// ImGui Marmalade binding with IwGx
// Copyright (C) 2015 by Giovanni Zito
// This file is part of ImGui
// https://github.com/ocornut/imgui

#include <imgui.h>
#include "imgui_impl_marmalade.h"

#include <s3eClipboard.h>
#include <s3ePointer.h> 
#include <s3eKeyboard.h>
#include <IwTexture.h>
#include <IwGx.h>

// Data
static double       g_Time = 0.0f;
static bool         g_MousePressed[3] = { false, false, false };
static float        g_MouseWheel = 0.0f;
static CIwTexture*  g_FontTexture = 0;
static char*        g_ClipboardText = 0 ;
static bool         g_osdKeyboardEnabled = false ;

// use this setting to scale the interface - e.g. on device you could use 2 or 3 scale factor
static ImVec2       g_scale = ImVec2(1.0f,1.0f) ;

// This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure)
void ImGui_Marmalade_RenderDrawLists(ImDrawData* draw_data)
{
    // Handle cases of screen coordinates != from framebuffer coordinates (e.g. retina displays)
    ImGuiIO& io = ImGui::GetIO();
    draw_data->ScaleClipRects(io.DisplayFramebufferScale);

    // Render command lists
    for(int n = 0; n < draw_data->CmdListsCount; n++)
    {
        const ImDrawList* cmd_list = draw_data->CmdLists[n];
        const unsigned char* vtx_buffer = (const unsigned char*)&cmd_list->VtxBuffer.front();
        const ImDrawIdx* idx_buffer = &cmd_list->IdxBuffer.front();
        int nVert = cmd_list->VtxBuffer.size() ;
        CIwFVec2* pVertStream = IW_GX_ALLOC(CIwFVec2,nVert) ;
        CIwFVec2* pUVStream = IW_GX_ALLOC(CIwFVec2,nVert) ;
        CIwColour* pColStream = IW_GX_ALLOC(CIwColour,nVert) ;

        for( int i=0; i < nVert; i++ ) {
            // todo - optimize multiplication on gpu using vertex shader
            pVertStream[i].x = cmd_list->VtxBuffer[i].pos.x * g_scale.x ;
            pVertStream[i].y = cmd_list->VtxBuffer[i].pos.y * g_scale.y ;
            pUVStream[i].x = cmd_list->VtxBuffer[i].uv.x ;
            pUVStream[i].y = cmd_list->VtxBuffer[i].uv.y ;
            pColStream[i] = cmd_list->VtxBuffer[i].col ;
        }

        IwGxSetVertStreamScreenSpace(pVertStream,nVert) ;
        IwGxSetUVStream(pUVStream) ;
        IwGxSetColStream(pColStream,nVert) ;
        IwGxSetNormStream(0) ;

        for(int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.size(); cmd_i++)
        {
            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
            if(pcmd->UserCallback)
            {
                pcmd->UserCallback(cmd_list,pcmd);
            }
            else
            {
                CIwMaterial* pCurrentMaterial = IW_GX_ALLOC_MATERIAL() ;
                pCurrentMaterial->SetShadeMode(CIwMaterial::SHADE_FLAT) ;
                pCurrentMaterial->SetCullMode(CIwMaterial::CULL_NONE) ;
                pCurrentMaterial->SetFiltering(false) ;
                pCurrentMaterial->SetAlphaMode(CIwMaterial::ALPHA_BLEND) ;
                pCurrentMaterial->SetDepthWriteMode(CIwMaterial::DEPTH_WRITE_NORMAL);
                pCurrentMaterial->SetAlphaTestMode(CIwMaterial::ALPHATEST_DISABLED);
                pCurrentMaterial->SetTexture((CIwTexture*)pcmd->TextureId) ;
                IwGxSetMaterial(pCurrentMaterial) ;

                IwGxDrawPrims(IW_GX_TRI_LIST,(uint16*)idx_buffer,pcmd->ElemCount) ;
            }
            idx_buffer += pcmd->ElemCount;
        }
        IwGxFlush() ;
    }

    // TODO restore modified state (i.e. mvp matrix)
}


static const char* ImGui_Marmalade_GetClipboardText()
{
    if(s3eClipboardAvailable()) {
        int size = s3eClipboardGetText( NULL, 0 );
        if( size > 0 ) {
            if(g_ClipboardText) {
                delete[] g_ClipboardText ;
                g_ClipboardText = 0 ;
            }
            g_ClipboardText = new char[size] ;
            g_ClipboardText[0] = '\0' ;
            s3eClipboardGetText(g_ClipboardText,size) ;
        }
    }

    return g_ClipboardText ;
}

static void ImGui_Marmalade_SetClipboardText(const char* text)
{
    if( s3eClipboardAvailable() ) {
        s3eClipboardSetText(text);
    }
}

int32 ImGui_Marmalade_PointerButtonEventCallback(void* SystemData,void* pUserData)
{
    // pEvent->m_Button is of type s3ePointerButton and indicates which mouse
    // button was pressed.  For touchscreens this should always have the value
    // S3E_POINTER_BUTTON_SELECT
    s3ePointerEvent* pEvent = (s3ePointerEvent*)SystemData ;

    if(pEvent->m_Pressed==1) {
        if(pEvent->m_Button == S3E_POINTER_BUTTON_LEFTMOUSE) {
            g_MousePressed[0] = true;
        }
        if(pEvent->m_Button == S3E_POINTER_BUTTON_RIGHTMOUSE) {
            g_MousePressed[1] = true;
        }
        if(pEvent->m_Button == S3E_POINTER_BUTTON_MIDDLEMOUSE) {
            g_MousePressed[2] = true;
        }
        if(pEvent->m_Button == S3E_POINTER_BUTTON_MOUSEWHEELUP) {
            g_MouseWheel += pEvent->m_y ;
        }
        if(pEvent->m_Button == S3E_POINTER_BUTTON_MOUSEWHEELDOWN) {
            g_MouseWheel += pEvent->m_y ;
        }
    }

    return 0;
}

//void ImGui_Marmalade_ScrollCallback(double /*xoffset*/,double yoffset)
//{
//  g_MouseWheel += (float)yoffset; // Use fractional mouse wheel, 1.0 unit 5 lines.
//}

int32 ImGui_Marmalade_KeyCallback(void* SystemData, void* userData)
{
    ImGuiIO& io = ImGui::GetIO();
    s3eKeyboardEvent* e = (s3eKeyboardEvent*)SystemData ;
    if( e->m_Pressed == 1 ) {
        io.KeysDown[e->m_Key] = true;
    }
    if(e->m_Pressed == 0) {
        io.KeysDown[e->m_Key] = false;
    }
    
    io.KeyCtrl = s3eKeyboardGetState(s3eKeyLeftControl) == S3E_KEY_STATE_DOWN || s3eKeyboardGetState(s3eKeyRightControl) == S3E_KEY_STATE_DOWN ;
    io.KeyShift = s3eKeyboardGetState(s3eKeyLeftShift) == S3E_KEY_STATE_DOWN || s3eKeyboardGetState(s3eKeyRightShift) == S3E_KEY_STATE_DOWN ;
    io.KeyAlt = s3eKeyboardGetState(s3eKeyLeftAlt) == S3E_KEY_STATE_DOWN || s3eKeyboardGetState(s3eKeyRightAlt) == S3E_KEY_STATE_DOWN ;

    return 0 ;
}

int32 ImGui_Marmalade_CharCallback(void* SystemData,void* userData)
{
    ImGuiIO& io = ImGui::GetIO();

    s3eKeyboardCharEvent* e = (s3eKeyboardCharEvent*)SystemData ;
    if( (e->m_Char > 0 && e->m_Char < 0x10000) ) {
        io.AddInputCharacter((unsigned short)e->m_Char);
    }

    return 0 ;
}

bool ImGui_Marmalade_CreateDeviceObjects()
{
    ImGuiIO& io = ImGui::GetIO();

    // Build texture atlas
    unsigned char* pixels;
    int width, height;
    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);

    // Create texture
    g_FontTexture = new CIwTexture() ;
    g_FontTexture->SetModifiable(true) ;
    CIwImage& image = g_FontTexture->GetImage() ;
    image.SetFormat(CIwImage::ARGB_8888) ;
    image.SetWidth(width) ;
    image.SetHeight(height) ;
    image.SetBuffers();                                    // allocates and own buffers
    image.ReadTexels(pixels) ;
    g_FontTexture->SetMipMapping(false) ;
    g_FontTexture->SetFiltering(false) ;
    g_FontTexture->Upload() ;

    // Store the pointer
    io.Fonts->TexID = (void *)g_FontTexture;

    // Cleanup (don't clear the input data if you want to append new fonts later)
    io.Fonts->ClearInputData();
    io.Fonts->ClearTexData();

    return true;
}

void    ImGui_Marmalade_InvalidateDeviceObjects()
{
    if(g_ClipboardText) {
        delete[] g_ClipboardText ;
        g_ClipboardText = 0 ;
    }

    if (g_FontTexture)
    {
        delete g_FontTexture ;
        ImGui::GetIO().Fonts->TexID = 0;
        g_FontTexture = 0;
    }
}

bool    ImGui_Marmalade_Init( bool install_callbacks)
{
    IwGxInit() ;

    ImGuiIO& io = ImGui::GetIO();
    io.KeyMap[ImGuiKey_Tab] = s3eKeyTab;                     // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array.
    io.KeyMap[ImGuiKey_LeftArrow] = s3eKeyLeft;
    io.KeyMap[ImGuiKey_RightArrow] = s3eKeyRight;
    io.KeyMap[ImGuiKey_UpArrow] = s3eKeyUp;
    io.KeyMap[ImGuiKey_DownArrow] = s3eKeyDown;
    io.KeyMap[ImGuiKey_PageUp] = s3eKeyPageUp;
    io.KeyMap[ImGuiKey_PageDown] = s3eKeyPageDown;
    io.KeyMap[ImGuiKey_Home] = s3eKeyHome;
    io.KeyMap[ImGuiKey_End] = s3eKeyEnd;
    io.KeyMap[ImGuiKey_Delete] = s3eKeyDelete;
    io.KeyMap[ImGuiKey_Backspace] = s3eKeyBackspace;
    io.KeyMap[ImGuiKey_Enter] = s3eKeyEnter;
    io.KeyMap[ImGuiKey_Escape] = s3eKeyEsc;
    io.KeyMap[ImGuiKey_A] = s3eKeyA;
    io.KeyMap[ImGuiKey_C] = s3eKeyC;
    io.KeyMap[ImGuiKey_V] = s3eKeyV;
    io.KeyMap[ImGuiKey_X] = s3eKeyX;
    io.KeyMap[ImGuiKey_Y] = s3eKeyY;
    io.KeyMap[ImGuiKey_Z] = s3eKeyZ;

    io.RenderDrawListsFn = ImGui_Marmalade_RenderDrawLists;      // Alternatively you can set this to NULL and call ImGui::GetDrawData() after ImGui::Render() to get the same ImDrawData pointer.
    io.SetClipboardTextFn = ImGui_Marmalade_SetClipboardText;
    io.GetClipboardTextFn = ImGui_Marmalade_GetClipboardText;

    if (install_callbacks)
    {
        s3ePointerRegister(S3E_POINTER_BUTTON_EVENT,ImGui_Marmalade_PointerButtonEventCallback,0) ;
        s3eKeyboardRegister(S3E_KEYBOARD_KEY_EVENT,ImGui_Marmalade_KeyCallback,0) ;
        s3eKeyboardRegister(S3E_KEYBOARD_CHAR_EVENT,ImGui_Marmalade_CharCallback,0) ;
    }

    return true;
}

void ImGui_Marmalade_Shutdown()
{
    ImGui_Marmalade_InvalidateDeviceObjects();
    ImGui::Shutdown();
    IwGxTerminate();
}

void ImGui_Marmalade_NewFrame()
{
    if (!g_FontTexture) {
        ImGui_Marmalade_CreateDeviceObjects();
    }

    ImGuiIO& io = ImGui::GetIO();

    // Setup display size (every frame to accommodate for window resizing)
    int w = IwGxGetScreenWidth(), h = IwGxGetScreenHeight() ;
    io.DisplaySize = ImVec2((float)w, (float)h);
     // For retina display or other situations where window coordinates are different from framebuffer coordinates. User storage only, presently not used by ImGui.
    io.DisplayFramebufferScale = g_scale;

    // Setup time step
    double current_time =  s3eTimerGetUST() / 1000.0f ;
    io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f/60.0f);
    g_Time = current_time;

    double mouse_x, mouse_y;
    mouse_x = s3ePointerGetX();
    mouse_y = s3ePointerGetY();
    io.MousePos = ImVec2((float)mouse_x/g_scale.x, (float)mouse_y/g_scale.y);   // Mouse position in screen coordinates (set to -1,-1 if no mouse / on another screen, etc.)
   
    for (int i = 0; i < 3; i++) {
        io.MouseDown[i] = g_MousePressed[i] || s3ePointerGetState((s3ePointerButton)i) != S3E_POINTER_STATE_UP;    // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.
        g_MousePressed[i] = false;
    }

    io.MouseWheel = g_MouseWheel;
    g_MouseWheel = 0.0f;

    // Hide OS mouse cursor if ImGui is drawing it
//   s3ePointerSetInt(S3E_POINTER_HIDE_CURSOR,(io.MouseDrawCursor ? 0 : 1));

    // Start the frame
    ImGui::NewFrame();

     // show/hide OSD keyboard
    if( io.WantTextInput ) {    // some text input widget is active?
        if( !g_osdKeyboardEnabled ) {
            g_osdKeyboardEnabled = true ;
            s3eKeyboardSetInt(S3E_KEYBOARD_GET_CHAR,1) ;    // show OSD keyboard
        }
    }
    else {    // no text input widget is active
        if(g_osdKeyboardEnabled) {
            g_osdKeyboardEnabled = false ;
            s3eKeyboardSetInt(S3E_KEYBOARD_GET_CHAR,0) ;    // hide OSD keyboard
        }
    }
}