#include "../include/MessageBoard.hpp"
#include "../include/Settings.hpp"
#include "../include/ResourceCache.hpp"
#include "../include/Gif.hpp"
#include "../include/ChannelSidePanel.hpp"
#include "../include/UsersSidePanel.hpp"
#include "../include/ChannelTopPanel.hpp"
#include "../include/Chatbar.hpp"
#include "../include/ColorScheme.hpp"
#include "../include/Theme.hpp"
#include "../include/GlobalContextMenu.hpp"
#include "../include/Channel.hpp"
#include <SFML/Graphics/CircleShape.hpp>
#include <SFML/Graphics/RectangleShape.hpp>
#include <SFML/Graphics/Sprite.hpp>
#include <SFML/Window/Mouse.hpp>
#include <SFML/Graphics/Rect.hpp>
#include <SFML/Graphics/Text.hpp>
#include <cmath>

using namespace std;

namespace dchat
{
    struct LineColor
    {
        sf::Color sideColor, centerColor;
    };
    
    const float USERNAME_PADDING_BOTTOM = 0.0f;
    
    const float PADDING_SIDE = 40.0f;
    const float PADDING_TOP = 0.0f;
    const float LINE_SIDE_PADDING = 20.0f;
    const float LINE_HEIGHT = 1.0f;
    const float TEXT_LINE_SPACING = 5.0f;
    const float USERNAME_TIMESTAMP_SIDE_PADDING = 15.0f;
    const float AVATAR_DIAMETER = 70.0f;
    const float AVATAR_PADDING_SIDE = 20.0f;
    const double SCROLL_MAX_SPEED = 20.0;
    
    // Merge messages from same user that are sent within one minute
    const int MERGE_TEXT_TIMESTAMP_DIFF_SEC = 60;
    
    MessageBoard::MessageBoard(Channel *_channel) : 
        channel(_channel),
        scroll(0.0),
        scrollSpeed(0.0),
        totalHeight(0.0),
        scrollToBottom(false),
        visibleMessageStartIndex(-1),
        visibleMessageEndIndex(-1)
    {
        scrollbar.backgroundColor = sf::Color(49, 52, 57);
        scrollbar.scrollColor = sf::Color(37, 39, 44);
    }
    
    MessageBoard::~MessageBoard()
    {
        for(Message *message : messages)
        {
            delete message;
        }
    }
    
    // TODO: Optimize this with binary search
    usize MessageBoard::findPositionToInsertMessageByTimestamp(Message *message)
    {
        for(usize i = 0; i < messages.size(); ++i)
        {
            if(message->timestampSeconds < messages[i]->timestampSeconds)
                return i;
        }
        return messages.size();
    }
    
    void MessageBoard::updateStaticContentTexture(const sf::Vector2u &newSize)
    {
        //if(!staticContentTexture.create(newSize.x, newSize.y))
        //    throw std::runtime_error("Failed to create render target for message board!");
        dirty = true;
    }
    
    bool MessageBoard::addMessage(Message *message, const odhtdb::Hash &id)
    {
        lock_guard<mutex> lock(messageProcessMutex);
        bool emptyHash = id.isEmpty();
        if(!emptyHash && messageIdMap.find(id) != messageIdMap.end())
        {
            delete message;
            return false;
        }
        auto positionToAddMessage = findPositionToInsertMessageByTimestamp(message);
        if(positionToAddMessage == messages.size())
            scrollToBottom = true;
        messages.insert(messages.begin() + positionToAddMessage, message);
        message->id = id;
        if(!emptyHash)
            messageIdMap[id] = message;
        dirty = true;
        return true;
    }
    
    void MessageBoard::deleteMessage(const odhtdb::Hash &id, const odhtdb::Signature::PublicKey &requestedByUser)
    {
        lock_guard<mutex> lock(messageProcessMutex);
        auto it = messageIdMap.find(id);
        if(it == messageIdMap.end()) return;
        if(it->second->user->isOnlineUser())
        {
            auto onlineUser = static_cast<const OnlineUser*>(it->second->user);
            if(onlineUser->getPublicKey() != requestedByUser)
            {
                fprintf(stderr, "Warning: user %s requested to delete a message owned by user %s, ignoring request\n", requestedByUser.toString().c_str(), onlineUser->getPublicKey().toString().c_str());
                return;
            }
        }
        
        // TODO: Instead of deleting message, cover it with black rectangle
        for(usize i = 0; i < messages.size(); ++i)
        {
            Message *message = messages[i];
            if(message == it->second)
            {
                delete message;
                messages.erase(messages.begin() + i);
                messageIdMap.erase(it);
                break;
            }
        }
    }
    
    void MessageBoard::drawDefault(sf::RenderWindow &window, Cache &cache)
    {
        const float LINE_SPACING = 5.0f * Settings::getScaling();
        const float MESSAGE_PADDING_TOP = 25.0f;
        const float MESSAGE_PADDING_BOTTOM = 30.0f;
        
        const sf::Font *usernameFont = ResourceCache::getFont("fonts/Nunito-Regular.ttf");
        const int usernameTextCharacterSize = 20 * Settings::getScaling();
        const float usernameTextHeight = usernameFont->getLineSpacing(usernameTextCharacterSize);
        
        const sf::Font *timestampFont = ResourceCache::getFont("fonts/Nunito-Regular.ttf");
        const int timestampTextCharacterSize = (float)usernameTextCharacterSize * 0.75f;
        const float timestampTextHeight = timestampFont->getLineSpacing(timestampTextCharacterSize);
        
        sf::RectangleShape lineRect(sf::Vector2f(backgroundSizeWithoutPadding.x - LINE_SIDE_PADDING  * Settings::getScaling() * 2.0f, LINE_HEIGHT));
        lineRect.setFillColor(ColorScheme::getBackgroundColor() + sf::Color(10, 10, 10));
        
        sf::Shader *circleShader = ResourceCache::getShader("shaders/circleMask.glsl", sf::Shader::Fragment);
        
        sf::Vector2<double> position(ChannelSidePanel::getWidth() + PADDING_SIDE * Settings::getScaling(), ChannelTopPanel::getHeight() + PADDING_TOP);
        double startHeight = position.y;
        position.y += scroll;
        
        visibleMessageStartIndex = -1;
        visibleMessageEndIndex = -1;
        usize numMessages = messages.size();
        for(usize i = 0; i < numMessages; ++i)
        {
            Message *message = messages[i];
            
            bool mergeTextWithPrev = false;
            if(i > 0)
            {
                Message *prevMessage = messages[i - 1];
                mergeTextWithPrev = prevMessage->user == message->user && (message->timestampSeconds == 0 || message->timestampSeconds - prevMessage->timestampSeconds <= MERGE_TEXT_TIMESTAMP_DIFF_SEC);
            }
            
            bool mergeTextWithNext = false;
            if(i < numMessages - 1)
            {
                Message *nextMessage = messages[i + 1];
                mergeTextWithNext = nextMessage->user == message->user && (nextMessage->timestampSeconds == 0 || nextMessage->timestampSeconds - message->timestampSeconds <= MERGE_TEXT_TIMESTAMP_DIFF_SEC);
            }
            
            bool visible = false;

            float startX = floor(position.x + LINE_SIDE_PADDING * Settings::getScaling() - PADDING_SIDE * Settings::getScaling());
            
            if(!mergeTextWithPrev)
            {
                position.y += (MESSAGE_PADDING_TOP * Settings::getScaling());
                if(position.y + usernameTextHeight > 0.0f && position.y < backgroundPos.y + backgroundSize.y)
                {
                    visible = true;
                    string usernameStr;
                    if(message->user->type == User::Type::ONLINE_DISCORD_USER)
                    {
                        usernameStr = "(Discord) ";
                        usernameStr += message->user->getName();
                    }
                    else
                    {
                        usernameStr = message->user->getName();
                    }
                    sf::Text usernameText(sf::String::fromUtf8(usernameStr.begin(), usernameStr.end()), *usernameFont, usernameTextCharacterSize);
                    usernameText.setFillColor(sf::Color(15, 192, 252));
                    usernameText.setPosition(sf::Vector2f(floor(startX + (AVATAR_DIAMETER + AVATAR_PADDING_SIDE) * Settings::getScaling()), floor(position.y)));
                    window.draw(usernameText);
                    
                    if(message->timestampSeconds)
                    {
                        time_t time = (time_t)message->timestampSeconds;
                        struct tm *localTimePtr = localtime(&time);
                        char date[30];
                        strftime(date, sizeof(date), "%Y-%m-%d at %T", localTimePtr);
                        
                        sf::Text timestamp(date, *timestampFont, timestampTextCharacterSize);
                        timestamp.setFillColor(ColorScheme::getTextRegularColor() * sf::Color(255, 255, 255, 50));
                        timestamp.setPosition(sf::Vector2f(floor(startX + (AVATAR_DIAMETER + AVATAR_PADDING_SIDE) * Settings::getScaling() + usernameText.getLocalBounds().width + USERNAME_TIMESTAMP_SIDE_PADDING * Settings::getScaling()), floor(position.y + 2.0f * Settings::getScaling() + usernameTextHeight * 0.5f - timestampTextHeight * 0.5f)));
                        window.draw(timestamp);
                    }
                    
                    // Max avatar size = 1mb
                    const ContentByUrlResult avatarResult = cache.getContentByUrl(message->user->avatarUrl, 1024 * 1024);
                    if(avatarResult.type == ContentByUrlResult::Type::CACHED)
                    {
                        circleShader->setUniform("texture", sf::Shader::CurrentTexture);
                        
                        if(avatarResult.cachedType == ContentByUrlResult::CachedType::TEXTURE)
                        {
                            // TODO: Store this sprite somewhere, might not be efficient to create a new sprite object every frame
                            sf::Sprite sprite(*avatarResult.texture);
                            auto textureSize = avatarResult.texture->getSize();
                            sprite.setPosition(sf::Vector2f(startX, floor(position.y)));
                            sprite.setScale(sf::Vector2f(AVATAR_DIAMETER * Settings::getScaling() / (float)textureSize.x, AVATAR_DIAMETER * Settings::getScaling() / (float)textureSize.y));
                            window.draw(sprite, circleShader);
                        }
                        else if(avatarResult.cachedType == ContentByUrlResult::CachedType::GIF)
                        {
                            auto gifSize = avatarResult.gif->getSize();
                            avatarResult.gif->setPosition(sf::Vector2f(startX, floor(position.y)));
                            avatarResult.gif->setScale(sf::Vector2f(AVATAR_DIAMETER * Settings::getScaling() / (float)gifSize.x, AVATAR_DIAMETER * Settings::getScaling() / (float)gifSize.y));
                            avatarResult.gif->setColor(sf::Color::White);
                            avatarResult.gif->draw(window, circleShader);
                        }
                    }
                    else
                    {
                        sf::CircleShape avatarCircle(AVATAR_DIAMETER * 0.5f * Settings::getScaling(), 60 * Settings::getScaling());
                        avatarCircle.setPosition(sf::Vector2f(startX, floor(position.y)));
                        avatarCircle.setFillColor(ColorScheme::getBackgroundColor() + sf::Color(30, 30, 30));
                        window.draw(avatarCircle);
                    }
                }
                
                position.y += usernameTextHeight + USERNAME_PADDING_BOTTOM * Settings::getScaling();
            }
            
            // No need to perform culling here, that is done in @Text draw function
            message->text.setCharacterSize(18.0f * Settings::getScaling());
            message->text.setMaxWidth(lineRect.getSize().x - (AVATAR_DIAMETER + AVATAR_PADDING_SIDE * 2.0f) * Settings::getScaling());
            message->text.setPosition(sf::Vector2f(floor(startX + (AVATAR_DIAMETER + AVATAR_PADDING_SIDE) * Settings::getScaling()), floor(position.y)));
            bool textDrawn = message->text.draw(window, cache);
            if(!visible)
                visible = textDrawn;
            position.y += message->text.getHeight() + (TEXT_LINE_SPACING * Settings::getScaling());
            if(!mergeTextWithNext)
            {
                position.y += (MESSAGE_PADDING_BOTTOM  * Settings::getScaling());
            
                if(position.y + LINE_HEIGHT > 0.0f && position.y < backgroundPos.y + backgroundSize.y && i + 1 != numMessages)
                {
                    visible = true;
                    lineRect.setPosition(sf::Vector2f(startX, floor(position.y)));
                    window.draw(lineRect);
                    //drawGradientLine(sf::Vector2f(position.x + LINE_SIDE_PADDING, floor(position.y)), sf::Vector2f(backgroundSizeWithoutPadding.x - LINE_SIDE_PADDING * 2.0f, LINE_HEIGHT), LINE_COLOR, window);
                }
            }
            position.y += LINE_HEIGHT;
            
            if(visible)
            {
                if(visibleMessageStartIndex == -1)
                    visibleMessageStartIndex = i;
                visibleMessageEndIndex = i;
            }
        }
        totalHeight = (position.y - scroll) - startHeight;
    }
    
    void MessageBoard::drawSimple(sf::RenderWindow &window, Cache &cache)
    {
        const float LINE_SPACING = 20.0f * Settings::getScaling();
        const float MESSAGE_PADDING_TOP = 0.0f;
        const float MESSAGE_PADDING_BOTTOM = 0.0f;
        
        const sf::Font *usernameFont = ResourceCache::getFont("fonts/Nunito-Regular.ttf");
        const int usernameTextCharacterSize = 20 * Settings::getScaling();
        const float usernameTextHeight = usernameFont->getLineSpacing(usernameTextCharacterSize);
        const float usernameMaxWidth = usernameTextHeight * 5.0f;
        
        const sf::Font *timestampFont = ResourceCache::getFont("fonts/Nunito-Regular.ttf");
        const int timestampTextCharacterSize = 15 * Settings::getScaling();
        const float timestampTextHeight = timestampFont->getLineSpacing(timestampTextCharacterSize);
        
        sf::Vector2<double> position(ChannelSidePanel::getWidth() + PADDING_SIDE * Settings::getScaling() + usernameMaxWidth, ChannelTopPanel::getHeight() + PADDING_TOP);
        double startHeight = position.y;
        position.y += scroll;
        usize numMessages = messages.size();
        for(usize i = 0; i < numMessages; ++i)
        {
            Message *message = messages[i];
            position.y += (MESSAGE_PADDING_TOP * Settings::getScaling());
            if(position.y + usernameTextHeight > 0.0f && position.y < backgroundPos.y + backgroundSize.y)
            {
                sf::String usernameTextStr = sf::String::fromUtf8(message->user->getName().begin(), message->user->getName().end());
                usernameTextStr += "  -  ";
                sf::Text usernameText(usernameTextStr, *usernameFont, usernameTextCharacterSize);
                usernameText.setFillColor(sf::Color(15, 192, 252));
                usernameText.setPosition(sf::Vector2f(floor(position.x - usernameText.getLocalBounds().width), floor(position.y)));
                window.draw(usernameText);
                
                if(message->timestampSeconds)
                {
                    time_t time = (time_t)message->timestampSeconds;
                    struct tm *localTimePtr = localtime(&time);
                    char date[30];
                    strftime(date, sizeof(date), "%Y-%m-%d at %T", localTimePtr);
                    
                    //sf::Text timestamp(date, *timestampFont, timestampTextCharacterSize);
                    //timestamp.setFillColor(ColorScheme::getTextRegularColor() * sf::Color(255, 255, 255, 30));
                    //timestamp.setPosition(sf::Vector2f(floor(position.x  - usernameText.getLocalBounds().width + usernameText.getLocalBounds().width + USERNAME_TIMESTAMP_SIDE_PADDING * Settings::getScaling()), floor(position.y + 2.0f * Settings::getScaling() + usernameTextHeight * 0.5f - timestampTextHeight * 0.5f)));
                    //window.draw(timestamp);
                }
            }
            
            // No need to perform culling here, that is done in @Text draw function
            message->text.setCharacterSize(18 * Settings::getScaling());
            message->text.setMaxWidth(backgroundSize.x - usernameMaxWidth * 2.0f);
            message->text.setPosition(sf::Vector2f(floor(position.x), floor(position.y)));
            message->text.setLineSpacing(LINE_SPACING);
            message->text.draw(window, cache);
            position.y += (message->text.getHeight() + MESSAGE_PADDING_BOTTOM  * Settings::getScaling());
        }
        totalHeight = (position.y - scroll) - startHeight;
    }
    
    void MessageBoard::processEvent(const sf::Event &event, Cache &cache)
    {
        lock_guard<mutex> lock(messageProcessMutex);
        
        OnlineLocalUser *onlineLocalUser = nullptr;
        if(channel->getLocalUser()->type == User::Type::ONLINE_LOCAL_USER)
            onlineLocalUser = static_cast<OnlineLocalUser*>(channel->getLocalUser());
        
        bool openContextMenu = false;
        if(onlineLocalUser && event.type == sf::Event::MouseButtonPressed && event.mouseButton.button == sf::Mouse::Button::Right)
            openContextMenu = true;
        
        if(visibleMessageStartIndex != -1 && visibleMessageStartIndex < messages.size() && visibleMessageEndIndex < messages.size())
        {
            //printf("visibleMessageStartIndex: %u, visibleMessageEndIndex: %u\n", visibleMessageStartIndex, visibleMessageEndIndex);
            for(usize i = visibleMessageStartIndex; i <= visibleMessageEndIndex; ++i)
            {
                Message *message = messages[i];
                message->text.processEvent(event, cache);
                
                auto textPos = message->text.getPosition();
                if(openContextMenu && message->user == channel->getLocalUser() && event.mouseButton.x >= textPos.x && event.mouseButton.x <= textPos.x + message->text.getMaxWidth() && event.mouseButton.y >= textPos.y && event.mouseButton.y <= textPos.y + message->text.getHeight())
                {
                    auto contextMenu = GlobalContextMenu::getEditMessageContextMenu();
                    contextMenu->setPosition(sf::Vector2f(event.mouseButton.x, event.mouseButton.y));
                    contextMenu->setVisible(true);
                    GlobalContextMenu::setClickDeleteMessageCallbackFunc([this, message, onlineLocalUser](ContextMenuItem *menuItem)
                    {
                        channel->deleteMessage(message->id, onlineLocalUser->getPublicKey());
                        GlobalContextMenu::setClickDeleteMessageCallbackFunc(nullptr);
                    });
                }
            }
        }
        
        if(event.type == sf::Event::MouseWheelScrolled && event.mouseWheelScroll.wheel == sf::Mouse::Wheel::VerticalWheel)
        {
            scrollSpeed += (event.mouseWheelScroll.delta * 5.0);
            if(scrollSpeed > SCROLL_MAX_SPEED)
                scrollSpeed = SCROLL_MAX_SPEED;
            else if(scrollSpeed < -SCROLL_MAX_SPEED)
                scrollSpeed = -SCROLL_MAX_SPEED;
        }
    }
    
    void MessageBoard::draw(sf::RenderWindow &window, Cache &cache)
    {
        auto windowSize = window.getSize();
        backgroundSizeWithoutPadding = sf::Vector2f(floor(windowSize.x - ChannelSidePanel::getWidth()), floor(windowSize.y - ChannelTopPanel::getHeight() - Chatbar::getHeight()));
        backgroundSize = sf::Vector2f(floor(windowSize.x - ChannelSidePanel::getWidth() - PADDING_SIDE * Settings::getScaling() * 2.0f), floor(windowSize.y - ChannelTopPanel::getHeight() - Chatbar::getHeight() - PADDING_TOP));
        backgroundPos = sf::Vector2f(ChannelSidePanel::getWidth(), ChannelTopPanel::getHeight());
        
        //if(backgroundSize != staticContentTexture.getSize())
        //    updateStaticContentTexture(backgroundSize);
        
        // TODO: Remove this when dchat::Text can render to static and dynamic render target
        dirty = true;
        //if(dirty)
        //    staticContentTexture.clear(BACKGROUND_COLOR);
        
        sf::RectangleShape backgroundRect(backgroundSizeWithoutPadding);
        backgroundRect.setFillColor(ColorScheme::getBackgroundColor());
        backgroundRect.setPosition(ChannelSidePanel::getWidth(), ChannelTopPanel::getHeight());
        window.draw(backgroundRect);
        
        double deltaTimeMicro = (double)frameTimer.getElapsedTime().asMicroseconds();
        frameTimer.restart();
        
        if(dirty)
        {
            lock_guard<mutex> lock(messageProcessMutex);
            switch(Theme::getType())
            {
                case Theme::Type::DEFAULT:
                    drawDefault(window, cache);
                    break;
                case Theme::Type::SIMPLE:
                    drawSimple(window, cache);
                    break;
            }
        }
        
        scroll += scrollSpeed;
        
        double deltaTimeScrollMultiplier = deltaTimeMicro * 0.0001;
        if(scrollSpeed > 0.0)
        {
            scrollSpeed -= deltaTimeScrollMultiplier;
        }
        else
        {
            scrollSpeed += deltaTimeScrollMultiplier;
        }
        
        if(abs(scrollSpeed - deltaTimeScrollMultiplier) <= deltaTimeScrollMultiplier)
            scrollSpeed = 0.0;
        
        double textOverflow = (double)backgroundSize.y - totalHeight;
        if(scroll > 0.0 || textOverflow > 0.0)
        {
            scroll = 0.0;
            scrollSpeed = 0.0;
        }
        else if(textOverflow < 0.0 && scroll < textOverflow)
        {
            scroll = textOverflow;
            scrollSpeed = 0.0;
        }
        
        if(scrollToBottom)
        {
            scrollToBottom = false;
            if(textOverflow < 0.0)
                scroll = textOverflow;
            else
                scroll = 0.0;
        }
        
        scrollbar.scroll = abs(scroll);
        scrollbar.maxScroll = totalHeight;
        scrollbar.width = 10.0f * Settings::getScaling();
        scrollbar.maxHeight = (float)backgroundSize.y;
        scrollbar.position.x = windowSize.x - scrollbar.width;
        scrollbar.position.y = backgroundPos.y;
        scrollbar.draw(window);
        scroll = scrollbar.getScrollingForContent();
        
        //staticContentTexture.display();
        dirty = false;
        
        // TODO: Save this, expensive to create on fly?
        //sf::Sprite textureSprite(staticContentTexture.getTexture());
        //textureSprite.setPosition(backgroundPos);
        //window.draw(textureSprite);
    }
    
    Message* MessageBoard::getLatestMessage()
    {
        if(!messages.empty())
            return messages.back();
        return nullptr;
    }

    const std::vector<Message*>& MessageBoard::getMessages() const
    {
        return messages;
    }
}