#include "heap4_common.h"

static uint8_t heap_area[192];
static HeapBlock start;
static HeapBlock *end_marker;

volatile int g_free_count;
volatile size_t g_merged_size;
volatile int g_merged_with_right;

static void insert_block_merge(HeapBlock *block)
{
    HeapBlock *iterator;
    uint8_t *block_end;

    for (iterator = &start; iterator->next < block; iterator = iterator->next)
        ;

    block_end = (uint8_t *)block + block->size;
    if (block_end == (uint8_t *)iterator->next) {
        block->size += iterator->next->size;
        block->next = iterator->next->next;
    } else {
        block->next = iterator->next;
    }

    if (iterator != &start && heap4_blocks_touch(iterator, block)) {
        iterator->size += block->size;
        iterator->next = block->next;
    } else {
        iterator->next = block;
    }
}

static int count_free(void)
{
    HeapBlock *block;
    int count;

    count = 0;
    for (block = start.next; block != end_marker; block = block->next)
        count++;
    return count;
}

int main(void)
{
    HeapBlock *left;
    HeapBlock *middle;
    HeapBlock *right;

    left = (HeapBlock *)&heap_area[0];
    middle = (HeapBlock *)&heap_area[48];
    right = (HeapBlock *)&heap_area[96];
    end_marker = (HeapBlock *)&heap_area[160];

    start.next = left;
    left->next = right;
    right->next = end_marker;
    end_marker->next = 0;

    left->size = 48U;
    middle->size = 48U;
    right->size = 64U;
    end_marker->size = 0U;

    insert_block_merge(middle);

    g_free_count = count_free();
    g_merged_size = start.next->size;
    g_merged_with_right = start.next->next == end_marker;

    TRACE_PRINTF("count=%d size=%u merged_right=%d\n",
                 g_free_count, (unsigned)g_merged_size, g_merged_with_right);
    return 0;
}