#include "../include/Chatbar.hpp"
#include "../include/ResourceCache.hpp"
#include "../include/Settings.hpp"
#include "../include/Channel.hpp"
#include <cmath>
#include <cstring>

using namespace std;

namespace dchat
{
    const float FONT_SIZE = 24;
    const float BOX_PADDING_X = 15.0f;
    const float BOX_PADDING_Y = 5.0f;
    const int BLINK_TIME_VISIBLE_MS = 500;
    const int BLINK_TIME_INVISIBLE_MS = 500;
    
    Chatbar::Chatbar() : 
        text("", ResourceCache::getFont("fonts/Roboto-Regular.ttf"), FONT_SIZE * Settings::getScaling()),
        caretIndex(0),
        focused(true)
    {
        text.setFillColor(sf::Color(240, 240, 240));
        background.setFillColor(sf::Color(60, 60, 60));
    }
    
    void Chatbar::addChar(sf::Uint32 codePoint)
    {
        auto str = text.getString();
        str.insert(caretIndex, codePoint);
        text.setString(str);
        ++caretIndex;
        caretOffset = text.findCharacterPos(caretIndex) - text.getPosition();
        blinkTimer.restart();
    }
    
    const sf::String& Chatbar::getString() const
    {
        return text.getString();
    }
    
    void Chatbar::removePreviousChar()
    {
        if(caretIndex > 0)
        {
            auto str = text.getString();
            str.erase(caretIndex - 1);
            text.setString(str);
            --caretIndex;
            caretOffset = text.findCharacterPos(caretIndex) - text.getPosition();
        }
        blinkTimer.restart();
    }
    
    void Chatbar::removeNextChar()
    {
        if(caretIndex < text.getString().getSize())
        {
            auto str = text.getString();
            str.erase(caretIndex);
            text.setString(str);
        }
        blinkTimer.restart();
    }
    
    void Chatbar::clear()
    {
        text.setString("");
        caretIndex = 0;
        caretOffset.x = 0.0f;
        caretOffset.y = 0.0f;
        blinkTimer.restart();
    }
    
    void Chatbar::moveCaretLeft()
    {
        caretIndex = max(0, caretIndex - 1);
        // TODO: Use glyph size to optimize this, no need to iterate all glyphs
        caretOffset = text.findCharacterPos(caretIndex) - text.getPosition();
        blinkTimer.restart();
    }
    
    void Chatbar::moveCaretRight()
    {
        caretIndex = min((int)text.getString().getSize(), caretIndex + 1);
        caretOffset = text.findCharacterPos(caretIndex) - text.getPosition();
        blinkTimer.restart();
    }
    
    bool Chatbar::isFocused() const
    {
        return focused;
    }
    
    void Chatbar::processEvent(const sf::Event &event, Channel *channel)
    {
        if(!focused) return;
        
        if(event.type == sf::Event::TextEntered)
        {
            if(event.text.unicode == 8) // backspace
                removePreviousChar();
            else if(event.text.unicode == 13) // enter
            {
                if(!getString().isEmpty())
                {
                    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Key::LShift) || sf::Keyboard::isKeyPressed(sf::Keyboard::Key::RShift))
                    {
                        addChar('\n');
                    }
                    else
                    {
                        auto chatbarMsgUtf8 = getString().toUtf8();
                        string msg;
                        msg.resize(chatbarMsgUtf8.size());
                        memcpy(&msg[0], chatbarMsgUtf8.data(), chatbarMsgUtf8.size());
                        channel->getMessageBoard().addMessage(new Message(channel->getLocalUser(), msg));
                        clear();
                    }
                }
            }
            else if(event.text.unicode == 127) // delete
            {
                removeNextChar();
            }
            else
            {
                addChar(event.text.unicode);
            }
        }
        else if(event.type == sf::Event::KeyPressed)
        {
            if(event.key.code == sf::Keyboard::Left)
                moveCaretLeft();
            else if(event.key.code == sf::Keyboard::Right)
                moveCaretRight();
        }
    }
    
    void Chatbar::draw(sf::RenderWindow &window, const sf::Vector2f &position)
    {
        auto windowSize = window.getSize();
        
        sf::Vector2f backgroundSize(floor(windowSize.x * 0.7f), floor(text.getCharacterSize() * 1.7f + BOX_PADDING_Y * 2.0f));
        sf::Vector2f backgroundPos(floor(position.x), floor(position.y + windowSize.y - backgroundSize.y - 20.0f));
        background.setSize(backgroundSize);
        background.setPosition(backgroundPos);
        text.setPosition(floor(backgroundPos.x + BOX_PADDING_X), floor(backgroundPos.y + backgroundSize.y * 0.5f - text.getCharacterSize() * 0.5f));
        
        window.draw(background);
        window.draw(text);
        
        int blinkElapsedTime = blinkTimer.getElapsedTime().asMilliseconds();
        if(focused && blinkElapsedTime <= BLINK_TIME_VISIBLE_MS)
        {
            sf::RectangleShape caretShape(sf::Vector2f(2.0f, backgroundSize.y - BOX_PADDING_Y * 2.0f));
            caretShape.setPosition(floor(text.getPosition().x + caretOffset.x), (caretOffset.y + backgroundPos.y + BOX_PADDING_Y));
            window.draw(caretShape);
        }
        
        if(blinkElapsedTime > BLINK_TIME_VISIBLE_MS + BLINK_TIME_INVISIBLE_MS)
            blinkTimer.restart();
    }
}