#include "test_utils.h"
#include <sys/stat.h>

static int expect_errno(const char *what, int exp)
{
    if (errno != exp) {
        fprintf(stderr, "%s: errno=%d expected=%d\n", what, errno, exp);
        return -1;
    }
    return 0;
}

static int test_phase2(const char *root)
{
    char dir[PATH_MAX];
    char file[PATH_MAX];
    char file2[PATH_MAX];
    struct stat st;
    int dfd = -1;
    int fd = -1;

    snprintf(dir, sizeof(dir), "%s/p2db", root);
    snprintf(file, sizeof(file), "%s/p2db/data.log", root);
    snprintf(file2, sizeof(file2), "%s/p2db/data2.log", root);

    (void)unlink(file2);
    (void)unlink(file);
    (void)rmdir(dir);

    if (mkdir(dir, 0755) != 0) { perror("mkdir"); return 1; }
    dfd = open(dir, O_RDONLY | O_DIRECTORY);
    if (dfd < 0) { perror("open dir"); return 2; }

    fd = openat(dfd, "data.log", O_CREAT | O_RDWR | O_TRUNC, 0644);
    if (fd < 0) { perror("openat create"); return 3; }

    if (write(fd, "ABCD", 4) != 4) { perror("write"); return 4; }
    if (pwrite(fd, "XYZ", 3, 8) != 3) { perror("pwrite"); return 5; }

    char buf[16] = {0};
    ssize_t n = pread(fd, buf, 11, 0);
    if (n != 11) { perror("pread"); return 6; }
    if (memcmp(buf, "ABCD", 4) != 0 || buf[4] || buf[5] || buf[6] || buf[7] ||
        memcmp(buf + 8, "XYZ", 3) != 0) {
        fprintf(stderr, "pread sparse verify failed\n");
        return 7;
    }

    if (fsync(fd) != 0) { perror("fsync"); return 8; }
    if (fdatasync(fd) != 0) { perror("fdatasync"); return 9; }

    if (fstat(fd, &st) != 0) { perror("fstat"); return 10; }
    if (st.st_size != 11) {
        fprintf(stderr, "fstat size=%ld expected=11\n", (long)st.st_size);
        return 11;
    }

    if (ftruncate(fd, 4) != 0) { perror("ftruncate"); return 12; }
    memset(buf, 0, sizeof(buf));
    n = pread(fd, buf, 16, 0);
    if (n != 4 || memcmp(buf, "ABCD", 4) != 0) {
        fprintf(stderr, "truncate readback failed n=%zd\n", n);
        return 13;
    }

    if (rename(file, file2) != 0) { perror("rename"); return 14; }
    if (access(file, F_OK) == 0 || expect_errno("access old", ENOENT) != 0) {
        return 15;
    }
    if (access(file2, F_OK) != 0) { perror("access new"); return 16; }

    int fd2 = open(file2, O_CREAT | O_EXCL | O_RDWR, 0644);
    if (fd2 >= 0 || expect_errno("open excl", EEXIST) != 0) {
        if (fd2 >= 0) close(fd2);
        return 17;
    }

    int rd = open(file2, O_RDONLY);
    if (rd < 0) { perror("open rdonly"); return 18; }
    if (write(rd, "Q", 1) >= 0 || expect_errno("write rdonly", EBADF) != 0) {
        close(rd);
        return 19;
    }
    close(rd);

    close(fd);
    close(dfd);
    if (unlink(file2) != 0) { perror("unlink"); return 20; }
    if (rmdir(dir) != 0) { perror("rmdir"); return 21; }
    return 0;
}

int main(int argc, char **argv)
{
    const char *root = argc >= 2 ? argv[1] : "/zvfs";
    int rc = test_phase2(root);
    return report_result("test_phase2_posix", rc);
}