#include <check.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "ucore/read_file.h"


START_TEST (test_read_file_non_existing_file)
{
    char *content;
    size_t len;
    int saved_errno;

    errno = 0;
    content = uc_read_file("non existing file 123765", &len, 1000000000);
    saved_errno = errno;

    ck_assert_ptr_null(content);
    ck_assert_int_ne(saved_errno, 0);
}
END_TEST

START_TEST (test_read_file_simple)
{
    char *content;
    const char *filename = "test_read_file_simple";
    size_t len;
    ssize_t rc;

    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0664);
    ck_assert_int_ne(fd, -1);

    rc = write(fd, "hello", 5);
    ck_assert_int_eq(rc, 5);

    close(fd);

    content = uc_read_file(filename, &len, 1000000000);
    unlink(filename);

    ck_assert_ptr_nonnull(content);
    ck_assert_uint_eq(len, 5);
    ck_assert_uint_eq(strlen(content), 5);
    ck_assert_str_eq("hello", content);
    free(content);
}
END_TEST

START_TEST (test_read_file_greater_than_max)
{
    char *content;
    const char *filename = "test_read_file_simple";
    size_t len;
    ssize_t rc;
    int saved_errno;

    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0664);
    fail_if(fd == -1);

    rc = write(fd, "hello", 5);
    fail_if(rc != 5);

    close(fd);

    content = uc_read_file(filename, &len, 4);
    saved_errno = errno;
    unlink(filename);

    ck_assert_ptr_null(content);
    ck_assert_int_eq(saved_errno, EMSGSIZE);
}
END_TEST

START_TEST (test_read_file_boundary)
{
    char *content;
    const char *filename = "test_read_file_boundary";
    size_t len;
    ssize_t rc;
    char buf[1030] = "";
    strcpy(&buf[1022], "foobar");

    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0664);
    fail_if(fd == -1);

    rc = write(fd, buf, sizeof buf);
    ck_assert_uint_eq(rc, sizeof buf);

    close(fd);

    content = uc_read_file(filename, &len, 1000000000);
    unlink(filename);

    ck_assert_ptr_nonnull(content);
    ck_assert_uint_eq(len, sizeof buf);
    ck_assert_str_eq("foobar", &content[1022]);
    free(content);
}
END_TEST

START_TEST (test_read_file_devnull)
{
    char *content;
    size_t len = 123;

    content = uc_read_file("/dev/null", &len, 1024);
    ck_assert_ptr_nonnull(content);
    ck_assert_uint_eq(len, 0);
    free(content);

}
END_TEST

START_TEST (test_read_file_too_big)
{
    char *content;
    const char *filename = "test_read_file_too_big";
    size_t len;
    ssize_t rc;

    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0664);
    fail_if(fd == -1);

    rc = write(fd, "hello", 5);
    fail_if(rc != 5);

    close(fd);

    content = uc_read_file(filename, &len, 4);

    ck_assert_int_eq(errno, EMSGSIZE);
    ck_assert_ptr_null(content);

    unlink(filename);
}
END_TEST

START_TEST (test_read_file_big)
{
    char *content;
    const char *filename = "test_read_file_big";
    char buf[4096 * 16];
    size_t len;
    ssize_t rc;

    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0664);
    ck_assert_int_ne(fd, -1);
    memset(buf, 'a', sizeof buf);

    rc = write(fd, buf, sizeof buf);
    ck_assert_uint_eq(rc, sizeof buf);

    close(fd);

    content = uc_read_file(filename, &len, 4096*16);
    fail_if(content == NULL);
    ck_assert_uint_eq(len, sizeof buf);
    ck_assert_int_eq(memcmp(content, buf, sizeof buf), 0);

    free(content);

    unlink(filename);
}
END_TEST

Suite *read_file_suite(void)
{
    Suite *s = suite_create("read_file");
    TCase *tc = tcase_create("read_file tests");
    tcase_add_test(tc, test_read_file_non_existing_file);
    tcase_add_test(tc, test_read_file_simple);
    tcase_add_test(tc, test_read_file_greater_than_max);
    tcase_add_test(tc, test_read_file_boundary);
    tcase_add_test(tc, test_read_file_devnull);
    tcase_add_test(tc, test_read_file_too_big);
    tcase_add_test(tc, test_read_file_big);


    suite_add_tcase(s, tc);

    return s;
}