{
  "id": "extent.json#",
  "$schema": "http://json-schema.org/draft-04/schema#",
  "description": "schema for extent",
  "type": "object",
  "additionalProperties": true,
  "properties": {
    "description": {
      "type": "string"
    },
    "geographicElement": {
      "type": "array",
      "items": {
        "properties": {
          "type": {
            "enum": ["Feature", "FeatureCollection", "GeometryCollection", "Point", "MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon"]
          }
        },
        "oneOf": [
          {
            "$ref": "geojson/geojson.json#"
          }
        ]
      }
    },
    "verticalElement": {
      "type": "array",
      "items": {
        "$ref": "#/definitions/verticalExtent"
      }
    },
    "temporalElement": {

      "$ref": "#/definitions/temporalElement"
    }
  },
  "definitions": {
    "timeInstant": {
      "type": "object",
      "required": ["timePosition"],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string"
        },
        "description": {
          "type": "string"
        },
        "timePosition": {
          "$ref": "../schema.json#/definitions/date"
        }
      }
    },
    "timePeriod": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string"
        },
        "description": {
          "type": "string"
        },
        "beginPosition": {
          "$ref": "../schema.json#/definitions/date"
        },
        "endPosition": {
          "$ref": "../schema.json#/definitions/date"
        }
      },
      "anyOf": [
        {
          "title": "beginPosition required",
          "required": ["beginPosition"]
        }, {
          "title": "endPosition required",
          "required": ["endPosition"]
        }
      ]
    },
    "temporalElement": {
      "type": "object",
      "additionalProperties": false,
      "minProperties": 1,
      "properties": {
        "timeInstant": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/timeInstant"
          }
        },
        "timePeriod": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/timePeriod"
          }
        },
        "date": {
          "type": "array",
          "items": {
            "$ref": "../schema.json#/definitions/date"
          }
        }
      }
    },
    "verticalExtent": {
      "type": "object",
      "additionalProperties": false,
      "required": ["minimumValue", "maximumValue", "verticalCRSTitle", "verticalCRSUri"],
      "properties": {
        "minimumValue": {
          "type": "number"
        },
        "maximumValue": {
          "type": "number"
        },
        "verticalCRSTitle": {
          "type": "string"
        },
        "verticalCRSUri": {
          "$ref": "../schema.json#/definitions/uri"
        }
      }
    }
  }
}