{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://thinkloom.app/schemas/provenance/1.0/expression-segment.schema.json",
  "title": "Surviving expression segment",
  "description": "Stable surviving deposit expression with revision-bound range, digest, recorded origin, lineage, transformations, and separate selection/arrangement assertions.",
  "type": "object",
  "properties": {
    "schema_version": {
      "const": "1.0"
    },
    "segment_id": {
      "type": "string",
      "pattern": "^segment_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "project_id": {
      "type": "string",
      "pattern": "^project_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "revision_id": {
      "type": "string",
      "pattern": "^revision_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "segment_sequence": {
      "type": "integer",
      "minimum": 1
    },
    "range": {
      "$ref": "https://thinkloom.app/schemas/provenance/1.0/text-fragment-reference.schema.json"
    },
    "content_sha256": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$"
    },
    "normalized_unicode_scalar_length": {
      "type": "integer",
      "minimum": 1
    },
    "recorded_origin_kind": {
      "enum": [
        "recorded_direct_human_input",
        "human_expressive_input_via_transcription",
        "accepted_ai_output",
        "imported_or_pasted",
        "system_restoration",
        "unattested"
      ]
    },
    "actor_identity_status": {
      "enum": [
        "verified",
        "self_declared",
        "unknown",
        "not_applicable"
      ]
    },
    "generation_status": {
      "enum": [
        "recorded",
        "unknown"
      ]
    },
    "lineage_status": {
      "enum": [
        "recorded",
        "unattested",
        "unknown"
      ]
    },
    "lineage_reference_ids": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^[a-z][a-z0-9_]*_[0-9A-HJKMNP-TV-Z]{26}$"
      },
      "uniqueItems": true
    },
    "operation_ids": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^operation_[0-9A-HJKMNP-TV-Z]{26}$"
      },
      "uniqueItems": true
    },
    "transformation_relationships": {
      "type": "array",
      "items": {
        "enum": [
          "inserted",
          "deleted",
          "replaced",
          "moved",
          "pasted_from_external",
          "transcribed_from_human_speech",
          "generated_by_ai",
          "modified_by_human",
          "restored_from_revision",
          "derived_from"
        ]
      },
      "uniqueItems": true
    },
    "assertion_ids": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^assertion_[0-9A-HJKMNP-TV-Z]{26}$"
      },
      "uniqueItems": true
    },
    "selection_arrangement_assertion_ids": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^assertion_[0-9A-HJKMNP-TV-Z]{26}$"
      },
      "uniqueItems": true
    },
    "included_in_deposit_assertion_id": {
      "anyOf": [
        {
          "type": "string",
          "pattern": "^assertion_[0-9A-HJKMNP-TV-Z]{26}$"
        },
        {
          "type": "null"
        }
      ]
    },
    "classification_status": {
      "enum": [
        "exact",
        "degraded",
        "stale",
        "unverified"
      ]
    }
  },
  "required": [
    "schema_version",
    "segment_id",
    "project_id",
    "revision_id",
    "segment_sequence",
    "range",
    "content_sha256",
    "normalized_unicode_scalar_length",
    "recorded_origin_kind",
    "actor_identity_status",
    "generation_status",
    "lineage_status",
    "lineage_reference_ids",
    "operation_ids",
    "transformation_relationships",
    "assertion_ids",
    "selection_arrangement_assertion_ids",
    "included_in_deposit_assertion_id",
    "classification_status"
  ],
  "additionalProperties": false,
  "allOf": [
    {
      "if": {
        "properties": {
          "classification_status": {
            "const": "exact"
          }
        },
        "required": [
          "classification_status"
        ]
      },
      "then": {
        "properties": {
          "recorded_origin_kind": {
            "enum": [
              "recorded_direct_human_input",
              "human_expressive_input_via_transcription",
              "accepted_ai_output",
              "imported_or_pasted",
              "system_restoration"
            ]
          },
          "actor_identity_status": {
            "enum": [
              "verified",
              "self_declared",
              "not_applicable"
            ]
          },
          "generation_status": {
            "const": "recorded"
          },
          "lineage_status": {
            "const": "recorded"
          },
          "lineage_reference_ids": {
            "type": "array",
            "minItems": 1
          },
          "operation_ids": {
            "type": "array",
            "minItems": 1
          },
          "assertion_ids": {
            "type": "array",
            "minItems": 1
          },
          "included_in_deposit_assertion_id": {
            "type": "string",
            "pattern": "^assertion_[0-9A-HJKMNP-TV-Z]{26}$"
          }
        }
      }
    }
  ],
  "examples": [
    {
      "schema_version": "1.0",
      "segment_id": "segment_01J0000000000000000000000Y",
      "project_id": "project_01J00000000000000000000001",
      "revision_id": "revision_01J0000000000000000000000B",
      "segment_sequence": 1,
      "range": {
        "schema_version": "1.0",
        "document_revision_id": "revision_01J0000000000000000000000B",
        "coordinate_system": "unicode_scalar",
        "start": 0,
        "end": 12,
        "preimage_sha256": "sha256:2222222222222222222222222222222222222222222222222222222222222222",
        "text_fragment_id": "fragment_01J0000000000000000000000C"
      },
      "content_sha256": "sha256:2222222222222222222222222222222222222222222222222222222222222222",
      "normalized_unicode_scalar_length": 12,
      "recorded_origin_kind": "recorded_direct_human_input",
      "actor_identity_status": "self_declared",
      "generation_status": "recorded",
      "lineage_status": "recorded",
      "lineage_reference_ids": [
        "operation_01J0000000000000000000000X"
      ],
      "operation_ids": [
        "operation_01J0000000000000000000000X"
      ],
      "transformation_relationships": [
        "inserted"
      ],
      "assertion_ids": [
        "assertion_01J0000000000000000000000V"
      ],
      "selection_arrangement_assertion_ids": [],
      "included_in_deposit_assertion_id": "assertion_01J0000000000000000000000V",
      "classification_status": "exact"
    }
  ]
}