/**
 * Logic for generating Pixel Art Monsters
 * Adapted from monster_preview.html
 */

export const MONSTER_STAGES = {
    EGG: 0,
    BASIC: 1,
    EVOLVED: 2,
    FINAL: 3
};

// Monster Definitions
export const MONSTER_DEFS = [
    { id: 'Egg', name: '🥚 像素蛋', type: 'neutral', stage: 0, arch: 'egg', fam: 'Origin' },
    // Stage 1
    { id: 'L1_C', name: '🔴 灰塵球 Dust-Ball', type: 'glitch', stage: 1, arch: 'dust', fam: 'Dust' },
    { id: 'L1_B', name: '🟡 像素狗 Pixel-Pup', type: 'animal', stage: 1, arch: 'beast_pup', fam: 'Beast' },
    { id: 'L1_A', name: '🔵 光之靈 Lumina', type: 'holy', stage: 1, arch: 'spirit_orb', fam: 'Spirit' },
    // Stage 2
    { id: 'L2_CC', name: '🔴 垃圾怪 Trash-Mob', type: 'glitch', stage: 2, arch: 'dust_trash', fam: 'Dust' },
    { id: 'L2_CB', name: '🟡 史萊姆 Slime-Box', type: 'slime', stage: 2, arch: 'dust_slime', fam: 'Dust' },
    { id: 'L2_CA', name: '🔵 駭客蟲 Hacker-Bug', type: 'tech', stage: 2, arch: 'dust_tech', fam: 'Dust' },
    { id: 'L2_BC', name: '🔴 廢鐵狼 Rusty-Wolf', type: 'grunge', stage: 2, arch: 'beast_wolf', fam: 'Beast' },
    { id: 'L2_BB', name: '🟡 勇者貓 Hero-Cat', type: 'animal', stage: 2, arch: 'beast_cat', fam: 'Beast' },
    { id: 'L2_BA', name: '🔵 機甲獅 Mecha-Lion', type: 'mech', stage: 2, arch: 'beast_mech', fam: 'Beast' },
    { id: 'L2_AC', name: '🔴 幽靈火 Ghost-Fire', type: 'spirit', stage: 2, arch: 'spirit_fire', fam: 'Spirit' },
    { id: 'L2_AB', name: '🟡 天使鳥 Angel-Bird', type: 'holy', stage: 2, arch: 'spirit_wing', fam: 'Spirit' },
    { id: 'L2_AA', name: '🔵 星雲龍 Cosmos-Dragon', type: 'cosmic', stage: 2, arch: 'spirit_dragon', fam: 'Spirit' },
    // Stage 3
    { id: 'L3_CCC', name: '🗑️ 崩潰垃圾山', type: 'glitch', stage: 3, arch: 'pile_big', fam: 'Glitch/Trash' },
    { id: 'L3_CCB', name: '📦 寶箱怪', type: 'mimic', stage: 3, arch: 'box_teeth', fam: 'Glitch/Trash' },
    { id: 'L3_CCA', name: '🦠 病毒王', type: 'virus', stage: 3, arch: 'corona', fam: 'Glitch/Trash' },
    { id: 'L3_CBC', name: '💧 汙泥怪', type: 'grunge', stage: 3, arch: 'fluid', fam: 'Slime' },
    { id: 'L3_CBB', name: '🧊 果凍騎士', type: 'slime', stage: 3, arch: 'knight_slime', fam: 'Slime' },
    { id: 'L3_CBA', name: '💎 鑽石魔像', type: 'crystal', stage: 3, arch: 'golem', fam: 'Slime' },
    { id: 'L3_CAC', name: '🕷️ 錯誤蜘蛛', type: 'glitch', stage: 3, arch: 'spider', fam: 'Hacker' },
    { id: 'L3_CAB', name: '👾 程式遊俠', type: 'tech', stage: 3, arch: 'ranger', fam: 'Hacker' },
    { id: 'L3_CAA', name: '🧠 量子主腦', type: 'tech', stage: 3, arch: 'brain', fam: 'Hacker' },
    { id: 'L3_BAC', name: '🚜 重裝推土機', type: 'mech', stage: 3, arch: 'tank', fam: 'Mech Lion' },
    { id: 'L3_BAB', name: '✈️ 變形戰機', type: 'mech', stage: 3, arch: 'jet', fam: 'Mech Lion' },
    { id: 'L3_BAA', name: '🤖 究極鋼彈', type: 'mech', stage: 3, arch: 'gundam', fam: 'Mech Lion' },
    { id: 'L3_ACC', name: '💀 骷髏法師', type: 'undead', stage: 3, arch: 'mage_skull', fam: 'Ghost' },
    { id: 'L3_ACB', name: '🕯️ 南瓜燈杰克', type: 'spirit', stage: 3, arch: 'pumpkin', fam: 'Ghost' },
    { id: 'L3_ACA', name: '👻 虛空死神', type: 'void', stage: 3, arch: 'reaper', fam: 'Ghost' },
    // Stage 3 - REDESIGN TARGETS (Wolf V2 & Cat)
    { id: 'L3_BCC', name: '🧟 喪屍犬', type: 'undead', stage: 3, arch: 'wolf_zombie_v2', fam: 'Wolf' },
    { id: 'L3_BCB', name: '🐕 警備犬', type: 'animal', stage: 3, arch: 'wolf_guard_v2', fam: 'Wolf' },
    { id: 'L3_BCA', name: '🐺 合金戰狼', type: 'mech', stage: 3, arch: 'wolf_alloy_v2', fam: 'Wolf' },
    { id: 'L3_BBC', name: '😼 流浪劍客', type: 'warrior', stage: 3, arch: 'ronin', fam: 'Cat' },
    { id: 'L3_BBB', name: '👑 貓咪國王', type: 'royal', stage: 3, arch: 'king_cat', fam: 'Cat' },
    { id: 'L3_BBA', name: '🦁 雷霆獅王', type: 'elemental', stage: 3, arch: 'lion_mane', fam: 'Cat' },
    // Stage 3 - NEW ADDITIONS (Angel & Cosmos)
    { id: 'L3_ABC', name: '👁️ 座天使 Ophanim', type: 'holy', stage: 3, arch: 'biblical_angel', fam: 'Angel' },
    { id: 'L3_ABB', name: '⚔️ 女武神 Valkyrie', type: 'warrior', stage: 3, arch: 'valkyrie', fam: 'Angel' },
    { id: 'L3_ABA', name: '🔥 聖火鳳凰 Phoenix', type: 'divine', stage: 3, arch: 'phoenix', fam: 'Angel' },
    { id: 'L3_AAC', name: '🛡️ 大地泰坦 Titan', type: 'cosmic', stage: 3, arch: 'terra_titan', fam: 'Cosmos' },
    { id: 'L3_AAB', name: '🐋 星海鯨 Astro-Whale', type: 'cosmic', stage: 3, arch: 'cosmo_whale', fam: 'Cosmos' },
    { id: 'L3_AAA', name: '🌌 創世龍 Genesis', type: 'god', stage: 3, arch: 'genesis_dragon', fam: 'Cosmos' },
];

const palettes = {
    base: ['#94A3B8', '#64748B', '#475569', '#334155'],

    // Standard
    glitch: ['#18181b', '#27272a', '#3f3f46', '#ef4444'],
    trash: ['#3f3f46', '#71717a', '#a1a1aa', '#ef4444'],
    mimic: ['#854d0e', '#a16207', '#ca8a04', '#eab308'],
    virus: ['#2e1065', '#581c87', '#7e22ce', '#bef264', '#84cc16'],
    spider: ['#1e293b', '#0f172a', '#b91c1c', '#ef4444'],
    slime: ['#059669', '#10b981', '#34d399', '#d1fae5'],
    fluid: ['#3f3f46', '#52525b', '#4b5563', '#a1a1aa'],
    knight: ['#0ea5e9', '#38bdf8', '#7dd3fc', '#ffffff'],
    crypto: ['#0891b2', '#06b6d4', '#22d3ee', '#cffafe'],
    tech: ['#22d3ee', '#06b6d4', '#0891b2', '#155e75'],
    ranger: ['#3b82f6', '#2563eb', '#1d4ed8', '#fbbf24'],
    brain: ['#d8b4fe', '#c084fc', '#a855f7', '#7e22ce', '#22d3ee'],
    tank: ['#3f3f46', '#18181b', '#facc15', '#fbbf24'],
    jet: ['#cbd5e1', '#94a3b8', '#ef4444', '#dc2626'],
    gundam: ['#ffffff', '#2563eb', '#dc2626', '#facc15'],
    mage: ['#4c1d95', '#a855f7', '#172554', '#fbbf24'],
    pumpkin: ['#ea580c', '#c2410c', '#3f3f46', '#facc15'],
    reaper: ['#000000', '#171717', '#7f1d1d', '#9ca3af'],

    // Wolf V2
    wolf: ['#c2410c', '#9a3412', '#7c2d12', '#ef4444'], // Rust/Browns
    zombie: ['#44403c', '#78716c', '#991b1b', '#fecaca'],
    guard: ['#172554', '#1e3a8a', '#fbbf24', '#f59e0b', '#3b82f6'],
    alloy: ['#e2e8f0', '#94a3b8', '#0ea5e9', '#0284c7', '#38bdf8', '#ffffff'], // Added white/brights

    // Cat V2
    cat: ['#fb923c', '#ea580c', '#c2410c', '#fff7ed'],
    ronin: ['#c2410c', '#9a3412', '#fde047', '#e2e8f0'],
    king: ['#7e22ce', '#a855f7', '#fbbf24', '#ffffff'],
    thunder: ['#facc15', '#eab308', '#fefce8', '#f59e0b', '#ffffff'],

    // Base Fams
    beast: ['#fbbf24', '#f59e0b', '#d97706', '#78350f'],
    mech_lion: ['#60a5fa', '#3b82f6', '#1d4ed8', '#93c5fd'],
    holy: ['#fef3c7', '#fde68a', '#f59e0b', '#ffffff'],
    fire: ['#c084fc', '#a855f7', '#7e22ce', '#ffffff'],
    space: ['#4f46e5', '#312e81', '#818cf8', '#f472b6', '#22d3ee'],

    // Angel V3
    biblical: ['#facc15', '#eab308', '#ffffff', '#ef4444', '#3b82f6'], // Gold + Eyes
    valkyrie: ['#e2e8f0', '#94a3b8', '#facc15', '#38bdf8', '#fbbf24'], // Silver/Gold
    seraphim: ['#dc2626', '#ef4444', '#fbbf24', '#facc15', '#ffffff'], // Fire/Gold

    // Cosmos V3
    meteor: ['#475569', '#334155', '#ea580c', '#f97316'], // Rock/Magma
    whale: ['#1e1b4b', '#312e81', '#6366f1', '#c7d2fe', '#ffffff'], // Deep Space
    genesis: ['#000000', '#171717', '#c084fc', '#22d3ee', '#f472b6', '#ffffff'] // Cosmic
};

function mulberry32(a) {
    return function () {
        var t = a += 0x6D2B79F5;
        t = Math.imul(t ^ (t >>> 15), t | 1);
        t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
        return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
    }
}

/**
 * Generates an SVG string of the monster
 * @param {Object} monster The monster object (from MONSTER_DEFS)
 * @returns {string} SVG string
 */
export function generateMonsterSVG(monster) {
    // If no monster provided, return empty
    if (!monster) return '';

    const W = 24; const H = 24; const C = W / 2;

    let seed = 0;
    // Use monster ID as seed source
    for (let i = 0; i < monster.id.length; i++) seed += monster.id.charCodeAt(i);
    const rng = mulberry32(seed);

    let palette = palettes.base;
    const t = monster.type;
    const a = monster.arch;

    // Palette Select (Simplified Logic from original)
    if (a.includes('wolf')) {
        if (a.includes('zombie')) palette = palettes.zombie;
        else if (a.includes('guard')) palette = palettes.guard;
        else if (a.includes('alloy')) palette = palettes.alloy;
        else palette = palettes.wolf;
    }
    else if (a === 'ronin') palette = palettes.ronin;
    else if (a === 'king_cat') palette = palettes.king;
    else if (a === 'lion_mane') palette = palettes.thunder;
    else if (a === 'tank') palette = palettes.tank;
    else if (a === 'jet') palette = palettes.jet;
    else if (a === 'gundam') palette = palettes.gundam;
    else if (a === 'mage_skull') palette = palettes.mage;
    else if (a === 'pumpkin') palette = palettes.pumpkin;
    else if (a === 'reaper') palette = palettes.reaper;
    else if (a === 'biblical_angel') palette = palettes.biblical;
    else if (a === 'valkyrie') palette = palettes.valkyrie;
    else if (a === 'phoenix') palette = palettes.seraphim;
    else if (a === 'terra_titan') palette = palettes.meteor;
    else if (a === 'cosmo_whale') palette = palettes.whale;
    else if (a === 'genesis_dragon') palette = palettes.genesis;
    else if (a === 'beast_pup') palette = palettes.beast;
    else if (a === 'beast_cat') palette = palettes.cat;
    else if (a === 'beast_mech') palette = palettes.mech_lion;
    else if (a === 'spirit_orb') palette = palettes.holy;
    else if (a === 'spirit_fire') palette = palettes.fire;
    else if (a === 'spirit_wing') palette = palettes.holy;
    else if (a === 'spirit_dragon') palette = palettes.space;

    // Safety Fallbacks
    else if (a.includes('dust')) {
        if (a === 'dust_trash' || a === 'pile_big' || a === 'box_teeth' || a === 'corona') palette = palettes.glitch;
        else if (a.includes('slime') || a === 'fluid' || a === 'knight_slime' || a === 'golem') palette = palettes.slime;
        else if (a.includes('tech') || a === 'spider' || a === 'ranger' || a === 'brain') palette = palettes.tech;
        else palette = palettes.trash; // Generic
    }
    // Specific Overrides
    if (a === 'pile_big') palette = palettes.trash;
    if (a === 'box_teeth') palette = palettes.mimic;
    if (a === 'corona') palette = palettes.virus;
    if (a === 'fluid') palette = palettes.fluid;
    if (a === 'knight_slime') palette = palettes.knight;
    if (a === 'golem') palette = palettes.crypto;
    if (a === 'spider') palette = palettes.spider;
    if (a === 'ranger') palette = palettes.ranger;
    if (a === 'brain') palette = palettes.brain;

    let grid = new Array(H).fill(0).map(() => new Array(W).fill(null));

    const rect = (x, y, w, h, col) => {
        for (let i = Math.max(0, Math.floor(x)); i < Math.min(W, x + w); i++)
            for (let j = Math.max(0, Math.floor(y)); j < Math.min(H, y + h); j++)
                grid[j][i] = col;
    }
    const circle = (cx, cy, r, col) => {
        for (let y = 0; y < H; y++)
            for (let x = 0; x < W; x++)
                if (Math.sqrt((x - cx) ** 2 + (y - cy) ** 2) < r) grid[y][x] = col;
    }
    const line = (x1, y1, x2, y2, col) => {
        let dx = Math.abs(x2 - x1), sx = x1 < x2 ? 1 : -1;
        let dy = -Math.abs(y2 - y1), sy = y1 < y2 ? 1 : -1;
        let err = dx + dy, e2;
        while (true) {
            if (y1 >= 0 && y1 < H && x1 >= 0 && x1 < W) grid[y1][x1] = col;
            if (x1 == x2 && y1 == y2) break;
            const e2_val = 2 * err;
            if (e2_val >= dy) { err += dy; x1 += sx; }
            if (e2_val <= dx) { err += dx; y1 += sy; }
        }
    }

    const mainCol = palette[Math.floor(rng() * (palette.length - 1))];
    const secCol = palette[Math.floor(rng() * (palette.length - 2))] || palette[1];
    const thirdCol = palette[palette.length - 1];

    // --- DRAWING LOGIC ---
    if (a === 'egg') { circle(C, C, 7, mainCol); circle(C - 2, C - 3, 2, '#ffffff'); rect(C + 1, C + 2, 2, 2, secCol); rect(C - 4, C + 1, 2, 2, secCol); }
    else if (a === 'dust') { circle(C, C, 5, '#1e293b'); for (let i = 0; i < 30; i++) { let angle = rng() * Math.PI * 2; let r = 4 + rng() * 4; rect(C + Math.cos(angle) * r, C + Math.sin(angle) * r, 1, 1, '#334155'); } rect(C - 4, C - 2, 3, 3, '#ffffff'); rect(C + 1, C - 2, 3, 3, '#ffffff'); rect(C - 3, C - 1, 1, 1, '#000000'); rect(C + 2, C - 1, 1, 1, '#000000'); }
    else if (a === 'dust_trash') { circle(C, C, 6, mainCol); for (let i = 0; i < 40; i++) { let s = 7 + rng() * 3; rect(C + (rng() - 0.5) * s * 1.5, C + (rng() - 0.5) * s, 2, 2, i % 2 == 0 ? secCol : thirdCol); } rect(C - 3, C - 3, 3, 3, '#ffffff'); rect(C - 2, C - 2, 1, 1, '#000000'); rect(C + 1, C - 1, 2, 2, '#ffffff'); rect(C + 1, C - 1, 1, 1, '#000000'); }
    else if (a === 'dust_slime') { for (let i = 0; i < 8; i++) circle(C + (rng() - 0.5) * 10, C + 3 + rng() * 3, 3, mainCol); rect(C - 3, C - 3, 2, 2, '#ffffff'); rect(C - 3, C - 1, 2, 2, '#000000'); rect(C + 1, C - 1, 2, 2, '#000000'); }
    else if (a === 'dust_tech') { rect(C - 1, C - 9, 2, 4, secCol); rect(C - 5, C - 7, 10, 2, secCol); rect(C - 6, C + 2, 2, 4, mainCol); rect(C + 4, C + 2, 2, 4, mainCol); rect(C - 4, C - 1, 3, 2, '#a5f3fc'); rect(C + 1, C - 1, 3, 2, '#a5f3fc'); }
    else if (a === 'beast_pup') { rect(C - 5, C - 1, 10, 6, mainCol); rect(C - 6, C - 5, 3, 4, secCol); rect(C + 3, C - 5, 3, 4, secCol); rect(C - 2, C + 1, 4, 3, secCol); rect(C - 1, C + 1, 2, 1, '#000000'); }
    else if (a === 'beast_wolf') { rect(C - 6, C - 2, 12, 6, mainCol); rect(C - 7, C - 6, 5, 5, mainCol); for (let i = 0; i < 10; i++) rect(C - 7 + rng() * 14, C - 4 + rng() * 6, 1, 1, secCol); rect(C - 7, C - 8, 2, 3, secCol); rect(C - 4, C - 8, 2, 3, secCol); rect(C + 6, C, 4, 2, secCol); rect(C - 6, C - 5, 1, 1, '#ef4444'); }
    else if (a === 'beast_cat') { rect(C - 6, C - 2, 12, 6, mainCol); rect(C - 7, C - 6, 5, 5, mainCol); rect(C - 7, C - 8, 2, 2, mainCol); rect(C - 4, C - 8, 2, 2, mainCol); rect(C - 6, C - 3, 1, 1, '#f9a8d4'); rect(C - 2, C - 3, 6, 6, '#ef4444'); }
    else if (a === 'beast_mech') { rect(C - 6, C - 2, 12, 6, secCol); rect(C - 7, C - 6, 5, 5, mainCol); rect(C - 4, C - 8, 2, 6, thirdCol); rect(C - 6, C - 5, 3, 1, '#3b82f6'); }
    else if (a === 'spirit_orb') { circle(C, C, 6, mainCol); for (let t = 0; t < Math.PI * 2; t += 0.4) { let r = 8; rect(C + Math.cos(t) * r, C + Math.sin(t) * r, 1, 1, secCol); } rect(C - 8, C - 2, 3, 4, '#ffffff'); rect(C + 5, C - 2, 3, 4, '#ffffff'); }
    else if (a === 'spirit_fire') { circle(C, C + 1, 5, '#ffffff'); for (let i = 0; i < 40; i++) { let r = 4 + rng() * 6; let t = rng() * Math.PI * 2; let py = C + Math.sin(t) * r - (rng() * 6); let px = C + Math.cos(t) * r; rect(px, py, 2, 2, i % 3 == 0 ? thirdCol : secCol); } rect(C - 3, C - 1, 2, 3, '#000000'); rect(C + 1, C - 1, 2, 3, '#000000'); }
    else if (a === 'spirit_wing') { circle(C, C, 5, mainCol); rect(C - 7, C + 2, 14, 2, secCol); rect(C - 11, C - 4, 2, 2, '#ffffff'); rect(C - 10, C - 5, 2, 4, '#ffffff'); rect(C - 8, C - 3, 4, 4, '#ffffff'); rect(C + 9, C - 4, 2, 2, '#ffffff'); rect(C + 8, C - 5, 2, 4, '#ffffff'); rect(C + 4, C - 3, 4, 4, '#ffffff'); rect(C - 4, C - 9, 8, 1, '#fbbf24'); rect(C - 5, C - 8, 1, 1, '#fbbf24'); rect(C + 4, C - 8, 1, 1, '#fbbf24'); rect(C - 1, C, 2, 2, '#fbbf24'); rect(C - 3, C - 2, 1, 1, '#3b82f6'); rect(C + 2, C - 2, 1, 1, '#3b82f6'); }
    else if (a === 'spirit_dragon') { circle(C, C, 7, '#1e1b4b'); for (let i = 0; i < 20; i++) { let px = C + (rng() - 0.5) * 12; let py = C + (rng() - 0.5) * 10; rect(px, py, 1, 1, i % 3 == 0 ? '#f472b6' : (i % 2 == 0 ? '#22d3ee' : '#ffffff')); } rect(C - 9, C - 5, 4, 4, secCol); rect(C - 8, C - 9, 2, 4, thirdCol); rect(C + 6, C - 2, 6, 2, secCol); rect(C - 4, C - 2, 2, 1, '#22d3ee'); }

    // --- STAGE 3 ---
    else if (a === 'pile_big') { circle(C, C, 8, '#000000'); for (let i = 0; i < 60; i++) rect(C + (rng() - 0.5) * 16, C + (rng() - 0.5) * 16, 2, 2, '#ef4444'); rect(C - 4, C - 2, 2, 2, '#ffffff'); rect(C - 3, C - 2, 1, 1, '#000000'); rect(C + 4, C, 2, 2, '#ffffff'); rect(C + 4, C, 1, 1, '#000000'); rect(C, C - 5, 3, 3, '#ffffff'); rect(C + 1, C - 5, 1, 1, '#000000'); }
    else if (a === 'box_teeth') { rect(C - 8, C - 6, 16, 14, mainCol); rect(C - 8, C, 16, 2, '#000000'); rect(C - 1, C + 4, 2, 2, '#000000'); rect(C - 6, C + 2, 1, 2, '#ffffff'); rect(C - 2, C + 2, 1, 2, '#ffffff'); rect(C + 2, C + 2, 1, 2, '#ffffff'); rect(C + 5, C + 2, 1, 2, '#ffffff'); rect(C - 4, C - 3, 2, 1, '#ef4444'); rect(C + 2, C - 3, 2, 1, '#ef4444'); }
    else if (a === 'corona') { circle(C, C, 6, mainCol); for (let t = 0; t < 6.28; t += 0.8) rect(C + Math.cos(t) * 10, C + Math.sin(t) * 10, 3, 3, secCol); rect(C - 4, C - 8, 8, 2, '#facc15'); rect(C - 4, C - 10, 2, 2, '#facc15'); rect(C + 2, C - 10, 2, 2, '#facc15'); rect(C - 3, C - 1, 2, 1, '#bef264'); rect(C + 1, C - 1, 2, 1, '#bef264'); rect(C - 2, C + 2, 4, 1, '#000000'); }
    else if (a === 'fluid') { for (let i = 0; i < 4; i++) rect(C - 10 + i * 2, C + 4, 18 - i * 4, 4, mainCol); rect(C - 6, C, 2, 6, mainCol); rect(C + 4, C - 2, 3, 8, mainCol); rect(C - 5, C - 6, 3, 3, secCol); rect(C + 2, C - 5, 2, 2, secCol); rect(C - 2, C + 2, 4, 4, '#ffffff'); rect(C - 1, C + 2, 2, 2, '#000000'); }
    else if (a === 'knight_slime') { rect(C - 3, C - 4, 6, 8, mainCol); rect(C - 4, C - 9, 8, 6, mainCol); rect(C - 2, C - 3, 4, 6, '#e0f2fe'); rect(C + 4, C, 8, 2, secCol); rect(C + 4, C - 2, 2, 6, secCol); rect(C - 7, C - 2, 4, 8, thirdCol); rect(C - 3, C - 7, 6, 1, '#000000'); }
    else if (a === 'golem') { rect(C - 4, C - 4, 8, 8, mainCol); rect(C - 8, C - 8, 4, 4, secCol); rect(C + 4, C - 8, 4, 4, secCol); rect(C - 6, C + 4, 4, 6, secCol); rect(C + 2, C + 4, 4, 6, secCol); rect(C - 2, C - 10, 4, 4, thirdCol); rect(C - 3, C - 3, 2, 2, '#ffffff'); rect(C + 5, C - 7, 1, 1, '#ffffff'); rect(C - 1, C - 9, 2, 1, '#000000'); }
    else if (a === 'spider') { rect(C - 4, C - 4, 8, 8, mainCol); rect(C - 5, C - 5, 10, 2, secCol); line(C - 4, C, C - 10, C - 4, secCol); line(C - 4, C + 2, C - 10, C + 4, secCol); line(C - 4, C + 4, C - 8, C + 8, secCol); line(C + 4, C, C + 10, C - 4, secCol); line(C + 4, C + 2, C + 10, C + 4, secCol); line(C + 4, C + 4, C + 8, C + 8, secCol); rect(C - 3, C - 2, 2, 2, '#ef4444'); rect(C + 1, C - 2, 2, 2, '#ef4444'); rect(C - 1, C + 1, 2, 2, '#ef4444'); }
    else if (a === 'ranger') { rect(C - 4, C - 10, 8, 8, mainCol); rect(C - 3, C - 9, 2, 6, secCol); rect(C + 1, C - 9, 2, 6, secCol); rect(C - 1, C - 5, 2, 2, '#fbbf24'); rect(C - 4, C - 2, 8, 6, mainCol); rect(C + 4, C - 2, 6, 4, mainCol); rect(C + 8, C - 1, 2, 2, '#22d3ee'); rect(C - 4, C + 4, 3, 6, mainCol); rect(C + 1, C + 4, 3, 6, mainCol); }
    else if (a === 'brain') { rect(C - 6, C - 6, 12, 12, '#a5f3fc'); rect(C - 6, C + 6, 12, 2, secCol); rect(C - 6, C - 8, 12, 2, secCol); rect(C - 4, C - 4, 8, 6, '#d8b4fe'); rect(C - 2, C - 2, 4, 1, '#ffffff'); line(C - 6, C, C - 10, C + 4, secCol); line(C + 6, C, C + 10, C + 4, secCol); }
    else if (a === 'tank') {
        rect(C - 8, C + 4, 16, 4, '#1e293b'); rect(C - 9, C + 5, 18, 2, '#000000');
        rect(C - 6, C - 2, 12, 6, mainCol); rect(C - 4, C - 6, 8, 4, mainCol); rect(C, C - 5, 8, 2, '#3f3f46'); rect(C - 5, C, 10, 2, '#facc15');
        rect(C - 3, C - 3, 2, 2, '#3f3f46'); rect(C - 1, C - 2, 2, 1, '#ef4444');
    }
    else if (a === 'jet') {
        rect(C - 2, C - 10, 4, 6, '#ef4444'); rect(C - 4, C - 4, 8, 10, mainCol); rect(C - 10, C, 6, 8, secCol); rect(C + 4, C, 6, 8, secCol);
        rect(C - 3, C - 6, 6, 2, '#38bdf8'); rect(C - 3, C + 6, 2, 4, '#ef4444'); rect(C + 1, C + 6, 2, 4, '#ef4444');
    }
    else if (a === 'gundam') {
        rect(C - 4, C - 10, 8, 6, '#ffffff'); rect(C - 5, C - 8, 10, 2, '#ffffff'); rect(C - 1, C - 11, 2, 3, '#dc2626'); rect(C - 3, C - 9, 6, 1, '#facc15');
        rect(C - 4, C - 4, 8, 8, '#2563eb'); rect(C - 2, C - 4, 4, 2, '#dc2626'); rect(C - 5, C - 4, 2, 4, '#ffffff'); rect(C + 3, C - 4, 2, 4, '#ffffff');
        rect(C - 4, C + 4, 3, 6, '#ffffff'); rect(C + 1, C + 4, 3, 6, '#ffffff'); rect(C + 5, C, 2, 6, '#334155');
    }
    else if (a === 'mage_skull') {
        rect(C - 4, C - 5, 8, 14, '#172554'); rect(C - 3, C - 9, 6, 5, '#e5e5e5'); rect(C - 2, C - 8, 1, 1, '#000000'); rect(C + 1, C - 8, 1, 1, '#000000');
        rect(C - 6, C - 10, 12, 1, '#4c1d95'); rect(C - 3, C - 13, 6, 3, '#4c1d95'); rect(C + 5, C - 8, 1, 16, '#fbbf24'); circle(C + 5, C - 9, 2, '#a855f7');
    }
    else if (a === 'pumpkin') {
        rect(C - 4, C - 2, 8, 10, '#3f3f46'); circle(C, C - 6, 6, '#ea580c'); rect(C - 2, C - 7, 1, 1, '#facc15'); rect(C + 1, C - 7, 1, 1, '#facc15');
        rect(C - 2, C - 5, 4, 1, '#facc15'); rect(C, C - 13, 1, 2, '#166534'); rect(C - 6, C, 2, 2, '#ea580c'); rect(C + 4, C, 2, 2, '#ea580c');
    }
    else if (a === 'reaper') {
        rect(C - 5, C - 8, 10, 16, '#000000'); rect(C - 3, C - 6, 6, 4, '#171717'); rect(C - 1, C - 5, 1, 1, '#ef4444'); rect(C, C - 5, 1, 1, '#ef4444');
        rect(C + 6, C - 8, 1, 16, '#7f1d1d'); rect(C + 4, C - 10, 6, 2, '#9ca3af'); rect(C + 3, C - 10, 1, 6, '#9ca3af');
    }

    // --- REDESIGNED STAGE 3 (Wolf V2 & Cat V2 Targets) ---
    else if (a === 'wolf_zombie_v2') {
        rect(C - 6, C - 3, 13, 6, '#4b5563'); // Darker rot body
        rect(C - 2, C - 2, 5, 4, '#991b1b'); // Ribcage
        rect(C - 8, C - 7, 6, 6, '#4b5563'); // Head
        rect(C - 6, C - 6, 2, 2, '#e7e5e4'); // Skull patch
        rect(C - 5, C - 5, 1, 1, '#000000'); // Eye empty
        rect(C - 7, C + 3, 2, 5, '#4b5563'); // Leg FL
        rect(C + 4, C + 3, 2, 5, '#e7e5e4'); // Leg BR (Bone)
        for (let i = 0; i < 4; i++) rect(C + (rng() - 0.5) * 14, C - 6 + (rng() - 0.5) * 8, 1, 1, '#bef264');
    }
    else if (a === 'wolf_guard_v2') {
        rect(C - 7, C - 3, 14, 7, '#1e3a8a'); // Body Armor
        rect(C - 3, C - 4, 6, 6, '#fbbf24'); // Heavy Plating
        rect(C - 9, C - 8, 7, 7, '#172554'); // Helmet
        rect(C - 9, C - 6, 7, 1, '#60a5fa'); // Visor
        rect(C - 3, C - 6, 3, 3, '#1e40af'); // Pad
        rect(C - 7, C + 4, 3, 5, '#3b82f6');
        rect(C + 5, C + 4, 3, 5, '#3b82f6');
    }
    else if (a === 'wolf_alloy_v2') {
        rect(C - 7, C - 3, 14, 5, '#e2e8f0'); // Silver Body
        rect(C - 2, C - 8, 4, 6, '#94a3b8'); // Booster base
        rect(C - 3, C - 9, 2, 4, '#0ea5e9'); // Thruster
        rect(C - 9, C - 6, 7, 5, '#e2e8f0'); // Head
        rect(C - 6, C - 6, 4, 1, '#0ea5e9'); // Visor
        line(C + 7, C, C + 11, C - 4, '#0ea5e9'); // Saber tail
        rect(C - 7, C + 5, 2, 3, '#94a3b8');
        rect(C + 6, C + 5, 2, 3, '#94a3b8');
    }
    else if (a === 'ronin') {
        rect(C - 3, C - 4, 6, 8, '#c2410c'); // Orange Gi
        rect(C - 4, C - 10, 8, 4, '#fde047'); // Hat
        rect(C - 3, C + 4, 2, 4, '#3f3f46'); // Hakama
        rect(C + 1, C + 4, 2, 4, '#3f3f46');
        line(C + 4, C - 4, C + 8, C - 8, '#e5e5e5'); // Blade handle
        rect(C - 4, C - 3, 2, 2, '#ef4444'); // Scarf
    }
    else if (a === 'king_cat') {
        rect(C - 4, C - 3, 8, 8, '#7e22ce'); // Robe
        rect(C - 2, C - 3, 4, 8, '#ffffff'); // Fur
        rect(C - 4, C - 10, 8, 3, '#fbbf24'); // Crown
        rect(C - 1, C - 10, 2, 2, '#ef4444');
        line(C + 6, C, C + 6, C + 6, '#fbbf24'); // Scepter
        circle(C + 6, C - 1, 2, '#ef4444');
    }
    else if (a === 'lion_mane') {
        rect(C - 4, C - 3, 8, 8, '#ffffff');
        for (let t = 0; t < 6.3; t += 0.6) rect(C + Math.cos(t) * 11, C + Math.sin(t) * 11 - 5, 2, 2, '#facc15'); // Mane
        rect(C - 2, C - 6, 4, 4, '#fff7ed'); // Face
        rect(C - 1, C - 5, 2, 1, '#3b82f6'); // Eyes
        line(C - 8, C, C - 4, C + 4, '#facc15'); // Lightning
        line(C + 8, C, C + 4, C - 4, '#facc15');
    }

    // --- ANGEL FAMILY V3 ---
    else if (a === 'biblical_angel') {
        for (let t = 0; t < 6.3; t += 0.1) {
            let r = 9;
            let x1 = C + Math.cos(t) * r; let y1 = C + Math.sin(t) * r * 0.4;
            rect(x1, y1, 1, 1, mainCol);
            let x2 = C + Math.cos(t) * r * 0.4; let y2 = C + Math.sin(t) * r;
            rect(x2, y2, 1, 1, secCol);
        }
        circle(C, C, 4, '#ffffff');
        for (let i = 0; i < 8; i++) {
            rect(C + Math.cos(i * 0.8) * 9, C + Math.sin(i * 0.8) * 3.5, 2, 2, '#ffffff');
            rect(C + Math.cos(i * 0.8) * 9, C + Math.sin(i * 0.8) * 3.5, 1, 1, '#3b82f6');
        }
    }
    else if (a === 'valkyrie') {
        rect(C - 3, C - 5, 6, 8, '#e2e8f0'); rect(C - 3, C - 9, 6, 4, '#facc15');
        rect(C - 4, C + 3, 3, 5, '#e2e8f0'); rect(C + 1, C + 3, 3, 5, '#e2e8f0');
        rect(C - 8, C - 6, 4, 10, '#ffffff'); rect(C + 5, C - 6, 4, 10, '#ffffff');
        line(C + 4, C + 8, C + 10, C - 8, '#fbbf24'); rect(C + 9, C - 9, 2, 4, '#38bdf8');
    }
    else if (a === 'phoenix') {
        rect(C - 2, C - 4, 4, 8, mainCol); rect(C - 2, C - 8, 4, 4, mainCol);
        rect(C, C - 7, 1, 1, '#fbbf24'); rect(C - 3, C - 6, 1, 2, '#fbbf24');
        for (let i = 0; i < 8; i++) {
            rect(C - 2 - i, C - 4 - i, 1, 2, '#ef4444');
            rect(C + 1 + i, C - 4 - i, 1, 2, '#ef4444');
            rect(C - 2 - i, C - 2 - i, 1, 4, secCol);
            rect(C + 1 + i, C - 2 - i, 1, 4, secCol);
        }
        rect(C - 1, C + 4, 2, 6, '#fbbf24'); rect(C - 3, C + 6, 2, 4, '#ef4444'); rect(C + 1, C + 6, 2, 4, '#ef4444');
    }

    // --- COSMOS FAMILY V3 ---
    else if (a === 'terra_titan') {
        rect(C - 6, C - 6, 12, 10, mainCol); rect(C - 8, C - 8, 4, 6, secCol); rect(C + 4, C - 8, 4, 6, secCol);
        rect(C - 3, C - 9, 6, 4, mainCol); rect(C - 2, C - 8, 4, 1, '#f97316');
        rect(C - 8, C - 2, 3, 8, mainCol); rect(C + 5, C - 2, 3, 8, mainCol);
        rect(C - 6, C + 4, 4, 6, secCol); rect(C + 2, C + 4, 4, 6, secCol);
        circle(C, C - 2, 3, '#ea580c'); rect(C - 1, C - 3, 2, 2, '#f97316');
    }
    else if (a === 'cosmo_whale') {
        rect(C - 10, C - 6, 14, 10, mainCol); rect(C + 4, C - 4, 6, 6, mainCol); rect(C + 10, C - 2, 4, 3, mainCol);
        rect(C - 10, C + 2, 12, 2, '#c7d2fe'); rect(C + 12, C - 5, 2, 8, mainCol);
        rect(C + 11, C - 6, 1, 2, mainCol); rect(C + 11, C + 4, 1, 2, mainCol);
        rect(C - 5, C, 2, 1, '#ffffff');
        for (let k = 0; k < 5; k++) rect(C - 6 + (rng() - 0.5) * 4, C - 10 + (rng() - 0.5) * 4, 1, 1, '#22d3ee');
        rect(C - 8, C - 3, 1, 1, '#ffffff'); rect(C - 2, C - 4, 1, 1, '#ffffff'); rect(C + 6, C - 1, 1, 1, '#ffffff');
    }
    else if (a === 'genesis_dragon') {
        let px = C, py = C;
        for (let i = 0; i < 30; i++) {
            rect(px, py, 3, 3, i % 2 == 0 ? '#000000' : secCol);
            px += Math.cos(i * 0.4) * 2;
            py += Math.sin(i * 0.4) * 2;
        }
        circle(C, C, 5, '#c084fc');
        for (let k = 0; k < 20; k++) {
            rect(C + (rng() - 0.5) * 20, C + (rng() - 0.5) * 20, 1, 1, k % 3 == 0 ? '#22d3ee' : '#f472b6');
        }
    }

    let svg = '';
    for (let y = 0; y < H; y++) {
        for (let x = 0; x < W; x++) {
            if (grid[y][x]) svg += `<rect x="${x}" y="${y}" width="1" height="1" fill="${grid[y][x]}"/>`;
        }
    }
    return `<svg viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg" class="w-full h-full drop-shadow-md shape-rendering-crispEdges">${svg}</svg>`;
}

/**
 * Determines the next monster form based on parameters
 * @param {number} currentStage - Current evolutionary stage (0-3)
 * @param {number} likes - Student's total likes
 * @param {number} classSize - Active class size
 * @param {string} [currentFam] - Current family hint (optional, for persistent lineage)
 * @returns {Object} Selected Monster Definition
 */
export function getNextMonster(currentStage, likes, classSize, currentFam = null) {
    if (currentStage === 0) return MONSTER_DEFS.find(m => m.id === 'Egg');

    // Stage 1: Basic Families
    if (currentStage === 1) {
        // Simple logic for Stage 1? Or Random?
        // Let's use simple hash of likes or random to distribute if there's no clear indicator?
        // Requirements say "After beginner 5 tasks, Stage 1 unlocks".
        // Let's default to Dust or something based on likes?
        // Actually the prompt says:
        // "Stage 1 (Basic): Unlocks after Beginner... Three basic families: Dust, Pup, Spirit"
        // Let's pick based on (Likes % 3) for variety or just return one?
        // Let's return Spirit if Likes are high, Dust if low?

        // Simple distribution for now:
        if (likes > 5) return MONSTER_DEFS.find(m => m.id === 'L1_A'); // Spirit
        if (likes > 2) return MONSTER_DEFS.find(m => m.id === 'L1_B'); // Pup
        return MONSTER_DEFS.find(m => m.id === 'L1_C'); // Dust
    }

    // Branching Logic for Stage 2 & 3
    // A: High Likes ( > classSize / 2 )
    // B: Mid Likes ( 1 < likes <= classSize / 2 )
    // C: Low Likes ( <= 1 )

    const ratio = classSize > 0 ? likes / classSize : 0;

    // Tier Logic
    let tier = 'C';
    if (likes > classSize / 2) tier = 'A';
    else if (likes > 1) tier = 'B';

    // Safety check for small classes
    if (classSize <= 2 && likes >= 1) tier = 'A'; // Boost for testing pairs

    // Filter potential monsters for this Stage
    const candidates = MONSTER_DEFS.filter(m => m.stage === currentStage);

    // Filter by Tier (Suffix A/B/C)
    // IDs are like L2_AA, L2_AB... allow flexible matching.
    // Last char of ID corresponds to Tier? (A=High, B=Mid, C=Low)
    // Yes: L3_AAA (High), L3_CAA (High? No wait, logic in readme says:
    // Tier 1 (Low) -> C route.
    // Tier 3 (High) -> A route.

    const targetSuffix = tier;

    // If we have a current family, try to stick to it?
    // Implementation Plan didn't specify strict lineage tracking yet, but usually we want to.

    // Let's filter candidates ending in targetSuffix
    let match = candidates.find(m => m.id.endsWith(targetSuffix) && (!currentFam || m.fam === currentFam));

    // If no match (e.g. family change allowed or not found), just pick any of that Tier
    if (!match) match = candidates.find(m => m.id.endsWith(targetSuffix));

    return match || MONSTER_DEFS[0]; // Fallback
}