#include "test.h"
#include "../src/buffer.h"
#include <stdio.h>

// @copilot add test for reading from a file.
// Create test_buffer_xyz.txt if you need multiple,
// otherwise simply test_buffer.txt

static void test_buffer_string_reads_chars(void) {
    Buffer* buf = buffer_open_string("hi");
    if (buffer_read(buf) != 'h') fail("expected 'h'");
    if (buffer_read(buf) != 'i') fail("expected 'i'");
    buffer_close(buf);
}

static void test_buffer_string_eof(void) {
    Buffer* buf = buffer_open_string("");
    if (buffer_read(buf) != (char)-1) fail("expected -1 on empty string");
    buffer_close(buf);
}

static void test_buffer_string_eof_after_content(void) {
    Buffer* buf = buffer_open_string("a");
    buffer_read(buf);
    if (buffer_read(buf) != (char)-1) fail("expected -1 after end of string");
    buffer_close(buf);
}

static void test_buffer_file_reads_chars(void) {
    Buffer* buf = buffer_open_file("v0/tests/test_buffer.txt");
    if (buf == NULL) fail("could not open file");
    if (buffer_read(buf) != 'a') fail("expected 'a'");
    if (buffer_read(buf) != 'b') fail("expected 'b'");
    if (buffer_read(buf) != 'c') fail("expected 'c'");
    if (buffer_read(buf) != '\n') fail("expected newline after content");
    if (buffer_read(buf) != (char)-1) fail("expected -1 after file");
    buffer_close(buf);
}

static void test_buffer_file_open_fail(void) {
    Buffer* buf = buffer_open_file("v0/tests/does_not_exist.txt");
    if (buf != NULL) fail("expected NULL for non-existent file");
}