/*
 * Copyright (c) 2026, Chloe M.
 * Provided under the BSD-3 clause.
 *
 * Description: Pool allocator
 * Author:      Chloe M.
 */

#include <ex/pool.h>
#include <ex/trace.h>
#include <mm/vmm.h>
#include <string.h>

#define DTRACE(Fmt, ...) \
    TRACE("[ POOL ]: " Fmt, ##__VA_ARGS__)

/* Globals */
static USIZE PoolCount = 0;

static ST_STATUS
PoolInitBlock(MEMORY_BLOCK *Block)
{
    if (Block == NULL) {
        return STATUS_INVALID_PARAM;
    }

    Block->FirstPage = MmAllocPages(1);
    if (Block->FirstPage == NULL) {
        return STATUS_NO_MEMORY;
    }

    Block->LastPage = Block->FirstPage;
    Block->PageCount = 1;
    RtlMemSet(Block->FirstPage, 0, PAGESIZE);
    return STATUS_SUCCESS;
}

ST_STATUS
ExPoolInit(MEMORY_POOL *Pool)
{
    UCHAR LevelIdx;
    MEMORY_BLOCK *Block;
    ST_STATUS Status;

    if (Pool == NULL) {
        return STATUS_INVALID_PARAM;
    }

    /* Initialize the pools */
    DTRACE("bringing up pool #%d\n", PoolCount);
    for (LevelIdx = 0; LevelIdx < LEVEL_COUNT; ++LevelIdx) {
        Block = &Pool->BlockLevels[LevelIdx];
        Status = PoolInitBlock(Block);

        /* XXX: We may wanna clean up our mess we made */
        if (Status != STATUS_SUCCESS) {
            DTRACE("critical: failed to initialize pool\n");
            return STATUS_NO_MEMORY;
        }
    }

    DTRACE("brought up %d levels for pool #%d : ok\n", LEVEL_COUNT, PoolCount);
    ++PoolCount;
    return STATUS_SUCCESS;
}