#include "UIManager.h"
#include "config.h"
#include "SharedState.h"

// --- HARDWARE CONFIGURATION ---
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1 
#define SCREEN_ADDRESS 0x3C
#define PIN_NEOPIXEL 2
#define NUM_PIXELS   64

UIManager ui;

UIManager::UIManager() 
    : display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET),
      pixels(NUM_PIXELS, PIN_NEOPIXEL, NEO_GRB + NEO_KHZ800)
{
}

void UIManager::begin() {
    // Setup Display
    Wire.begin();
    if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
        Serial.println(F("SSD1306 allocation failed"));
        for(;;);
    }
    display.clearDisplay();
    display.display();

    // Setup NeoPixel Matrix
    pixels.setPin(PIN_NEOPIXEL);
    pixels.begin();
    pixels.setBrightness(40);
    pixels.clear();
    pixels.show();
}

void UIManager::showMessage(const char* msg) {
    display.clearDisplay();
    display.setCursor(10, 25);
    display.setTextColor(SSD1306_WHITE);
    display.setTextSize(2);
    display.print(msg);
    display.display();
    delay(500);
    display.setTextSize(1);
}
 
void UIManager::draw(UIState currentState, int menuSelection, 
          int midiChannel, int tempo, MelodyStrategy* currentStrategy, 
          int queuedTheme, int currentThemeIndex, 
          int numScaleNotes, const int* scaleNotes, int melodySeed, int numSteps,
          bool mutationEnabled, bool songModeEnabled, 
          const Step sequence[][NUM_STEPS], int playbackStep, bool isPlaying,
          int randomizeTrack, const bool* trackMute) {
 
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);

    switch(currentState) {
        case UI_MENU_MAIN:
            drawMenu(menuSelection, currentState, midiChannel, tempo, currentStrategy->getName(), queuedTheme, currentThemeIndex, numScaleNotes, scaleNotes, melodySeed, numSteps, mutationEnabled, songModeEnabled, isPlaying, randomizeTrack, trackMute);
            break;
        case UI_SETUP_CHANNEL_EDIT:
            display.println(F("SET MIDI CHANNEL"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            display.setCursor(20, 25);
            display.setTextSize(2);
            display.print(F("CH: "));
            if (midiChannel < 10) display.print(F(" "));
            display.print(midiChannel);
            display.setTextSize(1);
            display.setCursor(0, 50);
            display.println(F(" (Press to confirm)"));
            break;
        case UI_EDIT_TEMPO:
            display.println(F("SET TEMPO"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            display.setCursor(20, 25);
            display.setTextSize(2);
            display.print(F("BPM: "));
            display.print(tempo);
            display.setTextSize(1);
            display.setCursor(0, 50);
            display.println(F(" (Press to confirm)"));
            break;
        case UI_EDIT_STEPS:
            display.println(F("SET STEPS"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            display.setCursor(20, 25);
            display.setTextSize(2);
            display.print(F("LEN: "));
            display.print(numSteps);
            display.setTextSize(1);
            display.setCursor(0, 50);
            display.println(F(" (Press to confirm)"));
            break;
        case UI_EDIT_FLAVOUR:
            display.println(F("SET FLAVOUR"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            display.setCursor(20, 25);
            display.setTextSize(2);
            display.print(currentStrategy->getName());
            display.setTextSize(1);
            display.setCursor(0, 50);
            display.println(F(" (Press to confirm)"));
            break;
        case UI_RANDOMIZE_TRACK_EDIT:
            display.println(F("SET TRACK"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            display.setCursor(20, 25);
            display.setTextSize(2);
            display.print(F("TRK: "));
            display.print(randomizeTrack + 1);
            display.setTextSize(1);
            display.setCursor(0, 50);
            display.println(F(" (Press to confirm)"));
            break;
        case UI_SCALE_EDIT:
        case UI_SCALE_NOTE_EDIT:
        case UI_SCALE_TRANSPOSE:
            display.println(F("EDIT SCALE"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            
            int totalItems = numScaleNotes + 5; // Back + Randomize + Notes + Add + Remove + Transpose
            int startIdx = 0;
            if (menuSelection >= 4) startIdx = menuSelection - 3;
            
            int y = 12;
            for (int i = startIdx; i < totalItems; i++) {
                if (y > 54) break;
                
                if (i == menuSelection) {
                    display.fillRect(0, y, 75, 9, SSD1306_WHITE);
                    display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
                } else {
                    display.setTextColor(SSD1306_WHITE);
                }
                display.setCursor(2, y + 1);
                
                if (i == 0) {
                    display.print(F("Back"));
                } else if (i == 1) {
                    display.print(F("Randomize"));
                } else if (i <= numScaleNotes + 1) {
                    int noteIdx = i - 2;
                    const char* noteNames[] = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
                    display.print(noteNames[scaleNotes[noteIdx]]);
                    if (currentState == UI_SCALE_NOTE_EDIT && i == menuSelection) {
                        display.print(F(" <"));
                    }
                } else if (i == numScaleNotes + 2) {
                    display.print(F("Transpose"));
                    if (currentState == UI_SCALE_TRANSPOSE) {
                        display.print(F(" < >"));
                    }
                } else if (i == numScaleNotes + 3) {
                    display.print(F("Add Note"));
                } else if (i == numScaleNotes + 4) {
                    display.print(F("Remove Note"));
                }
                y += 9;
            }

            // Piano Roll Preview
            int px = 82;
            int py = 20;
            int wk_w = 5;
            int wk_h = 20;
            int bk_w = 4;
            int bk_h = 12;
            
            // White keys: C, D, E, F, G, A, B
            int whiteNotes[] = {0, 2, 4, 5, 7, 9, 11};
            for (int k = 0; k < 7; k++) {
                bool active = false;
                for (int j = 0; j < numScaleNotes; j++) {
                    if (scaleNotes[j] == whiteNotes[k]) { active = true; break; }
                }
                if (active) display.fillRect(px + k*6, py, wk_w, wk_h, SSD1306_WHITE);
                else display.drawRect(px + k*6, py, wk_w, wk_h, SSD1306_WHITE);
            }
            
            // Black keys: C#, D#, F#, G#, A#
            int blackNotes[] = {1, 3, 6, 8, 10};
            int blackOffsets[] = {3, 9, 21, 27, 33};
            for (int k = 0; k < 5; k++) {
                bool active = false;
                for (int j = 0; j < numScaleNotes; j++) {
                    if (scaleNotes[j] == blackNotes[k]) { active = true; break; }
                }
                int bx = px + blackOffsets[k];
                display.fillRect(bx - 1, py - 1, bk_w + 2, bk_h + 2, SSD1306_BLACK);
                if (active) display.fillRect(bx, py, bk_w, bk_h, SSD1306_WHITE);
                else display.drawRect(bx, py, bk_w, bk_h, SSD1306_WHITE);
            }
            break;
    }
    display.display();
}

void UIManager::drawMenu(int selection, UIState currentState, int midiChannel, int tempo, const char* flavourName, 
              int queuedTheme, int currentThemeIndex, int numScaleNotes, 
              const int* scaleNotes, int melodySeed, int numSteps, bool mutationEnabled, 
              bool songModeEnabled, bool isPlaying, int randomizeTrack, const bool* trackMute) {

    // Calculate visual cursor position and scroll offset
    int visualCursor = 0;
    for(int i=0; i<selection; i++) {
        if(isItemVisible(i)) visualCursor++;
    }
    
    const int MAX_LINES = 7; // No title, so we have more space
    int startVisualIndex = 0;
    if (visualCursor >= MAX_LINES) {
        startVisualIndex = visualCursor - (MAX_LINES - 1);
    }
    
    int currentVisualIndex = 0;
    int y = 0;

    for (int i = 0; i < menuItemsCount; i++) {
        if (!isItemVisible(i)) continue;
        
        if (currentVisualIndex >= startVisualIndex) {
            if (y > 55) break;

        if (i == selection) {
            display.fillRect(0, y, 128, 9, SSD1306_WHITE);
            display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
        } else {
            display.setTextColor(SSD1306_WHITE);
        }
        
        int x = 2 + (menuItems[i].indentLevel * 6);
        display.setCursor(x, y + 1);
        
        if (menuItems[i].isGroup) {
            display.print(menuItems[i].expanded ? F("v ") : F("> "));
        }
        
        display.print(menuItems[i].label);

        MenuItemID id = menuItems[i].id;

        if (id == MENU_ID_CHANNEL) {
            display.print(F(": ")); display.print(midiChannel);
        }
        
        // Dynamic values
            if (id == MENU_ID_PLAYBACK) { display.print(F(": ")); display.print(isPlaying ? F("ON") : F("OFF")); }
            else if (id == MENU_ID_MELODY) {
                display.print(F(": ")); display.print(melodySeed);
            } else if (id == MENU_ID_SCALE) {
                display.print(F(": "));
                if (numScaleNotes > 0) {
                    const char* noteNames[] = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
                    for (int j = 0; j < min(numScaleNotes, 6); j++) {
                        display.print(noteNames[scaleNotes[j]]);
                        if (j < min(numScaleNotes, 6) - 1) display.print(F(" "));
                    }
                }
            } else if (id == MENU_ID_TEMPO) { display.print(F(": ")); display.print(tempo); }
            else if (id == MENU_ID_STEPS) { display.print(F(": ")); display.print(numSteps); }
            else if (id == MENU_ID_SONG_MODE) { display.print(F(": ")); display.print(songModeEnabled ? F("ON") : F("OFF")); }
            else if (id == MENU_ID_TRACK_SELECT) { display.print(F(": ")); display.print(randomizeTrack + 1); }
            else if (id == MENU_ID_MUTE) { display.print(F(": ")); display.print(trackMute[randomizeTrack] ? F("YES") : F("NO")); }
            else if (id == MENU_ID_FLAVOUR) { display.print(F(": ")); display.print(flavourName); }
            else if (id == MENU_ID_MUTATION) { display.print(F(": ")); display.print(mutationEnabled ? F("ON") : F("OFF")); }
            else if (id == MENU_ID_PROTECTED_MODE) { display.print(F(": ")); display.print(protectedMode ? F("ON") : F("OFF")); }
            
            if (id >= MENU_ID_THEME_1 && id <= MENU_ID_THEME_7) {
                int themeIdx = id - MENU_ID_THEME_1 + 1;
                if (queuedTheme == themeIdx) display.print(F(" [NEXT]"));
                if (currentThemeIndex == themeIdx) display.print(F(" *"));
            }

        y += 9;
        }
        
        currentVisualIndex++;
    }
}

uint32_t UIManager::getNoteColor(int note, bool dim) {
    if (note == -1) return 0;
    uint16_t hue = 30000 + (note % 12) * 3628;
    return Adafruit_NeoPixel::ColorHSV(hue, 255, dim ? 10 : 50);
}

int UIManager::getPixelIndex(int x, int y) {
    return y * 8 + x;
}

void UIManager::updateLeds(const Step sequence[][NUM_STEPS], int playbackStep, bool isPlaying, 
                UIState currentState, bool songModeEnabled, 
                int songRepeatsRemaining, bool sequenceChangeScheduled, PlayMode playMode,
                int selectedTrack, int numSteps, int numScaleNotes, const int* scaleNotes, const bool* trackMute) {
    pixels.clear();
    
    const uint32_t COLOR_PLAYHEAD = pixels.Color(0, 255, 0);
    const uint32_t COLOR_PLAYHEAD_DIM = pixels.Color(0, 32, 0);
    const uint32_t COLOR_MUTED_PLAYHEAD = pixels.Color(0, 0, 255);
    const uint32_t COLOR_CURSOR = pixels.Color(255, 255, 255);
    const uint32_t COLOR_CURSOR_DIM = pixels.Color(32, 0, 0);

    if(playMode == MODE_POLY) {
        for(int t=0; t<NUM_TRACKS; t++) {
            for(int s=0; s<NUM_STEPS; s++) {
                if (s >= numSteps) continue;

                int row = t * 2 + (s / 8);
                int col = s % 8;
                
                uint32_t color = 0;
                int note = sequence[t][s].note;
                
                if (note != -1) {
                    color = getNoteColor(note, !sequence[t][s].accent);
                }
                
                if (isPlaying && s == playbackStep) {
                    if (trackMute[t]) {
                        color = COLOR_MUTED_PLAYHEAD;
                    } else {
                        color = (note != -1) ? COLOR_PLAYHEAD : COLOR_PLAYHEAD_DIM;
                    }
                }
                
                pixels.setPixelColor(getPixelIndex(col, row), color);
            }
        }
    } else {
        // --- Mono Mode (original) ---
        const Step* trackSequence = sequence[selectedTrack];
        for (int s = 0; s < NUM_STEPS; s++) {
            if (s >= numSteps) continue;

            int x = s % 8;
            int yBase = (s / 8) * 4;
            uint32_t color = 0, dimColor = 0;
            bool isCursorHere = (isPlaying && s == playbackStep);
            if (trackSequence[s].note != -1) {
                color = getNoteColor(trackSequence[s].note, trackSequence[s].tie);
                dimColor = getNoteColor(trackSequence[s].note, true);
            }
            uint32_t c[4] = {0};
            if (trackSequence[s].note != -1) {
                int octave = trackSequence[s].note / 12;
                if (octave > 4) { c[0] = color; if (trackSequence[s].accent) c[1] = dimColor; }
                else if (octave < 4) { c[2] = color; if (trackSequence[s].accent) c[1] = dimColor; }
                else { c[1] = color; if (trackSequence[s].accent) { c[0] = dimColor; c[2] = dimColor; } }
            }
            uint32_t cursorColor = pixels.Color(0, 0, 50);
            if (isPlaying) {
                 cursorColor = pixels.Color(0, 50, 0);
                 if (songModeEnabled && s >= 8) {
                     int repeats = min(songRepeatsRemaining, 8);
                     if (x >= (8 - repeats)) cursorColor = (songRepeatsRemaining == 1 && x == 7 && (millis()/250)%2) ? pixels.Color(255, 200, 0) : pixels.Color(100, 220, 40);
                 }
            }
            
            if (cursorColor != 0) {
                if (isCursorHere) {
                    for(int i=0; i<4; i++) {
                        if (c[i] == 0) c[i] = cursorColor;
                    }
                } else {
                    uint8_t r = (uint8_t)(cursorColor >> 16), g = (uint8_t)(cursorColor >> 8), b = (uint8_t)cursorColor;
                    c[3] = pixels.Color(r/5, g/5, b/5);
                }
            }
            for(int i=0; i<4; i++) pixels.setPixelColor(getPixelIndex(x, yBase + i), c[i]);
        }
    }
    if (sequenceChangeScheduled && (millis() / 125) % 2) pixels.setPixelColor(NUM_PIXELS - 1, pixels.Color(127, 50, 0));
    pixels.show();
}