{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://docforge.local/schema/generation-diff-page-v1.json",
  "title": "DocForge bounded latest-generation diff page",
  "$defs": {
    "sha256": {
      "type": "string",
      "pattern": "^[0-9a-f]{64}$"
    },
    "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
    },
    "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
    },
    "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",
          "uniqueItems": true,
          "items": {
            "enum": [
              "title",
              "family",
              "authority",
              "status",
              "tags",
              "summary",
              "content",
              "source_path",
              "source_anchor",
              "content_hash"
            ]
          }
        },
        "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
    },
    "receipt_header": {
      "type": "object",
      "required": [
        "schema_version",
        "diff_semantics_version",
        "project_id",
        "project_root_fingerprint",
        "adapter",
        "kind",
        "reason",
        "from_generation",
        "to_generation",
        "summary",
        "full_item_count",
        "retained_item_count",
        "details_truncated",
        "truncation_reason",
        "full_collection_hash",
        "retained_collection_hash",
        "index_signature",
        "stored_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": "#/$defs/generation" },
        "summary": { "$ref": "#/$defs/summary" },
        "full_item_count": { "type": "integer", "minimum": 0 },
        "retained_item_count": {
          "type": "integer",
          "minimum": 0,
          "maximum": 1000
        },
        "details_truncated": { "type": "boolean" },
        "truncation_reason": {
          "enum": [null, "receipt_item_limit", "receipt_byte_limit"]
        },
        "full_collection_hash": { "$ref": "#/$defs/sha256" },
        "retained_collection_hash": { "$ref": "#/$defs/sha256" },
        "index_signature": {
          "type": "object",
          "required": ["device", "inode", "size", "mtime_ns", "ctime_ns"],
          "properties": {
            "device": { "type": "integer", "minimum": 0 },
            "inode": { "type": "integer", "minimum": 0 },
            "size": { "type": "integer", "minimum": 0 },
            "mtime_ns": { "type": "integer", "minimum": 0 },
            "ctime_ns": { "type": "integer", "minimum": 0 }
          },
          "additionalProperties": false
        },
        "stored_receipt_hash": { "$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": "#/$defs/generation" },
              "reason": { "type": "null" }
            }
          }
        },
        {
          "if": {
            "properties": { "truncation_reason": { "const": null } },
            "required": ["truncation_reason"]
          },
          "then": {
            "properties": {
              "details_truncated": { "const": false },
              "full_item_count": { "maximum": 1000 }
            }
          }
        },
        {
          "if": {
            "properties": {
              "truncation_reason": { "const": "receipt_item_limit" }
            },
            "required": ["truncation_reason"]
          },
          "then": {
            "properties": {
              "details_truncated": { "const": true },
              "full_item_count": { "minimum": 1001 },
              "retained_item_count": { "const": 1000 }
            }
          }
        },
        {
          "if": {
            "properties": {
              "truncation_reason": { "const": "receipt_byte_limit" }
            },
            "required": ["truncation_reason"]
          },
          "then": {
            "properties": {
              "details_truncated": { "const": true }
            }
          }
        }
      ],
      "additionalProperties": false
    },
    "page_body": {
      "type": "object",
      "required": [
        "page_schema_version",
        "receipt_header",
        "items",
        "omissions",
        "page_hash"
      ],
      "properties": {
        "page_schema_version": { "const": 1 },
        "receipt_header": { "$ref": "#/$defs/receipt_header" },
        "items": {
          "type": "array",
          "maxItems": 1000,
          "items": {
            "oneOf": [
              { "$ref": "#/$defs/node_item" },
              { "$ref": "#/$defs/edge_item" }
            ]
          }
        },
        "omissions": {
          "type": "array",
          "maxItems": 1,
          "items": {
            "type": "object",
            "required": ["code", "item_hash"],
            "properties": {
              "code": { "const": "response_limit" },
              "item_hash": { "$ref": "#/$defs/sha256" }
            },
            "additionalProperties": false
          }
        },
        "page_hash": { "$ref": "#/$defs/sha256" }
      },
      "additionalProperties": false
    },
    "pagination": {
      "type": "object",
      "required": [
        "schema_version",
        "kind",
        "returned_count",
        "limit",
        "total_count",
        "has_more",
        "next_cursor"
      ],
      "properties": {
        "schema_version": { "const": 1 },
        "kind": { "const": "generation-diff.items" },
        "returned_count": { "type": "integer", "minimum": 0 },
        "limit": { "type": "integer", "minimum": 1, "maximum": 1000 },
        "total_count": { "type": "integer", "minimum": 0, "maximum": 1000 },
        "has_more": { "type": "boolean" },
        "next_cursor": {
          "type": ["string", "null"],
          "minLength": 1,
          "maxLength": 8192
        }
      },
      "allOf": [
        {
          "if": {
            "properties": { "has_more": { "const": true } },
            "required": ["has_more"]
          },
          "then": {
            "properties": {
              "next_cursor": { "type": "string", "minLength": 1 }
            }
          },
          "else": {
            "properties": {
              "next_cursor": { "type": "null" }
            }
          }
        }
      ],
      "additionalProperties": false
    }
  },
  "type": "object",
  "required": ["generation_diff", "pagination"],
  "properties": {
    "generation_diff": { "$ref": "#/$defs/page_body" },
    "pagination": { "$ref": "#/$defs/pagination" }
  },
  "additionalProperties": false
}