import { hexToHsl, hslToHex, rgbToHsl, rgbToHex } from './converter.js';

const MAX_FARBEN = 4;
const THUMB_SIZE = 120;
const DISTINCT_THRESHOLD = 45; // Mindest-RGB-Abstand damit zwei Farben als verschieden gelten

// --- K-Means Farbextraktion ---

function colorDist(a, b) {
  return Math.sqrt((a[0]-b[0])**2 + (a[1]-b[1])**2 + (a[2]-b[2])**2);
}

function samplePixels(dataUrl, maxSamples, callback) {
  const img = new Image();
  img.onload = () => {
    const c = document.createElement('canvas');
    c.width = img.width; c.height = img.height;
    const ctx = c.getContext('2d');
    ctx.drawImage(img, 0, 0);
    const data = ctx.getImageData(0, 0, c.width, c.height).data;
    const total = c.width * c.height;
    const step = Math.max(1, Math.floor(total / maxSamples));
    const pixels = [];
    for (let i = 0; i < total; i += step) {
      const idx = i * 4;
      if (data[idx + 3] < 128) continue;
      pixels.push([data[idx], data[idx+1], data[idx+2]]);
    }
    callback(pixels);
  };
  img.src = dataUrl;
}

function kMeans(pixels, k, iterations = 15) {
  if (pixels.length <= k) return pixels.map(p => [...p]);
  // K-Means++ Initialisierung: erste zufällig, dann maximaler Mindestabstand
  const centroids = [pixels[Math.floor(Math.random() * pixels.length)].slice()];
  for (let c = 1; c < k; c++) {
    let maxD = -1, best = centroids[0];
    for (const px of pixels) {
      const d = Math.min(...centroids.map(ce => colorDist(px, ce)));
      if (d > maxD) { maxD = d; best = px; }
    }
    centroids.push(best.slice());
  }
  for (let iter = 0; iter < iterations; iter++) {
    const clusters = Array.from({length: k}, () => []);
    for (const px of pixels) {
      let minD = Infinity, minI = 0;
      for (let i = 0; i < k; i++) {
        const d = colorDist(px, centroids[i]);
        if (d < minD) { minD = d; minI = i; }
      }
      clusters[minI].push(px);
    }
    for (let i = 0; i < k; i++) {
      if (clusters[i].length === 0) continue;
      centroids[i] = [0, 1, 2].map(ch =>
        Math.round(clusters[i].reduce((s, p) => s + p[ch], 0) / clusters[i].length)
      );
    }
  }
  return centroids;
}

function extractDominantColors(dataUrl, callback) {
  samplePixels(dataUrl, 600, (pixels) => {
    if (pixels.length === 0) { callback([]); return; }
    const raw = kMeans(pixels, Math.min(3, pixels.length), 15);
    // Nur hinreichend verschiedene Farben behalten
    const distinct = [raw[0]];
    for (let i = 1; i < raw.length; i++) {
      if (distinct.every(d => colorDist(raw[i], d) >= DISTINCT_THRESHOLD)) {
        distinct.push(raw[i]);
      }
    }
    callback(distinct.map(rgb => ({
      hex: rgbToHex({ r: rgb[0], g: rgb[1], b: rgb[2] }),
      hsl: rgbToHsl({ r: rgb[0], g: rgb[1], b: rgb[2] })
    })));
  });
}

// Aktuell gesammelter Zustand des Modals
let farben = [];           // Array von HSL-Objekten
let aktuelleHex = '';      // Hex-Wert des aktuellen Eingabefelds
let vorschaubild = null;   // Base64-String des Thumbnails oder null
let editOriginalName = null; // Name des zu bearbeitenden Schemas (null = neu)
let savedOnSave = null;    // onSave-Callback aus initSchemaModal

function compressToThumbnail(file) {
  return new Promise((resolve) => {
    const reader = new FileReader();
    reader.onload = (e) => {
      const img = new Image();
      img.onload = () => {
        const scale = Math.min(THUMB_SIZE / img.width, THUMB_SIZE / img.height, 1);
        const w = Math.round(img.width * scale);
        const h = Math.round(img.height * scale);
        const c = document.createElement('canvas');
        c.width = w;
        c.height = h;
        c.getContext('2d').drawImage(img, 0, 0, w, h);
        resolve(c.toDataURL('image/jpeg', 0.8));
      };
      img.src = e.target.result;
    };
    reader.readAsDataURL(file);
  });
}

function resetModal() {
  farben = [];
  aktuelleHex = '';
  vorschaubild = null;
  document.getElementById('schema-name-input').value = '';
  document.getElementById('schema-hex-input').value = '';
  document.getElementById('schema-hex-preview').style.background = '#eee';
  document.getElementById('schema-farben-preview').textContent = '';
  document.getElementById('schema-canvas').style.display = 'none';
  document.getElementById('schema-canvas').getContext('2d').clearRect(0, 0, 1, 1);
  document.getElementById('schema-vorschlag').style.display = 'none';
  document.getElementById('schema-farbe-eingabe').style.display = 'none';
  document.getElementById('schema-abschliessen-btn').disabled = true;
  editOriginalName = null;
  document.getElementById('schema-modal-title').textContent = 'Neues Farbschema';
  const preview = document.getElementById('schema-bild-preview');
  preview.style.backgroundImage = '';
  preview.classList.remove('hat-bild');
  document.getElementById('schema-bild-input').value = '';
  document.getElementById('schema-bild-entfernen-btn').style.display = 'none';
  updateFarbeLabel();
}

function showVorschlag(farbenVorschlag) {
  const container = document.getElementById('schema-vorschlag-farben');
  container.textContent = '';
  farbenVorschlag.forEach(({ hex }) => {
    const cell = document.createElement('div');
    cell.style.cssText = 'display:inline-flex;flex-direction:column;align-items:center;gap:0.2rem';
    const swatch = document.createElement('div');
    swatch.style.cssText = 'width:44px;height:44px;border-radius:6px;border:1px solid #ddd;background:' + hex;
    const label = document.createElement('span');
    label.style.cssText = 'font-size:0.7rem;font-family:monospace;color:#666';
    label.textContent = hex;
    cell.appendChild(swatch);
    cell.appendChild(label);
    container.appendChild(cell);
  });
  document.getElementById('schema-vorschlag').style.display = 'block';
  document.getElementById('schema-farbe-eingabe').style.display = 'none';
  return farbenVorschlag;
}

function updateFarbeLabel() {
  document.getElementById('schema-farbe-label').textContent =
    'Farbe ' + (farben.length + 1) + (farben.length === MAX_FARBEN - 1 ? ' (letzte)' : '');
}

function renderFarbenPreview() {
  const container = document.getElementById('schema-farben-preview');
  container.textContent = '';
  farben.forEach((hsl, i) => {
    const hex = hslToHex(hsl);
    const cell = document.createElement('div');
    cell.style.cssText = 'display:inline-flex;flex-direction:column;align-items:center;gap:0.2rem';

    const swatch = document.createElement('div');
    swatch.style.cssText = 'width:44px;height:44px;border-radius:6px;border:1px solid #ddd;background:' + hex;
    swatch.title = hex;

    const label = document.createElement('span');
    label.style.cssText = 'font-size:0.7rem;font-family:monospace;color:#666';
    label.textContent = hex;

    const removeBtn = document.createElement('button');
    removeBtn.className = 'action-btn';
    removeBtn.style.fontSize = '0.65rem';
    removeBtn.textContent = '✕';
    removeBtn.addEventListener('click', () => {
      farben.splice(i, 1);
      renderFarbenPreview();
      updateFarbeLabel();
      document.getElementById('schema-farbe-eingabe').style.display = 'block';
      document.getElementById('schema-abschliessen-btn').disabled = farben.length === 0;
    });

    cell.appendChild(swatch);
    cell.appendChild(label);
    cell.appendChild(removeBtn);
    container.appendChild(cell);
  });
}

function loadImageOnCanvas(file) {
  const reader = new FileReader();
  reader.onload = (e) => {
    const img = new Image();
    img.onload = () => {
      const canvas = document.getElementById('schema-canvas');
      canvas.width = img.width;
      canvas.height = img.height;
      const ctx = canvas.getContext('2d');
      ctx.drawImage(img, 0, 0);
      canvas.style.display = 'block';

      // Mittlerer Pixel als Vorschlag
      const px = ctx.getImageData(Math.floor(img.width / 2), Math.floor(img.height / 2), 1, 1).data;
      setAktuelleHex(rgbToHex({ r: px[0], g: px[1], b: px[2] }));

      canvas.onclick = (ev) => {
        const rect = canvas.getBoundingClientRect();
        const x = Math.floor((ev.clientX - rect.left) * canvas.width / rect.width);
        const y = Math.floor((ev.clientY - rect.top) * canvas.height / rect.height);
        const d = ctx.getImageData(x, y, 1, 1).data;
        setAktuelleHex(rgbToHex({ r: d[0], g: d[1], b: d[2] }));
      };
    };
    img.src = e.target.result;
  };
  reader.readAsDataURL(file);
}

function setAktuelleHex(hex) {
  aktuelleHex = hex;
  document.getElementById('schema-hex-input').value = hex;
  document.getElementById('schema-hex-preview').style.background = hex;
}

export function openForEdit(schema) {
  resetModal();
  editOriginalName = schema.name;
  document.getElementById('schema-modal-title').textContent = 'Schema bearbeiten';
  document.getElementById('schema-name-input').value = schema.name;

  if (schema.bild) {
    vorschaubild = schema.bild;
    const preview = document.getElementById('schema-bild-preview');
    preview.style.backgroundImage = 'url(' + schema.bild + ')';
    preview.classList.add('hat-bild');
    document.getElementById('schema-bild-entfernen-btn').style.display = 'inline-block';
  }

  farben = schema.farben.map(hsl => ({ ...hsl }));
  renderFarbenPreview();
  document.getElementById('schema-abschliessen-btn').disabled = false;

  if (farben.length < MAX_FARBEN) {
    updateFarbeLabel();
    document.getElementById('schema-farbe-eingabe').style.display = 'block';
  }

  document.getElementById('schema-modal-overlay').style.display = 'flex';
  document.getElementById('schema-name-input').focus();
}

export function initSchemaModal(onSave) {
  savedOnSave = onSave;

  // Button öffnet Modal
  document.getElementById('schema-erstellen-btn').addEventListener('click', () => {
    resetModal();
    document.getElementById('schema-modal-overlay').style.display = 'flex';
    document.getElementById('schema-name-input').focus();
  });

  // Abbrechen
  document.getElementById('schema-abbrechen-btn').addEventListener('click', () => {
    document.getElementById('schema-modal-overlay').style.display = 'none';
  });

  // Klick außerhalb schließt Modal
  document.getElementById('schema-modal-overlay').addEventListener('click', (e) => {
    if (e.target === document.getElementById('schema-modal-overlay')) {
      document.getElementById('schema-modal-overlay').style.display = 'none';
    }
  });

  // Hex-Eingabe → Vorschau aktualisieren
  document.getElementById('schema-hex-input').addEventListener('input', (e) => {
    const val = e.target.value.trim();
    if (/^#[0-9a-fA-F]{6}$/.test(val)) {
      aktuelleHex = val;
      document.getElementById('schema-hex-preview').style.background = val;
    }
  });

  // Datei-Upload
  document.getElementById('schema-file-trigger').addEventListener('click', () => {
    document.getElementById('schema-file-input').click();
  });

  document.getElementById('schema-file-input').addEventListener('change', (e) => {
    if (e.target.files[0]) loadImageOnCanvas(e.target.files[0]);
  });

  // Drag & Drop auf Modal-Dropzone
  const dropzone = document.getElementById('schema-dropzone');
  dropzone.addEventListener('dragover', (e) => { e.preventDefault(); dropzone.style.borderColor = '#222'; });
  dropzone.addEventListener('dragleave', () => { dropzone.style.borderColor = '#ccc'; });
  dropzone.addEventListener('drop', (e) => {
    e.preventDefault();
    dropzone.style.borderColor = '#ccc';
    const file = e.dataTransfer.files[0];
    if (file && file.type.startsWith('image/')) loadImageOnCanvas(file);
  });

  // Farbe hinzufügen
  document.getElementById('schema-farbe-hinzufuegen-btn').addEventListener('click', () => {
    if (!/^#[0-9a-fA-F]{6}$/.test(aktuelleHex)) {
      document.getElementById('schema-hex-input').style.borderColor = '#e55';
      document.getElementById('schema-hex-input').focus();
      return;
    }
    document.getElementById('schema-hex-input').style.borderColor = '';

    const hsl = hexToHsl(aktuelleHex);
    if (!hsl) return;
    farben.push(hsl);

    renderFarbenPreview();
    document.getElementById('schema-abschliessen-btn').disabled = false;

    // Eingabe zurücksetzen
    aktuelleHex = '';
    document.getElementById('schema-hex-input').value = '';
    document.getElementById('schema-hex-preview').style.background = '#eee';
    document.getElementById('schema-canvas').style.display = 'none';
    document.getElementById('schema-file-input').value = '';

    if (farben.length >= MAX_FARBEN) {
      // Alle 4 Farben gesammelt — Eingabe ausblenden
      document.getElementById('schema-farbe-eingabe').style.display = 'none';
    } else {
      updateFarbeLabel();
      document.getElementById('schema-hex-input').focus();
    }
  });

  // Abschließen
  document.getElementById('schema-abschliessen-btn').addEventListener('click', () => {
    const name = document.getElementById('schema-name-input').value.trim();
    if (!name) {
      document.getElementById('schema-name-input').style.borderColor = '#e55';
      document.getElementById('schema-name-input').focus();
      return;
    }
    if (farben.length === 0) return;

    savedOnSave(name, farben, vorschaubild, editOriginalName);
    document.getElementById('schema-modal-overlay').style.display = 'none';
  });

  // Vorschaubild hochladen
  document.getElementById('schema-bild-trigger').addEventListener('click', () => {
    document.getElementById('schema-bild-input').click();
  });

  let letzterVorschlag = [];

  document.getElementById('schema-bild-input').addEventListener('change', async (e) => {
    const file = e.target.files[0];
    if (!file) return;
    vorschaubild = await compressToThumbnail(file);
    const preview = document.getElementById('schema-bild-preview');
    preview.style.backgroundImage = 'url(' + vorschaubild + ')';
    preview.classList.add('hat-bild');
    document.getElementById('schema-bild-entfernen-btn').style.display = 'inline-block';

    // Farben extrahieren und Vorschlag zeigen
    extractDominantColors(vorschaubild, (vorschlag) => {
      if (vorschlag.length > 0) {
        letzterVorschlag = showVorschlag(vorschlag);
      } else {
        // Keine Farben erkannt → direkt manuell
        document.getElementById('schema-farbe-eingabe').style.display = 'block';
      }
    });
  });

  // Vorschlag annehmen
  document.getElementById('schema-vorschlag-annehmen-btn').addEventListener('click', () => {
    farben = letzterVorschlag.map(v => v.hsl);
    renderFarbenPreview();
    document.getElementById('schema-abschliessen-btn').disabled = false;
    document.getElementById('schema-vorschlag').style.display = 'none';
    if (farben.length < MAX_FARBEN) {
      updateFarbeLabel();
      document.getElementById('schema-farbe-eingabe').style.display = 'block';
      document.getElementById('schema-hex-input').focus();
    }
  });

  // Vorschlag ablehnen → manuell
  document.getElementById('schema-vorschlag-ablehnen-btn').addEventListener('click', () => {
    letzterVorschlag = [];
    document.getElementById('schema-vorschlag').style.display = 'none';
    document.getElementById('schema-farbe-eingabe').style.display = 'block';
    document.getElementById('schema-hex-input').focus();
  });

  document.getElementById('schema-bild-entfernen-btn').addEventListener('click', () => {
    vorschaubild = null;
    letzterVorschlag = [];
    const preview = document.getElementById('schema-bild-preview');
    preview.style.backgroundImage = '';
    preview.classList.remove('hat-bild');
    document.getElementById('schema-bild-input').value = '';
    document.getElementById('schema-bild-entfernen-btn').style.display = 'none';
    document.getElementById('schema-vorschlag').style.display = 'none';
    document.getElementById('schema-farbe-eingabe').style.display = 'block';
    // Farben zurücksetzen falls nur vom Vorschlag
    if (farben.length === 0) updateFarbeLabel();
  });
}