/* test_mem.c — mem backend: basic CRUD, directory markers (Section 9.3),
 * rename, readdir. */

#include "packfs.h"
#include "test_harness.h"

int main(void) {
    /* pfs_version() must report exactly what this header's own macros say,
     * so a dynamically-linked consumer's runtime check and a
     * statically-linked consumer's compile-time PACKFS_VERSION_* agree by
     * construction, not by two places having to be kept in sync by hand. */
    CHECK_STR_EQ(pfs_version(), PACKFS_VERSION_STRING);
    CHECK_STR_EQ(PACKFS_VERSION_STRING, "0.1.0");
    CHECK_EQ_INT(PACKFS_VERSION_MAJOR, 0);
    CHECK_EQ_INT(PACKFS_VERSION_MINOR, 1);
    CHECK_EQ_INT(PACKFS_VERSION_PATCH, 0);

    Vfs *v = vfs_new();
    Backend *mem = backend_mem_new();
    CHECK_EQ_INT(vfs_mount(v, "/", mem), VFS_OK);

    /* create + write + read back */
    int err = 0;
    VfsFile *f = vfs_open(v, "/hello.txt", VFS_O_WRONLY | VFS_O_CREAT, &err);
    CHECK(f != NULL);
    CHECK_EQ_INT(vfs_write(f, "hello", 5), 5);
    CHECK_EQ_INT(vfs_close(f), VFS_OK);

    f = vfs_open(v, "/hello.txt", VFS_O_RDONLY, &err);
    CHECK(f != NULL);
    char buf[16] = {0};
    CHECK_EQ_INT(vfs_read(f, buf, sizeof(buf)), 5);
    CHECK_STR_EQ(buf, "hello");
    CHECK_EQ_INT(vfs_close(f), VFS_OK);

    VfsStat st;
    CHECK_EQ_INT(vfs_stat(v, "/hello.txt", &st), VFS_OK);
    CHECK_EQ_INT(st.size, 5);
    CHECK_EQ_INT(st.kind, VFS_KIND_FILE);

    /* nonexistent path */
    CHECK_EQ_INT(vfs_stat(v, "/nope.txt", &st), VFS_ERR_NOENT);

    /* path escape rejected (Section 6.1) */
    f = vfs_open(v, "/../etc/passwd", VFS_O_RDONLY, &err);
    CHECK(f == NULL);
    CHECK_EQ_INT(err, VFS_ERR_INVAL);

    /* directories: explicit empty dir (Section 9.3) and implicit dir from a file */
    CHECK_EQ_INT(vfs_mkdir(v, "/empty"), VFS_OK);
    CHECK_EQ_INT(vfs_stat(v, "/empty", &st), VFS_OK);
    CHECK_EQ_INT(st.kind, VFS_KIND_DIR);

    f = vfs_open(v, "/nested/deep/file.txt", VFS_O_WRONLY | VFS_O_CREAT, &err);
    CHECK(f != NULL);
    CHECK_EQ_INT(vfs_write(f, "x", 1), 1);
    CHECK_EQ_INT(vfs_close(f), VFS_OK);
    CHECK_EQ_INT(vfs_stat(v, "/nested", &st), VFS_OK);
    CHECK_EQ_INT(st.kind, VFS_KIND_DIR);
    CHECK_EQ_INT(vfs_stat(v, "/nested/deep", &st), VFS_OK);
    CHECK_EQ_INT(st.kind, VFS_KIND_DIR);

    /* readdir at root: hello.txt, empty, nested */
    VfsDir dir;
    CHECK_EQ_INT(vfs_readdir(v, "/", &dir), VFS_OK);
    int saw_hello = 0, saw_empty = 0, saw_nested = 0;
    for (pfs_usize i = 0; i < dir.count; i++) {
        if (strcmp(dir.entries[i].name, "hello.txt") == 0) { saw_hello = 1; CHECK_EQ_INT(dir.entries[i].kind, VFS_KIND_FILE); }
        if (strcmp(dir.entries[i].name, "empty") == 0) { saw_empty = 1; CHECK_EQ_INT(dir.entries[i].kind, VFS_KIND_DIR); }
        if (strcmp(dir.entries[i].name, "nested") == 0) { saw_nested = 1; CHECK_EQ_INT(dir.entries[i].kind, VFS_KIND_DIR); }
    }
    CHECK(saw_hello && saw_empty && saw_nested);
    vfs_dir_free(&dir);

    /* rename */
    CHECK_EQ_INT(vfs_rename(v, "/hello.txt", "/hello2.txt"), VFS_OK);
    CHECK_EQ_INT(vfs_stat(v, "/hello.txt", &st), VFS_ERR_NOENT);
    CHECK_EQ_INT(vfs_stat(v, "/hello2.txt", &st), VFS_OK);

    /* unlink + rmdir-of-nonempty rejected */
    CHECK_EQ_INT(vfs_unlink(v, "/hello2.txt"), VFS_OK);
    CHECK_EQ_INT(vfs_unlink(v, "/nested"), VFS_ERR_NOTEMPTY);

    /* buffer growth across the 64-byte initial capacity (Section 5.7) */
    f = vfs_open(v, "/big.bin", VFS_O_WRONLY | VFS_O_CREAT, &err);
    CHECK(f != NULL);
    unsigned char chunk[100];
    for (int i = 0; i < 100; i++) chunk[i] = (unsigned char)i;
    for (int i = 0; i < 50; i++) CHECK_EQ_INT(vfs_write(f, chunk, sizeof(chunk)), sizeof(chunk));
    CHECK_EQ_INT(vfs_close(f), VFS_OK);
    CHECK_EQ_INT(vfs_stat(v, "/big.bin", &st), VFS_OK);
    CHECK_EQ_INT(st.size, 5000);
    f = vfs_open(v, "/big.bin", VFS_O_RDONLY, &err);
    unsigned char rb[5000];
    CHECK_EQ_INT(vfs_read(f, rb, sizeof(rb)), 5000);
    CHECK_EQ_INT(memcmp(rb, rb, 0), 0); /* smoke */
    int ok = 1;
    for (int i = 0; i < 5000; i++) if (rb[i] != (unsigned char)(i % 100)) ok = 0;
    CHECK(ok);
    CHECK_EQ_INT(vfs_close(f), VFS_OK);

    vfs_unmount(v, "/");
    backend_free(mem);
    vfs_free(v);
    TEST_MAIN_END();
}