#include <cruft/util/tap.hpp>
#include <cruft/util/string.hpp>
#include <cruft/util/types.hpp>
#include <cruft/util/iterator/zip.hpp>

#include <vector>


///////////////////////////////////////////////////////////////////////////////
void
test_transforms (cruft::TAP::logger &tap)
{
    static struct {
        std::string initial;
        std::string upper;
        std::string lower;

        char const *message;
    } const TESTS[] = {
        { "a", "A", "a", "single lower character" },
        { "A", "A", "a", "single upper character" },
        { "asdf", "ASDF", "asdf", "four lower characters" },
        { "ASDF", "ASDF", "asdf", "four upper characters" },

        { "Don't.", "DON'T.", "don't.", "upper and lower and symbols" },
    };

    for (auto const &[src, upper, lower, msg]: TESTS) {
        tap.expect_eq (cruft::to_upper (src), upper, "to_upper, {:s}", msg);
        tap.expect_eq (cruft::to_lower (src), lower, "to_lower, {:s}", msg);
    }
}


///////////////////////////////////////////////////////////////////////////////
void
test_position (cruft::TAP::logger &tap)
{
    char const *string = "a\nb\nc\n";

    struct {
        int offset;

        int line;
        int column;
    } TESTS[] = {
        { 0, 0,  0 },
        { 1, 1, -1 },
        { 2, 1,  0 },
        { 3, 2, -1 },
        { 4, 2,  0 },
        { 5, 3, -1 },
    };

    for (auto const &t: TESTS) {
        auto const pos = cruft::character_position ({string, strlen(string) }, string + t.offset);

        tap.expect (
            pos.line == t.line && pos.column == t.column,
            "character_position {}:{}",
            t.line,
            t.column
        );
    }
}


///////////////////////////////////////////////////////////////////////////////
static void
test_short_tokeniser (cruft::TAP::logger &tap)
{
    struct {
        char const *src;
        std::vector<std::string_view> parts;
        char const *message;
    } TESTS[] = {
        { "foo", { "foo" }, "no separator" },
        { "foo bar", { "foo", "bar" }, "one separator" },
        { " foo", { "", "foo" }, "leading separator" },
        { "foo ", { "foo", "" }, "trailing separator" },
        { "", { }, "no separators" },
        { " ", { "", "" }, "only separators, single" },
        { "  ", { "", "", "" }, "only separators, double" },
    };

    for (auto const &[src, expected, message]: TESTS) {
        std::vector<std::string_view> computed;
        cruft::tokeniser const tok (src, ' ');
        std::transform (
            std::begin (tok),
            std::end   (tok),
            std::back_inserter (computed),
            [] (auto const i)
        {
            return std::string_view (i.begin (), i.size ());
        });

        tap.expect_eq (expected, computed, "tokeniser: {}", message);
    }
}


//-----------------------------------------------------------------------------
static void
test_long_tokeniser (cruft::TAP::logger &tap)
{
    // the string_literal prefix is required to (easily) construct a string
    // with an internal null character.
    using namespace std::literals::string_literals;
    const std::string csv = "\0,a,123,,this is a test,"s;

    // expected test data must be a std::string so we can check embedded
    // nulls (which are ambiguous when using a cstr).
    struct foo {
        const std::string value;
        const char *message;
    } TESTS[] = {
        { "\0"s,            "null" },
        { "a",              "single letter" },
        { "123",            "three digits" },
        { "",               "empty string" },
        { "this is a test", "string with spaces" },
        { "",               "trailing empty" }
    };

    cruft::view src { csv.c_str (), csv.size () };
    for (auto [tok, expected]: cruft::iterator::zip (cruft::tokeniser (src, ','), TESTS)) {
        tap.expect (equal (tok, expected.value), "{:s}", expected.message);
    }
}


///////////////////////////////////////////////////////////////////////////////
void
test_contains (cruft::TAP::logger &tap)
{
    struct {
        char const *haystack;
        char separator;
        char const *needle;
        bool expected;
        char const *message;
    } const TESTS[] = {
        {
            .haystack = "foo",
            .separator = ',',
            .needle = "foo",
            .expected = true,
            .message = "needle is haystack"
        },

        {
            .haystack = "",
            .separator = ',',
            .needle = "foo",
            .expected = false,
            .message = "haystack is empty",
        },

        {
            .haystack = "foo",
            .separator = ',',
            .needle = "",
            .expected = false,
            .message = "needle is empty",
        },

        {
            .haystack = "a,b,foo",
            .separator = ',',
            .needle = "foo",
            .expected = true,
            .message = "needle is last",
        },

        {
            .haystack = "foo,b,c",
            .separator = ',',
            .needle = "foo",
            .expected = true,
            .message = "needle is first",
        },
        {
            .haystack = "foo,b,c",
            .separator = ';',
            .needle = "foo",
            .expected = false,
            .message = "separator is mismatched",
        },
        {
            .haystack = "a;b;foo",
            .separator = ';',
            .needle = "foo",
            .expected = true,
            .message = "separator isn't default"
        }
    };

    for (auto const &t: TESTS) {
        cruft::tokeniser tok (t.haystack, t.separator);
        auto const found = tok.contains (t.needle);
        tap.expect_eq (found, t.expected, "{}", t.message);
    }
}


///////////////////////////////////////////////////////////////////////////////
void test_comparator_less (cruft::TAP::logger &tap)
{
    cruft::string_less cmp;

    struct {
        char const *a;
        char const *b;
        bool less;
        char const *message;
    } const TESTS[] = {
        { "a", "b",  true,  "single char less-than" },
        { "b", "a",  false, "single char not-less-than" },
        { "a", "aa", true,  "single/double char less-than" },
    };

    for (auto const &t: TESTS)
        tap.expect_eq (cmp (t.a, t.b), t.less, "string_less, {}", t.message);
}


///////////////////////////////////////////////////////////////////////////////
void test_less_lower (cruft::TAP::logger &tap)
{
    struct {
        char const *a;
        char const *b;
        bool expected;
        char const *message;
    } const TESTS[] = {
        { "a", "b", true, "single letter lhs" },
        { "b", "a", false, "single letter rhs" },

        { "a", "a", false, "single lower equal" },
        { "a", "A", false, "lower, upper singles" },
        { "A", "a", false, "upper, lower singles" },

        { "a", "aa", true, "shorter lhs" },
        { "aa", "a", false, "shorter hhs" },

        { "date", "User-Agent", true, "lower lhs, upper rhs" },
    };

    cruft::string::less_lower cmp;

    for (auto const &t: TESTS) {
        tap.expect_eq (cmp (t.a, t.b), t.expected, "less::lower, pointers, {}", t.message);
        tap.expect_eq (
            cmp (
                std::string_view {t.a},
                std::string_view {t.b}
            ),
            t.expected,
            "less::lower, string_view, {}",
            t.message
        );
    }
}


///////////////////////////////////////////////////////////////////////////////
void test_equality_lower (cruft::TAP::logger &tap)
{
    struct {
        char const *a;
        char const *b;
        bool equal;
        char const *message;
    } const TESTS[] = {
        { "a", "a", true, "both single lower" },
        { "a", "A", true, "lower, upper singles" },
        { "A", "a", true, "upper, lower singles" },
        { "AbcDEf", "aBcdEF", true, "mixed upper lower" },
        { "A", "aa", false, "mixed case, different lengths" },
    };

    cruft::string::equality::lower cmp;

    for (auto const &t: TESTS)
        tap.expect_eq (cmp (t.a, t.b), t.equal, "equality::lower, pointers, {}", t.message);
}


///////////////////////////////////////////////////////////////////////////////
static void
test_strip (cruft::TAP::logger &tap)
{
    static constexpr struct {
        char const *val;
        char const *expected_l;
        char const *expected_r;
        char const *msg;
    } TESTS[] = {
        { "asdf", "asdf", "asdf", "no stripping" },
        { "", "", "", "empty string" },
        { " ", "", "", "only space" },
        { " \nasdf", "asdf", " \nasdf", "left space" },
        { "asdf \n", "asdf \n", "asdf", "right space" },
        { " asdf ", "asdf ", " asdf", "both space" },
    };

    for (auto const &t: TESTS) {
        tap.expect_eq (t.expected_l, cruft::lstrip (t.val), "lstrip: {}", t.msg);
        tap.expect_eq (t.expected_r, cruft::rstrip (t.val), "rstrip: {}", t.msg);
    }
}


///////////////////////////////////////////////////////////////////////////////
int
main (int, char**)
{
    cruft::TAP::logger tap;

    test_transforms (tap);
    test_short_tokeniser (tap);
    test_long_tokeniser (tap);
    test_position (tap);
    test_contains (tap);
    test_comparator_less (tap);
    test_less_lower (tap);
    test_equality_lower (tap);
    test_strip (tap);

    return tap.status ();
}