#include <stdio.h>
#include <string.h>
#include <stdint.h>

/* mock SnapRec (与 snapshot.h 一致, 64B) */
typedef struct {
    uint8_t  magic;
    uint8_t  len;
    uint8_t  flags;
    uint8_t  rsvd;
    uint32_t seq;
    uint32_t ts_ms;
    uint16_t boot_seq;
    uint16_t rsvd2;
    uint8_t  coils[48];
} SnapRec;

#define SNAP_COILS_MAX  4
#define SNAP_COIL_BYTES 12

int snap_rec_to_hex(const SnapRec *r, char *buf, int buf_len)
{
    int i, pos = 0;
    const uint8_t *p = (const uint8_t *)r;
    for (i = 0; i < (int)sizeof(SnapRec); i++) {
        if (pos >= buf_len - 3) break;
        pos += snprintf(buf + pos, buf_len - pos, "%02x", p[i]);
    }
    return pos;
}

#define CHECK(cond) do { if (!(cond)) { printf("FAIL %d: %s\n", __LINE__, #cond); fails++; } else { passes++; } } while (0)
static int passes = 0, fails = 0;

int main(void)
{
    char buf[256];
    SnapRec r;

    /* 用例1: 与 test_snap_to_json case2 相同数据, 验证 hex 与 JSON 语义一致
       ch1: cfg=0xE8(11 1 0 0000: 低频/方向/初始/灵敏度0) cond=0xFF(cond15/断/有车/relay)
       freq=0x00C383=50051, variation=-10, misc=128 */
    memset(&r, 0, sizeof(r));
    r.magic = 0xA6; r.len = 48; r.seq = 999; r.ts_ms = 1234; r.boot_seq = 3;
    r.coils[0] = 0xE8; r.coils[1] = 0xFF;
    r.coils[2] = 0x83; r.coils[3] = 0xC3; r.coils[4] = 0x00;  /* 50051 */
    r.coils[5] = 0xF6; r.coils[6] = 0xFF; r.coils[7] = 0xFF;  /* -10 */
    r.coils[8] = 0x80; r.coils[9] = 0x00; r.coils[10] = 0x00; r.coils[11] = 0x00;  /* 128 */

    int n = snap_rec_to_hex(&r, buf, sizeof(buf));
    printf("hex(%d): %s\n", n, buf);
    CHECK(n == 128);
    CHECK(strlen(buf) == 128);
    /* 头部: magic=0xA6 len=0x30(48) flags=0 rsvd=0 seq=0xE7030000(999 LE) */
    CHECK(strncmp(buf, "a6300000e7030000d204", 20) == 0);
    /* ch1 12B: e8 ff 83 c3 00 f6 ff ff 80 00 00 00 */
    CHECK(strncmp(buf + 32, "e8ff83c300f6ffff80000000", 24) == 0);
    /* 全部小写 */
    CHECK(strspn(buf, "0123456789abcdef") == 128);

    /* 用例2: 空记录 len=0 */
    memset(&r, 0, sizeof(r));
    r.magic = 0xA6;
    n = snap_rec_to_hex(&r, buf, sizeof(buf));
    CHECK(n == 128);
    CHECK(strncmp(buf, "a60000000000000000000000", 24) == 0);

    /* 用例3: 缓冲不足截断安全 (buf_len=10 不越界) */
    memset(&r, 0, sizeof(r));
    n = snap_rec_to_hex(&r, buf, 10);
    CHECK(n == 8);
    CHECK(strlen(buf) == 8);

    printf("PASS=%d FAIL=%d\n", passes, fails);
    return fails ? 1 : 0;
}