{
  "title": "Sprague Fuel Order Structure",
  "description": "Hierarchical structure of a Sprague Energy fuel delivery order",
  "type": "object",
  "fields": [
    {"name": "order_id", "type": "string", "description": "Unique order reference (SPR-YYYY-NNNNNN)"},
    {"name": "status", "type": "enum", "values": ["pending", "scheduled", "in_transit", "delivered", "cancelled"]},
    {"name": "order_date", "type": "date", "description": "ISO 8601 date placed"},
    {"name": "delivery_date", "type": "date", "description": "Scheduled or actual delivery date"},
    {
      "name": "customer",
      "type": "object",
      "fields": [
        {"name": "account_id", "type": "string", "required": true},
        {"name": "name", "type": "string", "required": true},
        {"name": "contact_name", "type": "string"},
        {"name": "phone", "type": "string"},
        {"name": "email", "type": "string", "format": "email"}
      ]
    },
    {
      "name": "delivery_location",
      "type": "object",
      "fields": [
        {"name": "name", "type": "string", "description": "Site or facility name"},
        {"name": "street", "type": "string", "required": true},
        {"name": "city", "type": "string", "required": true},
        {"name": "state", "type": "string", "required": true},
        {"name": "zip", "type": "string", "required": true},
        {"name": "country", "type": "string", "default": "US"}
      ]
    },
    {
      "name": "product",
      "type": "object",
      "fields": [
        {"name": "type", "type": "enum", "values": ["heating_oil", "diesel", "ultra_low_sulfur_diesel", "gasoline", "kerosene", "biofuel", "bunker_fuel", "residual_fuel"]},
        {"name": "blend", "type": "string"},
        {"name": "sulfur_content", "type": "string"}
      ]
    },
    {
      "name": "quantity",
      "type": "object",
      "fields": [
        {"name": "amount", "type": "number", "required": true},
        {"name": "unit", "type": "enum", "values": ["gallons", "barrels", "liters"]},
        {"name": "fill_type", "type": "enum", "values": ["keep_full", "will_call", "automatic"]}
      ]
    },
    {
      "name": "pricing",
      "type": "object",
      "fields": [
        {"name": "price_per_unit", "type": "number"},
        {"name": "currency", "type": "string", "default": "USD"},
        {"name": "pricing_type", "type": "enum", "values": ["fixed", "index", "market"]},
        {"name": "total_amount", "type": "number"},
        {"name": "fuel_surcharge", "type": "number"}
      ]
    },
    {
      "name": "terminal",
      "type": "object",
      "fields": [
        {"name": "terminal_id", "type": "string"},
        {"name": "name", "type": "string"},
        {"name": "location", "type": "string"}
      ]
    },
    {"name": "driver_notes", "type": "string"},
    {"name": "created_at", "type": "datetime"},
    {"name": "updated_at", "type": "datetime"}
  ]
}