#include <stdio.h>
#include <ctype.h>
#include <math.h>

typedef struct {
    int id;
    char name[100];
    char document[14];
    float testGrade;
} Candidate;

typedef struct {
    int id;
    float testGrade;
} Grade;

FILE * openFile(char filename[100], char filemode[3]) {
    FILE *p = fopen(filename, filemode);

    if (!p) {
        printf("Error to open %s file. \nThe program will be closed.",filename);
        exit(1);
    }
}


void addCandidate(int newId, int numbersOfNewCandidate, char candidateFilename[100], char gradeFilename[100]) {
    int counter = 0;
    float testGrade = 0;

    Candidate*candidate;
    candidate= malloc(sizeof(Candidate) * numbersOfNewCandidate);

    Grade *grade;
    grade= malloc(sizeof(Grade) * numbersOfNewCandidate);

    for(;counter< numbersOfNewCandidate; counter++) {
        system("@cls||clear");
        printf("Adding  #%d:",newId);
        printf("\n---------------\n");

        printf("\nName of candidate: ");
        gets(&candidate[counter].name);

        printf("\nDocument: ");
        gets(&candidate[counter].document);

        do {
            printf("\nTest grade (between 0 and 10): ");
            scanf("%f",&testGrade);
            printf("\n---------------\n");

            if (testGrade < 0 || testGrade > 10) {
                printf("\nERROR!\nTest grade %.2f invalid, please try again with a grade between 0 and 10.\n",testGrade);
            }

        } while(testGrade < 0 || testGrade > 10);

        candidate[counter].id = newId;
        grade[counter].id = newId;
        candidate[counter].testGrade = testGrade;
        grade[counter].testGrate = testGrade;
        newId++;
        fflush(stdin);
    }

    FILE *candidateFile = openFile(candidateFilename, "a+b");
    fwrite(candidate, sizeof(candidate),numbersOfNewCandidate, candidateFile );

    FILE *gradeFile = openFile(gradeFilename, "a+b");
    fwrite(grade, sizeof(grade),numbersOfNewCandidate, gradeFile );

    fclose(candidateFile);
    fclose(gradeFile);

    free(candidate);
    free(grade);
}

void showCandidate(int typeOfSearch, char valueToSearch[100]) {}

void listAllCandidates(char candid[100]) {
    FILE *fp = openFile(candidateFilename, "rb");

    //fseek(fp,0,SEEK_SET);

    Candidate *candidate = NULL;

    candidate = malloc(sizeof(Candidate) + 1);

    while(fread(&candidate,sizeof(Candidate),1,fp) == 1) {
        printf("\n\nId: %d \nName: %s \nDocument: %s \nGrade: %.2f",candidate->id,candidate->name,candidate->document, candidate->testGrade);
    }
    getche();
    free(candidate);
}

void main(){
    int lastId = 0;
    char candidateFilename[100] = "candidates.bin";
    char gradeFilename[100] = "classificationList.bin";
    char option;

    do {
        system("@cls||clear");
        printf("Menu: \n");
        printf("1 - Add candidates \n");
        // printf("2 - Search by name \n");
        // printf("3 - Search by document  \n");
        // printf("---------------------------\n");
        // printf("4 - Show Max Grade, Minimum, Avg \n");
        printf("5 - List candidates \n");
        printf("6 - Erase files \n");
        printf("---------------------------\n");
        printf("S - Exit \n");
        printf("\n\n");

        option = toupper(getche());

        switch(option) {
            case '1':
                system("@cls||clear");

                int numbersOfNewCandidate = 0;
                int newId = 0;

                printf("Home > Add candidates\n\n");
                printf("Please give the number of new candidates: ");
                scanf("%d",&numbersOfNewCandidate);
                newId = lastId;
                lastId += numbersOfNewCandidate;

                fflush(stdin);
                addCandidate(newId + 1, numbersOfNewCandidate, candidateFilename, gradeFilename);

                printf("\n\nAdding new candidates: Finished \n");
            break;
            // case '2':
            //     printf("\noption %c@\n",option);
            // break;
            // case '3':
            //     printf("\noption %c#\n",option);
            // break;
            // case '4':
            //     printf("\noption %c?\n",option);
            // break;
            case '5':
                listAllCandidates(candidateFilename);
            break;
            case '6':
                remove(candidateFilename);
                remove(gradeFilename);
                printf("\nRemoved!!\n");
            break;
            case 'S':
                printf("\noption %c, the program will be ended...\n",option);
            break;
            default:
                printf("\nWrong option!!\n");
            break;
        }
    } while (option != 'S');
}