#include "ImGui.h"                // https://github.com/ocornut/imgui
#include "imgui_markdown.h"       // https://github.com/juliettef/imgui_markdown
#include "IconsFontAwesome5.h"    // https://github.com/juliettef/IconFontCppHeaders

// Following includes for Windows LinkCallback
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include "Shellapi.h"
#include <string>

void LinkCallback( ImGui::MarkdownLinkCallbackData data_ );
inline ImGui::MarkdownImageData ImageCallback( ImGui::MarkdownLinkCallbackData data_ );

// You can make your own Markdown function with your prefered string container and markdown config.
static ImGui::MarkdownConfig mdConfig{ LinkCallback, ImageCallback, ICON_FA_LINK, { { NULL, true }, { NULL, true }, { NULL, false } } };

void LinkCallback( ImGui::MarkdownLinkCallbackData data_ )
{
    std::string url( data_.link, data_.linkLength );
    if( !data_.isImage )
    {
        ShellExecuteA( NULL, "open", url.c_str(), NULL, NULL, SW_SHOWNORMAL );
    }
}

inline ImGui::MarkdownImageData ImageCallback( ImGui::MarkdownLinkCallbackData data_ )
{
    // In your application you would load an image based on data_ input. Here we just use the imgui font texture.
    ImTextureID image = ImGui::GetIO().Fonts->TexID;
    ImGui::MarkdownImageData imageData{ true, false, image, ImVec2( 40.0f, 20.0f ) };
    return imageData;
}

void LoadFonts( float fontSize_ = 12.0f )
{
    ImGuiIO& io = ImGui::GetIO();
    io.Fonts->Clear();
    // Base font
    io.Fonts->AddFontFromFileTTF( "myfont.ttf", fontSize_ );
    // Bold headings H2 and H3
    mdConfig.headingFormats[ 1 ].font = io.Fonts->AddFontFromFileTTF( "myfont-bold.ttf", fontSize_ );
    mdConfig.headingFormats[ 2 ].font = mdConfig.headingFormats[ 1 ].font;
    // bold heading H1
    float fontSizeH1 = fontSize_ * 1.1f;
    mdConfig.headingFormats[ 0 ].font = io.Fonts->AddFontFromFileTTF( "myfont-bold.ttf", fontSizeH1 );
}

void Markdown( const std::string& markdown_ )
{
    // fonts for, respectively, headings H1, H2, H3 and beyond
    ImGui::Markdown( markdown_.c_str(), markdown_.length(), mdConfig );
}

void MarkdownExample()
{
    const std::string markdownText = u8R"(
# H1 Header: Text and Links
You can add [links like this one to enkisoftware](https://www.enkisoftware.com/) and lines will wrap well.
## H2 Header: indented text.
  This text has an indent (two leading spaces).
    This one has two.
### H3 Header: Lists
  * Unordered lists
    * Lists can be indented with two extra spaces.
  * Lists can have [links like this one to Avoyd](https://www.avoyd.com/)
)";
    Markdown( markdownText );
}