/*****************************************************************************
 * Copyright (c) 2014-2019 OpenRCT2 developers
 *
 * For a complete list of all authors, please refer to contributors.md
 * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
 *
 * OpenRCT2 is licensed under the GNU General Public License version 3.
 *****************************************************************************/

#include <openrct2-ui/interface/Graph.h>
#include <openrct2/Context.h>
#include <openrct2/localisation/Date.h>
#include <openrct2/localisation/Localisation.h>

static void graph_draw_months_uint8_t(
    rct_drawpixelinfo* dpi, const uint8_t* history, int32_t count, int32_t baseX, int32_t baseY)
{
    int32_t i, yearOver32, currentMonth, currentDay;

    currentMonth = date_get_month(gDateMonthsElapsed);
    currentDay = gDateMonthTicks;
    yearOver32 = (currentMonth * 4) + (currentDay >> 14) - 31;
    auto screenCoords = ScreenCoordsXY{ baseX, baseY };
    for (i = count - 1; i >= 0; i--)
    {
        if (history[i] != 255 && yearOver32 % 4 == 0)
        {
            // Draw month text
            auto ft = Formatter::Common();
            ft.Add<uint32_t>(DateGameShortMonthNames[date_get_month((yearOver32 / 4) + MONTH_COUNT)]);
            gfx_draw_string_centred(
                dpi, STR_GRAPH_LABEL, screenCoords - ScreenCoordsXY{ 0, 10 }, COLOUR_BLACK, gCommonFormatArgs);

            // Draw month mark
            gfx_fill_rect(dpi, screenCoords.x, screenCoords.y, screenCoords.x, screenCoords.y + 3, PALETTE_INDEX_10);
        }

        yearOver32 = (yearOver32 + 1) % 32;
        screenCoords.x += 6;
    }
}

static void graph_draw_line_a_uint8_t(
    rct_drawpixelinfo* dpi, const uint8_t* history, int32_t count, int32_t baseX, int32_t baseY)
{
    int32_t i, x, y, lastX, lastY;
    lastX = -1;
    lastY = -1;
    x = baseX;
    for (i = count - 1; i >= 0; i--)
    {
        if (history[i] != 255)
        {
            y = baseY + ((255 - history[i]) * 100) / 256;

            if (lastX != -1)
            {
                gfx_draw_line(dpi, lastX + 1, lastY + 1, x + 1, y + 1, PALETTE_INDEX_10);
                gfx_draw_line(dpi, lastX, lastY + 1, x, y + 1, PALETTE_INDEX_10);
            }
            if (i == 0)
                gfx_fill_rect(dpi, x, y, x + 2, y + 2, PALETTE_INDEX_10);

            lastX = x;
            lastY = y;
        }
        x += 6;
    }
}

static void graph_draw_line_b_uint8_t(
    rct_drawpixelinfo* dpi, const uint8_t* history, int32_t count, int32_t baseX, int32_t baseY)
{
    int32_t i, x, y, lastX, lastY;

    lastX = -1;
    lastY = -1;
    x = baseX;
    for (i = count - 1; i >= 0; i--)
    {
        if (history[i] != 255)
        {
            y = baseY + ((255 - history[i]) * 100) / 256;

            if (lastX != -1)
                gfx_draw_line(dpi, lastX, lastY, x, y, PALETTE_INDEX_21);
            if (i == 0)
                gfx_fill_rect(dpi, x - 1, y - 1, x + 1, y + 1, PALETTE_INDEX_21);

            lastX = x;
            lastY = y;
        }
        x += 6;
    }
}

void graph_draw_uint8_t(rct_drawpixelinfo* dpi, uint8_t* history, int32_t count, int32_t baseX, int32_t baseY)
{
    graph_draw_months_uint8_t(dpi, history, count, baseX, baseY);
    graph_draw_line_a_uint8_t(dpi, history, count, baseX, baseY);
    graph_draw_line_b_uint8_t(dpi, history, count, baseX, baseY);
}

static void graph_draw_months_money32(
    rct_drawpixelinfo* dpi, const money32* history, int32_t count, int32_t baseX, int32_t baseY)
{
    int32_t i, yearOver32, currentMonth, currentDay;

    currentMonth = date_get_month(gDateMonthsElapsed);
    currentDay = gDateMonthTicks;
    yearOver32 = (currentMonth * 4) + (currentDay >> 14) - 31;
    auto screenCoords = ScreenCoordsXY{ baseX, baseY };
    for (i = count - 1; i >= 0; i--)
    {
        if (history[i] != MONEY32_UNDEFINED && yearOver32 % 4 == 0)
        {
            // Draw month text
            int32_t monthFormat = DateGameShortMonthNames[date_get_month((yearOver32 / 4) + MONTH_COUNT)];
            gfx_draw_string_centred(dpi, STR_GRAPH_LABEL, screenCoords - ScreenCoordsXY{ 0, 10 }, COLOUR_BLACK, &monthFormat);

            // Draw month mark
            gfx_fill_rect(dpi, screenCoords.x, screenCoords.y, screenCoords.x, screenCoords.y + 3, PALETTE_INDEX_10);
        }

        yearOver32 = (yearOver32 + 1) % 32;
        screenCoords.x += 6;
    }
}

static void graph_draw_line_a_money32(
    rct_drawpixelinfo* dpi, const money32* history, int32_t count, int32_t baseX, int32_t baseY, int32_t modifier,
    int32_t offset)
{
    int32_t i, x, y, lastX, lastY;
    lastX = -1;
    lastY = -1;
    x = baseX;
    for (i = count - 1; i >= 0; i--)
    {
        if (history[i] != MONEY32_UNDEFINED)
        {
            y = baseY + 170 - 6 - ((((history[i] >> modifier) + offset) * 170) / 256);

            if (lastX != -1)
            {
                gfx_draw_line(dpi, lastX + 1, lastY + 1, x + 1, y + 1, PALETTE_INDEX_10);
                gfx_draw_line(dpi, lastX, lastY + 1, x, y + 1, PALETTE_INDEX_10);
            }
            if (i == 0)
                gfx_fill_rect(dpi, x, y, x + 2, y + 2, PALETTE_INDEX_10);

            lastX = x;
            lastY = y;
        }
        x += 6;
    }
}

static void graph_draw_line_b_money32(
    rct_drawpixelinfo* dpi, const money32* history, int32_t count, int32_t baseX, int32_t baseY, int32_t modifier,
    int32_t offset)
{
    int32_t i, x, y, lastX, lastY;

    lastX = -1;
    lastY = -1;
    x = baseX;
    for (i = count - 1; i >= 0; i--)
    {
        if (history[i] != MONEY32_UNDEFINED)
        {
            y = baseY + 170 - 6 - ((((history[i] >> modifier) + offset) * 170) / 256);

            if (lastX != -1)
                gfx_draw_line(dpi, lastX, lastY, x, y, PALETTE_INDEX_21);
            if (i == 0)
                gfx_fill_rect(dpi, x - 1, y - 1, x + 1, y + 1, PALETTE_INDEX_21);

            lastX = x;
            lastY = y;
        }
        x += 6;
    }
}

struct FinancialTooltipInfo
{
    const ScreenCoordsXY coords;
    const money32 money{};
};

struct ScreenRect
{
    const ScreenCoordsXY LeftTop;
    const ScreenCoordsXY RightBottom;

    int32_t GetLeft() const
    {
        return LeftTop.x;
    }
    int32_t GetTop() const
    {
        return LeftTop.y;
    }
    int32_t GetRight() const
    {
        return RightBottom.x;
    }
    int32_t GetBottom() const
    {
        return RightBottom.y;
    }
    int32_t GetWidth() const
    {
        return RightBottom.x - LeftTop.x;
    }
    int32_t GetHeight() const
    {
        return RightBottom.y - LeftTop.y;
    }
    bool Contains(const ScreenCoordsXY& coords) const
    {
        return coords.x >= GetLeft() && coords.x <= GetRight() && coords.y >= GetTop() && coords.y <= GetBottom();
    }
};

static constexpr auto CHART_MAX_DATA_COUNT = 64;
static constexpr auto CHART_MAX_INDEX = CHART_MAX_DATA_COUNT - 1;
static constexpr auto CHART_DATA_WIDTH = 6;
static constexpr auto CHART_MAX_WIDTH = CHART_MAX_INDEX * CHART_DATA_WIDTH;
static constexpr auto CHART_MAX_HEIGHT = 164;
static constexpr auto CURSOR_X_OFFSET = 3;
static constexpr auto DEFAULT_DASHED_LENGTH = 2;

static int32_t IndexForCursorAndHistory(const int32_t historyCount, const int32_t cursorX, const int32_t chartX)
{
    const auto offsettedCursorX = cursorX + CURSOR_X_OFFSET;
    return (historyCount - 1) - (offsettedCursorX - chartX) / CHART_DATA_WIDTH;
}

static const ScreenCoordsXY ScreenCoordsForHistoryIndex(
    const int32_t index, const money32* history, const int32_t chartX, const int32_t chartY, const int32_t modifier,
    const int32_t offset)
{
    ScreenCoordsXY coords;
    coords.x = chartX + CHART_DATA_WIDTH * (CHART_MAX_INDEX - index);
    coords.y = chartY + CHART_MAX_HEIGHT - ((((history[index] >> modifier) + offset) * 170) / 256);
    return coords;
}

static const FinancialTooltipInfo finance_tooltip_info_from_money(
    const money32* history, const int32_t historyCount, const int32_t modifier, const int32_t offset,
    const ScreenRect& chartFrame, const ScreenCoordsXY& cursorPosition)
{
    if (!chartFrame.Contains(cursorPosition))
    {
        return { {}, MONEY32_UNDEFINED };
    }

    const auto historyIndex = IndexForCursorAndHistory(historyCount, cursorPosition.x, chartFrame.GetLeft());
    const auto coords = ScreenCoordsForHistoryIndex(
        historyIndex, history, chartFrame.GetLeft(), chartFrame.GetTop(), modifier, offset);

    return { { coords.x, coords.y }, history[historyIndex] };
}

static void graph_draw_hovered_value(
    rct_drawpixelinfo* dpi, const money32* history, const int32_t historyCount, const int32_t baseX, const int32_t baseY,
    const int32_t modifier, const int32_t offset)
{
    const auto cursorPosition = context_get_cursor_position_scaled();
    const ScreenRect chartFrame{ { baseX, baseY }, { baseX + CHART_MAX_WIDTH, baseY + CHART_MAX_HEIGHT } };

    if (!chartFrame.Contains(cursorPosition))
    {
        return;
    }

    const auto info = finance_tooltip_info_from_money(
        history, CHART_MAX_DATA_COUNT, modifier, offset, chartFrame, cursorPosition);

    if (info.money == MONEY32_UNDEFINED)
    {
        return;
    }

    gfx_draw_dashed_line(dpi, info.coords.x, chartFrame.GetTop(), info.coords.x, info.coords.y, DEFAULT_DASHED_LENGTH, 0);
    gfx_draw_dashed_line(dpi, chartFrame.GetLeft() - 10, info.coords.y, info.coords.x, info.coords.y, DEFAULT_DASHED_LENGTH, 0);

    if (cursorPosition.y > info.coords.y)
    {
        gfx_draw_dashed_line(dpi, info.coords.x, info.coords.y, info.coords.x, cursorPosition.y, DEFAULT_DASHED_LENGTH, 0);
    }

    gfx_draw_string_centred(
        dpi, STR_FINANCES_SUMMARY_EXPENDITURE_VALUE, info.coords - ScreenCoordsXY{ 0, 16 }, COLOUR_BLACK, &info.money);

    gfx_fill_rect(dpi, info.coords.x - 2, info.coords.y - 2, info.coords.x + 2, info.coords.y + 2, PALETTE_INDEX_10);
    gfx_fill_rect(dpi, info.coords.x - 1, info.coords.y - 1, info.coords.x + 1, info.coords.y + 1, PALETTE_INDEX_21);
}

void graph_draw_money32(
    rct_drawpixelinfo* dpi, const money32* history, const int32_t count, const int32_t baseX, const int32_t baseY,
    const int32_t modifier, const int32_t offset)
{
    graph_draw_months_money32(dpi, history, count, baseX, baseY);
    graph_draw_line_a_money32(dpi, history, count, baseX, baseY, modifier, offset);
    graph_draw_line_b_money32(dpi, history, count, baseX, baseY, modifier, offset);
    graph_draw_hovered_value(dpi, history, count, baseX, baseY, modifier, offset);
}