// test_db_sync.c — тестирование db_sync: dh_match tail-send и peer empty
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <time.h>
#include <sys/stat.h>
#include "../lib/platform_compat.h"
#include "test_utils.h"
#ifdef _WIN32
#include <windows.h>
#include <direct.h>
#else
#include <unistd.h>
#endif

#include "../src/etcp.h"
#include "../src/etcp_connections.h"
#include "../src/config_parser.h"
#include "../src/config_updater.h"
#include "../src/utun_instance.h"
#include "../src/routing.h"
#include "../src/tun_if.h"
#include "../src/secure_channel.h"
#include "../src/secure_channel.h"
#include "../src/db_sync.h"
#include "../lib/u_async.h"
#include "../lib/debug_config.h"
#include "../lib/mem.h"

#define TEST_TIMEOUT_TB  600000  // 60s
#define PHASE_TIMEOUT_TB 250000  // 25s
#define POLL_INTERVAL_MS 5

static struct UTUN_INSTANCE* inst_a = NULL;
static struct UTUN_INSTANCE* inst_b = NULL;
static struct DB_SYNC_INSTANCE* si_a = NULL;
static struct DB_SYNC_INSTANCE* si_b = NULL;
static struct UASYNC* ua = NULL;
static int test_phase = 0;
static void* timeout_id = NULL;

static char temp_dir[] = "/tmp/utun_dbsync_XXXXXX";
static char config_a[256], config_b[256];
static int port_a_srv, port_b_srv;

static int write_file(const char* path, const char* fmt, ...) {
    va_list ap; FILE* f = fopen(path, "w");
    if (!f) return -1;
    va_start(ap, fmt); vfprintf(f, fmt, ap); va_end(ap);
    fclose(f); return 0;
}
static char* get_pubkey(const char* path) {
    struct utun_config* cfg = parse_config(path);
    if (!cfg) return NULL;
    char* pub = strdup(cfg->global.my_public_key_hex);
    free_config(cfg); return pub;
}

static int create_temp_configs(void) {
    if (test_mkdtemp(temp_dir) != 0) { fprintf(stderr, "mkdtemp failed\n"); return -1; }
    int base = 42000 + (getpid() % 15000);
    port_a_srv = base; port_b_srv = base + 1;
    snprintf(config_a, sizeof(config_a), "%s/a.conf", temp_dir);
    snprintf(config_b, sizeof(config_b), "%s/b.conf", temp_dir);
    char db_path[320];
    snprintf(db_path, sizeof(db_path), "%s/db_a", temp_dir); utun_mkdir(db_path, 0755);
    snprintf(db_path, sizeof(db_path), "%s/db_b", temp_dir); utun_mkdir(db_path, 0755);

    if (write_file(config_a,
        "[global]\nmy_node_id=0xAAAAAAAAAAAAAAAA\ntun_ip=10.200.0.1/24\n"
        "tun_ifname=tun200\nkeepalive_adaptive=0\ndb_path=%s/db_a\ndb_sync_enabled=1\n\n"
        "[server: srv_a]\naddr=127.0.0.1:%d\ntype=public\n\n"
        "[allowed_keys]\nallow_all=1\n", temp_dir, port_a_srv) != 0) return -1;
    if (config_ensure_keys_and_node_id(config_a) != 0) return -1;
    char* pub_a = get_pubkey(config_a); if (!pub_a) return -1;

    if (write_file(config_b,
        "[global]\nmy_node_id=0xBBBBBBBBBBBBBBBB\ntun_ip=10.200.0.2/24\n"
        "tun_ifname=tun201\nkeepalive_adaptive=0\ndb_path=%s/db_b\ndb_sync_enabled=1\n\n"
        "[server: srv_b]\naddr=127.0.0.1:%d\ntype=public\n\n"
        "[client: to_a]\nkeepalive=1\npeer_public_key=%s\nlink=srv_b:127.0.0.1:%d\n\n"
        "[allowed_keys]\nallow_all=1\n",
        temp_dir, port_b_srv, pub_a, port_a_srv) != 0) { free(pub_a); return -1; }
    free(pub_a);
    if (config_ensure_keys_and_node_id(config_b) != 0) return -1;
    return 0;
}

static void cleanup_temp_configs(void) {
    unlink(config_a); unlink(config_b);
    char pa[320];
    snprintf(pa, sizeof(pa), "%s/db_a/sync", temp_dir); unlink(pa);
    snprintf(pa, sizeof(pa), "%s/db_a/sync-wal", temp_dir); unlink(pa);
    snprintf(pa, sizeof(pa), "%s/db_a/sync-shm", temp_dir); unlink(pa);
    snprintf(pa, sizeof(pa), "%s/db_b/sync", temp_dir); unlink(pa);
    snprintf(pa, sizeof(pa), "%s/db_b/sync-wal", temp_dir); unlink(pa);
    snprintf(pa, sizeof(pa), "%s/db_b/sync-shm", temp_dir); unlink(pa);
    snprintf(pa, sizeof(pa), "%s/db_a", temp_dir); test_rmdir(pa);
    snprintf(pa, sizeof(pa), "%s/db_b", temp_dir); test_rmdir(pa);
    test_rmdir(temp_dir);
}

static void test_timeout(void* arg) { (void)arg; test_phase = 2; }

static int wait_for(const char* desc, int (*cond)(void), int timeout_tb) {
    uint64_t start = get_time_tb();
    while (!cond() && (get_time_tb() - start) < (uint64_t)timeout_tb && test_phase == 0)
        uasync_poll(ua, POLL_INTERVAL_MS);
    if (cond()) return 1;
    if (test_phase == 0) { fprintf(stderr, "TIMEOUT: %s\n", desc); test_phase = 2; }
    return 0;
}

static int cond_links_init(void) {
    if (!inst_a || !inst_b) return 0;
    struct ll_entry* e = inst_a->connections->head;
    while (e) { struct conn_queue_entry* ce = (struct conn_queue_entry*)e->data;
        struct ETCP_LINK* l = ce->conn->links; while (l) { if (l->initialized) return 1; l = l->next; }
        e = e->next; }
    return 0;
}
static uint32_t ca_target, cb_target;
static int _cond_ca(void) { return si_a && db_sync_count(si_a) == ca_target; }
static int _cond_cb(void) { return si_b && db_sync_count(si_b) == cb_target; }

static int insert_many(struct DB_SYNC_INSTANCE* si, struct UTUN_INSTANCE* inst, int start, int count) {
    char buf[128];
    for (int i = start; i < start + count && test_phase == 0; i++) {
        snprintf(buf, sizeof(buf), "{\"idx\":%d,\"val\":\"data_%d\",\"pad\":\"%.50s\"}", i, i,
                 "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
        uint64_t ts = db_sync_next_timestamp(si);
        uint8_t sig_msg[256]; size_t off = 0;
        memcpy(sig_msg + off, &ts, 8);  off += 8;
        size_t jl = strlen(buf); memcpy(sig_msg + off, buf, jl); off += jl;
        uint8_t sig[64];
        if (sc_ed25519_sign(inst->my_ed25519_privkey, sig_msg, off, sig) != SC_OK) { fprintf(stderr,"sign fail %d\n", i); return -1; }
        if (db_sync_insert_signed(si, buf, jl, sig, 64, ts) < 0) { fprintf(stderr,"insert_many fail %d\n", i); return -1; }
    }
    return 0;
}

static void remove_si(struct DB_SYNC_INSTANCE** psi) {
    if (*psi) { db_sync_instance_remove(*psi); *psi = NULL; }
}

// ---- Main test ----
int main(void) {
    printf("=== test_db_sync ===\n");

    debug_config_init(); debug_set_level(DEBUG_LEVEL_ERROR);
    if (create_temp_configs() != 0) { fprintf(stderr, "config creation failed\n"); return 1; }

    utun_instance_set_tun_init_enabled(0);
    ua = uasync_create();
    if (!ua) { cleanup_temp_configs(); return 1; }

    inst_a = utun_instance_create(ua, config_a);
    inst_b = utun_instance_create(ua, config_b);
    if (!inst_a || !inst_b || utun_instance_init(inst_a) != 0 || utun_instance_init(inst_b) != 0) {
        fprintf(stderr, "instance create/init failed\n"); cleanup_temp_configs(); return 1;
    }
    timeout_id = uasync_set_timeout(ua, TEST_TIMEOUT_TB, NULL, test_timeout, "global_timeout");

    // ===================================================================
    // Phase 1: late B — A=50, B=0. B создан ПОСЛЕ conn_up (A не инициирует).
    // Только B инициирует: divergence → REFINE → SEND_DATA(1) → SYNC_DONE
    // mismatch → A ретраит → dh_match(tp=0,sc=0) → должен отправить хвост [1..49].
    // ===================================================================
    printf("Phase 1: late B — dh_match at tp=0 (sc=0) + tail-send 49 records\n");
    if (!wait_for("links up", cond_links_init, PHASE_TIMEOUT_TB)) { test_phase=2; goto done; }

    si_a = db_sync_instance_add(inst_a, "test", 1);
    if (!si_a || insert_many(si_a, inst_a, 0, 50) != 0) { test_phase=2; goto done; }
    if (db_sync_count(si_a) != 50) { fprintf(stderr, "FAIL: A!=50\n"); test_phase=2; goto done; }
    printf("  A has 50 records, creating B now (B empty, A conn_up already fired)\n");

    si_b = db_sync_instance_add(inst_b, "test", 1);
    if (!si_b || db_sync_count(si_b) != 0) { test_phase=2; goto done; }

    cb_target = 50;
    if (!wait_for("B count=50 (dh_match tp=0 tail)", _cond_cb, PHASE_TIMEOUT_TB)) { test_phase=2; goto done; }
    printf("  Phase 1 PASS: B=%u A=%u\n", db_sync_count(si_b), db_sync_count(si_a));

    // ===================================================================
    // Phase 2: recreate A after adding 30 more — A=80, B=50.
    // A инициирует: dh_match(tp=49, sc>0, sparse hashes) — должен отправить хвост [50..79].
    // ===================================================================
    printf("Phase 2: recreate A — dh_match at tp=49 (sc>0 sparse) + tail-send 30 records\n");

    if (insert_many(si_a, inst_a, 50, 30) != 0) { test_phase=2; goto done; }
    if (db_sync_count(si_a) != 80) { fprintf(stderr, "FAIL: A!=80\n"); test_phase=2; goto done; }

    remove_si(&si_a);
    si_a = db_sync_instance_add(inst_a, "test", 1);
    if (!si_a || db_sync_count(si_a) != 80) { test_phase=2; goto done; }
    printf("  A recreated (80 records), B has 50 — A will initiate with tail\n");

    cb_target = 80;
    if (!wait_for("B count=80 (dh_match tp=49 sparse)", _cond_cb, PHASE_TIMEOUT_TB)) { test_phase=2; goto done; }
    printf("  Phase 2 PASS: B=%u A=%u\n", db_sync_count(si_b), db_sync_count(si_a));

    // ===================================================================
    // Phase 3: fresh instances, A=30, B=0, both created simultaneously.
    // A инициирует: peer empty (peer_dh=0, sc=0) — отправляет все 30.
    // B тоже инициирует но расходится через divergence+reinit+dh_match(tp=0) —  
    // но A уже всё отправил, так что B и так получит через A's sync.
    // ===================================================================
    printf("Phase 3: fresh instances A=30 B=0, both initiate — peer empty\n");

    remove_si(&si_a);
    remove_si(&si_b);
    si_a = db_sync_instance_add(inst_a, "test2", 2);
    si_b = db_sync_instance_add(inst_b, "test2", 2);
    if (!si_a || !si_b) { test_phase=2; goto done; }

    if (insert_many(si_a, inst_a, 0, 30) != 0 || db_sync_count(si_a) != 30) { test_phase=2; goto done; }

    cb_target = 30;
    if (!wait_for("B count=30 (peer empty)", _cond_cb, PHASE_TIMEOUT_TB)) { test_phase=2; goto done; }
    printf("  Phase 3 PASS: B=%u A=%u\n", db_sync_count(si_b), db_sync_count(si_a));

done:
    remove_si(&si_a);
    remove_si(&si_b);
    if (timeout_id && ua) { uasync_cancel_timeout(ua, timeout_id); timeout_id = NULL; }
    if (inst_a) { inst_a->running = 0; utun_instance_destroy(inst_a); inst_a = NULL; }
    if (inst_b) { inst_b->running = 0; utun_instance_destroy(inst_b); inst_b = NULL; }
    if (ua) { uasync_destroy(ua, 0); ua = NULL; }
    cleanup_temp_configs();

    if (test_phase == 0) test_phase = 1;
    printf("=== %s ===\n", test_phase == 1 ? "PASS" : "FAIL");
    return test_phase == 1 ? 0 : 1;
}