#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>

typedef char String[50];

typedef struct Node{

    String filename;
    int instances;
    struct Node* nextNode;

}Filenode;

void toLowerCase(String text){

    int i;

    for(i = 0 ; text[i] ; i++){
        if(text[i] >= 65 && text[i] <= 90){
            text[i] += 32;
        }
    }

}

int search(String filename, String keyword){

    FILE *fp;
    String phrase;
    int found = 0;

    fp = fopen(filename,"r");

    if(fp == NULL){
        printf("\n### FILE NOT FOUND ###\n");
    }else{

    while(fscanf(fp, "%s", phrase) == 1){
        //printf("%s",phrase);
        toLowerCase(phrase);
        toLowerCase(keyword);
        if(strstr(phrase, keyword) != NULL){
            found++;
            //printf(" +++ hit");
        }
        //printf("\n");
    }

    }

    fclose(fp);

    return found;

}

void newFilenode(String filename, int instances, Filenode** filelist){

    Filenode* newNode = malloc(sizeof(Filenode));
    strcpy(newNode->filename,filename);
    newNode->instances = instances;
    newNode->nextNode = *filelist;
    *filelist = newNode;

}

void traverse(String pathname, String oldpathname, String keyword, Filenode** filelist){

  chdir(pathname);

  DIR *d = opendir(".");
  struct dirent *dir;

  if (d){

    while ((dir = readdir(d)) != NULL){

        if(!(strcmp(dir->d_name,".") == 0)&&!(strcmp(dir->d_name,"..") == 0)){

            //printf("%s", dir->d_name);

            char *fi = dir->d_name;
            struct stat fileinfo;

            int status = stat(fi, &fileinfo);

            if (status != 0) {
                return;
            }

            if (S_ISDIR (fileinfo.st_mode)) {

               String newpathname;
               strcpy(newpathname, pathname);
               strcat(newpathname,"\\");
               strcat(newpathname,dir->d_name);

               traverse(newpathname,pathname,keyword,filelist);

            }else if (S_ISREG (fileinfo.st_mode)) {

               //printf (" - FILE\n");
               //printf("### %d hits ###\n",search(dir->d_name,keyword));
               int instances = search(dir->d_name,keyword);

               if(instances > 0){

                String newpathname;
                strcpy(newpathname, pathname);
                strcat(newpathname,"\\");
                strcat(newpathname,dir->d_name);

                newFilenode(newpathname,instances,filelist);

               }

            }else{

               //printf(" - ???\n");

            }

        }

    }

    closedir(d);

  }

    chdir(oldpathname);

}

int main(){

    String keyword;
    String pathname;
    Filenode* filelist = NULL;

    printf("Pathname: ");
    scanf("%s",pathname);

    printf("Keyword: ");
    scanf("%s",keyword);

    traverse(pathname,"C:\\",keyword,&filelist);

    if(filelist != NULL){

        while(filelist != NULL){

            printf("\nPath: %s\n",filelist->filename);
            printf("Number of instances: %d\n",filelist->instances);
            filelist = filelist->nextNode;

        }

    }

    return 0;

}