/*-
 * 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.
 *
 */

#include <stddef.h>
#include <stdbool.h>
#include <exec/types.h>
#include <exec/memory.h>
#include <exec/semaphores.h>
#include <proto/exec.h>
#define ALLOC_MEM(x) AllocVec(x, MEMF_ANY | MEMF_CLEAR)
#define FREE_MEM(x) FreeVec(x)

#include "mem.h"
#include "log.h"

#include "logmod.h"
#define MODULENAME "Memory"
#define LogMemTrace(...) LogMemTrace(MODULENAME, __VA_ARGS__)
//#define MEM_TRACE 1

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

/*
 * Block of allocated memory.
 */
struct MemoryBlock
{
    struct MemoryBlock *next;
    size_t size;
    void *address;
    char *file;
    char *function;
    int line;
};

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

/*
 * Global list of allocated memory.
 */
volatile static struct MemoryList *list = NULL;

/*
 * Get the length of a null terminated string.
 */
int MemStrLen(const char *string)
{
    char *i = (char *)string;
    char *s = i;
    while (*i)
        i++;
    return (int)(i - s);
}

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

    if (size != NULL)
    {
        *size = (long)list->size;
    }

    if (peak != NULL)
    {
        *peak = (long)list->peak;
    }
}

/*
 * Log a memory allocation error.
 */
static void AllocationError(const char *descr, size_t size, const char *file, const char *function, int line)
{
    LogDebug("Memory allocation error (%s) from %s, %s, line %ld, %ld bytes",
             descr, function, file, line, (long)size);
}

/*
 * Log a memory deallocation error.
 */
static void DeAllocationError(const char *descr, void *p, const char *file, const char *function, int line)
{
    LogDebug("Memory deallocation error (%s) from %s, %s, line %ld at 0x%lx",
             descr, function, file, line, p);
}

static char *StrDupRaw(const char *s1)
{
    char *s2;
    size_t len = s1 != NULL ? MemStrLen(s1) : 1;
    s2 = ALLOC_MEM(++len);

    if (s2 == NULL)
    {
        return NULL;
    }

    CopyMem((void *)s1, s2, --len);
    return s2;
}

static void MemZero(void *address, size_t size)
{
    if (address == NULL || size == 0)
    {
        return;
    }

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

void InitMemSafe(void)
{
    volatile struct MemoryList *m = (volatile struct MemoryList *)ALLOC_MEM(sizeof(struct MemoryList));
    bool newList = false;

    if (m == NULL)
    {
        return;
    }

    Forbid();
    if (list == NULL)
    {
        list = m;
        ;
        list->first = NULL;
        list->peak = 0;
        list->size = 0;
        list->count = 0;
        newList = true;
    }
    Permit();

    if (newList && !list)
    {
        AllocationError("list", sizeof(struct MemoryList), __FILE__, __FUNCTION__, __LINE__);
    }

    if (!newList)
    {
        FREE_MEM((void *)m);
    }
}

/*
 * Allocate memory and add it to the global memory list.
 */
void *AllocMemTraced(size_t size, const char *file, const char *function, int line, bool trace)
{
    struct MemoryBlock *newblock;
#ifdef P64BIT // Align to bytes of 8
    size_t allocsize = (size + 7) & ~0x07;
#else // Align to bytes of 4
    size_t allocsize = (size + 3) & ~0x03;
#endif

    newblock = (struct MemoryBlock *)ALLOC_MEM(sizeof(struct MemoryBlock));
    if (!newblock)
    {
        AllocationError("block", sizeof(struct MemoryBlock), file, function, line);
        return 0;
    }

    newblock->address = (struct MemoryBlock *)ALLOC_MEM(allocsize);
    if (!newblock->address)
    {
        FREE_MEM(newblock);
        AllocationError("memory", allocsize, file, function, line);
        return 0;
    }

    newblock->size = allocsize;
    newblock->file = StrDupRaw(file);
    newblock->function = StrDupRaw(function);
    newblock->line = line;

    Forbid();
    newblock->next = list->first;
    list->first = newblock;
    list->size += allocsize;
    list->count++;
    if (list->size > list->peak)
    {
        list->peak = list->size;
    }
    Permit();

#ifdef MEM_TRACE
    if (trace)
    {
        LogMemTrace("[Memory] Allocated memory block from %s, %s, line %ld, %ld bytes at 0x%lx",
                    newblock->function, newblock->file, newblock->line,
                    newblock->size, newblock->address);
    }
#endif

    // Memory allocated
    return newblock->address;
}

static void RemoveMemSafe(void *block, const char *file, const char *function, int line, bool deallocate)
{
    struct MemoryBlock *current, *previous;
    bool found = true;

    if (list == NULL)
    {
        DeAllocationError("list", 0, file, function, line);
        return;
    }

    if (block == NULL)
    {
        DeAllocationError("block", 0, file, function, line);
        return;
    }

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

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

        list->size -= current->size;
        list->count--;
    }
    else
    {
        found = false;
    }
    Permit();

    if (found)
    {
#ifdef MEM_TRACE
        LogMemTrace("[Memory] Deallocated memory block from %s, %s, line %ld, %ld bytes at 0x%lx",
                    current->function, current->file, current->line,
                    current->size, current->address);
#endif

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

        if (current->file != NULL)
        {
            MemZero(current->file, MemStrLen(current->file));
            FREE_MEM(current->file);
        }

        if (current->function != NULL)
        {
            MemZero(current->function, MemStrLen(current->function));
            FREE_MEM(current->function);
        }

        MemZero(current, sizeof(struct MemoryBlock));
        FREE_MEM(current);
    }
    else
    {
        DeAllocationError("address not found", block, file, function, line);
    }
}

/*
 * Deallocate memory from the global memory list.
 */
void FreeMemTraced(void *block, const char *file, const char *function, int line)
{
    RemoveMemSafe(block, file, function, line, true);
}

void *MemDupTraced(const void *s1, size_t len, const char *file, const char *function, int line, bool trace)
{
    char *dup;
    dup = AllocMemTraced(len, file, function, line, trace);
    CopyMem((void *)s1, dup, len);
    return dup;
}

char *StrDupTraced(const char *s1, const char *file, const char *function, int line, bool trace)
{
    char *s2;
    size_t len = s1 != NULL ? MemStrLen(s1) : 1;
    s2 = AllocMemTraced(++len, file, function, line, trace);

    if (s2 == NULL)
    {
        return NULL;
    }

    CopyMem((void *)s1, s2, --len);
    return s2;
}

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

    Forbid();
    m = list;
    list = NULL;
    Permit();

    if (m == NULL)
    {
        return;
    }

    current = m->first;
    while (current != NULL)
    {
        if (current->file && current->function)
        {
            LogDebug("Released forgotten memory block from %s, %s, line %ld, %ld bytes at 0x%lx",
                     current->function, current->file, current->line,
                     (long)current->size, current->address);
        }
        else
        {
            LogDebug("Released forgotten memory block on %ld bytes at 0x%lx",
                     (long)current->size,
                     current->address);
        }

        next = current->next;

        MemZero(current->address, current->size);
        FREE_MEM(current->address);

        if (current->file != NULL)
        {
            MemZero(current->file, MemStrLen(current->file));
            FREE_MEM(current->file);
        }

        if (current->function != NULL)
        {
            MemZero(current->function, MemStrLen(current->function));
            FREE_MEM(current->function);
        }

        MemZero(current->file, sizeof(struct MemoryBlock));
        FREE_MEM(current);

        current = next;
    }

    LogDebug("Memory clear");
    FREE_MEM((void *)m);
}