module.exports = (sequelize, DataTypes) => {
  const Product = sequelize.define('Product', {
    id: {
      type: DataTypes.UUID,
      defaultValue: DataTypes.UUIDV4,
      primaryKey: true
    },
    name: {
      type: DataTypes.STRING,
      allowNull: false,
      validate: {
        len: [2, 100]
      }
    },
    description: {
      type: DataTypes.TEXT,
      allowNull: true
    },
    category: {
      type: DataTypes.ENUM('compute', 'storage', 'networking', 'database', 'security', 'analytics', 'ai_ml', 'other'),
      allowNull: false
    },
    subcategory: {
      type: DataTypes.STRING,
      allowNull: true
    },
    sku: {
      type: DataTypes.STRING,
      allowNull: false,
      unique: true
    },
    basePrice: {
      type: DataTypes.DECIMAL(10, 2),
      allowNull: false,
      validate: {
        min: 0
      }
    },
    currency: {
      type: DataTypes.STRING,
      allowNull: false,
      defaultValue: 'INR'
    },
    billingType: {
      type: DataTypes.ENUM('one_time', 'recurring', 'usage_based', 'tiered'),
      allowNull: false
    },
    billingCycle: {
      type: DataTypes.ENUM('hourly', 'daily', 'weekly', 'monthly', 'quarterly', 'yearly'),
      allowNull: true
    },
    unit: {
      type: DataTypes.STRING,
      allowNull: true // e.g., 'GB', 'vCPU', 'instance', 'request'
    },
    specifications: {
      type: DataTypes.JSON,
      defaultValue: {}
    },
    features: {
      type: DataTypes.JSON,
      defaultValue: []
    },
    tierPricing: {
      type: DataTypes.JSON,
      defaultValue: {
        bronze: { margin: 20 },
        silver: { margin: 25 },
        gold: { margin: 30 },
        platinum: { margin: 35 },
        diamond: { margin: 40 }
      }
    },
    status: {
      type: DataTypes.ENUM('active', 'inactive', 'deprecated', 'coming_soon'),
      allowNull: false,
      defaultValue: 'active'
    },
    availability: {
      type: DataTypes.JSON,
      defaultValue: {
        regions: [],
        zones: []
      }
    },
    minimumCommitment: {
      type: DataTypes.JSON,
      allowNull: true
    },
    tags: {
      type: DataTypes.JSON,
      defaultValue: []
    },
    metadata: {
      type: DataTypes.JSON,
      defaultValue: {}
    },
    createdBy: {
      type: DataTypes.UUID,
      allowNull: true,
      references: {
        model: 'users',
        key: 'id'
      }
    },
    updatedBy: {
      type: DataTypes.UUID,
      allowNull: true,
      references: {
        model: 'users',
        key: 'id'
      }
    }
  }, {
    tableName: 'products',
    indexes: [
      {
        unique: true,
        fields: ['sku']
      },
      {
        fields: ['category']
      },
      {
        fields: ['status']
      },
      {
        fields: ['billing_type']
      },
      {
        fields: ['name']
      }
    ]
  });

  // Instance methods
  Product.prototype.calculateResellerPrice = function(resellerTier, customMargin = null) {
    let margin = customMargin;
    
    if (!margin && this.tierPricing[resellerTier]) {
      margin = this.tierPricing[resellerTier].margin;
    }
    
    if (!margin) {
      margin = 20; // Default margin
    }
    
    const markupAmount = (this.basePrice * margin) / 100;
    return parseFloat(this.basePrice) + markupAmount;
  };

  Product.prototype.getMarginForTier = function(tier) {
    return this.tierPricing[tier]?.margin || 20;
  };

  Product.prototype.isAvailableInRegion = function(region) {
    return this.availability.regions.length === 0 || this.availability.regions.includes(region);
  };

  Product.prototype.isActive = function() {
    return this.status === 'active';
  };

  // Class methods
  Product.associate = function(models) {
    Product.belongsTo(models.User, {
      foreignKey: 'createdBy',
      as: 'creator'
    });
    
    Product.belongsTo(models.User, {
      foreignKey: 'updatedBy',
      as: 'updater'
    });
    
    Product.hasMany(models.ResellerPricing, {
      foreignKey: 'productId',
      as: 'resellerPricing'
    });
    
    Product.hasMany(models.OrderItem, {
      foreignKey: 'productId',
      as: 'orderItems'
    });
  };

  return Product;
};