# -*- coding: utf-8 -*-
#  CCP in Tomographic Imaging (CCPi) Core Imaging Library (CIL).

#   Copyright 2017 UKRI-STFC
#   Copyright 2017 University of Manchester

#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at

#   http://www.apache.org/licenses/LICENSE-2.0

#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
import unittest
from ccpi.optimisation.operators import BlockOperator
from ccpi.framework import BlockDataContainer
from ccpi.optimisation.operators import Identity
from ccpi.framework import ImageGeometry, ImageData
import numpy
from ccpi.optimisation.operators import FiniteDifferenceOperator


class TestBlockOperator(unittest.TestCase):

    def test_BlockOperator(self):
        print ("test_BlockOperator")
        ig = [ ImageGeometry(10,20,30) , \
               ImageGeometry(10,20,30) , \
               ImageGeometry(10,20,30) ]
        x = [ g.allocate() for g in ig ]
        ops = [ Identity(g) for g in ig ]

        K = BlockOperator(*ops)
        X = BlockDataContainer(x[0])
        Y = K.direct(X)
        self.assertTrue(Y.shape == K.shape)

        numpy.testing.assert_array_equal(Y.get_item(0).as_array(),X.get_item(0).as_array())
        numpy.testing.assert_array_equal(Y.get_item(1).as_array(),X.get_item(0).as_array())
        #numpy.testing.assert_array_equal(Y.get_item(2).as_array(),X.get_item(2).as_array())
        
        X = BlockDataContainer(*x) + 1
        Y = K.T.direct(X)
        # K.T (1,3) X (3,1) => output shape (1,1)
        self.assertTrue(Y.shape == (1,1))
        zero = numpy.zeros(X.get_item(0).shape)
        numpy.testing.assert_array_equal(Y.get_item(0).as_array(),len(x)+zero)
        
        K2 = BlockOperator(*(ops+ops), shape=(3,2))
        Y = K2.T.direct(X)
        # K.T (2,3) X (3,1) => output shape (2,1)
        self.assertTrue(Y.shape == (2,1))

        try:
            # this should fail as the domain is not compatible
            ig = [ ImageGeometry(10,20,31) , \
                ImageGeometry(10,20,30) , \
                ImageGeometry(10,20,30) ]
            x = [ g.allocate() for g in ig ]
            ops = [ Identity(g) for g in ig ]
            
            K = BlockOperator(*ops)
            self.assertFalse(K.column_wise_compatible())
        except ValueError as ve:
            print (ve)
            self.assertTrue(True)
        
        try:
            # this should fail as the range is not compatible
            ig = [ ImageGeometry(10,20,30) , \
                ImageGeometry(10,20,30) , \
                ImageGeometry(10,20,30) ]
            rg0 = [ ImageGeometry(10,20,31) , \
                ImageGeometry(10,20,31) , \
                ImageGeometry(10,20,31) ]
            rg1 = [ ImageGeometry(10,22,31) , \
                   ImageGeometry(10,22,31) , \
                   ImageGeometry(10,20,31) ]
            x = [ g.allocate() for g in ig ]
            ops = [ Identity(g, range_geometry=r) for g,r in zip(ig, rg0) ]
            ops += [ Identity(g, range_geometry=r) for g,r in zip(ig, rg1) ]

            K = BlockOperator(*ops, shape=(2,3))
            print ("K col comp? " , K.column_wise_compatible())
            print ("K row comp? " , K.row_wise_compatible())
            for op in ops:
                print ("range" , op.range_geometry().shape)
            for op in ops:
                print ("domain" , op.domain_geometry().shape)
            self.assertFalse(K.row_wise_compatible())
        except ValueError as ve:
            print (ve)
            self.assertTrue(True)
            
    def test_ScaledBlockOperatorSingleScalar(self):
        ig = [ ImageGeometry(10,20,30) , \
               ImageGeometry(10,20,30) , \
               ImageGeometry(10,20,30) ]
        x = [ g.allocate() for g in ig ]
        ops = [ Identity(g) for g in ig ]

        val = 1
        # test limit as non Scaled
        scalar = 1
        k = BlockOperator(*ops)
        K = scalar * k
        X = BlockDataContainer(*x) + val
        
        Y = K.T.direct(X)
        self.assertTrue(Y.shape == (1,1))
        zero = numpy.zeros(X.get_item(0).shape)
        xx = numpy.asarray([val for _ in x])
        numpy.testing.assert_array_equal(Y.get_item(0).as_array(),((scalar*xx).sum()+zero))
        
        scalar = 0.5
        k = BlockOperator(*ops)
        K = scalar * k
        X = BlockDataContainer(*x) + 1
        
        Y = K.T.direct(X)
        self.assertTrue(Y.shape == (1,1))
        zero = numpy.zeros(X.get_item(0).shape)
        numpy.testing.assert_array_equal(Y.get_item(0).as_array(),scalar*(len(x)+zero))
        
        
    def test_ScaledBlockOperatorScalarList(self):
        ig = [ ImageGeometry(2,3) , \
               #ImageGeometry(10,20,30) , \
               ImageGeometry(2,3    ) ]
        x = [ g.allocate() for g in ig ]
        ops = [ Identity(g) for g in ig ]


        # test limit as non Scaled
        scalar = numpy.asarray([1 for _ in x])
        k = BlockOperator(*ops)
        K = scalar * k
        val = 1
        X = BlockDataContainer(*x) + val
        
        Y = K.T.direct(X)
        self.assertTrue(Y.shape == (1,1))
        zero = numpy.zeros(X.get_item(0).shape)
        xx = numpy.asarray([val for _ in x])
        numpy.testing.assert_array_equal(Y.get_item(0).as_array(),(scalar*xx).sum()+zero)
        
        scalar = numpy.asarray([i+1 for i,el in enumerate(x)])
        #scalar = numpy.asarray([6,0])
        k = BlockOperator(*ops)
        K = scalar * k
        X = BlockDataContainer(*x) + val
        Y = K.T.direct(X)
        self.assertTrue(Y.shape == (1,1))
        zero = numpy.zeros(X.get_item(0).shape)
        xx = numpy.asarray([val for _ in x])
        

        numpy.testing.assert_array_equal(Y.get_item(0).as_array(),
          (scalar*xx).sum()+zero)
        

    def test_TomoIdentity(self):
        ig = ImageGeometry(10,20,30)
        img = ig.allocate()
        print (img.shape, ig.shape)
        self.assertTrue(img.shape == (30,20,10))
        self.assertEqual(img.sum(), 0)
        Id = Identity(ig)
        y = Id.direct(img)
        numpy.testing.assert_array_equal(y.as_array(), img.as_array())

    def skiptest_CGLS_tikhonov(self):
        from ccpi.optimisation.algorithms import CGLS

        from ccpi.plugins.ops import CCPiProjectorSimple
        from ccpi.optimisation.ops import PowerMethodNonsquare
        from ccpi.optimisation.operators import Identity
        from ccpi.optimisation.funcs import Norm2sq, Norm1
        from ccpi.framework import ImageGeometry, AcquisitionGeometry
        from ccpi.optimisation.Algorithms import GradientDescent
        #from ccpi.optimisation.Algorithms import CGLS
        import matplotlib.pyplot as plt

        
        # Set up phantom size N x N x vert by creating ImageGeometry, initialising the 
        # ImageData object with this geometry and empty array and finally put some
        # data into its array, and display one slice as image.
        
        # Image parameters
        N = 128
        vert = 4
        
        # Set up image geometry
        ig = ImageGeometry(voxel_num_x=N,
                        voxel_num_y=N, 
                        voxel_num_z=vert)
        
        # Set up empty image data
        Phantom = ImageData(geometry=ig,
                            dimension_labels=['horizontal_x',
                                            'horizontal_y',
                                            'vertical'])
        Phantom += 0.05
        # Populate image data by looping over and filling slices
        i = 0
        while i < vert:
            if vert > 1:
                x = Phantom.subset(vertical=i).array
            else:
                x = Phantom.array
            x[round(N/4):round(3*N/4),round(N/4):round(3*N/4)] = 0.5
            x[round(N/8):round(7*N/8),round(3*N/8):round(5*N/8)] = 0.94
            if vert > 1 :
                Phantom.fill(x, vertical=i)
            i += 1
        
        
        perc = 0.02
        # Set up empty image data
        noise = ImageData(numpy.random.normal(loc = 0.04 ,
                                scale = perc , 
                                size = Phantom.shape), geometry=ig,
                            dimension_labels=['horizontal_x',
                                            'horizontal_y',
                                            'vertical'])
        Phantom += noise
        
        # Set up AcquisitionGeometry object to hold the parameters of the measurement
        # setup geometry: # Number of angles, the actual angles from 0 to 
        # pi for parallel beam, set the width of a detector 
        # pixel relative to an object pixe and the number of detector pixels.
        angles_num = 20
        det_w = 1.0
        det_num = N
        
        angles = numpy.linspace(0,numpy.pi,angles_num,endpoint=False,dtype=numpy.float32)*\
                    180/numpy.pi
        
        # Inputs: Geometry, 2D or 3D, angles, horz detector pixel count, 
        #         horz detector pixel size, vert detector pixel count, 
        #         vert detector pixel size.
        ag = AcquisitionGeometry('parallel',
                                '3D',
                                angles,
                                N, 
                                det_w,
                                vert,
                                det_w)
        
        # Set up Operator object combining the ImageGeometry and AcquisitionGeometry
        # wrapping calls to CCPi projector.
        A = CCPiProjectorSimple(ig, ag)
        
        # Forward and backprojection are available as methods direct and adjoint. Here 
        # generate test data b and some noise
        
        b = A.direct(Phantom)
        
        
        #z = A.adjoint(b)
        
        
        # Using the test data b, different reconstruction methods can now be set up as
        # demonstrated in the rest of this file. In general all methods need an initial 
        # guess and some algorithm options to be set. Note that 100 iterations for 
        # some of the methods is a very low number and 1000 or 10000 iterations may be
        # needed if one wants to obtain a converged solution.
        x_init = ImageData(geometry=ig, 
                        dimension_labels=['horizontal_x','horizontal_y','vertical'])
        X_init = BlockDataContainer(x_init)
        B = BlockDataContainer(b, 
                                ImageData(geometry=ig, dimension_labels=['horizontal_x','horizontal_y','vertical']))
        
        # setup a tomo identity
        Ibig = 1e5 * Identity(ig)
        Ismall = 1e-5 * Identity(ig)
        
        # composite operator
        Kbig = BlockOperator(A, Ibig, shape=(2,1))
        Ksmall = BlockOperator(A, Ismall, shape=(2,1))
        
        #out = K.direct(X_init)
        
        f = Norm2sq(Kbig,B)
        f.L = 0.00003
        
        fsmall = Norm2sq(Ksmall,B)
        f.L = 0.00003
        
        simplef = Norm2sq(A, b)
        simplef.L = 0.00003
        
        gd = GradientDescent( x_init=x_init, objective_function=simplef,
                            rate=simplef.L)
        gd.max_iteration = 10
        
        cg = CGLS()
        cg.set_up(X_init, Kbig, B )
        cg.max_iteration = 1
        
        cgsmall = CGLS()
        cgsmall.set_up(X_init, Ksmall, B )
        cgsmall.max_iteration = 1
        
        
        cgs = CGLS()
        cgs.set_up(x_init, A, b )
        cgs.max_iteration = 6
    #    
        #out.__isub__(B)
        #out2 = K.adjoint(out)
        
        #(2.0*self.c)*self.A.adjoint( self.A.direct(x) - self.b )
        
        #for _ in gd:
        #    print ("iteration {} {}".format(gd.iteration, gd.get_current_loss()))
        
        #cg.run(10, lambda it,val: print ("iteration {} objective {}".format(it,val)) )
        
        #cgs.run(10, lambda it,val: print ("iteration {} objective {}".format(it,val)))
        
        #cgsmall.run(10, lambda it,val: print ("iteration {} objective {}".format(it,val)))
        #cgsmall.run(10, lambda it,val: print ("iteration {} objective {}".format(it,val)))
    #    for _ in cg:
    #        print ("iteration {} {}".format(cg.iteration, cg.get_current_loss()))
    #    
    #    fig = plt.figure()
    #    plt.imshow(cg.get_output().get_item(0,0).subset(vertical=0).as_array())
    #    plt.title('Composite CGLS')
    #    plt.show()
    #    
    #    for _ in cgs:
    #        print ("iteration {} {}".format(cgs.iteration, cgs.get_current_loss()))
    #    
        fig = plt.figure()
        plt.subplot(1,5,1)
        plt.imshow(Phantom.subset(vertical=0).as_array())
        plt.title('Simulated Phantom')
        plt.subplot(1,5,2)
        plt.imshow(gd.get_output().subset(vertical=0).as_array())
        plt.title('Simple Gradient Descent')
        plt.subplot(1,5,3)
        plt.imshow(cgs.get_output().subset(vertical=0).as_array())
        plt.title('Simple CGLS')
        plt.subplot(1,5,4)
        plt.imshow(cg.get_output().get_item(0,0).subset(vertical=0).as_array())
        plt.title('Composite CGLS\nbig lambda')
        plt.subplot(1,5,5)
        plt.imshow(cgsmall.get_output().get_item(0,0).subset(vertical=0).as_array())
        plt.title('Composite CGLS\nsmall lambda')
        plt.show()

    def test_FiniteDiffOperator(self):
        N, M = 200, 300

        
        ig = ImageGeometry(voxel_num_x = M, voxel_num_y = N)    
        u = ig.allocate('random_int')
        G = FiniteDifferenceOperator(ig, direction=0, bnd_cond = 'Neumann')
        print(type(u), u.as_array())    
        print(G.direct(u).as_array())

        # Gradient Operator norm, for one direction should be close to 2
        numpy.testing.assert_allclose(G.norm(), numpy.sqrt(4), atol=0.1)

        M1, N1, K1 = 200, 300, 2
        ig1 = ImageGeometry(voxel_num_x = M1, voxel_num_y = N1, channels = K1)
        u1 = ig1.allocate('random_int')
        G1 = FiniteDifferenceOperator(ig1, direction=2, bnd_cond = 'Periodic')
        print(ig1.shape==u1.shape)
        print (G1.norm())
        numpy.testing.assert_allclose(G1.norm(), numpy.sqrt(4), atol=0.1)
