/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * -----------------------------------------------------------------------------
 * File: Stack.c
 * Description:
 *  This file contains the functions for modifying the stack. It includes functions 
 *  to Push, Pop, Peek and check if empty.
 * 
 * Author: Mineplay
 * -----------------------------------------------------------------------------
 */
#include "../../Include/Fledasty/Core/Stack.h"

#include <Hallocy/Core/Allocator.h>
#include <Hallocy/Core/Memory.h>
#include <Hallocy/Utils/Error.h>

FledastyError fledasty_stack_initialize(FledastyStack *new_stack, void *values, const size_t values_size, const size_t element_byte_size) {
    if (new_stack == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    new_stack->element_byte_size = element_byte_size;
    if (values == NULL || values_size == 0) {
        new_stack->size = 0;
        new_stack->capacity = 10;

        new_stack->buffer = (unsigned char*)hallocy_malloc(new_stack->capacity * element_byte_size);
        if (new_stack->buffer == NULL) {
            return FLEDASTY_ERROR_FAILED_ALLOCATION;
        }
    } else {
        new_stack->size = values_size;
        new_stack->capacity = new_stack->size + new_stack->size;
        
        new_stack->buffer = (unsigned char*)hallocy_malloc(new_stack->capacity * element_byte_size);
        if (new_stack->buffer == NULL) {
            return FLEDASTY_ERROR_FAILED_ALLOCATION;
        }

        hallocy_copy_memory(new_stack->buffer, values, values_size * element_byte_size);
    }

    return FLEDASTY_ERROR_NONE;
}

FledastyError fledasty_stack_destroy(FledastyStack *current_stack) {
    if (current_stack == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    HallocyError result = hallocy_free(current_stack->buffer);
    if (result != HALLOCY_ERROR_NONE) {
        return FLEDASTY_ERROR_FAILED_ALLOCATION;
    }

    current_stack->buffer = NULL;
    return FLEDASTY_ERROR_NONE;
}

FledastyError fledasty_stack_push(FledastyStack *current_stack, void *value) {
    if (current_stack == NULL || value == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    if (current_stack->size == current_stack->capacity) {
        current_stack->capacity += current_stack->capacity;
        current_stack->buffer = (unsigned char*)hallocy_realloc(current_stack->buffer, current_stack->capacity);

        if (current_stack->buffer == NULL) {
            return FLEDASTY_ERROR_FAILED_ALLOCATION;
        }
    }

    hallocy_copy_memory(current_stack->buffer + (current_stack->size * current_stack->element_byte_size), value, current_stack->element_byte_size);
    current_stack->size += 1;

    return FLEDASTY_ERROR_NONE;
}

void *fledasty_stack_peek(const FledastyStack *current_stack) {
    if (current_stack == NULL) {
        return NULL;
    }

    return current_stack->buffer + ((current_stack->size - 1) * current_stack->element_byte_size);
}

void *fledasty_stack_pop(FledastyStack *current_stack) {
    if (current_stack == NULL) {
        return NULL;
    }

    void *value_address = current_stack->buffer + ((current_stack->size - 1) * current_stack->element_byte_size);
    current_stack->size -= 1;

    return value_address;
}

FledastyError fledasty_stack_clear(FledastyStack *current_stack) {
    if (current_stack == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    current_stack->size = 0;
    return FLEDASTY_ERROR_NONE;
}