$id: https://schema.beckn.io/FnBOffer/v2.0
$schema: https://json-schema.org/draft/2020-12/schema
description: |
  A Beckn schema for food and beverage offer attributes.

  FnBOffer extends beckn:RetailCoreOfferAttributes with F&B-specific offer
  customization groups — the structured mechanism by which a food item's
  configurable options (size, crust, toppings, add-ons) are declared and
  priced within an offer.

  A CustomizationGroup represents one dimension of configurability (e.g.
  pizza size, crust type, topping selection). Each group has one or more
  options with optional price deltas.

  Inheritance: beckn:RetailCoreOfferAttributes ← beckn:FnBOffer
  Use in: beckn:Offer.offerAttributes for F&B catalog items
title: FnBOffer
x-tags: [retail, food-and-beverages]
allOf:
  - $ref: 'https://schema.beckn.io/RetailCoreOfferAttributes/v2.0'
  - type: object
    properties:
      '@context':
        type: string
        format: uri
        const: 'https://schema.beckn.io/FnBOffer/v2.0/context.jsonld'
        description: JSON-LD context URI for the FnBOffer schema.
      '@type':
        type: string
        const: 'beckn:FnBOffer'
        description: JSON-LD type.
      customization:
        type: object
        description: >
          Structured customization configuration for this offer.
          Groups represent independent dimensions of configurability.
        properties:
          groups:
            type: array
            description: List of customization groups for this offer.
            items:
              $ref: '#/$defs/CustomizationGroup'
        x-jsonld:
          '@id': 'beckn:customization'
    required:
      - '@context'
      - '@type'

$defs:
  CustomizationGroup:
    type: object
    description: >
      A single dimension of configurability for a food item offer.
      Examples: pizza size selection, crust type, topping selection,
      add-on selection, sauce choice.
    required: [code, selection, options]
    properties:
      code:
        type: string
        description: >
          Machine-readable code for this customization group
          (e.g. SIZE, CRUST, TOPPINGS, ADDONS, SAUCE).
      name:
        type: string
        description: Human-readable name for this customization group.
      selection:
        type: string
        description: >
          Selection mode for this group.
          - SINGLE_REQUIRED: Exactly one option must be chosen (e.g. pizza size)
          - SINGLE_OPTIONAL: Zero or one option may be chosen
          - MULTIPLE_OPTIONAL: Zero or more options may be chosen (e.g. toppings)
        enum:
          - SINGLE_REQUIRED
          - SINGLE_OPTIONAL
          - MULTIPLE_OPTIONAL
      minSelections:
        type: integer
        description: Minimum number of options that must be selected (for MULTIPLE_OPTIONAL).
        minimum: 0
      maxSelections:
        type: integer
        description: Maximum number of options that may be selected (for MULTIPLE_OPTIONAL).
        minimum: 1
      options:
        type: array
        description: Available options within this customization group.
        minItems: 1
        items:
          $ref: '#/$defs/CustomizationOption'

  CustomizationOption:
    type: object
    description: >
      A single selectable option within a CustomizationGroup.
      Each option may carry a price delta (positive or negative) relative
      to the base offer price.
    required: [code, name]
    properties:
      code:
        type: string
        description: Machine-readable option code (e.g. MEDIUM, CHEESE_BURST, MUSHROOM).
      name:
        type: string
        description: Human-readable option name (e.g. "Medium", "Cheese Burst", "Mushroom").
      priceDelta:
        type: object
        description: >
          Incremental price change relative to the base offer price when this
          option is selected. Positive for upcharges, negative for discounts.
        required: [type, value]
        properties:
          type:
            type: string
            description: >
              - FIXED: Absolute price change in the offer currency
              - PERCENTAGE: Percentage change of the base price
            enum: [FIXED, PERCENTAGE]
          value:
            type: number
            description: Amount of the price change (positive or negative).
        additionalProperties: false
      itemRef:
        type: string
        description: Optional reference to a catalog Item ID for this option.
      offerRef:
        type: string
        description: Optional reference to another Offer ID (for combo sub-offers).
      available:
        type: boolean
        description: Whether this option is currently available for selection.
        default: true