#include "list.h"
#include <groundext.h>
#include <groundvm.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

const uint8_t STARTING_ELEMENTS = 2;


GroundValue appendToListStruct(GroundScope* scope, List args) {
    GroundValue newValue = args.values[0];

    // grab fields we need from struct
    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }

    GroundVariable* memSizeField = groundFindVariable(scope, "memSize");
    if (memSizeField == NULL) {
        ERROR("A field called \"memSize\" was not found", "FieldNotFound");
    }

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    GroundVariable* capacityField = groundFindVariable(scope, "capacity");
    if (capacityField == NULL) {
        ERROR("A field called \"capacity\" was not found", "FieldNotFound");
    }
    int64_t capacity = capacityField->value.data.intVal;

    sizeField->value.data.intVal++;

    if (capacity <= sizeField->value.data.intVal) {
        capacity *= 2;
        capacityField->value.data.intVal = capacity;

        uint64_t newSize = sizeof(GroundValue) * capacity;
        memSizeField->value.data.intVal = newSize;

        items = realloc(items, newSize);
        if (items == NULL) {
            ERROR("Failed to allocate memory when increasing list size!", "MemoryAllocationFailed");
        }

        ptrField->value.data.intVal = (int64_t)items;
    }

    items[sizeField->value.data.intVal - 1] = newValue;

    return groundCreateValue(INT, 0);
}

GroundValue listStructAt(GroundScope* scope, List args) {

    uint64_t index = args.values[0].data.intVal;
    if (index < 0) {
        ERROR("Attempt to access list at negative index", "OutOfBounds");
    }

    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    int64_t size = sizeField->value.data.intVal;
    if (index >= size) {
        char buffer[512];
        sprintf(buffer, "Attempt to access list at index %ld when list is of length %ld", index, size);
        ERROR(buffer, "OutOfBounds");
    }

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    return items[index];
}

GroundValue listStructToString(GroundScope* scope, List args) {
    return groundCreateValue(STRING, "TODO");
}

GroundValue clearListStruct(GroundScope* scope, List args) {
    // grab fields we need from struct
    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }

    GroundVariable* memSizeField = groundFindVariable(scope, "memSize");
    if (memSizeField == NULL) {
        ERROR("A field called \"memSize\" was not found", "FieldNotFound");
    }

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }

    GroundVariable* capacityField = groundFindVariable(scope, "capacity");
    if (capacityField == NULL) {
        ERROR("A field called \"capacity\" was not found", "FieldNotFound");
    }

    GroundValue* newBuffer = calloc(STARTING_ELEMENTS, sizeof(GroundValue));
    if (newBuffer == NULL) {
        ERROR("Failed to allocate memory when clearing list!", "MemoryAllocationFailed");
    }

    sizeField->value.data.intVal = 0;
    ptrField->value.data.intVal = (int64_t)newBuffer;
    capacityField->value.data.intVal = STARTING_ELEMENTS;
    memSizeField->value.data.intVal = sizeof(GroundValue) * STARTING_ELEMENTS;

    return groundCreateValue(INT, 0);
}

GroundValue insertIntoListStruct(GroundScope* scope, List args) {
    GroundValue value = args.values[0];
    uint64_t index = args.values[1].data.intVal;
    if (index < 0) {
        ERROR("Attempt to insert element into list at negative index", "OutOfBounds");
    }

    // grab fields we need from struct
    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    
    GroundVariable* memSizeField = groundFindVariable(scope, "memSize");
    if (memSizeField == NULL) {
        ERROR("A field called \"memSize\" was not found", "FieldNotFound");
    }

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    GroundVariable* capacityField = groundFindVariable(scope, "capacity");
    if (capacityField == NULL) {
        ERROR("A field called \"capacity\" was not found", "FieldNotFound");
    }
    int64_t capacity = capacityField->value.data.intVal;

    
    if (sizeField->value.data.intVal <= index) {
        sizeField->value.data.intVal = index+1;
    } else {
        sizeField->value.data.intVal++;
    }

    // check if we have enough space to insert the element
    if (capacity <= sizeField->value.data.intVal+1) {
        // not enough space, double size
        capacity = sizeField->value.data.intVal + 1;
        capacityField->value.data.intVal = capacity;
    }

    // allocate new buffer
    GroundValue* newBuffer = calloc(capacity, sizeof(GroundValue));
    if (newBuffer == NULL) {
        ERROR("Failed to allocate memory when increasing list size!", "MemoryAllocationFailed");
    }
    ptrField->value.data.intVal = (int64_t)newBuffer;
    memSizeField->value.data.intVal = sizeof(GroundValue) * capacity;

    // copy elements from 0 to i-1 into new buffer
    memcpy(newBuffer, items, sizeof(GroundValue) * index);
    // insert element at i
    newBuffer[index] = value;
    // copy elements 0 to i+1 into new buffer
    memcpy(newBuffer + (index+1), items + index, sizeof(GroundValue) * (sizeField->value.data.intVal - index));

    // free older buffer
    free(items);

    // retur null
    return groundCreateValue(INT, 0);
}

GroundValue listStructDelete(GroundScope* scope, List args) {
    uint64_t index = args.values[0].data.intVal;
    if (index < 0) {
        ERROR("Attempt to remove element into list at negative index", "OutOfBounds");
    }

    // grab fields we need from struct
    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    

    GroundVariable* memSizeField = groundFindVariable(scope, "memSize");
    if (memSizeField == NULL) {
        ERROR("A field called \"memSize\" was not found", "FieldNotFound");
    }

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    GroundVariable* capacityField = groundFindVariable(scope, "capacity");
    if (capacityField == NULL) {
        ERROR("A field called \"capacity\" was not found", "FieldNotFound");
    }
    int64_t capacity = capacityField->value.data.intVal;

    printf("size = %ld, index = %ld\n", sizeField->value.data.intVal, index);
    if (sizeField->value.data.intVal < index) {
        char buffer[512];
        sprintf(buffer, "Attempt to delete element at index %ld when list is of size %ld", index, sizeField->value.data.intVal);
        ERROR(buffer, "OutOfBounds");
    } else {
        sizeField->value.data.intVal--;
    }

    int64_t size = sizeField->value.data.intVal;

    // check if we have enough space to insert the element
    if (capacity > size+1) {
        // too much space, make list smaller
        capacity = size + 1;
        capacityField->value.data.intVal = capacity;
    }

    // allocate new buffer
    GroundValue* newBuffer = calloc(capacity, sizeof(GroundValue));
    if (newBuffer == NULL) {
        ERROR("Failed to allocate memory when decreasing list size!", "MemoryAllocationFailed");
    }
    ptrField->value.data.intVal = (int64_t)newBuffer;
    memSizeField->value.data.intVal = sizeof(GroundValue) * capacity;

    // copy elements from 0 to i-1 into new buffer    
    if (index > 0)
        memcpy(newBuffer, items, sizeof(GroundValue) * index);
    // copy elements 0 to i+1 into new buffer
    if (index < size)
        memcpy(newBuffer + index, items + index + 1, sizeof(GroundValue) * (size - index));
    

    // free older buffer
    free(items);

    // retur null
    return groundCreateValue(INT, 0);
}

GroundValue listStructSet(GroundScope* scope, List args) {
    GroundValue value = args.values[0];
    uint64_t index = args.values[1].data.intVal;
    if (index < 0) {
        ERROR("Attempt to set element in list at negative index", "OutOfBounds");
    }

    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    int64_t size = sizeField->value.data.intVal;

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    if (index >= size) {
        insertIntoListStruct(scope, args);
    } else {
        items[index] = value;
    }

    return groundCreateValue(INT, 0);
}

GroundValue listStructIsEmpty(GroundScope* scope, List args) {
    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    int64_t size = sizeField->value.data.intVal;

    return groundCreateValue(BOOL, size <= 0);
}

bool areGroundValuesEqual(GroundValue a, GroundValue b) {
    if (a.type != b.type) {

        if (a.type == INT && b.type == DOUBLE) {
            return a.data.intVal == b.data.doubleVal;
        } else if (a.type == DOUBLE && b.type == INT) {
            return a.data.doubleVal == b.data.intVal;
        }

    } else {
        switch (a.type) {
            case INT:
                return a.data.intVal == b.data.intVal;
            case DOUBLE:
                return a.data.doubleVal == b.data.doubleVal;
            case BOOL:
                return a.data.boolVal == b.data.boolVal;
            case CHAR:
                return a.data.charVal == b.data.charVal;
            case STRING:
                return strcmp(a.data.stringVal, b.data.stringVal) == 0;
            default:
                return false;
        }
    }

    return false;
}

GroundValue listStructContains(GroundScope* scope, List args) {
    GroundValue targetValue = args.values[0];

    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    int64_t size = sizeField->value.data.intVal;

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    for (uint64_t i = 0; i < size; i++) {
        if (areGroundValuesEqual(items[i], targetValue)) {
            return groundCreateValue(BOOL, true);
        }
    }

    return groundCreateValue(BOOL, false);
}

GroundValue reverseListStruct(GroundScope* scope, List args) {
    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    int64_t size = sizeField->value.data.intVal;

    GroundVariable* capacityField = groundFindVariable(scope, "capacity");
    if (capacityField == NULL) {
        ERROR("A field called \"capacity\" was not found", "FieldNotFound");
    }
    int64_t capacity = capacityField->value.data.intVal;

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    GroundValue* newBuffer = calloc(capacity, sizeof(GroundValue));

    int z = 0;
    for (int i = size - 1; i >= 0; i--, z++) {
        newBuffer[z] = items[i];
    }

    ptrField->value.data.intVal = (int64_t)newBuffer;
    free(items);

    return groundCreateValue(INT, 0);
}

GroundValue findListStruct(GroundScope* scope, List args) {
    GroundValue targetValue = args.values[0];

    GroundVariable* sizeField = groundFindVariable(scope, "size");
    if (sizeField == NULL) {
        ERROR("A field called \"size\" was not found", "FieldNotFound");
    }
    int64_t size = sizeField->value.data.intVal;

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    for (uint64_t i = 0; i < size; i++) {
        if (areGroundValuesEqual(items[i], targetValue)) {
            return groundCreateValue(INT, i);
        }
    }

    return groundCreateValue(INT, (int64_t)-1);
}

GroundValue reserveListStruct(GroundScope* scope, List args) {
    int64_t amount = args.values[0].data.intVal;

    GroundVariable* capacityField = groundFindVariable(scope, "capacity");
    if (capacityField == NULL) {
        ERROR("A field called \"capacity\" was not found", "FieldNotFound");
    }
    int64_t capacity = capacityField->value.data.intVal;

    GroundVariable* ptrField = groundFindVariable(scope, "private_ptr");
    if (ptrField == NULL) {
        ERROR("A field called \"private_ptr\" was not found", "FieldNotFound");
    }
    GroundValue* items = (GroundValue*)ptrField->value.data.intVal;

    GroundVariable* memSizeField = groundFindVariable(scope, "memSize");
    if (memSizeField == NULL) {
        ERROR("A field called \"memSize\" was not found", "FieldNotFound");
    }

    if (capacity > amount) {
        return groundCreateValue(BOOL, false);
    }

    capacityField->value.data.intVal = amount;
    items = realloc(items, sizeof(GroundValue) * amount);
    if (items == NULL) {
        ERROR("Failed to allocate memory when reserving list space!", "MemoryAllocationFailed");
    }

    memSizeField->value.data.intVal = sizeof(GroundValue) * amount;

    return groundCreateValue(BOOL, true);
}

GroundValue createListStruct() {
    GroundStruct listStruct = groundCreateStruct();

    GroundValue* items = calloc(STARTING_ELEMENTS, sizeof(GroundValue));

    groundAddFieldToStruct(&listStruct, "size", groundCreateValue(INT, 0));                                                  // number of elements
    groundAddFieldToStruct(&listStruct, "memSize", groundCreateValue(INT, sizeof(GroundValue) * STARTING_ELEMENTS));         // number of bytes allocated
    groundAddFieldToStruct(&listStruct, "capacity", groundCreateValue(INT, STARTING_ELEMENTS));                              // number of elements that can fit in the currently allocated space
    groundAddFieldToStruct(&listStruct, "private_ptr", groundCreateValue(INT, items));                                       // pointer to internal list struct

    groundAddFunctionToStruct(&listStruct, "append", appendToListStruct, INT, 1, ANY, "value");                 // append item to end of list
    groundAddFunctionToStruct(&listStruct, "insert", insertIntoListStruct, INT, 2, ANY, "value", INT, "index"); // insert value at index
    groundAddFunctionToStruct(&listStruct, "remove", listStructDelete, INT, 1, INT, "index");                   // delete value at index
    groundAddFunctionToStruct(&listStruct, "at", listStructAt, ANY, 1, INT, "index");                           // get value at index
    groundAddFunctionToStruct(&listStruct, "clear", clearListStruct, INT, 0);                                   // clear list
    groundAddFunctionToStruct(&listStruct, "set", listStructSet, INT, 2, ANY, "value", INT, "index");           // replace a value at an index
    groundAddFunctionToStruct(&listStruct, "isEmpty", listStructIsEmpty, BOOL, 0);                              // returns true if list is empty, otherwise false
    groundAddFunctionToStruct(&listStruct, "contains", listStructContains, BOOL, 1, ANY, "value");              // returns true if value is in list
    groundAddFunctionToStruct(&listStruct, "reverse", reverseListStruct, INT, 0);                               // return list struct in reverse order
    groundAddFunctionToStruct(&listStruct, "find", findListStruct, INT, 1, ANY, "value");                       // return index of value in list, if not found, returns -1
    groundAddFunctionToStruct(&listStruct, "reserve", reserveListStruct, BOOL, 1, INT, "amount");               // ensure list capacity >= amount. returns true if the list's capacity was expanded

    return groundCreateValue(STRUCTVAL, listStruct);
}