// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

// Copyright 2007, Daniel Fontijne, University of Amsterdam -- fontijne@science.uva.nl

#include <libgasandbox/e3ga.h>
#include <libgasandbox/e3ga_util.h>
#include <libgasandbox/timing.h>

using namespace e3ga;


// SPOILER WARNING: solution to Chapter 6, Exercise 1 directly below

// exercise 1a: complete in this function
mv outerProduct_1a(const e3ga::vector &a, const mv &B) {
    return 0.5f * (gp(a, B) + gp(gradeInvolution(B), a));
}

// exercise 1a: complete in this function
mv leftContraction_1a(const e3ga::vector &a, const mv &B) {
    return 0.5f * (gp(a, B) - gp(gradeInvolution(B), a));
}

// exercise 1b: complete in this function
mv outerProduct_1b(const mv &A, const mv &B) {
    mv result;
    for (int i = 0; i <= 3; i++) {
        if ((A.gu() & (1 << i)) == 0) continue; // skip if not in use
        for (int j = 0; j <= 3-i; j++) {
            if ((B.gu() & (1 << j)) == 0) continue; // skip if not in use
            if (i + j <= 3) {
                result += takeGrade(gp(takeGrade(A, 1 << i), takeGrade(B, 1 << j)), 1 << (i + j));
            }
        }
    }
    return result;
}

// exercise 1b: complete in this function
mv leftContraction_1b(const mv &A, const mv &B) {
    mv result;
    for (int i = 0; i <= 3; i++) {
        if ((A.gu() & (1 << i)) == 0) continue; // skip if not in use
        for (int j = i; j <= 3; j++) { // not j starts at i'
            if ((B.gu() & (1 << j)) == 0) continue; // skip if not in use
            result += takeGrade(gp(takeGrade(A, 1 << i), takeGrade(B, 1 << j)), 1 << (j - i));
        }
    }
    return result;
}

int main(int argc, char*argv[]) {
    // profiling for Gaigen 2:
    e3ga::g2Profiling::init();

    const int NB_TESTS = 100000;

    // A test for Exercise 1a
    // We generate random vectors and random multivectors, and use
    // the regular outer product/left contraction functions to verify the results:
    bool OK1a = true;
    for (int i = 0; i < NB_TESTS; i++) {
        e3ga::vector a = _vector(randomBlade(1));
        mv B = randomMultivector(GRADE_1 | GRADE_2 | GRADE_3);

        // test outer product
        {
            mv X = op(a, B);
            mv Y = outerProduct_1a(a, B);

            if (_Float(norm_e2(X - Y)) > 1e-7f) {
                // Not equal: complain
                printf("\n\nouterProduct_1a() failed for\n%s\nand\n%s\n", a.toString_f().c_str(), B.toString_f().c_str());
                OK1a = false;
            }
        }

        // test left contraction
        {
            mv X = lcont(a, B);
            mv Y = leftContraction_1a(a, B);
            /*intf("a  = %s\n", a.toString_e().c_str());
            printf("B  = %s\n", B.toString_e().c_str());
            printf("X  = %s\n", X.toString_e().c_str());
            printf("Y  = %s\n", Y.toString_e().c_str());*/

            if (_Float(norm_e2(X - Y)) > 1e-7f) {
                // Not equal: complain
                printf("\n\nleftContraction_1a() failed for\n%s\nand\n%s\n", a.toString_f().c_str(), B.toString_f().c_str());
            }
        }
    }
    if (OK1a)
        printf("outerProduct_1a() and leftContraction_1a() seem to be OK.\n");


    // A test for Exercise 1b
    // We generate pairs of random multivector, and use
    // the regular outer product/left contraction functions to verify the results:
    bool OK1b = true;
    for (int i = 0; i < NB_TESTS; i++) {
        mv A = randomMultivector();
        mv B = randomMultivector();

        // test outer product
        {
            mv X = op(A, B);
            mv Y = outerProduct_1b(A, B);
            if (_Float(norm_e2(X - Y)) > 1e-7f) {
                // Not equal: complain
                printf("\n\nouterProduct_1b() failed for\n%s\nand\n%s\n", A.toString().c_str(), B.toString().c_str());
                OK1b = false;
            }
        }

        // test left contraction
    {
            mv X = lcont(A, B);
            mv Y = leftContraction_1b(A, B);
            if (_Float(norm_e2(X - Y)) > 1e-7f) {
                // Not equal: complain
                printf("\n\nleftContraction_1b() failed for\n%s\nand\n%s\n", A.toString().c_str(), B.toString().c_str());
                OK1b = false;
            }
        }
    }

    if (OK1b)
        printf("outerProduct_1b() and leftContraction_1b() seem to be OK.\n");


    return 0;
}