#include "gtest/gtest.h"
#include "BufferView.h"

static std::shared_ptr<Buffer> buffer1()
{
    static const char data[] =
        "0\n"
        "1ab\n"
        "2abc\n"
        "3\n"
        "4\n"
        "5\n"
        "6abcdefg\n"
        "7\n"
        "8\n"
        "9abcdefghijklmno\n"
        "10\n"
        "11\n"
        "12\n";
    return std::make_shared<Buffer>((const uint8_t *)data, strlen(data));
}

static std::shared_ptr<Buffer> buffer_empty()
{
    return std::make_shared<Buffer>(nullptr, 0u);
}

class MyCharacterWidthDeterminer : public CharacterWidthDeterminer
{
    int operator()(uint32_t character)
    {
        if (character < 32)
        {
            return 2;
        }
        else
        {
            return 1;
        }
    }
} Cwd;

static int LineNumber(const Buffer::Iterator & iterator)
{
    int line_number = 0;
    Buffer::Iterator i = iterator;
    for (;;)
    {
        uint32_t c = *i;
        if ((c < '0') || (c > '9'))
            break;
        line_number *= 10;
        line_number += ((int)c - '0');
        i.go_forward();
    }
    return line_number;
}

TEST(BufferViewTest, iter_lines_does_not_call_callback_for_empty_buffer)
{
    std::shared_ptr<Buffer> b = buffer_empty();
    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
    BufferView bv(b, iterator, Cwd);
    bv.resize(40, 8);
    int times_called = 0;
    bv.iter_lines([&times_called](int row_offset, const Buffer::Iterator & iterator) -> bool {
            times_called++;
            return true;
            });
    EXPECT_EQ(0, times_called);
    EXPECT_EQ(0, bv.cursor_screen_row());
    EXPECT_EQ(0, bv.cursor_screen_column());
    EXPECT_EQ(0, bv.cursor_virtual_column());
}

TEST(BufferViewTest, iterates_through_screen_lines_with_no_wrapping)
{
    std::shared_ptr<Buffer> b = buffer1();
    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
    BufferView bv(b, iterator, Cwd);
    bv.resize(40, 8);
    int times_called = 0;
    bv.iter_lines([&times_called](int row_offset, const Buffer::Iterator & iterator) -> bool {
            EXPECT_EQ(times_called, LineNumber(iterator));
            times_called++;
            return true;
            });
    EXPECT_EQ(8, times_called);
    EXPECT_EQ(0, bv.cursor_screen_row());
    EXPECT_EQ(0, bv.cursor_screen_column());
    EXPECT_EQ(0, bv.cursor_virtual_column());
}

TEST(BufferViewTest, iterates_through_screen_lines_with_wrapping)
{
    std::shared_ptr<Buffer> b = buffer1();
    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
    BufferView bv(b, iterator, Cwd);
    bv.resize(3, 10);
    int times_called = 0;
    int expected_row_offsets[] = {0, 1, 2, 4, 5, 6, 7};
    bv.iter_lines([&times_called, &expected_row_offsets](int row_offset, const Buffer::Iterator & iterator) -> bool {
            EXPECT_EQ(times_called, LineNumber(iterator));
            EXPECT_EQ(expected_row_offsets[times_called], row_offset);
            times_called++;
            return true;
            });
    EXPECT_EQ(7, times_called);
    EXPECT_EQ(0, bv.cursor_screen_row());
    EXPECT_EQ(0, bv.cursor_screen_column());
    EXPECT_EQ(0, bv.cursor_virtual_column());
}

TEST(BufferViewTest, fills_view_with_last_lines_of_buffer_when_cursor_warps_to_last_line)
{
    std::shared_ptr<Buffer> b = buffer1();
    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
    BufferView bv(b, iterator, Cwd);
    while (iterator->go_next_line())
    {
    }
    bv.resize(40, 3);
    int times_called = 0;
    int expected_row_offsets[] = {0, 1, 2};
    bv.iter_lines([&times_called, &expected_row_offsets](int row_offset, const Buffer::Iterator & iterator) -> bool {
            EXPECT_EQ(10 + times_called, LineNumber(iterator));
            EXPECT_EQ(expected_row_offsets[times_called], row_offset);
            times_called++;
            return true;
            });
    EXPECT_EQ(3, times_called);
    EXPECT_EQ(2, bv.cursor_screen_row());
    EXPECT_EQ(0, bv.cursor_screen_column());
    EXPECT_EQ(0, bv.cursor_virtual_column());
}