/*

    pHash, the open source perceptual hash library
    Copyright (C) 2009 Aetilius, Inc.
    All rights reserved.

    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 3 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, see <http://www.gnu.org/licenses/>.

    Evan Klinger - eklinger@phash.org
    David Starkweather - dstarkweather@phash.org

*/

#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <algorithm>
#include <vector>
#include "pHash.h"

using namespace std;

#define TRUE 1
#define FALSE 0

// data structure for a hash and id
struct ph_imagepoint {
    ulong64 hash;
    char *id;
};

// aux function to create imagepoint data struct
struct ph_imagepoint *ph_malloc_imagepoint() {
    return (struct ph_imagepoint *)malloc(sizeof(struct ph_imagepoint));
}

// auxiliary function for sorting list of hashes
bool cmp_lt_imp(struct ph_imagepoint dpa, struct ph_imagepoint dpb) {
    int result = strcmp(dpa.id, dpb.id);
    if (result < 0) return TRUE;
    return FALSE;
}
/** TEST for image DCT hash function
 *  The program reads all images from the two directories given on the command
 *line. The program expects the same number of image files in each directory.
 *Each image should be perceptually similar to a corresponding file in the other
 *directory and have the same exact name.  For example, one directory could
 *contain the originals, and the other directory blurred counterparts.  The
 *program calculates the hashes. First, the hamming distances are calculated
 *between all similar image hashes (-i.e. the intra compares), and then hamming
 *distances for different images hashes (-i.e. the inter compares).
 **/
int main(int argc, char **argv) {
    const char *msg = ph_about();
    printf(" %s\n", msg);

    if (argc < 3) {
        printf("no input args\n");
        printf("expected: \"test_imagephash [dir name] [dir_name]\"\n");
        exit(1);
    }
    const char *dir_name = argv[1];
    const char *dir_name2 = argv[2];
    struct dirent *dir_entry;
    vector<ph_imagepoint> hashlist1;  // for hashes in first directory
    vector<ph_imagepoint> hashlist2;  // for hashes in second directory
    ph_imagepoint *dp = NULL;

    // first directory
    DIR *dir = opendir(dir_name);
    if (!dir) {
        printf("unable to open directory\n");
        exit(1);
    }
    errno = 0;
    int i = 0;
    ulong64 tmphash;
    char path[100];
    path[0] = '\0';
    while ((dir_entry = readdir(dir)) != 0) {
        if (strcmp(dir_entry->d_name, ".") && strcmp(dir_entry->d_name, "..")) {
            strcat(path, dir_name);
            strcat(path, "/");
            strcat(path, dir_entry->d_name);
            if (ph_dct_imagehash(path, tmphash) < 0)  // calculate the hash
                continue;
            dp = ph_malloc_imagepoint();  // store in structure with file name
            dp->id = dir_entry->d_name;
            dp->hash = tmphash;
            hashlist1.push_back(*dp);
            i++;
        }
        errno = 0;
        path[0] = '\0';
    }

    if (errno) {
        printf("error reading directory\n");
        exit(1);
    }

    sort(hashlist1.begin(), hashlist1.end(), cmp_lt_imp);

    // second directory
    dir_entry = NULL;
    DIR *dir2 = opendir(dir_name2);
    if (!dir) {
        printf("unable to open directory\n");
        exit(1);
    }
    errno = 0;
    path[0] = '\0';
    i = 0;
    while ((dir_entry = readdir(dir2)) != 0) {
        if (strcmp(dir_entry->d_name, ".") && strcmp(dir_entry->d_name, "..")) {
            strcat(path, dir_name2);
            strcat(path, "/");
            strcat(path, dir_entry->d_name);
            if (ph_dct_imagehash(path, tmphash) < 0)  // calculate the hash
                continue;
            dp = ph_malloc_imagepoint();  // store in structure with filename
            dp->id = dir_entry->d_name;
            dp->hash = tmphash;
            hashlist2.push_back(*dp);
            i++;
        }
        errno = 0;
        path[0] = '\0';
    }

    if (errno) {
        printf("error reading directory\n");
        exit(1);
    }

    sort(hashlist2.begin(), hashlist2.end(), cmp_lt_imp);

    int nbfiles1 = hashlist1.size();
    int nbfiles2 = hashlist2.size();
    int nbfiles = nbfiles1;
    if (nbfiles1 != nbfiles2) {
        nbfiles = (nbfiles2 > nbfiles1) ? nbfiles2 : nbfiles1;
    }

    int distance = -1;
    printf("**************************\n");
    printf("intra distance comparisons\n");
    printf("**************************\n");
    for (i = 0; i < nbfiles; i++) {
        printf(" %d %s %s ", i, hashlist1[i].id, hashlist2[i].id);

        // calculate distance
        distance = ph_hamming_distance(hashlist1[i].hash, hashlist2[i].hash);

        printf(" dist = %d\n", distance);
    }

    printf("**************************\n");
    printf("inter distance comparisons\n");
    printf("**************************\n");
    for (i = 0; i < nbfiles1; i++) {
        for (int j = i + 1; j < nbfiles1; j++) {
            printf(" %s %s ", hashlist1[i].id, hashlist1[j].id);

            // calculate distance
            distance =
                ph_hamming_distance(hashlist1[i].hash, hashlist1[j].hash);

            printf(" dist = %d\n", distance);
        }
    }
    printf("**************************\n");

    return 0;
}