#include "ResolutionEditor.h"
#include "UIWidgets.h"
#include "libultraship/src/Context.h"

#include <imgui.h>
#include <libultraship/libultraship.h>
#include <graphic/Fast3D/gfx_pc.h>

/*  Console Variables are grouped under gAdvancedResolution. (e.g. "gAdvancedResolution.Enabled")

    The following CVars are used in Libultraship and can be edited here:
        - Enabled                                       - Turns Advanced Resolution Mode on.
        - AspectRatioX, AspectRatioY                    - Aspect ratio controls. To toggle off, set either to zero.
        - VerticalPixelCount, VerticalResolutionToggle  - Resolution controls.
        - PixelPerfectMode, IntegerScale.Factor         - Pixel Perfect Mode a.k.a. integer scaling controls.
    (Waiting on a second PR merge on LUS for this to fully function.):
        - IntegerScale.FitAutomatically                 - Automatic resizing for Pixel Perfect Mode.
        - IntegerScale.NeverExceedBounds                - Prevents manual resizing from exceeding screen bounds.

    The following CVars are also implemented in LUS for niche use cases:
        - IgnoreAspectCorrection                        - Stretch framebuffer to fill screen.
            This is something of a power-user setting for niche setups that most people won't need or care about,
            but may be useful if playing the Switch/Wii U ports on a 4:3 television.
        - IntegerScale.ExceedBoundsBy                   - Offset the max screen bounds, usually by +1.
                                                          This isn't that useful at the moment.
*/

namespace AdvancedResolutionSettings {
    enum setting { UPDATE_aspectRatioX, UPDATE_aspectRatioY, UPDATE_verticalPixelCount };

    const char* aspectRatioPresetLabels[] = {
            "Off", "Custom", "Original (4:3)", "Widescreen (16:9)", "Nintendo 3DS (5:3)", "16:10 (8:5)", "Ultrawide (21:9)"
    };
    const float aspectRatioPresetsX[] = { 0.0f, 12.0f, 4.0f, 16.0f, 5.0f, 16.0f, 21.0f };
    const float aspectRatioPresetsY[] = { 0.0f, 9.0f, 3.0f, 9.0f, 3.0f, 10.0f, 9.0f };
    const int default_aspectRatio = 1; // Default combo list option

    const char* pixelCountPresetLabels[] = { "Custom",     "Native N64 (240p)", "2x (480p)",       "3x (720p)", "4x (960p)",
                                             "5x (1200p)", "6x (1440p)",        "Full HD (1080p)", "4K (2160p)" };
    const int pixelCountPresets[] = { 480, 240, 480, 720, 960, 1200, 1440, 1080, 2160, 480 };
    const int default_pixelCount = 0; // Default combo list option

    const uint32_t minVerticalPixelCount = 240; // see: Ship::AdvancedResolution()
    const uint32_t maxVerticalPixelCount = 4320;

    const unsigned short default_maxIntegerScaleFactor = 6; // Default size of Integer scale factor slider.

    const float enhancementSpacerHeight = 19.0f;
// This will need to be determined more intelligently when Hi-DPI UI support is added.

    void AdvancedResolutionSettingsWindow::InitElement() {
    }

    void AdvancedResolutionSettingsWindow::DrawElement() {
        ImGui::SetNextWindowSize(ImVec2(497, 532), ImGuiCond_FirstUseEver);
        if (ImGui::Begin("Advanced Resolution Settings", &mIsVisible)) {
            // Initialise update flags.
            bool update[sizeof(setting)];
            for (unsigned short i = 0; i < sizeof(setting); i++)
                update[i] = false;
            static short updateCountdown = 0;
            short countdownStartingValue = CVarGetInteger("gInterpolationFPS", 60) / 2; // half of a second, in frames.

            // Initialise integer scale bounds.
            short max_integerScaleFactor = default_maxIntegerScaleFactor; // default value, which may or may not get
            // overridden depending on viewport res

            short integerScale_maximumBounds = 1; // can change when window is resized
            // This is mostly just for UX purposes, as Fit Automatically logic is part of LUS.
            if (((float)gfx_current_game_window_viewport.width / gfx_current_game_window_viewport.height) >
                ((float)gfx_current_dimensions.width / gfx_current_dimensions.height)) {
                // Scale to window height
                integerScale_maximumBounds = gfx_current_game_window_viewport.height / gfx_current_dimensions.height;
            } else {
                // Scale to window width
                integerScale_maximumBounds = gfx_current_game_window_viewport.width / gfx_current_dimensions.width;
            }
            // Lower-clamping maximum bounds value to 1 is no-longer necessary as that's accounted for in LUS.
            // Letting it go below 1 in this Editor will even allow for checking if screen bounds are being exceeded.
            if (default_maxIntegerScaleFactor < integerScale_maximumBounds) {
                max_integerScaleFactor =
                        integerScale_maximumBounds + CVarGetInteger("gAdvancedResolution.IntegerScale.ExceedBoundsBy", 0);
            }

            // Stored Values for non-UIWidgets elements
            static float aspectRatioX = CVarGetFloat("gAdvancedResolution.AspectRatioX", 16.0f);
            static float aspectRatioY = CVarGetFloat("gAdvancedResolution.AspectRatioY", 9.0f);
            static int verticalPixelCount = CVarGetInteger("gAdvancedResolution.VerticalPixelCount", 480);
            // Combo List defaults
            static int item_aspectRatio = default_aspectRatio;
            static int item_pixelCount = default_pixelCount;
            // Additional settings
            static bool showHorizontalResField = false;
            static int horizontalPixelCount = (verticalPixelCount / aspectRatioY) * aspectRatioX;

#ifdef __APPLE__
            ImGui::Text("Note: these settings may behave incorrectly on Apple Retina Displays.");
            UIWidgets::PaddedSeparator(true, true, 3.0f, 3.0f);
#endif

            // The original resolution slider (for convenience)
            if (UIWidgets::EnhancementSliderFloat("Internal Resolution: %d %%", "##IMul", "gInternalResolution", 0.5f, 2.0f,
                                                  "", 1.0f, true, true,
                                                  (CVarGetInteger("gAdvancedResolution.VerticalResolutionToggle", 0) &&
                                                   CVarGetInteger("gAdvancedResolution.Enabled", 0)) ||
                                                  CVarGetInteger("gLowResMode", 0))) {
                Ship::Context::GetInstance()->GetWindow()->SetResolutionMultiplier(CVarGetFloat("gInternalResolution", 1));
            }
            UIWidgets::Tooltip("Multiplies your output resolution by the value entered, as a more intensive but effective "
                               "form of anti-aliasing"); // Description pulled from SohMenuBar.cpp

            // N64 Mode toggle (again for convenience)
            // UIWidgets::PaddedEnhancementCheckbox("(Enhancements>Graphics) N64 Mode", "gLowResMode", false, false, false,
            //                                      "", UIWidgets::CheckboxGraphics::Cross, false);

            UIWidgets::PaddedSeparator(true, true, 3.0f, 3.0f);
            // Activator
            UIWidgets::PaddedEnhancementCheckbox("Enable advanced settings.", "gAdvancedResolution.Enabled", false, false,
                                                 false, "", UIWidgets::CheckboxGraphics::Cross, false);
            // Error/Warning display
            if (!CVarGetInteger("gLowResMode", 0)) {
                if (IsDroppingFrames()) { // Significant frame drop warning
                    ImGui::TextColored({ 0.85f, 0.85f, 0.0f, 1.0f },
                                       ICON_FA_EXCLAMATION_TRIANGLE " Significant frame rate (FPS) drops may be occuring.");
                    UIWidgets::Spacer(2);
                } else { // No warnings
                    UIWidgets::Spacer(enhancementSpacerHeight);
                }
            } else { // N64 Mode warning
                ImGui::TextColored({ 0.0f, 0.85f, 0.85f, 1.0f },
                                   ICON_FA_QUESTION_CIRCLE " \"N64 Mode\" is overriding these settings.");
                ImGui::SameLine();
                if (ImGui::Button("Click to disable")) {
                    CVarSetInteger("gLowResMode", (int)false);
                    CVarSave();
                }
            }
            // Resolution visualiser
            ImGui::Text("Viewport dimensions: %d x %d", gfx_current_game_window_viewport.width,
                        gfx_current_game_window_viewport.height);
            ImGui::Text("Internal resolution: %d x %d", gfx_current_dimensions.width, gfx_current_dimensions.height);

            UIWidgets::PaddedSeparator(true, true, 3.0f, 3.0f);

            // Aspect Ratio
            ImGui::Text("Force aspect ratio:");
            ImGui::SameLine();
            ImGui::TextColored({ 0.75f, 0.75f, 0.75f, 1.0f }, "(Select \"Off\" to disable.)");
            if (ImGui::Combo(" ", &item_aspectRatio, aspectRatioPresetLabels,
                             IM_ARRAYSIZE(aspectRatioPresetLabels)) &&
                item_aspectRatio != default_aspectRatio) { // don't change anything if "Custom" is selected.
                aspectRatioX = aspectRatioPresetsX[item_aspectRatio];
                aspectRatioY = aspectRatioPresetsY[item_aspectRatio];
                update[UPDATE_aspectRatioX] = true;
                update[UPDATE_aspectRatioY] = true;

                if (showHorizontalResField) {
                    horizontalPixelCount = (verticalPixelCount / aspectRatioY) * aspectRatioX;
                }
            }
            if (item_aspectRatio == default_aspectRatio && !showHorizontalResField) {
                // Declaring the Y input interaction in particular as a variable beforehand
                // will prevent a bug where the Y field would disappear when modifying X.
                bool inputX = ImGui::InputFloat("X", &aspectRatioX, 0.1f, 1.0f, "%.3f");
                bool inputY = ImGui::InputFloat("Y", &aspectRatioY, 0.1f, 1.0f, "%.3f");
                if (inputX || inputY) {
                    item_aspectRatio = default_aspectRatio;
                    update[UPDATE_aspectRatioX] = true;
                    update[UPDATE_aspectRatioY] = true;
                }
            } else if (showHorizontalResField) { // Show calculated aspect ratio
                if (item_aspectRatio) {
                    UIWidgets::Spacer(2);
                    float resolvedAspectRatio = (float)gfx_current_dimensions.height / gfx_current_dimensions.width;
                    ImGui::Text("Aspect ratio: %.4f", resolvedAspectRatio);
                } else {
                    UIWidgets::Spacer(enhancementSpacerHeight);
                }
            }

            UIWidgets::Spacer(0);
            // Vertical Resolution
            UIWidgets::PaddedEnhancementCheckbox("Set fixed vertical resolution (disables Resolution slider)",
                                                 "gAdvancedResolution.VerticalResolutionToggle", true, false, false, "",
                                                 UIWidgets::CheckboxGraphics::Cross, false);
            UIWidgets::Tooltip(
                    "Override the resolution scale slider and use the settings below, irrespective of window size.");
            if (ImGui::Combo("Pixel Count Presets", &item_pixelCount, pixelCountPresetLabels,
                             IM_ARRAYSIZE(pixelCountPresetLabels)) &&
                item_pixelCount != default_pixelCount) { // don't change anything if "Custom" is selected.
                verticalPixelCount = pixelCountPresets[item_pixelCount];
                update[UPDATE_verticalPixelCount] = true;

                if (showHorizontalResField) {
                    horizontalPixelCount = (verticalPixelCount / aspectRatioY) * aspectRatioX;
                }
            }
            // Horizontal Resolution, if visibility is enabled for it.
            if (showHorizontalResField) {
                // Only show the field if Aspect Ratio is being enforced.
                if ((aspectRatioX > 0.0f) && (aspectRatioY > 0.0f)) {
                    // So basically we're "faking" this one by setting aspectRatioX instead.
                    if (ImGui::InputInt("Horiz. Pixel Count", &horizontalPixelCount, 8, 320)) {
                        item_aspectRatio = default_aspectRatio;
                        if (horizontalPixelCount < (minVerticalPixelCount / 3.0f) * 4.0f) {
                            horizontalPixelCount = (minVerticalPixelCount / 3.0f) * 4.0f;
                        }
                        aspectRatioX = aspectRatioY * horizontalPixelCount / verticalPixelCount;
                        update[UPDATE_aspectRatioX] = true;
                    }
                } else { // Display a notice instead.
                    ImGui::TextColored({ 0.0f, 0.85f, 0.85f, 1.0f },
                                       ICON_FA_QUESTION_CIRCLE " \"Force aspect ratio\" required.");
                    // ImGui::Text(" ");
                    ImGui::SameLine();
                    if (ImGui::Button("Click to resolve")) {
                        item_aspectRatio = default_aspectRatio; // Set it to Custom
                        aspectRatioX = aspectRatioPresetsX[2];  // but use the 4:3 defaults
                        aspectRatioY = aspectRatioPresetsY[2];
                        update[UPDATE_aspectRatioX] = true;
                        update[UPDATE_aspectRatioY] = true;
                        horizontalPixelCount = (verticalPixelCount / aspectRatioY) * aspectRatioX;
                    }
                }
            }
            // Vertical Resolution part 2
            if (ImGui::InputInt("Vertical Pixel Count", &verticalPixelCount, 8, 240)) {
                item_pixelCount = default_pixelCount;
                update[UPDATE_verticalPixelCount] = true;

                // Account for the natural instinct to enter horizontal first.
                // Ignore vertical resolutions that are below the lower clamp constant.
                if (showHorizontalResField && !(verticalPixelCount < minVerticalPixelCount)) {
                    aspectRatioX = aspectRatioY * horizontalPixelCount / verticalPixelCount;
                    update[UPDATE_aspectRatioX] = true;
                }
            }

            UIWidgets::Spacer(0);
            // UIWidgets::PaddedSeparator(true, true, 3.0f, 3.0f);

            // Integer scaling settings group
            if (ImGui::CollapsingHeader("Integer Scaling Settings")) {
                // Pixel-perfect Mode
                UIWidgets::PaddedEnhancementCheckbox("Pixel-perfect Mode", "gAdvancedResolution.PixelPerfectMode", true,
                                                     true,
                                                     !CVarGetInteger("gAdvancedResolution.VerticalResolutionToggle", 0), "",
                                                     UIWidgets::CheckboxGraphics::Cross, false);
                UIWidgets::Tooltip("Don't scale image to fill window.");
                if (!CVarGetInteger("gAdvancedResolution.VerticalResolutionToggle", 0)) {
                    CVarSetInteger("gAdvancedResolution.PixelPerfectMode", (int)false);
                    CVarSave();
                }

                // Integer Scaling
                UIWidgets::EnhancementSliderInt("Integer scale factor: %d", "##ARSIntScale",
                                                "gAdvancedResolution.IntegerScale.Factor", 1, max_integerScaleFactor, "%d",
                                                1, true,
                                                !CVarGetInteger("gAdvancedResolution.PixelPerfectMode", 0) ||
                                                CVarGetInteger("gAdvancedResolution.IntegerScale.FitAutomatically", 0));
                UIWidgets::Tooltip("Integer scales the image. Only available in pixel-perfect mode.");
                // Display warning if size is being clamped or if framebuffer is larger than viewport.
                if (CVarGetInteger("gAdvancedResolution.PixelPerfectMode", 0) &&
                    (CVarGetInteger("gAdvancedResolution.IntegerScale.NeverExceedBounds", 1) &&
                     CVarGetInteger("gAdvancedResolution.IntegerScale.Factor", 1) > integerScale_maximumBounds)) {
                    ImGui::SameLine();
                    ImGui::TextColored({ 0.85f, 0.85f, 0.0f, 1.0f }, ICON_FA_EXCLAMATION_TRIANGLE " Window exceeded.");
                }

                UIWidgets::PaddedEnhancementCheckbox("Automatically scale image to fit viewport",
                                                     "gAdvancedResolution.IntegerScale.FitAutomatically", true, true,
                                                     !CVarGetInteger("gAdvancedResolution.PixelPerfectMode", 0), "",
                                                     UIWidgets::CheckboxGraphics::Cross, false);
                UIWidgets::Tooltip("Automatically sets scale factor to fit window. Only available in pixel-perfect mode.");
                if (CVarGetInteger("gAdvancedResolution.IntegerScale.FitAutomatically", 0)) {
                    // This is just here to update the value shown on the slider.
                    // The function in LUS to handle this setting will ignore IntegerScaleFactor while active.
                    CVarSetInteger("gAdvancedResolution.IntegerScale.Factor", integerScale_maximumBounds);
                    // CVarSave();
                }
            }

            UIWidgets::PaddedSeparator(true, true, 3.0f, 3.0f);

            // Collapsible panel for additional settings
            if (ImGui::CollapsingHeader("Additional Settings")) {
                UIWidgets::Spacer(0);
#if defined(__SWITCH__) || defined(__WIIU__)
                // Disable aspect correction, stretching the framebuffer to fill the viewport.
            // This option is only really needed on systems limited to 16:9 TV resolutions, such as consoles.
            // The associated CVar is still functional on PC platforms if you want to use it though.
            UIWidgets::PaddedEnhancementCheckbox("Disable aspect correction and stretch the output image.\n"
                                                 "(Might be useful for 4:3 televisions!)\n"
                                                 "Not available in Pixel Perfect Mode.",
                                                 "gAdvancedResolution.IgnoreAspectCorrection", false, true,
                                                 CVarGetInteger("gAdvancedResolution.PixelPerfectMode", 0), "",
                                                 UIWidgets::CheckboxGraphics::Cross, false);
#else
                if (CVarGetInteger("gAdvancedResolution.IgnoreAspectCorrection", 0)) {
                    // This setting is intentionally not exposed on PC platforms,
                    // but may be accidentally activated for varying reasons.
                    // Having this button should hopefully prevent support headaches.
                    ImGui::TextColored({ 0.0f, 0.85f, 0.85f, 1.0f }, ICON_FA_QUESTION_CIRCLE
                                                                     " If the image is stretched and you don't know why, click this.");
                    if (ImGui::Button("Click to reenable aspect correction.")) {
                        CVarSetInteger("gAdvancedResolution.IgnoreAspectCorrection", (int)false);
                        CVarSave();
                    }
                    UIWidgets::Spacer(2);
                }
#endif

                if (ImGui::Checkbox("Show a horizontal resolution field.", &showHorizontalResField)) {
                    if (!showHorizontalResField && (aspectRatioX > 0.0f)) { // when turning this setting off
                        // Refresh relevant values
                        aspectRatioX = aspectRatioY * horizontalPixelCount / verticalPixelCount;
                        horizontalPixelCount = (verticalPixelCount / aspectRatioY) * aspectRatioX;
                    } else { // when turning this setting on
                        item_aspectRatio = default_aspectRatio;
                        if (aspectRatioX > 0.0f) {
                            // Refresh relevant values in the opposite order
                            horizontalPixelCount = (verticalPixelCount / aspectRatioY) * aspectRatioX;
                            aspectRatioX = aspectRatioY * horizontalPixelCount / verticalPixelCount;
                        }
                    }
                    update[UPDATE_aspectRatioX] = true;
                }

                UIWidgets::PaddedEnhancementCheckbox(
                        "Don't allow integer scaling to exceed screen bounds.\n"
                        "(Makes screen bounds take priority over specified factor.)",
                        "gAdvancedResolution.IntegerScale.NeverExceedBounds", true, false,
                        !CVarGetInteger("gAdvancedResolution.PixelPerfectMode", 0) ||
                        CVarGetInteger("gAdvancedResolution.IntegerScale.FitAutomatically", 0),
                        "", UIWidgets::CheckboxGraphics::Cross, true);

                if (!CVarGetInteger("gAdvancedResolution.IntegerScale.NeverExceedBounds", 1) ||
                    CVarGetInteger("gAdvancedResolution.IntegerScale.ExceedBoundsBy", 0)) {
                    ImGui::TextColored({ 0.0f, 0.85f, 0.85f, 1.0f },
                                       " " ICON_FA_QUESTION_CIRCLE
                                       " A scroll bar may become visible if screen bounds are exceeded.");
                    // Another helpful button for an unused CVar.
                    if (CVarGetInteger("gAdvancedResolution.IntegerScale.ExceedBoundsBy", 0)) {
                        if (ImGui::Button("Click to reset an unused CVar that may be causing this.")) {
                            CVarSetInteger("gAdvancedResolution.IntegerScale.ExceedBoundsBy", 0);
                            CVarSave();
                        }
                    }
                } else {
                    UIWidgets::Spacer(enhancementSpacerHeight);
                }

                // I've ended up dummying this one out because it doesn't function in a satisfactory way.
                // Consider this idea on the table, but I don't deem it an important enough feature to push for.
                /*
                UIWidgets::PaddedEnhancementCheckbox("Allow integer scale factor to go 1x above maximum screen bounds.",
                                                     "gAdvancedResolution.IntegerScale.ExceedBoundsBy", false, false,
                                                     !CVarGetInteger("gAdvancedResolution.PixelPerfectMode", 0), "",
                                                     UIWidgets::CheckboxGraphics::Cross, false);
                if (CVarGetInteger("gAdvancedResolution.IntegerScale.ExceedBoundsBy", 0)) {
                    ImGui::TextColored({ 0.0f, 0.85f, 0.85f, 1.0f },
                                       " " ICON_FA_QUESTION_CIRCLE
                                       " A scroll bar may become visible if screen bounds are exceeded.");
                }*/

            } // end of Additional Settings

            // Clamp and update the CVars that don't use UIWidgets
            if (IsBoolArrayTrue(update)) {
                if (update[UPDATE_aspectRatioX]) {
                    if (aspectRatioX < 0.0f) {
                        aspectRatioX = 0.0f;
                    }
                    CVarSetFloat("gAdvancedResolution.AspectRatioX", aspectRatioX);
                }
                if (update[UPDATE_aspectRatioY]) {
                    if (aspectRatioY < 0.0f) {
                        aspectRatioY = 0.0f;
                    }
                    CVarSetFloat("gAdvancedResolution.AspectRatioY", aspectRatioY);
                }
                if (update[UPDATE_verticalPixelCount]) {
                    // There's a upper and lower clamp on the Libultraship side too,
                    // so clamping it here is purely visual, so the vertical resolution field reflects it.
                    if (verticalPixelCount < minVerticalPixelCount) {
                        verticalPixelCount = minVerticalPixelCount;
                    }
                    if (verticalPixelCount > maxVerticalPixelCount) {
                        verticalPixelCount = maxVerticalPixelCount;
                    }
                    CVarSetInteger("gAdvancedResolution.VerticalPixelCount", verticalPixelCount);
                }
                // Delay saving this set of CVars by a predetermined length of time, in frames.
                updateCountdown = countdownStartingValue;
            }
            if (updateCountdown > 0) {
                updateCountdown--;
            } else {
                CVarSave();
            }
        }
        ImGui::End();
    }

    void AdvancedResolutionSettingsWindow::UpdateElement() {
    }

    bool AdvancedResolutionSettingsWindow::IsDroppingFrames() {
        // a rather imprecise way of checking for frame drops.
        // but it's mostly there to inform the player of large drops.
        const short targetFPS = CVarGetInteger("gInterpolationFPS", 60);
        const float threshold = targetFPS / 20.0f + 4.1f;
        return ImGui::GetIO().Framerate < targetFPS - threshold;
    }

    bool AdvancedResolutionSettingsWindow::IsBoolArrayTrue(bool* foo) {
        for (unsigned short i = 0; i < sizeof(&foo); i++)
            if (&foo[i])
                return true;
        return false;
    }
} // namespace AdvancedResolutionSettings