnet
#Weights from Caffe converted using https://github.com/ethereon/caffe-tensorflow
#
#
################################################################################

from numpy import *
import os
from pylab import *
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cbook as cbook
import time
from scipy.misc import imread
from scipy.misc import imresize
import matplotlib.image as mpimg
from scipy.ndimage import filters
import urllib
from numpy import random


import tensorflow as tf




x = tf.placeholder(tf.float32, [1, 277, 277, 3])
y = tf.placeholder(tf.float32, [1, 6])

net_data = load("bvlc_alexnet.npy").item()

def conv(input, kernel, biases, k_h, k_w, c_o, s_h, s_w,  padding="VALID", group=1):
    '''From https://github.com/ethereon/caffe-tensorflow
    '''
    c_i = input.get_shape()[-1]
    assert c_i%group==0
    assert c_o%group==0
    convolve = lambda i, k: tf.nn.conv2d(i, k, [1, s_h, s_w, 1], padding=padding)


    if group==1:
        conv = convolve(input, kernel)
    else:
        input_groups = tf.split(3, group, input)
        kernel_groups = tf.split(3, group, kernel)
        output_groups = [convolve(i, k) for i,k in zip(input_groups, kernel_groups)]
        conv = tf.concat(3, output_groups)
    return  tf.reshape(tf.nn.bias_add(conv, biases), conv.get_shape().as_list())




#conv1
#conv(11, 11, 96, 4, 4, padding='VALID', name='conv1')
k_h = 11; k_w = 11; c_o = 96; s_h = 4; s_w = 4
conv1W = tf.Variable(net_data["conv1"][0])
conv1b = tf.Variable(net_data["conv1"][1])
conv1_in = conv(x, conv1W, conv1b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=1)
conv1 = tf.nn.relu(conv1_in)

#lrn1
#lrn(2, 2e-05, 0.75, name='norm1')
radius = 2; alpha = 2e-05; beta = 0.75; bias = 1.0
lrn1 = tf.nn.local_response_normalization(conv1,
                                                  depth_radius=radius,
                                                  alpha=alpha,
                                                  beta=beta,
                                                  bias=bias)

#maxpool1
#max_pool(3, 3, 2, 2, padding='VALID', name='pool1')
k_h = 3; k_w = 3; s_h = 2; s_w = 2; padding = 'VALID'
maxpool1 = tf.nn.max_pool(lrn1, ksize=[1, k_h, k_w, 1], strides=[1, s_h, s_w, 1], padding=padding)


#conv2
#conv(5, 5, 256, 1, 1, group=2, name='conv2')
k_h = 5; k_w = 5; c_o = 256; s_h = 1; s_w = 1; group = 2
conv2W = tf.Variable(net_data["conv2"][0])
conv2b = tf.Variable(net_data["conv2"][1])
conv2_in = conv(maxpool1, conv2W, conv2b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv2 = tf.nn.relu(conv2_in)


#lrn2
#lrn(2, 2e-05, 0.75, name='norm2')
radius = 2; alpha = 2e-05; beta = 0.75; bias = 1.0
lrn2 = tf.nn.local_response_normalization(conv2,
                                                  depth_radius=radius,
                                                  alpha=alpha,
                                                  beta=beta,
                                                  bias=bias)

#maxpool2
#max_pool(3, 3, 2, 2, padding='VALID', name='pool2')
k_h = 3; k_w = 3; s_h = 2; s_w = 2; padding = 'VALID'
maxpool2 = tf.nn.max_pool(lrn2, ksize=[1, k_h, k_w, 1], strides=[1, s_h, s_w, 1], padding=padding)

#conv3
#conv(3, 3, 384, 1, 1, name='conv3')
k_h = 3; k_w = 3; c_o = 384; s_h = 1; s_w = 1; group = 1
conv3W = tf.Variable(net_data["conv3"][0])
conv3b = tf.Variable(net_data["conv3"][1])
conv3_in = conv(maxpool2, conv3W, conv3b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv3 = tf.nn.relu(conv3_in)

#conv4
#conv(3, 3, 384, 1, 1, group=2, name='conv4')
k_h = 3; k_w = 3; c_o = 384; s_h = 1; s_w = 1; group = 2
conv4W = tf.Variable(net_data["conv4"][0])
conv4b = tf.Variable(net_data["conv4"][1])
conv4_in = conv(conv3, conv4W, conv4b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv4 = tf.nn.relu(conv4_in)


# initialize this from snapshot if needed
snapshot = "new_snapshot_pass_0099.pkl"
if snapshot:
    snapshot = np.load(snapshot)
    outW = tf.Variable(snapshot["outW"])
    outb = tf.Variable(snapshot["outb"])
else:
    #out
    #fc(6, relu=False, name='fc8')
    outW = tf.Variable(tf.random_normal([16 * 16 * 384, 6], stddev=0.01))
    outb = tf.Variable(tf.random_normal([6], stddev=0.01));

out = tf.nn.xw_plus_b(tf.reshape(conv4, [1, 384 * 16 * 16]), outW, outb)

#prob
#softmax(name='prob'))
prob = tf.nn.softmax(out)

lam = 0.00000
decay_penalty =lam*tf.reduce_sum(tf.square(outW))
NLL = -tf.reduce_sum(y*tf.log(out)+decay_penalty)

train_step = tf.train.GradientDescentOptimizer(0.0005).minimize(NLL)

correct_prediction = tf.equal(tf.argmax(y, 1), tf.argmax(out, 1))
accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))

init = tf.initialize_all_Variables()
sess = tf.Session()
sess.run(init)

