{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://storyobjectmodel.com/schema/1.0/telling-event.schema.json",
  "title": "SOM 1.0 som.telling.* event payloads",
  "description": "Payloads for telling.started / telling.ended / telling.exposed (v0.3.1 Proposal \u00a73.2), implementing the ratified event-pair semantics (\u00a75): exposure_start/exposure_end immutable and event-stamped; scheduled_start mutable; instantaneous exposures carry both with exposure_start = exposure_end. Stuck-LIVE guard and clock discipline are normative in \u00a75. v0.3.2 addition: transforms[] \u2014 edge reshapes recorded against the Telling (Morag 5 Jul ask / John 9 Jul reply). Boundary test: if the reshaped output gets its own TAMS Source it is a new Source as today; if not, it is a transform on the telling. The array is APPLICATION-ORDERED and APPEND-ONLY \u2014 entries are never edited or removed (the provenance claim depends on it). Compliance invariant: a telling-side transform NEVER lifts a compliance[].media_range hold \u2014 holds evaluate against the Source time range regardless of transforms.",
  "type": "object",
  "required": [
    "message_type",
    "telling_id",
    "link_id"
  ],
  "properties": {
    "message_type": {
      "type": "string",
      "enum": [
        "telling.started",
        "telling.ended",
        "telling.exposed"
      ]
    },
    "telling_id": {
      "type": "string",
      "format": "uuid"
    },
    "link_id": {
      "type": "string",
      "format": "uuid",
      "description": "The link this Telling followed from \u2014 referenced, not duplicated"
    },
    "exposure_start": {
      "type": "string",
      "format": "date-time"
    },
    "exposure_end": {
      "type": "string",
      "format": "date-time"
    },
    "scheduled_start": {
      "type": "string",
      "format": "date-time",
      "description": "Mutable intended-air; never used to derive on-air state"
    },
    "extensions": {
      "type": "object",
      "patternProperties": {
        "^com\\.[a-z0-9-]+\\.": {}
      },
      "additionalProperties": false
    },
    "transforms": {
      "type": "array",
      "description": "Application-ordered, append-only edge reshapes on this telling; none of them new media.",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "transform_type",
          "applied_by",
          "applied_at"
        ],
        "properties": {
          "transform_type": {
            "anyOf": [
              {
                "type": "string",
                "enum": [
                  "CROP",
                  "TRIM",
                  "CAPTION_BURN"
                ]
              },
              {
                "type": "string",
                "pattern": "^x-[a-z0-9_]+$"
              }
            ],
            "description": "Governed-but-extensible registry (same model as Platform / framing_treatment); seed values CROP / TRIM / CAPTION_BURN; vendor values x-lowercase."
          },
          "params": {
            "type": "object",
            "description": "Per-type payload (not generic from/to): CROP {aspect_ratio | geometry}, TRIM {time_range}, CAPTION_BURN {caption_ref | style}. Shapes settle with the registry."
          },
          "applied_by": {
            "type": "object",
            "additionalProperties": false,
            "required": [
              "actor_id",
              "actor_type"
            ],
            "description": "Audit actor shape (shared convention).",
            "properties": {
              "actor_id": {
                "type": "string"
              },
              "actor_type": {
                "type": "string"
              }
            }
          },
          "applied_at": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    }
  },
  "additionalProperties": false,
  "allOf": [
    {
      "if": {
        "properties": {
          "message_type": {
            "const": "telling.started"
          }
        }
      },
      "then": {
        "required": [
          "exposure_start"
        ],
        "not": {
          "required": [
            "exposure_end"
          ]
        }
      }
    },
    {
      "if": {
        "properties": {
          "message_type": {
            "const": "telling.ended"
          }
        }
      },
      "then": {
        "required": [
          "exposure_end"
        ]
      }
    },
    {
      "if": {
        "properties": {
          "message_type": {
            "const": "telling.exposed"
          }
        }
      },
      "then": {
        "required": [
          "exposure_start",
          "exposure_end"
        ]
      }
    }
  ]
}