exports.generatePicturePrompt = (project = {}) => {
  const {
    title = "",
    lyrics: lyricsRaw,
    musicConfig = {},
    coverStyle: coverStyleRaw = "",
    artistName: artistNameRaw = "",
  } = project || {};

  // --- 1. Nettoyage et Normalisation ---
  const sanitizeInline = (value = "") => {
    if (typeof value !== "string") return "";
    return value
      .replace(/[\r\n]+/g, " ")
      .replace(/[<>]/g, "")
      .trim();
  };

  const titleForPrompt = sanitizeInline(title) || "Sans titre";
  const artistName =
    sanitizeInline(artistNameRaw) || sanitizeInline(project?.userName || "");
  const hasArtistName = artistName.length > 0;

  const {
    genres = [],
    tempo = "",
    mood = "",
    instruments = [],
  } = musicConfig || {};
  const userStyle = sanitizeInline(coverStyleRaw);

  // --- 2. Intelligence Visuelle (Mapping) ---

  // Détermination de l'énergie visuelle
  const isEnergetic =
    tempo &&
    /\b(rapid|fast|vite|agité|upbeat|energ|dance|rock|metal)\b/i.test(
      String(tempo),
    );
  const isDark =
    mood &&
    /\b(sombre|triste|dark|sad|mélancoli|nuit|night|eerie)\b/i.test(
      String(mood),
    );

  // Construction de la Palette & Lumière
  let visualAtmosphere = "";
  if (isDark) {
    visualAtmosphere =
      "Atmosphere: Cinematic dark lighting, moody shadows, deep contrast. Palette: Midnight blue, obsidian, deep purple, metallic accents.";
  } else if (isEnergetic) {
    visualAtmosphere =
      "Atmosphere: Dynamic lighting, high energy, vibrant saturation. Palette: Neon colors, electric blue, magenta, bright yellow, high contrast.";
  } else {
    visualAtmosphere =
      "Atmosphere: Soft natural lighting, harmonious and ethereal. Palette: Pastel tones, warm gold, soft coral, balanced and elegant colors.";
  }

  // Définition du Style de Rendu (Si l'utilisateur est vague, on renforce)
  let renderingStyle = userStyle
    ? `Art Style: ${userStyle}`
    : "Art Style: Digital Art, Mixed Media";

  if (
    userStyle.toLowerCase().includes("realist") ||
    userStyle.toLowerCase().includes("photo")
  ) {
    renderingStyle +=
      ", 8k resolution, highly detailed texture, photorealistic, cinematic depth of field, raytracing.";
  } else if (
    userStyle.toLowerCase().includes("illu") ||
    userStyle.toLowerCase().includes("dessin")
  ) {
    renderingStyle +=
      ", vector art, clean lines, professional illustration, flat design or detailed painting.";
  } else {
    // Style par défaut "Album Cover" qui marche bien
    renderingStyle +=
      ", abstract surrealism, conceptual album art, high fidelity, masterpiece.";
  }

  // --- 3. Extraction de l'Inspiration (Lyrics) ---

  // On cherche le REFRAIN en priorité pour l'image, car c'est le cœur visuel
  const sections = Array.isArray(lyricsRaw) ? lyricsRaw : [];
  const chorus = sections.find(
    (s) => s.type === "refrain" || s.type === "chorus",
  );
  const verse = sections.find(
    (s) => s.type === "couplet" || s.type === "verse",
  );

  // On prend 2 lignes max du refrain, ou du premier couplet
  const visualHook = (chorus?.lyrics || verse?.lyrics || "")
    .split("\n")
    .filter((l) => l.length > 10) // On évite les lignes trop courtes
    .slice(0, 2)
    .join(". ");

  const imageryPrompt = visualHook
    ? `Visual Inspiration: An artistic interpretation of these lyrics: "${visualHook}".`
    : "Visual Inspiration: Abstract visual representation of the song's mood.";

  // --- 4. Construction du Prompt Final (Structure Optimisée Imagen 3) ---

  const promptParts = [
    // Rôle
    "Design a professional, high-quality music album cover.",

    // 1. Le Texte (Crucial pour Imagen 3 - Doit être au début ou très clair)
    `**Typography & Text:**`,
    `The song title "${titleForPrompt}" must be the CENTERPIECE. Write it in a distinct, artistic font that matches the mood.`,
    hasArtistName
      ? `The artist name "${artistName}" must appear smaller, elegant, and legible near the bottom or top.`
      : "",
    "Ensure perfect spelling. The text should be integrated into the artwork (e.g., metallic texture, neon glow, or bold cut-out), not just pasted on top.",

    // 2. Le Visuel
    `**Visuals:**`,
    renderingStyle,
    imageryPrompt,
    `Subject: A central visual element that represents the song. ${isEnergetic ? "Dynamic composition." : "Balanced, centered composition."}`,

    // 3. L'Atmosphère (Context from music config)
    `**Mood & Color:**`,
    visualAtmosphere,
    genres.length > 0 ? `Musical Vibe Reference: ${genres.join(", ")}.` : "",

    // 4. Contraintes Négatives (Phrasées positivement pour l'IA)
    "**Constraints:**",
    "Use a square 1:1 aspect ratio.",
    "Do NOT depict literal musical instruments (like guitars or microphones) unless they are part of a surreal abstract composition.",
    "No blurry text. No messy borders. No watermarks.",
  ];

  return promptParts.filter(Boolean).join("\n\n");
};