#include <stdio.h>

#include "../imgui/imgui.h"
#include "TracyImGui.hpp"
#include "TracyPrint.hpp"

#include "TracySourceView.hpp"

namespace tracy
{

SourceView::SourceView( ImFont* font )
    : m_font( font )
    , m_file( nullptr )
    , m_data( nullptr )
    , m_dataSize( 0 )
    , m_targetLine( 0 )
    , m_selectedLine( 0 )
{
}

SourceView::~SourceView()
{
    delete[] m_data;
}

void SourceView::Open( const char* fileName, int line )
{
    m_targetLine = line;
    m_selectedLine = line;

    if( m_file != fileName )
    {
        m_file = fileName;
        FILE* f = fopen( fileName, "rb" );
        fseek( f, 0, SEEK_END );
        const auto sz = ftell( f );
        fseek( f, 0, SEEK_SET );
        if( sz > m_dataSize )
        {
            delete[] m_data;
            m_data = new char[sz+1];
            m_dataSize = sz;
        }
        fread( m_data, 1, sz, f );
        m_data[sz] = '\0';
        fclose( f );

        m_lines.clear();
        auto txt = m_data;
        for(;;)
        {
            auto end = txt;
            while( *end != '\n' && *end != '\r' && end - m_data < sz ) end++;
            m_lines.emplace_back( Line { txt, end } );
            if( *end == '\n' )
            {
                end++;
                if( *end == '\r' ) end++;
            }
            else if( *end == '\r' )
            {
                end++;
                if( *end == '\n' ) end++;
            }
            if( *end == '\0' ) break;
            txt = end;
        }
    }
}

void SourceView::Render()
{
    ImGui::BeginChild( "##sourceView", ImVec2( 0, 0 ), true );
    if( m_font ) ImGui::PushFont( m_font );
    const auto nw = ImGui::CalcTextSize( "123,345" ).x;
    if( m_targetLine != 0 )
    {
        int lineNum = 1;
        for( auto& line : m_lines )
        {
            if( m_targetLine == lineNum )
            {
                m_targetLine = 0;
                ImGui::SetScrollHereY();
            }
            RenderLine( line, lineNum++ );
        }
    }
    else
    {
        ImGuiListClipper clipper( m_lines.size() );
        while( clipper.Step() )
        {
            for( auto i=clipper.DisplayStart; i<clipper.DisplayEnd; i++ )
            {
                RenderLine( m_lines[i], i+1 );
            }
        }
    }
    if( m_font ) ImGui::PopFont();
    ImGui::EndChild();
}

void SourceView::RenderLine( const Line& line, int lineNum )
{
    const auto ty = ImGui::GetFontSize();
    auto draw = ImGui::GetWindowDrawList();
    const auto w = ImGui::GetWindowWidth();
    const auto wpos = ImGui::GetCursorScreenPos();
    if( lineNum == m_selectedLine )
    {
        draw->AddRectFilled( wpos, wpos + ImVec2( w, ty+1 ), 0xFF333322 );
    }

    const auto lineString = RealToString( lineNum );
    const auto linesz = strlen( lineString );
    char buf[16];
    memset( buf, ' ', 7 - linesz );
    memcpy( buf + 7 - linesz, lineString, linesz+1 );
    TextDisabledUnformatted( buf );
    ImGui::SameLine( 0, ty );
    ImGui::TextUnformatted( line.begin, line.end );

    draw->AddLine( wpos + ImVec2( 0, ty+2 ), wpos + ImVec2( w, ty+2 ), 0x08FFFFFF );
}

}