#include "Sequencer.h"
#include "PlaybackScreen.h"
#include "colors.h"
#include <iostream>
#include <cassert>

PlaybackScreen::PlaybackScreen(Sequencer& seq)
    : parent(seq), beatDisplayOffset(0), messageDisplayOffset(0)
{
}

void PlaybackScreen::enable()
{
    if(sequencer.beats.size() == 0) {
        beatDisplayOffset = 0;
    } else {
        beatDisplayOffset = std::min(
            beatDisplayOffset, 
            (Player::BeatIndex)(sequencer.beats.size() - 1) / beatDisplayWidth * beatDisplayWidth
            );
    }
    if(messageDisplayOffset >= sequencer.messages.size()) {
        messageDisplayOffset = sequencer.messages.size() - 1;
    }
    refreshAll();
    parent::enable();
}

void PlaybackScreen::beforeBeat(Player::BeatIndex beat)
{
    // std::cout << "before beat #" << beat << std::endl;
    beatDisplayOffset = beat / beatDisplayWidth * beatDisplayWidth;
    refreshAll();
}

void PlaybackScreen::afterBeat(Player::BeatIndex beat)
{
}

void PlaybackScreen::keyPressed(unsigned char x, unsigned char y)
{
    // std::cout << "clicked x=" << (int)x << ", y=" << (int)y << std::endl;

    if(x == 8) { // very right
        std::size_t messageIndex = y + messageDisplayOffset;
        if(messageIndex < sequencer.messages.size()) {
            std::shared_ptr<midi::Message> msg_ptr = sequencer.messages[messageIndex];
            msg_ptr->print(std::cout);
            sequencer.midiOut.sendMessage(*msg_ptr);
        }
    } else if(y == 8) { // very top
        bool playing = sequencer.player.isPlaying();
        switch(x) {
            case 0: // down
                if(messageDisplayOffset > 0) {
                    int offset = messageDisplayOffset;
                    offset -= messageDisplayShift;
                    messageDisplayOffset = std::max(0, offset);
                }
                break;
            case 1: // up
                if(messageDisplayOffset + beatsHeight < sequencer.messages.size()) {
                    messageDisplayOffset = std::min(
                        (MessageDisplayOffset)sequencer.messages.size() - 1, 
                        messageDisplayOffset + messageDisplayShift
                        );
                }
                break;
            case 2: // left
                if(!playing && beatDisplayOffset > 0) {
                    beatDisplayOffset = std::max(0, (int)beatDisplayOffset - beatDisplayWidth);
                }
                break;
            case 3: // right
                if(!playing && (beatDisplayOffset + beatDisplayWidth) < sequencer.beats.size()) {
                    beatDisplayOffset += beatDisplayWidth;
                }
                break;
            case 5: 
                disable();
                sequencer.configScreen.enable();
                break;
            case 7: // start / stop
                if(playing) {
                    sequencer.player.stop();
                } else {
                    sequencer.player.loop();
                }
                break;
        }
    } else {
        std::size_t messageIndex = y + messageDisplayOffset;
        Player::BeatIndex beatIndex = x + beatDisplayOffset;
        if(beatIndex < sequencer.beats.size() && messageIndex < sequencer.messages.size()) {
            std::shared_ptr<midi::NoteOnMessage> noteOnMessage_ptr
                = std::dynamic_pointer_cast<midi::NoteOnMessage>(sequencer.messages[messageIndex]);
            if(noteOnMessage_ptr) {
                toggleOnMessage(noteOnMessage_ptr, beatIndex);
            }
        }
    }

    refreshAll();
}

void PlaybackScreen::keyReleased(unsigned char x, unsigned char y)
{
    if(x == 8) { // very right
        // this might not be the right message
        std::size_t messageIndex = y + messageDisplayOffset;
        if(messageIndex < sequencer.messages.size()) {
            std::shared_ptr<midi::NoteOnMessage> msgOn_ptr
                = std::dynamic_pointer_cast<midi::NoteOnMessage>(sequencer.messages[messageIndex]);
            if(msgOn_ptr) {
                sequencer.midiOut.sendMessage(msgOn_ptr->toOffMessage(0));
            }
        }
    }

    refreshAll();
}

void PlaybackScreen::refresh(unsigned char x, unsigned char y)
{
    if(x == 8) { // very right
        std::size_t messageIndex = y + messageDisplayOffset;
        if(messageIndex < sequencer.messages.size()) {
            setColor(x, y, getKeyPressed(x, y) ? colors::activeOption : colors::inactiveOption);
        } else {
            setColor(x, y, colors::dark);
        }
    } else if(y == 8) { // very top
        bool playing = sequencer.player.isPlaying();
        switch(x) {
            case 0: // down
                if(messageDisplayOffset > 0) {
                    setColor(x, y, colors::inactiveOption);
                } else {
                    setColor(x, y, colors::dark);
                }
                break;
            case 1: // up
                if(messageDisplayOffset + beatsHeight < sequencer.messages.size()) {
                    setColor(x, y, colors::inactiveOption);
                } else {
                    setColor(x, y, colors::dark);
                }
                break;
            case 2: // left
                if(!playing && beatDisplayOffset > 0) {
                    setColor(x, y, colors::inactiveOption);
                } else {
                    setColor(x, y, colors::dark);
                }
                break;
            case 3: // right
                if(!playing && (beatDisplayOffset + beatDisplayWidth) < sequencer.beats.size()) {
                    setColor(x, y, colors::inactiveOption);
                } else {
                    setColor(x, y, colors::dark);
                }
                break;
            case 5: 
                setColor(x, y, colors::inactiveOption);
                break;
            case 7: // start / stop
                if(playing) {
                    setColor(x, y, colors::activeOption);
                } else {
                    setColor(x, y, colors::inactiveOption);
                }
                break;
        }
    } else {
        std::size_t messageIndex = y + messageDisplayOffset;
        Player::BeatIndex beatIndex = x + beatDisplayOffset;
        if(beatIndex < sequencer.beats.size() && messageIndex < sequencer.messages.size()) {
            std::shared_ptr<midi::NoteOnMessage> noteOnMessage_ptr
                = std::dynamic_pointer_cast<midi::NoteOnMessage>(sequencer.messages[messageIndex]);
            if(noteOnMessage_ptr) {
                setColor(x, y, getBeatColor(noteOnMessage_ptr, beatIndex));
            }
        } else {
            setColor(x, y, colors::dark);
        }
    }
}
    
void PlaybackScreen::toggleOnMessage(std::shared_ptr<midi::NoteOnMessage> onMsg_ptr, Player::BeatIndex beatIndex)
{
    onMsg_ptr->print(std::cout);

    midi::NoteOffMessage offMsg = onMsg_ptr->toOffMessage(0);

    const BeatSequenceNoteInformation& noteInfo
        = sequencer.beats.getNoteInfo(onMsg_ptr->channel, onMsg_ptr->pitch);

    midi::MessageList& beat = sequencer.beats[beatIndex];
    midi::MessageList::iterator beatOnMsg_it = beat.find(*onMsg_ptr);
    if(beatOnMsg_it == beat.end()) {
        // further steps depend on whether a off message has been inserted at the current position
        midi::MessageList::iterator beatOffMsg_it = beat.find(onMsg_ptr->toOffMessage(0));
        BeatIndex nextBeatIndex = (beatIndex + 1) % sequencer.beats.size();
        if(beatOffMsg_it == beat.end()) {
            // is there a ongoing msg, that has to be stopped first?
            BeatIndexMultiset::const_iterator precedingOnMsgBeatIndex_it
                = noteInfo.onBeatIndices.less_or_max(beatIndex);
            if(precedingOnMsgBeatIndex_it != noteInfo.onBeatIndices.end()) {
                // where is this preceding note being stopped?
                BeatIndexMultiset::const_iterator precedingOnFollowingOffMsgBeatIndex_it
                    = noteInfo.offBeatIndices.greater_or_min(*precedingOnMsgBeatIndex_it);
                std::cout << "preceding at " << *precedingOnMsgBeatIndex_it << std::endl;
                std::cout << "\tstop of preceding at " << *precedingOnFollowingOffMsgBeatIndex_it << std::endl;
                std::cout << "beatsInSequence(" << *precedingOnMsgBeatIndex_it << ", " << beatIndex + 1 << ", " << *precedingOnFollowingOffMsgBeatIndex_it << ")" << std::endl;
                if(precedingOnFollowingOffMsgBeatIndex_it == noteInfo.offBeatIndices.end()) {
                    // this preceding note was never stopped
                    // so stop it before the new note
                    sequencer.beats.pushFrontMessage(beatIndex, std::shared_ptr<midi::Message>(new midi::NoteOffMessage(offMsg)));
                } else if (beatsInSequence(*precedingOnMsgBeatIndex_it, beatIndex, *precedingOnFollowingOffMsgBeatIndex_it)) {
                    // this preceding note is currently being stopped after the beat
                    // of the new note. so stop it before the new note.
                    sequencer.beats.pushFrontMessage(beatIndex, std::shared_ptr<midi::Message>(new midi::NoteOffMessage(offMsg)));
                    // since the new note will be stopped on the next beat,
                    // remove this extra off message, which no longer stops the preceding note.
                    midi::MessageList& precedingOnFollowingOffBeat
                        = sequencer.beats[*precedingOnFollowingOffMsgBeatIndex_it];
                    const midi::MessageList::iterator precedingOnFollowingOffMsg_it
                        = precedingOnFollowingOffBeat.find(offMsg);
                    assert(precedingOnFollowingOffMsg_it != precedingOnFollowingOffBeat.end());
                    sequencer.beats.eraseMessage(
                        *precedingOnFollowingOffMsgBeatIndex_it, 
                        precedingOnFollowingOffMsg_it
                        );
                }
            }
            // on msg on current beat & off msg on next beat
            sequencer.beats.pushBackMessage(beatIndex, std::dynamic_pointer_cast<midi::Message>(onMsg_ptr));
        } else {
            // move off to next beat
            sequencer.beats.eraseMessage(beatIndex, beatOffMsg_it);
        }
        // stop at following beat
        sequencer.beats.pushFrontMessage(nextBeatIndex, std::shared_ptr<midi::Message>(new midi::NoteOffMessage(offMsg)));
    } else {
        // remove following off message, if not relevant for other on message. 
        BeatIndexMultiset::const_iterator followingOffBeatIndex_it
            = noteInfo.offBeatIndices.greater_or_min(beatIndex);
        if(followingOffBeatIndex_it != noteInfo.offBeatIndices.end()) {
            BeatIndex followingOffBeatIndex = *followingOffBeatIndex_it;
            BeatIndexMultiset::const_iterator offPrecedingOnBeatIndex_it
                = noteInfo.onBeatIndices.less_or_max(followingOffBeatIndex);
            assert(offPrecedingOnBeatIndex_it != noteInfo.onBeatIndices.end());
            assert(*offPrecedingOnBeatIndex_it >= beatIndex);
            if(*offPrecedingOnBeatIndex_it == beatIndex) {
                // no relevant on message before off found. so off may be removed.
                midi::MessageList& followingOffBeat = sequencer.beats[followingOffBeatIndex];
                midi::MessageList::iterator followingOffMsg_it = followingOffBeat.find(offMsg);
                assert(followingOffMsg_it != followingOffBeat.end());
                sequencer.beats.eraseMessage(*followingOffBeatIndex_it, followingOffMsg_it);
            }
        }

        // previous on without off before to-be-removed on ?
        BeatIndexMultiset::const_iterator precedingOnBeatIndex_it
            = noteInfo.onBeatIndices.less_or_max(beatIndex);
        if(precedingOnBeatIndex_it != noteInfo.onBeatIndices.end()) {
            std::cout << "previous: " << *precedingOnBeatIndex_it << std::endl;
        }

        // remove on message from beat
        sequencer.beats.eraseMessage(beatIndex, beatOnMsg_it);
    }

    sequencer.beats.printRegistry(std::cout);
}
    
midi::LaunchpadColor PlaybackScreen::getBeatColor(std::shared_ptr<midi::NoteOnMessage> onMsg_ptr, BeatIndex beatIndex)
{
    const BeatSequenceNoteInformation& noteInfo
        = sequencer.beats.getNoteInfo(onMsg_ptr->channel, onMsg_ptr->pitch);
    
    BeatIndexMultiset::const_iterator onIndex_it 
        = noteInfo.onBeatIndices.equal_or_less_or_max(beatIndex);
    if(onIndex_it == noteInfo.onBeatIndices.end()) {
        return colors::dark;
    } else {
        bool isNextBeat = (sequencer.player.getNextBeat() == beatIndex);
        if(*onIndex_it == beatIndex) {
            // on msg on current beat
            if(noteInfo.offBeatIndices.find(*onIndex_it) != noteInfo.offBeatIndices.end()) {
                return isNextBeat ? colors::activeOffOnBeat : colors::inactiveOffOnBeat;
            } else {
                return isNextBeat ? colors::activeOnBeat : colors::inactiveOnBeat;
            }
        } else {
            // continuing msg from previous beat ?
            BeatIndexMultiset::const_iterator offIndex_it 
                = noteInfo.offBeatIndices.greater_or_min(*onIndex_it);
            if(offIndex_it == noteInfo.offBeatIndices.end()
                || beatsInSequence(*onIndex_it, beatIndex, (*offIndex_it - 1) % sequencer.beats.size())) {
                return isNextBeat ? colors::activeContinuingBeat : colors::inactiveContinuingBeat;
            }
        }
    }
}
    
bool PlaybackScreen::beatsInSequence(BeatIndex a, BeatIndex b, BeatIndex c) 
{
    if(a <= b) {
        return b <= c || c < a;
    } else {
        return b <= c && c < a;
    }
}