#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int chooseStock();
void newStock();
void item_menu(char fileName[20], FILE *fp);

struct item newItem(char fileName[20], FILE *fp);
void searchItem(FILE *fp);
void updateItem(char fileName[20], FILE *fp);



struct item {
    int number; //item.number
    char name[20]; //item.name
    float price; //item.price
    int amount; //item.amount
};

int main()
{
    int answer;

    //Main Menu
    while(1) {
        system("cls");
        printf("Main Menu:\n\n"); //Utveckla. Skriv text.
        printf("(1) New Stock.\n");
        printf("(2) Choose Stock\n");
        printf("(3) Exit\n");
        fflush(stdin);
        scanf("%d", &answer);

        switch(answer) {
            case 1: newStock(); break;
            case 2: chooseStock(); break;
            case 3: return 0;
            default: printf("Please select a valid option");
        }
    }
    return 0;
}


void newStock() {
    int i;
    char fileName[20];
    FILE *fp;

    printf("What do you want to name your new stock?\n");
    fflush(stdin);
    gets(fileName);
    strcat(fileName, ".txt");

    if(fileName[0] == ' ')
        printf("Invalid File Name\n");

    for(i=0; i<20; i++)
        if(fileName[i] == ' ');
            fileName[i] = '\0';

    if((fp = fopen(fileName, "w")) == NULL)
        printf("Could not create file.");
    else {
        fclose(fp);
        rewind(fp);
        item_menu(fileName, fp);
    }
}

int chooseStock() {

    char fileName[20];
    FILE *fp;

    printf("Name the file you want to open.\n");
    fflush(stdin);
    gets(fileName);
    strcat(fileName, ".txt");

    //Checks if first letter in filename is spacebar.
    if(fileName[0] == ' ')
        printf("Invalid File Name\n");

    //Checks if file exists.
    if((fp = fopen(fileName, "r")) == NULL) {
        printf("File does not exist.\n");
        printf("Press any key to get back to Main Menu.\n");
        getch();
        return 0;
    }
    fclose(fp);
    rewind(fp);
    item_menu(fileName, fp);
    return 0;
}

void item_menu(char fileName[20], FILE *fp) {

    int answer;
    int menu = 1;
    int i = 0;
    struct item itemsInStock[100];

   //Menu 1
    while(1) {

        if((fp = fopen(fileName, "r")) == NULL) {
            printf("Could not open file.");
        }

        system("cls");
        printf("(1) Add Item\n");
        printf("(2) Update Item\n");
        printf("(3) Remove Item\n");
        printf("(4) Search For An Item\n");
        printf("(5) Statistics\n");
        printf("(6) Main Menu\n");
        fflush(stdin);
        scanf("%d", &answer);

        switch(answer) {
            case 1: fclose(fp); itemsInStock[i] = newItem(fileName, fp); break;
            case 2: updateItem(fileName, fp); break;
            case 3: removeItem(fileName, fp); break;
            case 4: searchItem(fp); break;
            default: ("Please select a valid option.\n");
        }
        rewind(fp);
        i++;
    }
}


struct item newItem(char fileName[20], FILE *fp) {

    struct item tempItem;

    if((fp = fopen(fileName, "a")) == NULL) {
        printf("Could not open file.");
    }

    printf("Insert name: ");
    fflush(stdin);
    gets(tempItem.name);

    printf("Insert price: ");

    while(1) {
        fflush(stdin);
        if(scanf("%f", &tempItem.price) == 0)
            printf("Please enter a number.\n");

        else
            break;
    }

    printf("Insert amount: ");

    while(1) {
        fflush(stdin);
        if(scanf("%d", &tempItem.amount) == 0)
            printf("Please enter a number.\n");

        else
            break;
    }

//    fprintf(fp, "Item %d:\n", idCounter+1);
    fprintf(fp, "%s\n", tempItem.name);
    fprintf(fp, "%.2f$\n", tempItem.price);
    fprintf(fp, "%d#\n\n", tempItem.amount);
//    fprintf(fp, "Item ID: %d\n\n", idCounter+1);
    fclose(fp);

    return tempItem;
}

void searchItem(FILE *fp) {

    char temp[20];
    char search[20];
    char tempChar;
    int i = 0;
    int lineCount[20];

    printf("Search: ");
    fflush(stdin);
    gets(search);
    lineCount[0] = 0;

    do
    {
        tempChar = fgetc(fp);

        if(tempChar == '\n')
        {
            temp[i] = '\0';

            if(strcmp(temp,search) == 0)
            {
                lineCount[0] = 1;
                i = 0;
                do
                {
                    tempChar = fgetc(fp);
                    temp[i] = tempChar;
                    i++;

                } while(tempChar != '$');

                temp[i] = '\0';
                printf("Price: %s\n", temp);

                i = 0;
                fgetc(fp);
                 do
                {
                    tempChar = fgetc(fp);
                    temp[i] = tempChar;
                    i++;
                } while(tempChar != '#');

                i--;
                temp[i] = '\0';
                printf("Amount: %s\n", temp);
                getch();
                break;
            }
            i = 0;
        }

        else
        {
            temp[i] = tempChar;
            i++;
        }

    } while(tempChar != EOF);
}

void updateItem(char fileName[20], FILE *fp) {

    char item[20];
    char tempWord[50];
    char tempChar;
    char name[20];
    int answer;
    int i = 0;
    int tempLine = 1;
    int deleteLine = 0;
    int amount;
    float price;
    FILE *fp2;

    printf("What item do you want to change?");
    fflush(stdin);
    gets(item);

    rewind(fp);

    do
    {
        tempChar = fgetc(fp);

        if(tempChar == '\n')
        {
            tempLine++;
            tempWord[i] = '\0';

            if(strcmp(tempWord,item) == 0)
            {
                tempLine--;
                printf("Do you want to change the name, price or amount?\n");
                printf("(1) Name.\n");
                printf("(2) Price.\n");
                printf("(3) Amount.\n");
                scanf("%d", &answer);

                switch(answer) {
                    case 1: deleteLine = tempLine;
                            printf("New name: ");
                            fflush(stdin);
                            scanf("%s", name);
                            break;
                    case 2: deleteLine = tempLine + 1;
                            printf("New price: ");
                            fflush(stdin);
                            scanf("%f", &price);
                            break;
                    case 3: deleteLine = tempLine + 2;
                            printf("New amount: ");
                            fflush(stdin);
                            scanf("%d", &amount);
                            break;
                    default: ("Please select a valid option.\n");
                }

                printf("Delete Line: %d", deleteLine);
                getch();
                rewind(fp);
                fp2 = fopen("tempfile.c", "w");
                tempLine = 1;
                i = 0;

                switch(answer){
                case 1: do
                        {
                            tempChar = fgetc(fp);

                            if(tempChar == EOF)
                            break;

                            if(tempChar == '\n')
                                tempLine++;

                            if(tempLine == deleteLine && i == 0){
                                fprintf(fp2, "\n");
                                fprintf(fp2, "%s", name);
                                i = 1;
                            }
                            else if(tempLine == deleteLine)
                                ;
                            else
                                putc(tempChar, fp2);

                        } while(tempChar != EOF);

                case 2: do
                        {
                            tempChar = fgetc(fp);

                            if(tempChar == EOF)
                            break;

                            if(tempChar == '\n')
                                tempLine++;

                            if(tempLine == deleteLine && i == 0){
                                fprintf(fp2, "\n");
                                fprintf(fp2, "%.2f$", price);
                                i = 1;
                            }
                            else if(tempLine == deleteLine)
                                ;
                            else
                                putc(tempChar, fp2);

                        } while(tempChar != EOF);

                case 3: do
                        {
                            tempChar = fgetc(fp);

                            if(tempChar == EOF)
                            break;

                            if(tempChar == '\n')
                                tempLine++;

                            if(tempLine == deleteLine && i == 0){
                                fprintf(fp2, "\n");
                                fprintf(fp2, "%d#", amount);
                                i = 1;
                            }
                            else if(tempLine == deleteLine)
                                ;
                            else
                                putc(tempChar, fp2);

                        } while(tempChar != EOF);
                    }

                rewind(fp);
                rewind(fp2);
                fclose(fp);
                fclose(fp2);
                remove(fileName);
                rename("tempfile.c", fileName);
            }
            i = 0;
        }

        else
        {
            tempWord[i] = tempChar;
            i++;
        }

    } while(tempChar != EOF);

    if(deleteLine == 0)
        printf("Sorry! There is no item named %c%s%c in this stock.\n", 34, item, 34);

    fclose(fp);
}

void removeItem(char fileName[20], FILE *fp) {

    char item[20];
    char tempWord[50];
    char tempChar;
    char name[20];
    int answer;
    int i = 0;
    int tempLine = 1;
    int deleteLine = 0;
    int amount;
    float price;
    FILE *fp2;

    printf("What item do you want to remove?");
    fflush(stdin);
    gets(item);

    rewind(fp);

    do
    {
        tempChar = fgetc(fp);

        if(tempChar == '\n')
        {
            tempLine++;
            tempWord[i] = '\0';

            if(strcmp(tempWord,item) == 0)
            {
                deleteLine = tempLine;
                printf("Delete Line: %d", deleteLine);
                getch();
                rewind(fp);
                fp2 = fopen("tempfile.c", "w");
                tempLine = 1;
                i = 0;

                do
                {
                    tempChar = fgetc(fp);

                    if(tempChar == EOF)
                        break;

                    if(tempChar == '\n')
                        tempLine++;

                    if(tempLine != deleteLine && tempLine != (deleteLine + 1) && tempLine != (deleteLine - 1) && tempLine != (deleteLine + 2))
                        putc(tempChar, fp2);

                } while(tempChar != EOF);

                rewind(fp);
                rewind(fp2);
                fclose(fp);
                fclose(fp2);
                remove(fileName);
                rename("tempfile.c", fileName);
            }
            i = 0;
        }

        else
        {
            tempWord[i] = tempChar;
            i++;
        }

    } while(tempChar != EOF);

    if(deleteLine == 0)
        printf("Sorry! There is no item named %c%s%c in this stock.\n", 34, item, 34);

    fclose(fp);
}