#include "../include/ChannelTopPanel.hpp"
#include "../include/Settings.hpp"
#include "../include/ResourceCache.hpp"
#include "../include/Channel.hpp"
#include "../include/ColorScheme.hpp"
#include <SFML/Graphics/RectangleShape.hpp>
#include <cmath>

namespace dchat
{
    struct LineColor
    {
        sf::Color sideColor, centerColor;
    };
    
    const float FONT_SIZE = 40.0f;
    const float BOTTOM_LINE_HEIGHT = 2.0f;
    const float PADDING_TOP = 20.0f;
    const float PADDING_BOTTOM = PADDING_TOP;
    
    static void drawGradientLine(const sf::Vector2f &position, const sf::Vector2f &size, const LineColor &color, sf::RenderWindow &window)
    {
        sf::Vertex rectangle[] = 
        {
            sf::Vertex(position, color.sideColor),
            sf::Vertex(sf::Vector2f(position.x + size.x * 0.5f, position.y), color.centerColor),
            sf::Vertex(sf::Vector2f(position.x + size.x * 0.5f, position.y + size.y), color.centerColor),
            sf::Vertex(sf::Vector2f(position.x, position.y + size.y), color.sideColor),
            
            sf::Vertex(sf::Vector2f(position.x + size.x * 0.5f, position.y), color.centerColor),
            sf::Vertex(sf::Vector2f(position.x + size.x, position.y), color.sideColor),
            sf::Vertex(sf::Vector2f(position.x + size.x, position.y + size.y), color.sideColor),
            sf::Vertex(sf::Vector2f(position.x + size.x * 0.5f, position.y + size.y), color.centerColor)
        };
        window.draw(rectangle, 8, sf::Quads);
    }
    
    void ChannelTopPanel::draw(sf::RenderWindow &window)
    {
        const sf::Color lineSideColor = ColorScheme::getBackgroundColor();
        const sf::Color lineCenterColor = lineSideColor + sf::Color(40, 0, 0);
        
        auto windowSize = window.getSize();
        sf::RectangleShape rect(sf::Vector2f(windowSize.x, getHeight() - BOTTOM_LINE_HEIGHT));
        rect.setFillColor(ColorScheme::getBackgroundColor());
        window.draw(rect);
        
        sf::Vector2f bottomLinePos(0.0f, getHeight() - BOTTOM_LINE_HEIGHT);
        sf::Vector2f bottomLineSize(windowSize.x, BOTTOM_LINE_HEIGHT);
        
        LineColor lineColor
        {
            .sideColor = lineSideColor,
            .centerColor = lineCenterColor
        };
        drawGradientLine(bottomLinePos, bottomLineSize, lineColor, window);
        
        Channel *currentChannel = Channel::getCurrent();
        if(!currentChannel) return;
        
        sf::String str = "# ";
        str += sf::String::fromUtf8(currentChannel->getName().begin(), currentChannel->getName().end());
        float fontSize = FONT_SIZE * Settings::getScaling();
        sf::Text text(str, *ResourceCache::getFont("fonts/Roboto-Regular.ttf"), fontSize);
        auto textBounds = text.getLocalBounds();
        text.setPosition(floor((float)windowSize.x * 0.5f - textBounds.width * 0.5f), PADDING_TOP);
        text.setFillColor(ColorScheme::getTextRegularColor());
        window.draw(text);
    }
    
    float ChannelTopPanel::getHeight()
    {
        float fontSize = FONT_SIZE * Settings::getScaling();
        return floor(ResourceCache::getFont("fonts/Roboto-Regular.ttf")->getLineSpacing(fontSize) + PADDING_TOP + PADDING_BOTTOM);
    }
}