{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://docforge.local/schema/generation-diff-v1.json",
  "title": "DocForge latest primary-graph generation diff receipt",
  "$defs": {
    "sha256": {
      "type": "string",
      "pattern": "^[0-9a-f]{64}$"
    },
    "generation": {
      "type": "object",
      "required": [
        "revision",
        "source_hash",
        "node_count",
        "node_hash",
        "edge_count",
        "edge_hash",
        "index_schema_version"
      ],
      "properties": {
        "revision": { "type": "string", "minLength": 1 },
        "source_hash": { "$ref": "#/$defs/sha256" },
        "node_count": { "type": "integer", "minimum": 0 },
        "node_hash": { "$ref": "#/$defs/sha256" },
        "edge_count": { "type": "integer", "minimum": 0 },
        "edge_hash": { "$ref": "#/$defs/sha256" },
        "index_schema_version": { "type": "integer", "minimum": 1 }
      },
      "additionalProperties": false
    },
    "node_item": {
      "type": "object",
      "required": [
        "entity",
        "change",
        "node_id",
        "before_content_hash",
        "after_content_hash",
        "before_source_path",
        "after_source_path",
        "before_node_hash",
        "after_node_hash",
        "changed_fields",
        "item_hash"
      ],
      "properties": {
        "entity": { "const": "node" },
        "change": { "enum": ["added", "removed", "changed"] },
        "node_id": { "type": "string", "minLength": 1 },
        "before_content_hash": {
          "oneOf": [
            { "$ref": "#/$defs/sha256" },
            { "type": "null" }
          ]
        },
        "after_content_hash": {
          "oneOf": [
            { "$ref": "#/$defs/sha256" },
            { "type": "null" }
          ]
        },
        "before_source_path": { "type": ["string", "null"] },
        "after_source_path": { "type": ["string", "null"] },
        "before_node_hash": {
          "oneOf": [
            { "$ref": "#/$defs/sha256" },
            { "type": "null" }
          ]
        },
        "after_node_hash": {
          "oneOf": [
            { "$ref": "#/$defs/sha256" },
            { "type": "null" }
          ]
        },
        "changed_fields": {
          "type": "array",
          "items": {
            "enum": [
              "title",
              "family",
              "authority",
              "status",
              "tags",
              "summary",
              "content",
              "source_path",
              "source_anchor",
              "content_hash"
            ]
          },
          "uniqueItems": true
        },
        "item_hash": { "$ref": "#/$defs/sha256" }
      },
      "allOf": [
        {
          "if": {
            "properties": { "change": { "const": "added" } },
            "required": ["change"]
          },
          "then": {
            "properties": {
              "before_content_hash": { "type": "null" },
              "before_source_path": { "type": "null" },
              "before_node_hash": { "type": "null" },
              "after_content_hash": { "$ref": "#/$defs/sha256" },
              "after_source_path": { "type": "string", "minLength": 1 },
              "after_node_hash": { "$ref": "#/$defs/sha256" },
              "changed_fields": { "maxItems": 0 }
            }
          }
        },
        {
          "if": {
            "properties": { "change": { "const": "removed" } },
            "required": ["change"]
          },
          "then": {
            "properties": {
              "before_content_hash": { "$ref": "#/$defs/sha256" },
              "before_source_path": { "type": "string", "minLength": 1 },
              "before_node_hash": { "$ref": "#/$defs/sha256" },
              "after_content_hash": { "type": "null" },
              "after_source_path": { "type": "null" },
              "after_node_hash": { "type": "null" },
              "changed_fields": { "maxItems": 0 }
            }
          }
        },
        {
          "if": {
            "properties": { "change": { "const": "changed" } },
            "required": ["change"]
          },
          "then": {
            "properties": {
              "before_content_hash": { "$ref": "#/$defs/sha256" },
              "before_source_path": { "type": "string", "minLength": 1 },
              "before_node_hash": { "$ref": "#/$defs/sha256" },
              "after_content_hash": { "$ref": "#/$defs/sha256" },
              "after_source_path": { "type": "string", "minLength": 1 },
              "after_node_hash": { "$ref": "#/$defs/sha256" },
              "changed_fields": { "minItems": 1 }
            }
          }
        }
      ],
      "additionalProperties": false
    },
    "edge_item": {
      "type": "object",
      "required": [
        "entity",
        "change",
        "source_id",
        "relation",
        "target_id",
        "item_hash"
      ],
      "properties": {
        "entity": { "const": "edge" },
        "change": { "enum": ["added", "removed"] },
        "source_id": { "type": "string", "minLength": 1 },
        "relation": { "type": "string", "minLength": 1 },
        "target_id": { "type": "string", "minLength": 1 },
        "item_hash": { "$ref": "#/$defs/sha256" }
      },
      "additionalProperties": false
    }
  },
  "type": "object",
  "required": [
    "schema_version",
    "diff_semantics_version",
    "project_id",
    "project_root_fingerprint",
    "adapter",
    "kind",
    "reason",
    "from_generation",
    "to_generation",
    "summary",
    "items",
    "full_item_count",
    "retained_item_count",
    "details_truncated",
    "truncation_reason",
    "full_collection_hash",
    "retained_collection_hash",
    "index_signature",
    "receipt_hash"
  ],
  "properties": {
    "schema_version": { "const": 1 },
    "diff_semantics_version": { "const": 1 },
    "project_id": { "type": "string", "minLength": 1 },
    "project_root_fingerprint": {
      "type": "string",
      "pattern": "^[0-9a-f]{16}$"
    },
    "adapter": { "type": "string", "minLength": 1 },
    "kind": { "enum": ["baseline", "transition"] },
    "reason": {
      "enum": [
        null,
        "no_predecessor",
        "predecessor_unsafe",
        "predecessor_unsupported_schema",
        "predecessor_foreign",
        "predecessor_policy_incompatible",
        "predecessor_corrupt",
        "predecessor_unattested",
        "predecessor_changed",
        "no_meaningful_transition"
      ]
    },
    "from_generation": {
      "oneOf": [
        { "$ref": "#/$defs/generation" },
        { "type": "null" }
      ]
    },
    "to_generation": { "$ref": "#/$defs/generation" },
    "summary": {
      "type": "object",
      "required": [
        "nodes_added",
        "nodes_removed",
        "nodes_changed",
        "edges_added",
        "edges_removed",
        "total_changes"
      ],
      "properties": {
        "nodes_added": { "type": "integer", "minimum": 0 },
        "nodes_removed": { "type": "integer", "minimum": 0 },
        "nodes_changed": { "type": "integer", "minimum": 0 },
        "edges_added": { "type": "integer", "minimum": 0 },
        "edges_removed": { "type": "integer", "minimum": 0 },
        "total_changes": { "type": "integer", "minimum": 0 }
      },
      "additionalProperties": false
    },
    "items": {
      "type": "array",
      "maxItems": 1000,
      "items": {
        "oneOf": [
          { "$ref": "#/$defs/node_item" },
          { "$ref": "#/$defs/edge_item" }
        ]
      }
    },
    "full_item_count": { "type": "integer", "minimum": 0 },
    "retained_item_count": {
      "type": "integer",
      "minimum": 0,
      "maximum": 1000
    },
    "details_truncated": { "type": "boolean" },
    "truncation_reason": {
      "enum": [null, "receipt_item_limit", "receipt_byte_limit"]
    },
    "full_collection_hash": { "$ref": "#/$defs/sha256" },
    "retained_collection_hash": { "$ref": "#/$defs/sha256" },
    "index_signature": {
      "type": "object",
      "required": ["device", "inode", "size", "mtime_ns", "ctime_ns"],
      "properties": {
        "device": { "type": "integer", "minimum": 0 },
        "inode": { "type": "integer", "minimum": 0 },
        "size": { "type": "integer", "minimum": 0 },
        "mtime_ns": { "type": "integer", "minimum": 0 },
        "ctime_ns": { "type": "integer", "minimum": 0 }
      },
      "additionalProperties": false
    },
    "receipt_hash": { "$ref": "#/$defs/sha256" }
  },
  "allOf": [
    {
      "if": {
        "properties": { "kind": { "const": "baseline" } },
        "required": ["kind"]
      },
      "then": {
        "properties": {
          "from_generation": { "type": "null" },
          "reason": { "not": { "type": "null" } },
          "summary": {
            "properties": {
              "nodes_added": { "const": 0 },
              "nodes_removed": { "const": 0 },
              "nodes_changed": { "const": 0 },
              "edges_added": { "const": 0 },
              "edges_removed": { "const": 0 },
              "total_changes": { "const": 0 }
            }
          },
          "full_item_count": { "const": 0 },
          "retained_item_count": { "const": 0 },
          "details_truncated": { "const": false },
          "truncation_reason": { "const": null },
          "full_collection_hash": {
            "const": "4f53cda18c2baa0c0354bb5f9a3ecbe5ed12ab4d8e11ba873c2f11161202b945"
          },
          "retained_collection_hash": {
            "const": "4f53cda18c2baa0c0354bb5f9a3ecbe5ed12ab4d8e11ba873c2f11161202b945"
          }
        }
      },
      "else": {
        "properties": {
          "from_generation": { "$ref": "#/$defs/generation" },
          "reason": { "type": "null" }
        }
      }
    },
    {
      "if": {
        "properties": { "truncation_reason": { "const": null } },
        "required": ["truncation_reason"]
      },
      "then": {
        "properties": {
          "details_truncated": { "const": false },
          "full_item_count": { "maximum": 1000 }
        }
      }
    },
    {
      "if": {
        "properties": {
          "truncation_reason": { "const": "receipt_item_limit" }
        },
        "required": ["truncation_reason"]
      },
      "then": {
        "properties": {
          "details_truncated": { "const": true },
          "full_item_count": { "minimum": 1001 },
          "retained_item_count": { "const": 1000 }
        }
      }
    },
    {
      "if": {
        "properties": {
          "truncation_reason": { "const": "receipt_byte_limit" }
        },
        "required": ["truncation_reason"]
      },
      "then": {
        "properties": {
          "details_truncated": { "const": true }
        }
      }
    }
  ],
  "additionalProperties": false
}