/* test_config_repl.c — Unity tests for config replication Phase 1 */
#define _GNU_SOURCE
#include <unity/unity.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <openssl/sha.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <utime.h>
#include <unistd.h>

#include "config_repl.h"
#include "myconf.h"
#include "xce/cluster_def.h"

/* Per-test directory helpers — not Unity setUp/tearDown (those are in
 * controller_test.c). Each test that needs a temp dir calls cr_setup()
 * at the top and cr_teardown() via the label before returning. */

static char g_tmpdir[256];
static char g_conf_dir[300];

/* tmpdir string for load_primary_config tests (no conf/current) */
static char tmpdir[256];

static void cr_setup(void)
{
    snprintf(g_tmpdir, sizeof(g_tmpdir), "/tmp/test_cr_%d_%ld",
             (int)getpid(), (long)time(NULL));
    mkdir(g_tmpdir, 0700);
    snprintf(g_conf_dir, sizeof(g_conf_dir), "%s/conf", g_tmpdir);
    mkdir(g_conf_dir, 0700);
}

static void cr_teardown(void)
{
    char cmd[512];
    snprintf(cmd, sizeof(cmd), "rm -rf %s", g_tmpdir);
    system(cmd);
    g_tmpdir[0]    = '\0';
    g_conf_dir[0]  = '\0';
}

/* ── conf_read_current_filename ─────────────────── */

static void test_conf_read_current_filename_missing(void)
{
    cr_setup();
    char out[256] = {0};
    int rc = conf_read_current_filename(g_tmpdir, out, sizeof(out));
    TEST_ASSERT_EQUAL_INT(-ENOENT, rc);
    cr_teardown();
    printf("test_conf_read_current_filename_missing: PASS\n");
}

static void test_conf_read_current_filename_empty_file(void)
{
    cr_setup();
    char ptr_path[400];
    snprintf(ptr_path, sizeof(ptr_path), "%s/current", g_conf_dir);
    int fd = open(ptr_path, O_WRONLY | O_CREAT | O_TRUNC, 0600);
    TEST_ASSERT_NOT_EQUAL(-1, fd);
    close(fd);

    char out[256] = {0};
    int rc = conf_read_current_filename(g_tmpdir, out, sizeof(out));
    TEST_ASSERT_EQUAL_INT(-ENODATA, rc);
    cr_teardown();
    printf("test_conf_read_current_filename_empty_file: PASS\n");
}

static void test_conf_read_current_filename_path_separator(void)
{
    cr_setup();
    char ptr_path[400];
    snprintf(ptr_path, sizeof(ptr_path), "%s/current", g_conf_dir);
    FILE *f = fopen(ptr_path, "w");
    fprintf(f, "cluster.bin/../evil\n");
    fclose(f);

    char out[256] = {0};
    int rc = conf_read_current_filename(g_tmpdir, out, sizeof(out));
    TEST_ASSERT_EQUAL_INT(-EINVAL, rc);
    cr_teardown();
    printf("test_conf_read_current_filename_path_separator: PASS\n");
}

static void test_conf_read_current_filename_bad_prefix(void)
{
    cr_setup();
    char ptr_path[400];
    snprintf(ptr_path, sizeof(ptr_path), "%s/current", g_conf_dir);
    FILE *f = fopen(ptr_path, "w");
    fprintf(f, "badprefix.aabbccddeeff\n");
    fclose(f);

    char out[256] = {0};
    int rc = conf_read_current_filename(g_tmpdir, out, sizeof(out));
    TEST_ASSERT_EQUAL_INT(-EINVAL, rc);
    cr_teardown();
    printf("test_conf_read_current_filename_bad_prefix: PASS\n");
}

static void test_conf_read_current_filename_wrong_hex_length(void)
{
    cr_setup();
    char ptr_path[400];
    snprintf(ptr_path, sizeof(ptr_path), "%s/current", g_conf_dir);
    FILE *f = fopen(ptr_path, "w");
    fprintf(f, "cluster.bin.aabb\n");   /* only 4 hex chars, need 12 */
    fclose(f);

    char out[256] = {0};
    int rc = conf_read_current_filename(g_tmpdir, out, sizeof(out));
    TEST_ASSERT_EQUAL_INT(-EINVAL, rc);
    cr_teardown();
    printf("test_conf_read_current_filename_wrong_hex_length: PASS\n");
}

/* ── conf_save_config + conf_read_current_filename round-trip ─ */

static void test_conf_save_creates_pointer_file(void)
{
    cr_setup();
    const uint8_t data[] = "fake capnproto config blob";
    size_t len = sizeof(data) - 1;
    uint8_t sha256[32];
    SHA256(data, len, sha256);

    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));
    myconf.workdir     = g_tmpdir;
    myconf.name        = "ctrl0";
    myconf.conf_keep_n = 2;
    myconf.conffile    = NULL;

    int rc = conf_save_config(&myconf, data, len, sha256);
    TEST_ASSERT_EQUAL_INT(0, rc);

    /* conf/current must exist */
    char ptr_path[400];
    snprintf(ptr_path, sizeof(ptr_path), "%s/current", g_conf_dir);
    TEST_ASSERT_EQUAL_INT(0, access(ptr_path, F_OK));

    free(myconf.conffile);
    cr_teardown();
    printf("test_conf_save_creates_pointer_file: PASS\n");
}

static void test_conf_save_filename_has_12_hex_suffix(void)
{
    cr_setup();
    const uint8_t data[] = "another fake blob";
    size_t len = sizeof(data) - 1;
    uint8_t sha256[32];
    SHA256(data, len, sha256);

    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));
    myconf.workdir     = g_tmpdir;
    myconf.name        = "ctrl0";
    myconf.conf_keep_n = 2;
    myconf.conffile    = NULL;

    conf_save_config(&myconf, data, len, sha256);

    char fname[256] = {0};
    int rc = conf_read_current_filename(g_tmpdir, fname, sizeof(fname));
    TEST_ASSERT_EQUAL_INT(0, rc);
    TEST_ASSERT_EQUAL_INT(0, strncmp(fname, "cluster.bin.", 12));
    const char *hex = fname + 12;
    TEST_ASSERT_EQUAL_INT(12, (int)strlen(hex));
    TEST_ASSERT_EQUAL_INT(12, (int)strspn(hex, "0123456789abcdef"));

    free(myconf.conffile);
    cr_teardown();
    printf("test_conf_save_filename_has_12_hex_suffix: PASS\n");
}

/* ── conf_trim_old_versions ─────────────────────── */

static void test_conf_trim_keeps_only_n_versions(void)
{
    cr_setup();
    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));
    myconf.workdir     = g_tmpdir;
    myconf.name        = "ctrl0";
    myconf.conf_keep_n = 2;
    myconf.conffile    = NULL;

    uint8_t sha256[32];
    for (int i = 0; i < 3; i++) {
        char data[32];
        snprintf(data, sizeof(data), "config version %d", i);
        SHA256((uint8_t *)data, strlen(data), sha256);
        usleep(15000);  /* ensure distinct mtime ordering */
        conf_save_config(&myconf, (uint8_t *)data, strlen(data), sha256);
        free(myconf.conffile);
        myconf.conffile = NULL;
    }

    /* Count cluster.bin.* files (exclude .tmp) */
    int count = 0;
    DIR *d = opendir(g_conf_dir);
    TEST_ASSERT_NOT_NULL(d);
    struct dirent *e;
    while ((e = readdir(d)) != NULL) {
        if (strncmp(e->d_name, "cluster.bin.", 12) == 0 &&
            strstr(e->d_name, ".tmp") == NULL)
            count++;
    }
    closedir(d);
    TEST_ASSERT_EQUAL_INT(2, count);

    free(myconf.conffile);
    cr_teardown();
    printf("test_conf_trim_keeps_only_n_versions: PASS\n");
}

/* ── conf_get_saved_tag ─────────────────────────── */

static void test_conf_get_saved_tag_no_config(void)
{
    cr_setup();
    uint64_t tag = conf_get_saved_tag(g_tmpdir);
    TEST_ASSERT_EQUAL_UINT64(0, tag);
    cr_teardown();
    printf("test_conf_get_saved_tag_no_config: PASS\n");
}

static void test_conf_get_saved_tag_after_save(void)
{
    cr_setup();
    const uint8_t data[] = "tag test blob";
    size_t len = sizeof(data) - 1;
    uint8_t sha256[32];
    SHA256(data, len, sha256);

    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));
    myconf.workdir     = g_tmpdir;
    myconf.name        = "ctrl0";
    myconf.conf_keep_n = 2;
    myconf.conffile    = NULL;

    conf_save_config(&myconf, data, len, sha256);
    free(myconf.conffile);

    uint64_t tag = conf_get_saved_tag(g_tmpdir);
    TEST_ASSERT_NOT_EQUAL(0, tag);

    /* Tag must equal first 8 bytes of sha256 in host order */
    uint64_t expected;
    memcpy(&expected, sha256, 8);
    /* be64toh conversion */
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
    expected = __builtin_bswap64(expected);
#endif
    TEST_ASSERT_EQUAL_UINT64(expected, tag);

    cr_teardown();
    printf("test_conf_get_saved_tag_after_save: PASS\n");
}

/* ── conf_check_stale ───────────────────────────── */

static void test_conf_check_stale_disabled(void)
{
    cr_setup();
    /* timeout 0 = disabled, never stale */
    TEST_ASSERT_EQUAL_INT(0, conf_check_stale(g_tmpdir, 0));
    cr_teardown();
    printf("test_conf_check_stale_disabled: PASS\n");
}

static void test_conf_check_stale_fresh(void)
{
    cr_setup();
    const uint8_t data[] = "stale test blob";
    uint8_t sha256[32];
    SHA256(data, sizeof(data) - 1, sha256);

    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));
    myconf.workdir     = g_tmpdir;
    myconf.name        = "ctrl0";
    myconf.conf_keep_n = 2;
    myconf.conffile    = NULL;
    conf_save_config(&myconf, data, sizeof(data) - 1, sha256);
    free(myconf.conffile);

    /* Just saved — not stale with 24h timeout */
    TEST_ASSERT_EQUAL_INT(0, conf_check_stale(g_tmpdir, 86400));
    cr_teardown();
    printf("test_conf_check_stale_fresh: PASS\n");
}

static void test_conf_check_stale_aged(void)
{
    cr_setup();
    const uint8_t data[] = "old config blob";
    uint8_t sha256[32];
    SHA256(data, sizeof(data) - 1, sha256);

    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));
    myconf.workdir     = g_tmpdir;
    myconf.name        = "ctrl0";
    myconf.conf_keep_n = 2;
    myconf.conffile    = NULL;
    conf_save_config(&myconf, data, sizeof(data) - 1, sha256);
    free(myconf.conffile);

    /* Age the versioned file by 20 seconds via utime */
    char fname[256] = {0};
    conf_read_current_filename(g_tmpdir, fname, sizeof(fname));
    char ver_path[512];
    snprintf(ver_path, sizeof(ver_path), "%s/%s", g_conf_dir, fname);

    struct utimbuf old_time;
    old_time.actime  = time(NULL) - 20;
    old_time.modtime = time(NULL) - 20;
    utime(ver_path, &old_time);

    /* 5-second threshold → stale */
    TEST_ASSERT_EQUAL_INT(1, conf_check_stale(g_tmpdir, 5));
    /* 30-second threshold → not stale */
    TEST_ASSERT_EQUAL_INT(0, conf_check_stale(g_tmpdir, 30));

    cr_teardown();
    printf("test_conf_check_stale_aged: PASS\n");
}

/* ── config_contains_reserved_name ─────────────── */

static void test_config_contains_reserved_name_absent(void)
{
    /* NULL config — no reserved name */
    TEST_ASSERT_EQUAL_INT(0, config_contains_reserved_name(NULL));
    printf("test_config_contains_reserved_name_absent: PASS\n");
}

/* ── sanitise_cn ────────────────────────────────── */

static void test_sanitise_cn_printable(void)
{
    char *out = sanitise_cn("ctrl01.example.com", 64);
    TEST_ASSERT_EQUAL_STRING("ctrl01.example.com", out);
    printf("test_sanitise_cn_printable: PASS\n");
}

static void test_sanitise_cn_control_chars(void)
{
    char *out = sanitise_cn("evil\ninjection", 64);
    /* newline replaced with '?' */
    TEST_ASSERT_NOT_NULL(strchr(out, '?'));
    TEST_ASSERT_NULL(strchr(out, '\n'));
    printf("test_sanitise_cn_control_chars: PASS\n");
}

static void test_sanitise_cn_truncated(void)
{
    char *out = sanitise_cn("abcdefghij", 5);
    TEST_ASSERT_EQUAL_INT(5, (int)strlen(out));
    printf("test_sanitise_cn_truncated: PASS\n");
}

/* ── load_primary_config (via test-only helper) ── */

#ifdef XCE_TESTING
static void test_load_primary_config_missing_returns_error(void)
{
    /* Create a minimal cluster_t with no conf/current file */
    cluster_t c;
    memset(&c, 0, sizeof(c));
    myconf_t myconf;
    memset(&myconf, 0, sizeof(myconf));

    /* Use a fresh tmpdir with no conf/current */
    snprintf(tmpdir, sizeof(tmpdir), "/tmp/test_lpc_%d_%ld",
             (int)getpid(), (long)time(NULL));
    mkdir(tmpdir, 0700);

    myconf.workdir            = tmpdir;
    myconf.name               = "ctrl0";
    myconf.conf_keep_n        = 2;
    myconf.conf_stale_timeout = 86400;
    myconf.conffile           = NULL;
    c.myconf                  = &myconf;

    /* No conf/current exists — must fail (not FATAL in test context) */
    int rc = load_primary_config_for_test(&c);
    TEST_ASSERT_TRUE(rc < 0);
    /* conffile must still be NULL (no heap allocation on failure) */
    TEST_ASSERT_NULL(myconf.conffile);

    /* Cleanup */
    char cmd[512];
    snprintf(cmd, sizeof(cmd), "rm -rf %s", tmpdir);
    system(cmd);

    printf("test_load_primary_config_missing_returns_error: PASS\n");
}
#endif

/* ── dispatch ───────────────────────────────────── */

void test_config_repl(void)
{
    RUN_TEST(test_conf_read_current_filename_missing);
    RUN_TEST(test_conf_read_current_filename_empty_file);
    RUN_TEST(test_conf_read_current_filename_path_separator);
    RUN_TEST(test_conf_read_current_filename_bad_prefix);
    RUN_TEST(test_conf_read_current_filename_wrong_hex_length);
    RUN_TEST(test_conf_save_creates_pointer_file);
    RUN_TEST(test_conf_save_filename_has_12_hex_suffix);
    RUN_TEST(test_conf_trim_keeps_only_n_versions);
    RUN_TEST(test_conf_get_saved_tag_no_config);
    RUN_TEST(test_conf_get_saved_tag_after_save);
    RUN_TEST(test_conf_check_stale_disabled);
    RUN_TEST(test_conf_check_stale_fresh);
    RUN_TEST(test_conf_check_stale_aged);
    RUN_TEST(test_config_contains_reserved_name_absent);
    RUN_TEST(test_sanitise_cn_printable);
    RUN_TEST(test_sanitise_cn_control_chars);
    RUN_TEST(test_sanitise_cn_truncated);
#ifdef XCE_TESTING
    RUN_TEST(test_load_primary_config_missing_returns_error);
#endif
}