/*
 *  <Short Description>
 *  Copyright (C) 2025  Brett Terpstra
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include <blt/parse/argparse_v2.h>
#include <blt/std/assert.h>

namespace blt::argparse
{
    namespace detail
    {
        std::string flag_prefixes_as_string()
        {
            std::string result;
            for (auto [i, v] : enumerate(allowed_flag_prefixes))
            {
                result += '\'';
                result += v;
                result += '\'';
                if (i != allowed_flag_prefixes.size() - 2)
                    result += ", ";
                else if (i != allowed_flag_prefixes.size() - 1)
                {
                    if (allowed_flag_prefixes.size() > 2)
                        result += ',';
                    result += " or ";
                }
            }
            return result;
        }
    }


    namespace detail
    {
        // Unit Tests for class argument_string_t
        // Test Case 1: Ensure the constructor handles flags correctly
        void test_argument_string_t_flag_basic()
        {
            const argument_string_t arg("-f");
            BLT_ASSERT(arg.is_flag() && "Expected argument to be identified as a flag.");
            BLT_ASSERT(arg.value() == "f" && "Flag value should match the input string.");
        }

        // Test Case 2: Ensure the constructor handles long flags correctly
        void test_argument_string_t_long_flag()
        {
            const argument_string_t arg("--file");
            BLT_ASSERT(arg.is_flag() && "Expected argument to be identified as a flag.");
            BLT_ASSERT(arg.value() == "file" && "Long flag value should match the input string.");
        }

        // Test Case 3: Ensure positional arguments are correctly identified
        void test_argument_string_t_positional_argument()
        {
            const argument_string_t arg("filename.txt");
            BLT_ASSERT(!arg.is_flag() && "Expected argument to be identified as positional.");
            BLT_ASSERT(arg.value() == "filename.txt" && "Positional argument value should match the input string.");
        }

        // Test Case 5: Handle an empty string
        void test_argument_string_t_empty_input()
        {
            const argument_string_t arg("");
            BLT_ASSERT(!arg.is_flag() && "Expected an empty input to be treated as positional, not a flag.");
            BLT_ASSERT(arg.value().empty() && "Empty input should have an empty value.");
        }

        // Test Case 6: Handle edge case of a single hyphen (`-`) which might be ambiguous
        void test_argument_string_t_single_hyphen()
        {
            const argument_string_t arg("-");
            BLT_ASSERT(arg.is_flag() && "Expected single hyphen (`-`) to be treated as a flag.");
            BLT_ASSERT(arg.value().empty() && "Single hyphen flag should have empty value.");
            BLT_ASSERT(arg.get_flag() == "-" && "Single hyphen flag should match the input string.");
        }

        // Test Case 8: Handle arguments with prefix only (like "--")
        void test_argument_string_t_double_hyphen()
        {
            const argument_string_t arg("--");
            BLT_ASSERT(arg.is_flag() && "Double hyphen ('--') should be treated as a flag.");
            BLT_ASSERT(arg.value().empty() && "Double hyphen flag should have empty value.");
            BLT_ASSERT(arg.get_flag() == "--" && "Double hyphen value should match the input string.");
        }

        // Test Case 9: Validate edge case of an argument with spaces
        void test_argument_string_t_with_spaces()
        {
            try
            {
                const argument_string_t arg("  ");
                BLT_ASSERT(!arg.is_flag() && "Arguments with spaces should not be treated as flags.");
                BLT_ASSERT(arg.value() == "  " && "Arguments with spaces should match the input string.");
            } catch (bad_flag&)
            {
                return;
            }
            BLT_ASSERT(false && "Expected an exception to be thrown for arguments with spaces.");
        }

        // Test Case 10: Validate arguments with numeric characters
        void test_argument_string_t_numeric_flag()
        {
            const argument_string_t arg("-123");
            BLT_ASSERT(arg.is_flag() && "Numeric flags should still be treated as flags.");
            BLT_ASSERT(arg.value() == "123" && "Numeric flag value should match the input string.");
        }

        void run_all_tests_argument_string_t()
        {
            test_argument_string_t_flag_basic();
            test_argument_string_t_long_flag();
            test_argument_string_t_positional_argument();
            test_argument_string_t_empty_input();
            test_argument_string_t_single_hyphen();
            test_argument_string_t_double_hyphen();
            test_argument_string_t_with_spaces();
            test_argument_string_t_numeric_flag();
        }
        void test()
        {
            run_all_tests_argument_string_t();
        }
    }
}