#include "gtest/gtest.h"
#include "Encoding.h"
#include <string>

TEST(Encoding_detect_encoding, returns_UTF_8_for_all_ascii)
{
    uint8_t buffer[] = "ABCDEFG 12345";
    EXPECT_EQ(Encoding::UTF_8, Encoding::detect_encoding(buffer, sizeof(buffer) - 1));
}

TEST(Encoding_detect_encoding, returns_UTF_8_for_valid_encodings)
{
    uint8_t buffer[] = "%\xC1\x82\xE1\x82\x83\xF1\x82\x83\x84\xF9\x82\x83\x84\x85\xFD\x82\x83\x84\x85\x86yay";
    EXPECT_EQ(Encoding::UTF_8, Encoding::detect_encoding(buffer, sizeof(buffer) - 1));
}

TEST(Encoding_detect_encoding, returns_CP_1252_if_not_valid_utf_8)
{
    uint8_t buffer[] = "ABC\xEE\xCC";
    EXPECT_EQ(Encoding::CP_1252, Encoding::detect_encoding(buffer, sizeof(buffer) - 1));
}


TEST(Encoding_num_bytes_in_code_point, returns_1_for_UTF_8_ascii_character)
{
    uint8_t buffer[] = "Z";
    EXPECT_EQ(1, Encoding::num_bytes_in_code_point(Encoding::UTF_8, buffer));
}

TEST(Encoding_num_bytes_in_code_point, returns_1_for_CP_1252_character)
{
    uint8_t buffer[] = "\x96";
    EXPECT_EQ(1, Encoding::num_bytes_in_code_point(Encoding::CP_1252, buffer));
}

TEST(Encoding_num_bytes_in_code_point, returns_3_for_UTF_8_multi_byte)
{
    uint8_t buffer[] = "\xE1\x82\x83";
    EXPECT_EQ(3, Encoding::num_bytes_in_code_point(Encoding::UTF_8, buffer));
}


TEST(Encoding_beginning_of_code_point, returns_pointer_to_beginning_of_code_point_for_UTF_8)
{
    uint8_t buffer[] = "12\xE1\x82\x83";
    EXPECT_EQ(&buffer[2], Encoding::beginning_of_code_point(Encoding::UTF_8, &buffer[4]));
}

TEST(Encoding_beginning_of_code_point, returns_pointer_to_beginning_of_code_point_for_CP_1252)
{
    uint8_t buffer[] = "12\xE1\x82\x83";
    EXPECT_EQ(&buffer[4], Encoding::beginning_of_code_point(Encoding::CP_1252, &buffer[4]));
}


TEST(Encoding_decode, decodes_UTF_8_correctly)
{
    uint8_t size = 0xFFu;
    EXPECT_EQ((uint32_t)'%', Encoding::decode(Encoding::UTF_8, (const uint8_t *)"%", &size));
    EXPECT_EQ(1u, size);
    EXPECT_EQ(0x42u, Encoding::decode(Encoding::UTF_8, (const uint8_t *)"\xC1\x82", &size));
    EXPECT_EQ(2u, size);
    EXPECT_EQ(0x1083u, Encoding::decode(Encoding::UTF_8, (const uint8_t *)"\xE1\x82\x83", &size));
    EXPECT_EQ(3u, size);
    EXPECT_EQ(0x420C4u, Encoding::decode(Encoding::UTF_8, (const uint8_t *)"\xF1\x82\x83\x84", &size));
    EXPECT_EQ(4u, size);
    EXPECT_EQ(0x1083105u, Encoding::decode(Encoding::UTF_8, (const uint8_t *)"\xF9\x82\x83\x84\x85", &size));
    EXPECT_EQ(5u, size);
    EXPECT_EQ(0x420C4146u, Encoding::decode(Encoding::UTF_8, (const uint8_t *)"\xFD\x82\x83\x84\x85\x86", &size));
    EXPECT_EQ(6u, size);
}

TEST(Encoding_decode, decodes_CP_1252_correctly)
{
    uint8_t size;
    EXPECT_EQ(0x99u, Encoding::decode(Encoding::CP_1252, (const uint8_t *)"\x99", &size));
    EXPECT_EQ(1u, size);
}


TEST(Encoding_encode, encodes_UTF_8_correctly)
{
    struct
    {
        uint32_t code_point;
        const char * expected;
    } tests[] = {
        {(uint32_t)'%', "%"},
        {0x567u, "\xD5\xA7"},
        {0x9876u, "\xE9\xA1\xB6"},
        {0x12345u, "\xF0\x92\x8D\x85"},
        {0x1234567u, "\xF9\x88\xB4\x95\xA7"},
        {0x12345678u, "\xFC\x92\x8D\x85\x99\xB8"},
    };
    for (unsigned int i = 0; i < sizeof(tests) / sizeof(tests[0]); i++)
    {
        char buffer[10] = {0};
        EXPECT_EQ(strlen(tests[i].expected), Encoding::encode(tests[i].code_point, Encoding::UTF_8, (uint8_t *)buffer));
        EXPECT_EQ(std::string(tests[i].expected), buffer);
    }
}

TEST(Encoding_encode, encodes_CP_1252_correctly)
{
    char buffer[10] = {0};
    EXPECT_EQ(1, Encoding::encode(0x89u, Encoding::CP_1252, (uint8_t *)buffer));
    EXPECT_EQ(std::string("\x89"), buffer);
}