const mongoose = require('mongoose');

const variantSchema = new mongoose.Schema(
  {
    label: { type: String, required: true, trim: true }, // e.g. "Half", "Full", "1 Litre"
    price: { type: Number, required: true, min: 0 },
    available: { type: Boolean, default: true },
  },
  { _id: true }
);

const menuItemSchema = new mongoose.Schema(
  {
    name: { type: String, required: true, trim: true },
    category: { type: mongoose.Schema.Types.ObjectId, ref: 'Category', required: true },
    image: { type: String, default: null }, // Cloudinary URL
    available: { type: Boolean, default: true },
    // Variants: every dish has at least one variant.
    // Single-price dish → one variant with label "Regular" or blank.
    // Deal → one variant with a fixed price, category = Deals category.
    variants: { type: [variantSchema], required: true, validate: [(v) => v.length > 0, 'At least one variant required'] },
  },
  { timestamps: true }
);

// Index for fast menu-all query
menuItemSchema.index({ category: 1, available: 1 });

module.exports = mongoose.model('MenuItem', menuItemSchema);