{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://schemas.orionhealth.com/fhir/observation.json",
  "title": "Orion Health FHIR Observation",
  "description": "A FHIR R4 Observation resource as represented in the Orion Health platform. Captures measurements, test results, vital signs, and other clinical findings including laboratory results, imaging observations, and patient-reported data.",
  "type": "object",
  "required": ["resourceType", "status", "code"],
  "properties": {
    "resourceType": {
      "type": "string",
      "const": "Observation",
      "description": "FHIR resource type identifier"
    },
    "id": {
      "type": "string",
      "description": "Logical ID of the observation resource"
    },
    "meta": {
      "type": "object",
      "properties": {
        "versionId": {
          "type": "string"
        },
        "lastUpdated": {
          "type": "string",
          "format": "date-time"
        },
        "profile": {
          "type": "array",
          "items": {
            "type": "string",
            "format": "uri"
          }
        }
      }
    },
    "identifier": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "system": {
            "type": "string",
            "format": "uri"
          },
          "value": {
            "type": "string"
          }
        }
      }
    },
    "status": {
      "type": "string",
      "enum": ["registered", "preliminary", "final", "amended", "corrected", "cancelled", "entered-in-error", "unknown"],
      "description": "Status of the observation"
    },
    "category": {
      "type": "array",
      "description": "Classification of the observation (e.g., vital-signs, laboratory)",
      "items": {
        "$ref": "#/$defs/CodeableConcept"
      }
    },
    "code": {
      "$ref": "#/$defs/CodeableConcept",
      "description": "Type of observation (LOINC code)"
    },
    "subject": {
      "$ref": "#/$defs/Reference",
      "description": "Patient the observation is about"
    },
    "encounter": {
      "$ref": "#/$defs/Reference",
      "description": "Healthcare event during which observation was made"
    },
    "effectiveDateTime": {
      "type": "string",
      "format": "date-time",
      "description": "Clinically relevant time for the observation"
    },
    "effectivePeriod": {
      "$ref": "#/$defs/Period",
      "description": "Clinically relevant time period"
    },
    "issued": {
      "type": "string",
      "format": "date-time",
      "description": "Date/time the result was made available"
    },
    "performer": {
      "type": "array",
      "description": "Who performed the observation",
      "items": {
        "$ref": "#/$defs/Reference"
      }
    },
    "valueQuantity": {
      "$ref": "#/$defs/Quantity",
      "description": "Numeric result with units"
    },
    "valueCodeableConcept": {
      "$ref": "#/$defs/CodeableConcept",
      "description": "Coded result value"
    },
    "valueString": {
      "type": "string",
      "description": "String result value"
    },
    "valueBoolean": {
      "type": "boolean",
      "description": "Boolean result value"
    },
    "valueInteger": {
      "type": "integer",
      "description": "Integer result value"
    },
    "valueDateTime": {
      "type": "string",
      "format": "date-time",
      "description": "Date/time result value"
    },
    "dataAbsentReason": {
      "$ref": "#/$defs/CodeableConcept",
      "description": "Why the result is missing"
    },
    "interpretation": {
      "type": "array",
      "description": "High, low, normal interpretation",
      "items": {
        "$ref": "#/$defs/CodeableConcept"
      }
    },
    "note": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "text": {
            "type": "string"
          },
          "time": {
            "type": "string",
            "format": "date-time"
          },
          "authorReference": {
            "$ref": "#/$defs/Reference"
          }
        },
        "required": ["text"]
      }
    },
    "bodySite": {
      "$ref": "#/$defs/CodeableConcept",
      "description": "Body site of the observation"
    },
    "method": {
      "$ref": "#/$defs/CodeableConcept",
      "description": "How the observation was performed"
    },
    "specimen": {
      "$ref": "#/$defs/Reference",
      "description": "Specimen used for the observation"
    },
    "device": {
      "$ref": "#/$defs/Reference",
      "description": "Device used to generate the observation"
    },
    "referenceRange": {
      "type": "array",
      "description": "Reference range for interpretation",
      "items": {
        "type": "object",
        "properties": {
          "low": {
            "$ref": "#/$defs/Quantity"
          },
          "high": {
            "$ref": "#/$defs/Quantity"
          },
          "type": {
            "$ref": "#/$defs/CodeableConcept"
          },
          "appliesTo": {
            "type": "array",
            "items": {
              "$ref": "#/$defs/CodeableConcept"
            }
          },
          "age": {
            "type": "object",
            "properties": {
              "low": {
                "$ref": "#/$defs/Quantity"
              },
              "high": {
                "$ref": "#/$defs/Quantity"
              }
            }
          },
          "text": {
            "type": "string"
          }
        }
      }
    },
    "component": {
      "type": "array",
      "description": "Component observations (e.g., systolic/diastolic for blood pressure)",
      "items": {
        "type": "object",
        "required": ["code"],
        "properties": {
          "code": {
            "$ref": "#/$defs/CodeableConcept"
          },
          "valueQuantity": {
            "$ref": "#/$defs/Quantity"
          },
          "valueCodeableConcept": {
            "$ref": "#/$defs/CodeableConcept"
          },
          "valueString": {
            "type": "string"
          },
          "interpretation": {
            "type": "array",
            "items": {
              "$ref": "#/$defs/CodeableConcept"
            }
          },
          "referenceRange": {
            "type": "array",
            "items": {
              "type": "object",
              "properties": {
                "low": {
                  "$ref": "#/$defs/Quantity"
                },
                "high": {
                  "$ref": "#/$defs/Quantity"
                },
                "text": {
                  "type": "string"
                }
              }
            }
          }
        }
      }
    }
  },
  "$defs": {
    "CodeableConcept": {
      "type": "object",
      "properties": {
        "coding": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/Coding"
          }
        },
        "text": {
          "type": "string"
        }
      }
    },
    "Coding": {
      "type": "object",
      "properties": {
        "system": {
          "type": "string",
          "format": "uri"
        },
        "code": {
          "type": "string"
        },
        "display": {
          "type": "string"
        }
      }
    },
    "Reference": {
      "type": "object",
      "properties": {
        "reference": {
          "type": "string"
        },
        "display": {
          "type": "string"
        }
      }
    },
    "Quantity": {
      "type": "object",
      "properties": {
        "value": {
          "type": "number"
        },
        "comparator": {
          "type": "string",
          "enum": ["<", "<=", ">=", ">"]
        },
        "unit": {
          "type": "string"
        },
        "system": {
          "type": "string",
          "format": "uri"
        },
        "code": {
          "type": "string"
        }
      }
    },
    "Period": {
      "type": "object",
      "properties": {
        "start": {
          "type": "string",
          "format": "date-time"
        },
        "end": {
          "type": "string",
          "format": "date-time"
        }
      }
    }
  }
}