#include "tiny_env_box.h"
#include <stdlib.h>
#include <stdatomic.h>

tiny_env_cfg_t g_tiny_env = {0};

static int env_flag(const char* name, int def_val) {
    const char* e = getenv(name);
    if (!e || *e == '\0') return def_val;
    return (*e != '0');
}

static int env_int(const char* name, int def_val) {
    const char* e = getenv(name);
    if (!e || *e == '\0') return def_val;
    return atoi(e);
}

void tiny_env_init_once(void) {
    static _Atomic int init_state = 0; // 0: uninit, 1: inited
    int expected = 0;
    if (!atomic_compare_exchange_strong_explicit(&init_state, &expected, 1,
                                                 memory_order_acq_rel, memory_order_relaxed)) {
        return; // already initialized
    }

    g_tiny_env.tiny_tls_sll        = env_flag("HAKMEM_TINY_TLS_SLL", 1);
    g_tiny_env.sll_multiplier      = env_int("HAKMEM_SLL_MULTIPLIER", 2);
    g_tiny_env.tiny_no_front_cache = env_flag("HAKMEM_TINY_NO_FRONT_CACHE", 0);
    g_tiny_env.tiny_no_quick       = env_flag("HAKMEM_TINY_NO_QUICK", 0);
    g_tiny_env.tiny_prefetch       = env_flag("HAKMEM_TINY_PREFETCH", 0);
    g_tiny_env.front_direct        = env_flag("HAKMEM_TINY_FRONT_DIRECT", 0);
    g_tiny_env.use_class_map       = env_flag("HAKMEM_TINY_NO_CLASS_MAP", 0) ? 0 : 1;
    g_tiny_env.route_enable        = env_flag("HAKMEM_ROUTE", 0);
    g_tiny_env.route_sample_lg     = env_int("HAKMEM_ROUTE_SAMPLE_LG", 10);
    g_tiny_env.larson_fix          = env_flag("HAKMEM_TINY_LARSON_FIX", 0);
    g_tiny_env.active_track        = env_flag("HAKMEM_TINY_ACTIVE_TRACK", 0);
    g_tiny_env.drain_to_sll        = env_int("HAKMEM_TINY_DRAIN_TO_SLL", 0);
    g_tiny_env.free_to_ss          = env_flag("HAKMEM_TINY_FREE_TO_SS", 0);
    g_tiny_env.route_free          = env_flag("HAKMEM_TINY_ROUTE_FREE", 0);
    g_tiny_env.sll_diag            = env_flag("HAKMEM_TINY_SLL_DIAG", 0);
    g_tiny_env.sll_safeheader      = env_flag("HAKMEM_TINY_SLL_SAFEHEADER", 0);
    g_tiny_env.sll_ring            = env_flag("HAKMEM_TINY_SLL_RING", 0);
    g_tiny_env.free_fast           = env_flag("HAKMEM_TINY_FREE_FAST", 1);
    g_tiny_env.sll_canary_fast     = env_flag("HAKMEM_TINY_SLL_CANARY_FAST", 0);
    g_tiny_env.ss_free_debug       = env_flag("HAKMEM_SS_FREE_DEBUG", 0);
    g_tiny_env.ss_adopt            = env_flag("HAKMEM_TINY_SS_ADOPT", 1);
    g_tiny_env.disable_remote      = env_flag("HAKMEM_TINY_DISABLE_REMOTE", 0);
    g_tiny_env.freelist_mask       = env_flag("HAKMEM_TINY_FREELIST_MASK", 0);
    g_tiny_env.alloc_1024_metric   = env_flag("HAKMEM_TINY_ALLOC_1024_METRIC", 0);
    g_tiny_env.tiny_profile        = env_flag("HAKMEM_TINY_PROFILE", 0);
    g_tiny_env.tiny_fast_stats     = env_flag("HAKMEM_TINY_FAST_STATS", 0);
    g_tiny_env.heap_v2_stats       = env_flag("HAKMEM_TINY_HEAP_V2_STATS", 0);
    g_tiny_env.front_slim          = env_flag("HAKMEM_TINY_FRONT_SLIM", 0);
    {
        int pct = env_int("HAKMEM_SFC_CASCADE_PCT", 50);
        if (pct < 0) pct = 0;
        if (pct > 100) pct = 100;
        g_tiny_env.sfc_cascade_pct = pct;
    }
    g_tiny_env.sfc_cascade         = env_flag("HAKMEM_TINY_SFC_CASCADE", 0);
    g_tiny_env.alloc_remote_relax  = env_flag("HAKMEM_TINY_ALLOC_REMOTE_RELAX", 0);
    g_tiny_env.ss_empty_reuse      = env_flag("HAKMEM_SS_EMPTY_REUSE", 1);
    g_tiny_env.ss_empty_scan_limit = env_int("HAKMEM_SS_EMPTY_SCAN_LIMIT", 32);
    g_tiny_env.ss_acquire_debug    = env_flag("HAKMEM_SS_ACQUIRE_DEBUG", 0);
    g_tiny_env.tension_drain_enable = env_flag("HAKMEM_TINY_TENSION_DRAIN_ENABLE", 1);
    g_tiny_env.tension_drain_threshold = env_int("HAKMEM_TINY_TENSION_DRAIN_THRESHOLD", 1024);

    g_tiny_env.inited = 1;
}