#include <gtest/gtest.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#include "mocs.h"
#include "tftp.h"

tftp_custom_file_t file = {
        .data = (char*)"1234567890",
        .len = 11,
        .name = (char*)"test.txt",
        .offset = 0
    };
tftp_custom_file_t write_file = {
        .data = NULL,
        .len = 0,
        .name = (char*)"test.txt",
        .offset = 0
    };

TEST(TFTP, custom_fseek)
{    
    tftp_custom_fseek(&file, 5, SEEK_SET);
    EXPECT_EQ(file.offset, 5);
    tftp_custom_fseek(&file, 5, SEEK_CUR);
    EXPECT_EQ(file.offset, 10);
}

TEST(TFTP, custom_fread)
{
    char buf[11];
    tftp_custom_fseek(&file, 0, SEEK_SET);
    size_t bytes = tftp_custom_fread(buf, 11, &file);
    EXPECT_EQ(bytes, 10);
    EXPECT_EQ(file.offset, 10);
    EXPECT_EQ(memcmp(buf, "1234567890", 10), 0);

    memset(buf, 0, 11);

    tftp_custom_fseek(&file, 0, SEEK_SET);
    bytes = tftp_custom_fread(buf, 11, &file);
    EXPECT_EQ(bytes, 10);
    EXPECT_EQ(memcmp(buf, "1234567890", 10), 0);

    memset(buf, 0, 11);

    tftp_custom_fseek(&file, 0, SEEK_SET);
    bytes = tftp_custom_fread(buf, 5, &file);
    EXPECT_EQ(bytes, 5);
    EXPECT_EQ(memcmp(buf, "12345", 5), 0);

    memset(buf, 0, 11);

    bytes = tftp_custom_fread(buf, 5, &file);
    EXPECT_EQ(bytes, 5);
    EXPECT_EQ(memcmp(buf, "67890", 5), 0);
}

TEST(TFTP, custom_fwrite) {
    write_file.data = (char*)malloc(22 * sizeof(char));
    write_file.len = 22;
    tftp_custom_fwrite("0987654321", 10, &write_file);
    EXPECT_EQ(write_file.offset, 10);
    EXPECT_EQ(write_file.len, 22);
    EXPECT_EQ(memcmp(write_file.data, "0987654321", 10), 0);

    tftp_custom_fwrite("1234567890", 10, &write_file);
    EXPECT_EQ(write_file.offset, 20);
    EXPECT_EQ(write_file.len, 22);
    EXPECT_EQ(memcmp(write_file.data, "09876543211234567890", 21), 0);

    free(write_file.data);
    write_file.data = NULL;
    write_file.len = 0;
}

TEST(TFTP, custom_fread_fwrite_suggested_by_Lorenz) {
    char buf[21];
    write_file.data = (char*)malloc(21 * sizeof(char));
    write_file.len = 21;
    write_file.offset = 0;
    tftp_custom_fwrite("1234567890123456789", 19, &write_file);

    tftp_custom_fwrite("0987654321", 11, &write_file);
    // the above function does not write the null terminator
    EXPECT_EQ(write_file.offset, 21);
    EXPECT_EQ(write_file.len, 21);
    EXPECT_EQ(memcmp(write_file.data, "12345678901234567890", 20), 0);

    tftp_custom_fseek(&write_file, 0, SEEK_SET);
    tftp_custom_fread(buf, 20, &write_file);
    // the above function does not write the null terminator
    buf[20] = '\0';
    EXPECT_EQ(memcmp(buf, "12345678901234567890", 21), 0);
    free(write_file.data);
    write_file.data = NULL;
    write_file.len = 0;

    file.offset = 9;
    tftp_custom_fread(buf, 20, &file);
    EXPECT_EQ(memcmp(buf, "0", 2), 0);
}