#include "stdio.h"
#include "stdlib.h"
#include "string.h"

typedef struct S_RacingCar {

    char name[12];
    char place[12];
    int speed;
    struct S_RacingCar *next;
    struct S_RacingCar *previous;

} RacingCar;

void PrintList(RacingCar *start) {
    RacingCar *currentCar = start;
    int count = 0;

    RacingCar *ahead = NULL;
    RacingCar *behind = NULL;

    while(currentCar != NULL) {
        count++;

        ahead = currentCar->next;
        behind = currentCar->previous;

        printf("Car:%d Name:%s Place:%s Speed:%d Ahead:%s Behind:%s\n",count,
            currentCar->name,
            currentCar->place,
            currentCar->speed,
            (ahead == NULL) ? "None" : ahead->name,
            (behind == NULL) ? "None" : behind->name
            );
        currentCar = currentCar->next;
        ahead = NULL;
        behind = NULL;
    }
    printf("Total Cars:%d\n",count);
}

RacingCar *MakeNewCar() {

    printf("Enter Name, Place And Speed: ");
    char input[16];
    fgets( input, 15, stdin);

    RacingCar *newCar = malloc(sizeof(RacingCar));
    sscanf(input, "%s %s %d", newCar->name, newCar->place, &newCar->speed);
    printf("Added:%s Place:%s Speed:%d\n\n",newCar->name, newCar->place, newCar->speed);

    newCar->next = NULL;
    newCar->previous = NULL;

    return newCar;
}

RacingCar *AddToStart(RacingCar *startPtr) {
    RacingCar *newCar = MakeNewCar();
    if(startPtr != NULL) {
        startPtr->previous = newCar;
        newCar->next = startPtr;
    }

    return newCar;
}

RacingCar *AddToEnd(RacingCar *startPtr) {
    RacingCar *returnPtr = startPtr;
    RacingCar *newCar = NULL;

    if(startPtr == NULL) {
        newCar = AddToStart(startPtr);
        returnPtr = newCar;
    } else {
        RacingCar *indexCar = startPtr;
        while (indexCar->next != NULL) {
            indexCar = indexCar->next;
        }
        newCar = MakeNewCar();
        indexCar->next = newCar;
        newCar->next = NULL;
        newCar->previous = indexCar;
    }
    return returnPtr;
}

RacingCar *Delete(RacingCar *startPtr) {

    printf("Enter Name To Delete:");
    char input[16];
    fgets(input, 15, stdin);

    RacingCar *carRef = startPtr;
    RacingCar *carToDelete = NULL;

    while(carRef != NULL) {

        if(strncmp(input, carRef->name, strlen(carRef->name)) == 0) {
            carToDelete = carRef;
            break;
        }

        carRef = carRef->next;
    }

    if(startPtr != NULL && carToDelete == startPtr) {
        if(carToDelete->next != NULL) {
            carToDelete->next->previous = NULL;
            startPtr = carToDelete->next;
        } else {
            startPtr = NULL;
        }
    } else {
        if(carToDelete != NULL) {
            if(carToDelete->previous != NULL) {
                carToDelete->previous->next = carToDelete->next;
            }

            if(carToDelete->next != NULL) {
                carToDelete->next->previous = carToDelete->previous;
            }
        }
    }

    if(carToDelete != NULL) {
        carToDelete = NULL;
        free(carToDelete);
    }

    return startPtr;

}

RacingCar *Insert(RacingCar *startPtr) {
    printf("Insert New Car After Car:");
    char input[16];
    fgets(input, 15, stdin);

    RacingCar *afterCar = startPtr;
    RacingCar *newCar = NULL;

    if(strncmp(input, afterCar->name, strlen(afterCar->name)) == 0) {
        newCar = MakeNewCar();
    } else {
        while(afterCar->next != NULL) {
            afterCar = afterCar->next;
            if(strncmp(input, afterCar->name, strlen(afterCar->name)) == 0) {
                newCar = MakeNewCar();
                break;
            }
        }
    }

    if(newCar != NULL) {
        newCar->next = afterCar->next;
        if(newCar->next != NULL) {
            newCar->next->previous = newCar;
        }
        afterCar->next = newCar;
        newCar->previous = afterCar;
    } else {
        printf("Car Not Found\n");
    }

    return startPtr;
}

void CleanUp(RacingCar *start) {

    RacingCar *freeMe = start;
    RacingCar *holdMe = NULL;
    while(freeMe != NULL) {
        holdMe = freeMe->next;
        printf("Free Name:%s Place:%s Speed:%d\n",
            freeMe->name,
            freeMe->place,
            freeMe->speed);
        free(freeMe);
        freeMe = holdMe;
    }
}

void WriteListToFile(RacingCar *start) {
    FILE *pFile;
    pFile = fopen("myList.bin", "wb");

    if(pFile != NULL) {
        RacingCar *currentCar = start;

        RacingCar *holdNext = NULL;
        RacingCar *holdPrevious = NULL;

        while(currentCar != NULL) {
            holdNext = currentCar->next;
            holdPrevious = currentCar->previous;

            currentCar->next = NULL;
            currentCar->previous = NULL;

            fseek(pFile, 0, SEEK_END);
            fwrite(currentCar, sizeof(RacingCar), 1, pFile);

            printf("Writing:%s to file\n",currentCar->name);

            currentCar->next = holdNext;
            currentCar->previous = holdPrevious;

            holdNext = NULL;
            holdPrevious = NULL;

            currentCar = currentCar->next;
        }
        fclose(pFile);
        pFile = NULL;
    } else {
        printf("FILE OPEN ERROR\n");
    }

}

RacingCar *ReadNextFromFile(RacingCar *start, FILE *pFile) {
    size_t returnValue;
    if(start == NULL) {
        start = malloc(sizeof(RacingCar));
        returnValue = fread(start, sizeof(RacingCar), 1, pFile);
        start->next = NULL;
        start->previous = NULL;
    } else {
        RacingCar *indexCar = start;
        RacingCar *newCar = malloc(sizeof(RacingCar));
        while(indexCar->next != NULL) {
            indexCar = indexCar->next;
        }
        returnValue = fread(newCar, sizeof(RacingCar), 1, pFile);
        indexCar->next = newCar;
        newCar->next = NULL;
        newCar->previous = indexCar;
    }
    return start;
}

RacingCar *ReadNextFromFile_mod(RacingCar *start, FILE *pFile) {
    size_t returnValue;
    if(start == NULL) {
        start = malloc(sizeof(RacingCar));
        returnValue = fread(start, sizeof(RacingCar), 1, pFile);
        start->next = NULL;
        start->previous = NULL;
    } else {
        RacingCar *indexCar = start;
        RacingCar *newCar = malloc(sizeof(RacingCar));
        while(indexCar->next != NULL) {
            indexCar = indexCar->next;
        }
        RacingCar temp;
        returnValue = fread(&temp, sizeof temp, 1, pFile);
        if (returnValue != 1) {
            if (ferror(pFile)) {
                puts("Error reading from file");
            }
            return start;
        }

        if (strncmp(temp.place, "street", sizeof temp.place)) {
            return start;
        }
        indexCar->next = newCar;
        newCar->next = NULL;
        newCar->previous = indexCar;
    }
    return start;
}

RacingCar *ReadListIn(RacingCar *start) {

    FILE *pFile;
    pFile = fopen("myList.bin", "rb");
    if(pFile != NULL) {

        CleanUp(start);
        start = NULL;

        fseek(pFile, 0, SEEK_END);
        long fileSize = ftell(pFile);
        rewind(pFile);

        int numEntries = (int)(fileSize / (sizeof(RacingCar)));
        printf("numEntries:%d\n",numEntries);

        int loop = 0;
        for(loop = 0; loop < numEntries; ++loop) {
            fseek(pFile, (sizeof(RacingCar) * loop), SEEK_SET);
            start = ReadNextFromFile(start, pFile);
        }
    }  else {
        printf("FILE OPEN ERROR FOR READ\n");
    }

    return start;

}

RacingCar *ReadListIn_mod(RacingCar *start) {

    FILE *pFile;
    pFile = fopen("myList.bin", "rb");
    if(pFile != NULL) {

        CleanUp(start);
        start = NULL;

        fseek(pFile, 0, SEEK_END);
        long fileSize = ftell(pFile);
        rewind(pFile);

        int numEntries = (int)(fileSize / (sizeof(RacingCar)));
        printf("numEntries:%d\n",numEntries);

        int loop = 0;
        for(loop = 0; loop < numEntries; ++loop) {
            fseek(pFile, (sizeof(RacingCar) * loop), SEEK_SET);
            start = ReadNextFromFile_mod(start, pFile);
        }
    }  else {
        printf("FILE OPEN ERROR FOR READ\n");
    }

    return start;

}

int main() {

    char command[16];
    char input[16];

    RacingCar *start = NULL;

    while( fgets( input, 15, stdin) ) {

        sscanf(input,"%s",command);

        if ( strncmp(command, "quit", 4) == 0) {
            printf("\n\nBreaking...\n");
            break;
        } else if ( strncmp(command, "print", 5) == 0) {
            PrintList(start);
        } else if ( strncmp(command, "write", 5) == 0) {
            WriteListToFile(start);
        } else if ( strncmp(command, "read", 4) == 0) {
            start = ReadListIn_mod(start);
        } else if ( strncmp(command, "addstart", 8) == 0) {
            start = AddToStart(start);
            PrintList(start);
        } else if ( strncmp(command, "add", 3) == 0) {
            start = AddToEnd(start);
            PrintList(start);
        } else if ( strncmp(command, "insert", 6) == 0) {
            if(start == NULL) {
                start = AddToStart(start);
            } else {
                start = Insert(start);
            }
            PrintList(start);
        }
    }

    CleanUp(start);

    return 0;

}