#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

UIManager ui;

UIManager::UIManager() 
    : display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET)
{
}

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
    ledMatrix.begin();
}

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 currentTrackNumSteps,
          bool mutationEnabled, bool songModeEnabled, 
          const Step sequence[][NUM_STEPS], int playbackStep, bool isPlaying,
          int randomizeTrack, const bool* trackMute, const int* trackIntensities) {
 
    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, currentTrackNumSteps, mutationEnabled, songModeEnabled, isPlaying, randomizeTrack, trackMute, trackIntensities);
            break;
        case UI_SETUP_CHANNEL_EDIT:
            drawEditScreen("SET MIDI CHANNEL", "CH: ", midiChannel);
            break;
        case UI_EDIT_TEMPO:
            drawEditScreen("SET TEMPO", "BPM: ", tempo);
            break;
        case UI_EDIT_STEPS:
            drawEditScreen("SET STEPS", "LEN: ", currentTrackNumSteps);
            break;
        case UI_EDIT_FLAVOUR:
            drawEditScreen("SET FLAVOUR", "", currentStrategy->getName());
            break;
        case UI_EDIT_ROOT:
            {
                const char* noteNames[] = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
                drawEditScreen("SET ROOT NOTE", "", noteNames[currentRoot % 12]);
            }
            break;
        case UI_EDIT_SCALE_TYPE:
            display.println(F("ENABLED SCALES"));
            display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
            display.setCursor(0, 20);
            if (menuSelection < 10) {
                const char* typeNames[] = {"Chrom", "Major", "Minor", "H.Min", "P.Maj", "P.Min", "ChdMaj", "ChdMin", "ChdDim", "Chd7"};
                display.setTextSize(2);
                display.print(typeNames[menuSelection]);
                display.setTextSize(1);
                display.setCursor(0, 45);
                bool isEnabled = (enabledScaleTypes & (1 << menuSelection));
                display.print(isEnabled ? F("[ENABLED]") : F("[DISABLED]"));
            } else {
                display.setTextSize(2);
                display.print(F("Back"));
            }
            display.setTextSize(1);
            display.setCursor(0, 55);
            display.println(F(" (Press to toggle)"));
            break;
        case UI_EDIT_INTENSITY:
            drawNumberEditor("SET INTENSITY", trackIntensities[randomizeTrack], 1, 10);
            break;
        case UI_RANDOMIZE_TRACK_EDIT:
            drawEditScreen("SET TRACK", "TRK: ", randomizeTrack + 1);
            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::drawNumberEditor(const char* title, int value, int minVal, int maxVal) {
    display.println(title);
    display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
    
    // Display value
    display.setCursor(20, 20);
    display.setTextSize(2);
    display.print(value);

    // Graphical bar
    int barWidth = 100;
    int barX = (SCREEN_WIDTH - barWidth) / 2;
    int barY = 40;
    int barHeight = 10;
    float percentage = (float)(value - minVal) / (maxVal - minVal);
    int fillWidth = (int)(percentage * barWidth);

    display.drawRect(barX, barY, barWidth, barHeight, SSD1306_WHITE);
    display.fillRect(barX, barY, fillWidth, barHeight, SSD1306_WHITE);

    display.setTextSize(1);
    display.setCursor(0, 54);
    display.println(F(" (Press to confirm)"));
}

void UIManager::drawEditScreen(const char* title, const char* label, const char* valueStr) {
    display.println(title);
    display.drawLine(0, 8, 128, 8, SSD1306_WHITE);
    display.setCursor(20, 25);
    display.setTextSize(2);
    if (label && *label) display.print(label);
    display.print(valueStr);
    display.setTextSize(1);
    display.setCursor(0, 50);
    display.println(F(" (Press to confirm)"));
}

void UIManager::drawEditScreen(const char* title, const char* label, int value) {
    char buf[16];
    itoa(value, buf, 10);
    drawEditScreen(title, label, buf);
}

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 currentTrackNumSteps, bool mutationEnabled,
              bool songModeEnabled, bool isPlaying, int randomizeTrack, const bool* trackMute, const int* trackIntensities) {

    // 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_ROOT) { 
                const char* noteNames[] = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
                display.print(F(": ")); display.print(noteNames[currentRoot % 12]); 
            }
            else if (id == MENU_ID_SCALE_TYPE) { 
                const char* typeNames[] = {"Chrom", "Major", "Minor", "H.Min", "P.Maj", "P.Min", "ChdMaj", "ChdMin", "ChdDim", "Chd7"};
                display.print(F(": ")); if (currentScaleType >= 0 && currentScaleType < 10) display.print(typeNames[currentScaleType]); 
            }
            else if (id == MENU_ID_STEPS) { display.print(F(": ")); display.print(currentTrackNumSteps); }
            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_INTENSITY) {
                display.print(F(": "));
                display.print(trackIntensities[randomizeTrack]);
                int val = trackIntensities[randomizeTrack];
                int barX = display.getCursorX() + 3;
                int barY = y + 2;
                int maxW = 20;
                int h = 5;
                uint16_t color = (i == selection) ? SSD1306_BLACK : SSD1306_WHITE;
                display.drawRect(barX, barY, maxW + 2, h, color);
                display.fillRect(barX + 1, barY + 1, (val * maxW) / 10, h - 2, color);
            }
            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++;
    }
}

void UIManager::updateLeds(const Step sequence[][NUM_STEPS], int playbackStep, bool isPlaying, 
                UIState currentState, bool songModeEnabled, 
                int songRepeatsRemaining, bool sequenceChangeScheduled, PlayMode playMode,
                int selectedTrack, const int* numSteps, int numScaleNotes, const int* scaleNotes, const bool* trackMute) {
    ledMatrix.update(sequence, playbackStep, isPlaying, currentState, songModeEnabled, songRepeatsRemaining, sequenceChangeScheduled, playMode, selectedTrack, numSteps, trackMute);
}