command_tmpl(cmd_ret) {
    std::string retstring;
    for (const std::string & arg : args){
        retstring.append(arg);
    }
    return retstring;
}

command_tmpl(cmd_catch) {
    if (args.size() != 1) {
        return badarguments;
    }
    std::string boolstr = *args.begin();
    if (str_lower(boolstr) == "true")
        catcherrs = true;
    else if (str_lower(boolstr) == "false")
        catcherrs = false;
    else
        return badarguments;
    return success;
}

command_tmpl(cmd_get) {
    if (args.size() != 2) {
        return badarguments;
    }
    auto argsit = args.begin();
    std::string string = *argsit;
    argsit++;
    long unsigned int position = std::stoi(*argsit);
    if (position < string.length()) {
        std::string res;
        res.push_back(string.at(position));
        return res;
    } else {
        return badarguments;
    }
}

command_tmpl(cmd_len) {
    int result = 0;
    for (const std::string & arg : args){
        result += arg.length();
    }
    return std::to_string(result);
}

command_tmpl(cmd_exit) {
    //Check amount of arguments
    if (args.size() != 1) {
        return badarguments;
    }
    std::string exitcode = *args.begin();
    if (is_float(exitcode))
        _exit(std::stoi(exitcode));
    else
        return badarguments;
}

command_tmpl(cmd_marker) {
    // Check amount of arguments
    if (args.size() != 2) {
        return badarguments;
    }
    // Get arguments
    auto argsit = args.begin();
    std::string action = *argsit;
    argsit++;
    std::string markername = *argsit;
    // Set or goto
    if (action == "goto") {
        markergotoname = markername;
        throw markergoto();
    } else if (action == "set") {
        markersetqueue.push_back(markername);
    } else {
        return badarguments;
    }
    return success;
}

command_tmpl(cmd_printnnl) {
    std::cout << cmd_ret(args) << std::flush;
    return success;
}

command_tmpl(cmd_print) {
    auto result = cmd_printnnl(args);
    std::cout << std::endl;
    return result;
}

command_tmpl(cmd_input) {
    std::string hint = cmd_ret(args);
    cmd_printnnl({hint});
    std::string result;
    std::getline(readkbd(hint), result);
    return result;
}

command_tmpl(cmd_set) {
    //Check amount of arguments
    if (args.size() != 2) {
        return badarguments;
    }
    // Get arguments
    auto argsit = args.begin();
    std::string key = *argsit;
    argsit++;
    std::string value = *argsit;
    // Store in environment
    variables[key] = value;
    // Return success
    return success;
}

command_tmpl(cmd_append) {
    //Check amount of arguments
    if (args.size() < 2) {
        return badarguments;
    }
    // Get arguments
    auto argsit = args.begin();
    std::string variablename = *argsit;
    argsit++;
    for (; argsit != args.end(); argsit++)
        variables[variablename].append(*argsit);
    return success;
}

std::string cmd_incdec(bool type, command_args) { // TODO
    bool asint = false;
    //Check amount of arguments
    if (args.size() < 1 or args.size() > 3) {
        return badarguments;
    }
    // Get arguments
    auto argsit = args.begin();
    if (*argsit == "asint") {
        asint = true;
        argsit++;
    }
    std::string variablename = *argsit;
    float incby;
    if (args.size() > 1) {
        argsit++;
        incby = std::atof((*argsit).c_str());
    } else {
        incby = 1;
    }
    // Modify variable if it exists
    if (variables.find(variablename) == variables.end()) {
        return nosuchvariable;
    } else {
        float currval = std::atof(variables[variablename].c_str());
        if (type)
            currval += incby;
        else
            currval -= incby;
        if (!asint)
            variables[variablename] = std::to_string(currval);
        else
            variables[variablename] = std::to_string((int)currval);
    }
    return success;
}
command_tmpl(cmd_inc) {
    return cmd_incdec(true, args);
}
command_tmpl(cmd_dec) {
    return cmd_incdec(false, args);
}

command_tmpl(cmd_del) {
    if (args.size() < 1) {
        return badarguments;
    }
    for (const std::string & arg : args) {
        auto varit = variables.find(arg);
        if (varit != variables.end()) {
            variables.erase(variables.find(arg));
        }
    }
    return success;
}

command_tmpl(cmd_eval) {
    if (args.size() < 1) {
        return badarguments;
    }
    std::string result;
    for (const std::string & arg : args) {
        result = execline(arg);
    }
    return result;
}

command_tmpl(cmd_cmp) {
    bool matches;
    //Check amount of arguments
    if (args.size() < 4) {
        return badarguments;
    }
    // Get arguments
    auto argsit = args.begin();
    std::string action = *argsit;
    argsit++;
    std::string var1 = *argsit;
    argsit++;
    std::string var2 = *argsit;
    argsit++;
    // Compare
    if      (action == "equal")
        matches = var1 == var2;
    else if (action == "nonequal")
        matches = var1 != var2;
    else if (action == "bigger")
        matches = std::atof(var1.c_str()) > std::atof(var2.c_str());
    else if (action == "smaller")
        matches = std::atof(var1.c_str()) < std::atof(var2.c_str());
    else if (action == "isnum" or action == "isnotnum") {
        matches = is_float(var1) and is_float(var2);
        if (action == "isnotnum")
            matches = !matches;
    } else
        return badarguments;
    // Eval on match
    if (matches) {
        std::string result;
        while (argsit != args.end()) {
            result = execline(*argsit);
            argsit++;
        }
        return result;
    } else {
        return failed;
    }
}

std::string cmd_lowerupper(bool type, command_args) {
    if (args.size() < 1) {
        return badarguments;
    }
    std::string result;
    for (auto argsit = args.begin(); argsit != args.end(); argsit++) {
        if (type)
            result.append(str_upper(*argsit));
        else
            result.append(str_lower(*argsit));
    }
    return result;
}
command_tmpl(cmd_upper) {
    return cmd_lowerupper(true, args);
}
command_tmpl(cmd_lower) {
    return cmd_lowerupper(false, args);
}

std::string cmd_addsub(bool type, command_args) {
    //Check amount of arguments
    if (args.size() < 2) {
        return badarguments;
    }
    // Initialise variables
    bool asint = false;
    float numarg;
    // Get arguments
    auto argsit = args.begin();
    if (*argsit == "asint") {
        asint = true;
        argsit++;
    }
    // Initialise initial result
    if (!is_float(*argsit))
        return badarguments;
    float result = std::atof((*argsit).c_str());
    argsit++;
    // Calculate
    for (; argsit != args.end(); argsit++) {
        if (!is_float(*argsit))
            return badarguments;
        numarg = std::atof((*argsit).c_str());
        if (type)
            result += numarg;
        else
            result -= numarg;
    }
    // Return result
    if (asint)
        return std::to_string((int) result);
    else
        return std::to_string(result);
}
command_tmpl(cmd_add) {
    return cmd_addsub(true, args);
}
command_tmpl(cmd_sub) {
    return cmd_addsub(false, args);
}

command_tmpl(cmd_sleep) {
    // Check amount of arguments
    if (args.size() != 1) {
        return badarguments;
    }
    // Check argument
    auto argsit = args.begin();
    if (!is_float(*argsit))
        return badarguments;
    // Get argument
    float sleepsecs = std::atof((*argsit).c_str());
    sleep(sleepsecs);
    return success;
}

command_tmpl(cmd_argv) {
    // Check amount of arguments
    if (args.size() != 1) {
        return badarguments;
    }
    // Check argument
    auto argsit = args.begin();
    if (!is_float(*argsit))
        return badarguments;
    long unsigned int argnum = std::atoi((*argsit).c_str());
    if (argnum >= cmdargs.size())
        return badarguments;
    // Get argument
    return cmdargs[argnum];
}

command_tmpl(cmd_argc) {
    return std::to_string(cmdargs.size());
}

command_tmpl(cmd_commands) {
    std::stringstream res;
    for (auto it = commands.begin(); it != commands.end(); it++) {
        res << &it->first[sizeof("cmd_") - 1] << " ";
    }
    return res.str();
}


void register_builtin_commands() {
    command_register(cmd_argc);
    command_register(cmd_argv);
    command_register(cmd_sleep);
    command_register(cmd_add);
    command_register(cmd_sub);
    command_register(cmd_upper);
    command_register(cmd_lower);
    command_register(cmd_eval);
    command_register(cmd_cmp);
    command_register(cmd_del);
    command_register(cmd_append);
    command_register(cmd_inc);
    command_register(cmd_dec);
    command_register(cmd_set);
    command_register(cmd_input);
    command_register(cmd_print);
    command_register(cmd_printnnl);
    command_register(cmd_marker);
    command_register(cmd_exit);
    command_register(cmd_len);
    command_register(cmd_get);
    command_register(cmd_catch);
    command_register(cmd_ret);
    command_register(cmd_commands);
}