{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/farmos/main/json-schema/farmos-quantity.json",
  "title": "farmOS Quantity",
  "description": "Represents a measurement quantity associated with a farmOS log. Quantities record numeric measurements with units (e.g., 50 lbs of feed, 2 acres planted).",
  "type": "object",
  "required": ["data"],
  "properties": {
    "data": {
      "type": "object",
      "required": ["type", "attributes"],
      "properties": {
        "type": {
          "type": "string",
          "description": "JSON:API resource type",
          "enum": [
            "quantity--standard",
            "quantity--material",
            "quantity--test"
          ]
        },
        "id": {
          "type": "string",
          "format": "uuid",
          "readOnly": true
        },
        "attributes": {
          "type": "object",
          "properties": {
            "measure": {
              "type": "string",
              "description": "The type of measurement being recorded",
              "enum": [
                "weight",
                "volume",
                "count",
                "length",
                "area",
                "time",
                "temperature",
                "pressure",
                "water_content",
                "rating",
                "ratio"
              ]
            },
            "value": {
              "type": ["object", "null"],
              "description": "The numeric value of the measurement",
              "properties": {
                "numerator": {
                  "type": "integer",
                  "description": "Numerator of the rational number representation"
                },
                "denominator": {
                  "type": "integer",
                  "description": "Denominator of the rational number representation",
                  "default": 1
                },
                "decimal": {
                  "type": "string",
                  "description": "Decimal string representation (e.g., '50.5')"
                }
              }
            },
            "label": {
              "type": ["string", "null"],
              "description": "Optional human-readable label for the quantity (e.g., 'Seed rate', 'Yield')"
            },
            "inventory_adjustment": {
              "type": ["string", "null"],
              "description": "Whether and how this quantity adjusts an asset's inventory",
              "enum": ["increment", "decrement", "reset", null]
            },
            "created": {
              "type": "integer",
              "readOnly": true
            },
            "changed": {
              "type": "integer",
              "readOnly": true
            }
          }
        },
        "relationships": {
          "type": "object",
          "properties": {
            "units": {
              "description": "Unit taxonomy term for this quantity",
              "type": "object",
              "properties": {
                "data": {
                  "oneOf": [
                    {
                      "type": "object",
                      "required": ["type", "id"],
                      "properties": {
                        "type": { "type": "string", "example": "taxonomy_term--unit" },
                        "id": { "type": "string", "format": "uuid" }
                      }
                    },
                    { "type": "null" }
                  ]
                }
              }
            },
            "inventory_asset": {
              "description": "Asset whose inventory is affected by this quantity",
              "type": "object",
              "properties": {
                "data": {
                  "oneOf": [
                    {
                      "type": "object",
                      "required": ["type", "id"],
                      "properties": {
                        "type": { "type": "string" },
                        "id": { "type": "string", "format": "uuid" }
                      }
                    },
                    { "type": "null" }
                  ]
                }
              }
            }
          }
        }
      }
    }
  }
}