{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://woahwhattheheck.github.io/commons/revenue/outcome_commerce/metering-event.schema.json",
  "title": "Append-only Outcome Commerce Metering Event",
  "type": "object",
  "additionalProperties": false,
  "required": ["schema_version", "event_id", "idempotency_key", "correlation_id", "listing_id", "event_type", "state", "occurred_at"],
  "properties": {
    "schema_version": {"const": "outcome-commerce-event/v1"},
    "event_id": {"$ref": "#/$defs/id"},
    "idempotency_key": {"$ref": "#/$defs/id"},
    "correlation_id": {"$ref": "#/$defs/id"},
    "causation_id": {"$ref": "#/$defs/nullableId"},
    "listing_id": {"$ref": "#/$defs/id"},
    "component_id": {"$ref": "#/$defs/id"},
    "contract_id": {"$ref": "#/$defs/id"},
    "job_id": {"$ref": "#/$defs/id"},
    "attempt_id": {"$ref": "#/$defs/id"},
    "order_id": {"$ref": "#/$defs/id"},
    "receipt_id": {"$ref": "#/$defs/id"},
    "event_type": {
      "enum": [
        "FIXED_ACTIVATED", "SUBSCRIPTION_CYCLE", "USAGE_RECORDED", "OUTCOME_VERIFIED",
        "OUTCOME_CANDIDATE", "OUTCOME_FAILED", "OUTCOME_ESCALATED", "MILESTONE_ACCEPTED",
        "GROSS_REVENUE_RECORDED", "LICENSE_ACTIVATED", "SPONSORSHIP_DELIVERED",
        "CREDIT_GRANTED", "ADJUSTMENT"
      ]
    },
    "state": {"enum": ["RECORDED", "VERIFIED", "ACCEPTED", "REVERSED"]},
    "occurred_at": {"$ref": "#/$defs/timestamp"},
    "quantity": {"$ref": "#/$defs/unsignedDecimal"},
    "amount": {"$ref": "#/$defs/signedDecimal"},
    "currency": {"type": "string", "pattern": "^[A-Z][A-Z0-9._-]{1,31}$"},
    "evidence": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["uri", "sha256"],
        "properties": {
          "uri": {"type": "string", "minLength": 1},
          "sha256": {"type": "string", "pattern": "^[0-9a-f]{64}$"}
        }
      }
    },
    "reverses_event_id": {"$ref": "#/$defs/id"},
    "source": {"type": "object", "description": "Context and lineage only; never admission or authorization."}
  },
  "allOf": [
    {
      "if": {"properties": {"state": {"const": "REVERSED"}}, "required": ["state"]},
      "then": {"required": ["reverses_event_id"]},
      "else": {
        "if": {"properties": {"event_type": {"enum": ["CREDIT_GRANTED", "ADJUSTMENT"]}}, "required": ["event_type"]},
        "then": {"required": ["amount", "currency"]},
        "else": {"required": ["component_id"]}
      }
    },
    {
      "if": {"properties": {"event_type": {"const": "OUTCOME_VERIFIED"}}, "required": ["event_type"]},
      "then": {"properties": {"state": {"const": "VERIFIED"}, "evidence": {"minItems": 1}}, "required": ["quantity", "evidence"]}
    },
    {
      "if": {"properties": {"event_type": {"enum": ["OUTCOME_CANDIDATE", "OUTCOME_FAILED", "OUTCOME_ESCALATED"]}}, "required": ["event_type"]},
      "then": {"properties": {"state": {"const": "RECORDED"}}, "required": ["component_id"]}
    },
    {
      "if": {"properties": {"event_type": {"enum": ["MILESTONE_ACCEPTED", "FIXED_ACTIVATED", "LICENSE_ACTIVATED"]}}, "required": ["event_type"]},
      "then": {"properties": {"state": {"const": "ACCEPTED"}}}
    }
  ],
  "$defs": {
    "id": {"type": "string", "minLength": 8, "maxLength": 80, "pattern": "^[A-Za-z0-9._-]+$"},
    "nullableId": {"anyOf": [{"$ref": "#/$defs/id"}, {"type": "null"}]},
    "timestamp": {"type": "string", "format": "date-time", "pattern": "(?:Z|[+-][0-9]{2}:[0-9]{2})$"},
    "unsignedDecimal": {"type": "string", "pattern": "^(0|[1-9][0-9]*)(\\.[0-9]{1,8})?$"},
    "signedDecimal": {"type": "string", "pattern": "^-?(0|[1-9][0-9]*)(\\.[0-9]{1,8})?$"}
  }
}