/*-
 * Copyright (c) 2014-2021 Carsten Sonne Larsen <cs@innolan.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Project homepage:
 * https://amath.innolan.net
 *
 */

#include "amathc.h"

#if defined(AMIGA)
#include <stddef.h>
#include <exec/types.h>
#include <exec/memory.h>
#include <exec/semaphores.h>
#include <clib/exec_protos.h>
#define ALLOC_LIST(x) AllocVec(x, MEMF_ANY | MEMF_CLEAR)
#define FREE_LIST(x) FreeVec(x)
#define ALLOC_MEM(x, y) AllocPooledZero(x, y)
#define FREE_MEM(x, y, z) FreePooled(x, y, z)
#define Debug(x, y, z)
#else
#include <stdlib.h>
#define ALLOC_LIST(x) calloc(1L, x)
#define FREE_LIST(x) free(x)
#define ALLOC_MEM(x, y) calloc(1L, y)
#define FREE_MEM(x, y, z) free(y)
#define Debug(x, y, z)
#endif

#if defined(__x86_64__) || defined(__aarch64__) || \
    defined(_M_AMD64) || defined(_M_ARM64) ||      \
    defined(__powerpc64__)
#define P64BIT
#endif

/**
 * @brief Block of allocated memory.
 */
struct MemoryBlock
{
    struct MemoryBlock *next;
    size_t size;
    void *address;
};

/**
 * @brief List of allocated memory. Uses the LIFO principle.
 */
struct MemoryList
{
    struct MemoryBlock *first;
    void *pool;
    size_t peak;
    size_t size;
    long count;
};

/**
 * @brief Global list of allocated memory.
 */
struct MemoryList *list = nullptr;

void alloc_error(char *, size_t);
void dealloc_error(char *, void *);

#if defined(AMIGA)

static void MemZero(void *address, ULONG size)
{
    char *c = (char *)address;
    int n = size;
    do
    {
        *c++ = '\0';
    } while (--n);
}

static void *AllocPooledZero(void *pool, size_t size)
{
    ULONG memSize = (ULONG)size;
    void *memory = AllocPooled(pool, memSize);
    if (memory != NULL)
    {
        MemZero(memory, memSize);
    }
    return memory;
}

#endif

/**
 * @brief Allocate memory and add it to the global memory list.
 */
void *AllocMemSafe(size_t size)
{
    struct MemoryBlock *newblock;
    size_t allocsize;

    if (list == nullptr)
    {
        list = (struct MemoryList *)ALLOC_LIST(sizeof(struct MemoryList));
        if (!list)
        {
            alloc_error("list", sizeof(struct MemoryList));
            return 0;
        }

#if defined(AMIGA)
        list->pool = CreatePool(MEMF_ANY, 4096, 512);
#endif
        list->first = nullptr;
        list->peak = 0;
        list->size = 0;
        list->count = 0;
    }

#ifdef P64BIT
    // Align to bytes of 8, remove 0 bytes allocations
    allocsize = (size + 8) & ~0x07;
#else
    // Align to bytes of 4, remove 0 bytes allocations
    allocsize = (size + 4) & ~0x03;
#endif

    newblock = (struct MemoryBlock *)ALLOC_MEM(list->pool, sizeof(struct MemoryBlock));
    if (newblock == NULL)
    {
        alloc_error("block", sizeof(struct MemoryBlock));
        return 0;
    }

    newblock->address = (struct MemoryBlock *)ALLOC_MEM(list->pool, allocsize);
    if (newblock->address == NULL)
    {
        FREE_MEM(list->pool, newblock, sizeof(struct MemoryBlock));
        alloc_error("memory", allocsize);
        return 0;
    }

    newblock->size = allocsize;
    newblock->next = list->first;
    list->first = newblock;
    list->size += allocsize;
    list->count++;

    if (list->size > list->peak)
    {
        list->peak = list->size;
    }

    // Memory allocated
    return newblock->address;
}

void RemoveMemSafe(void *block, bool deallocate)
{
    struct MemoryBlock *current, *previous;

    if (list == nullptr || block == nullptr)
    {
        dealloc_error("list", 0);
        return;
    }

    if (block == nullptr)
    {
        dealloc_error("memory", 0);
        return;
    }

    previous = nullptr;
    current = list->first;
    while (current != nullptr && current->address != block)
    {
        previous = current;
        current = current->next;
    }

    if (current == nullptr)
    {
        dealloc_error("address not found", block);
        return;
    }

    if (previous == nullptr)
    {
        list->first = current->next;
    }
    else
    {
        previous->next = current->next;
    }

    list->size -= current->size;
    list->count--;

    if (deallocate)
    {
        FREE_MEM(list->pool, current->address, current->size);
    }

    current->address = nullptr;
    current->next = nullptr;
    current->size = 0;
    FREE_MEM(list->pool, current, sizeof(struct MemoryBlock));
}

/**
 * @brief Deallocate memory from the global memory list.
 */
void FreeMemSafe(void *block)
{
    RemoveMemSafe(block, true);
}

/**
 * @brief   Detach an allocated memory from the global memory list.
 * @details The memory block is only detached, not deallocated.
 */
void DetachMemSafe(void *block)
{
    RemoveMemSafe(block, false);
}

/**
 * @brief Deallocate all memory in the global memory list.
 */
void FreeAllSafe()
{
    struct MemoryBlock *current, *next;

    if (list == nullptr)
    {
        return;
    }

    current = list->first;
    while (current != nullptr)
    {
        next = current->next;
        FREE_MEM(list->pool, current->address, current->size);
        FREE_MEM(list->pool, current, sizeof(struct MemoryBlock));
        current = next;
    }

#if defined(AMIGA)
    DeletePool(list->pool);
#endif

    FREE_LIST(list);
    list = nullptr;
}

/**
 * @brief Get memory usage in the global memory list.
 */
void MemUsage(long *blocks, long *size, long *peak)
{
    *blocks = list->count;
    *size = (long)list->size;
    *peak = (long)list->peak;
    ;
}

/**
 * @brief Log a memory allocation error
 */
void alloc_error(char *descr, size_t size)
{
    Debug("Memory allocation error (%s) with size (%d)\n", descr, size);
    //if (size == 0)
    //    exit(10);
}

/**
 * @brief Log a memory deallocation error
 */
void dealloc_error(char *descr, void *p)
{
    Debug("Memory deallocation error (%s) address (%x)\n", descr, p);
}