{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://cadset.local/contracts/designir-3.0.schema.json",
  "title": "DesignIR 3.0",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "schema_version",
    "designir_kind",
    "model_id",
    "units",
    "document_status",
    "reconstruction_mode",
    "semantic_layer",
    "edit_interface",
    "validation_contract"
  ],
  "properties": {
    "schema_version": {"const": "3.0"},
    "designir_kind": {"const": "independent_parametric_cad"},
    "model_id": {"type": "string", "minLength": 1},
    "family": {"type": "string", "minLength": 1},
    "units": {"const": "mm"},
    "authoring_mode": {
      "enum": ["semantic_feature_program", "final_brep_inference"]
    },
    "backend_hint": {"enum": ["build123d", "simplecadapi", "auto"]},
    "document_status": {"enum": ["geometry_present", "empty_geometry"]},
    "reconstruction_mode": {
      "enum": [
        "fully_semantic_parametric",
        "hybrid_semantic_surface_parametric",
        "surface_parametric"
      ]
    },
    "semantic_layer": {
      "type": "object",
      "required": ["parameters", "datums", "features", "constraints"],
      "properties": {
        "reconstruction_status": {
          "enum": ["ready", "partial", "unsupported_feature_vocabulary"]
        },
        "coordinate_system": {"$ref": "#/$defs/coordinateSystem"},
        "parameters": {"type": "object"},
        "datums": {"type": "object"},
        "expressions": {"type": "object"},
        "sketches": {"type": "array", "items": {"type": "object"}},
        "features": {"type": "array", "items": {"type": "object"}},
        "constraints": {"type": "array", "items": {"type": "object"}},
        "patterns": {"type": "array", "items": {"type": "object"}},
        "attachments": {"type": "array", "items": {"type": "object"}},
        "construction_stages": {"type": "array", "items": {"type": "object"}},
        "missing_capabilities": {"type": "array", "items": {"type": "string"}},
        "applied_experience_ids": {"type": "array", "items": {"type": "string"}}
      }
    },
    "surface_layer": {
      "type": "object",
      "oneOf": [
        {
          "required": [
            "vertices",
            "solids",
            "free_shells",
            "surface_vocabulary",
            "curve_vocabulary"
          ]
        },
        {
          "required": [
            "format",
            "encoding",
            "uncompressed_bytes",
            "compressed_bytes",
            "sha256",
            "data"
          ]
        }
      ],
      "properties": {
        "format": {"const": "surfaceir-3.0"},
        "encoding": {"const": "gzip+base64+json"},
        "uncompressed_bytes": {"type": "integer", "minimum": 2},
        "compressed_bytes": {"type": "integer", "minimum": 2},
        "sha256": {
          "type": "string",
          "pattern": "^[a-f0-9]{64}$"
        },
        "data": {
          "type": "string",
          "minLength": 1,
          "contentEncoding": "base64"
        },
        "vertices": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["id", "point", "tolerance"],
            "properties": {
              "id": {"type": "string"},
              "point": {"$ref": "#/$defs/point3"},
              "tolerance": {"type": "number", "minimum": 0}
            }
          }
        },
        "solids": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["id", "shells"],
            "properties": {
              "id": {"type": "string"},
              "orientation": {"type": "integer"},
              "shells": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": ["id", "faces"],
                  "properties": {
                    "id": {"type": "string"},
                    "orientation": {"type": "integer"},
                    "faces": {
                      "type": "array",
                      "items": {"$ref": "#/$defs/face"}
                    }
                  }
                }
              }
            }
          }
        },
        "free_shells": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["id", "faces"],
            "properties": {
              "id": {"type": "string"},
              "orientation": {"type": "integer"},
              "faces": {
                "type": "array",
                "items": {"$ref": "#/$defs/face"}
              }
            }
          }
        },
        "surface_vocabulary": {
          "type": "array",
          "items": {
            "enum": ["plane", "cylinder", "cone", "sphere", "torus", "bspline"]
          },
          "uniqueItems": true
        },
        "curve_vocabulary": {
          "type": "array",
          "items": {
            "enum": ["line", "circle", "ellipse", "bspline", "degenerate"]
          },
          "uniqueItems": true
        }
      }
    },
    "reconstruction_strategy": {
      "type": "object",
      "required": ["boundary_strategy", "selection_status"],
      "properties": {
        "boundary_strategy": {
          "enum": [
            "exact_3d",
            "exact_3d_pcurve",
            "first_pcurve",
            "analytic_uv_rect",
            "uv_rect_all"
          ]
        },
        "selection_status": {
          "enum": ["default", "geometry_validated", "unresolved"]
        }
      }
    },
    "edit_interface": {
      "type": "object",
      "required": [
        "semantic_parameters",
        "surface_parameter_groups",
        "modification_levels"
      ],
      "properties": {
        "semantic_parameters": {
          "type": "array",
          "items": {"type": "string"},
          "uniqueItems": true
        },
        "surface_parameter_groups": {
          "type": "array",
          "items": {"type": "string"},
          "uniqueItems": true
        },
        "modification_levels": {
          "type": "array",
          "items": {
            "enum": ["semantic_feature", "analytic_surface", "spline_control"]
          },
          "uniqueItems": true
        },
        "preserved_interfaces": {"type": "array", "items": {"type": "string"}}
      }
    },
    "validation_contract": {
      "type": "object",
      "required": ["source_independence", "geometry_checks", "edit_checks"],
      "properties": {
        "source_independence": {"const": true},
        "geometry_checks": {"type": "array", "items": {"type": "string"}},
        "edit_checks": {"type": "array", "items": {"type": "string"}},
        "invariants": {"type": "array", "items": {"type": "object"}},
        "perturbations": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["parameter", "scale", "expected_change"],
            "properties": {
              "parameter": {"type": "string"},
              "scale": {"type": "number", "exclusiveMinimum": 0},
              "expected_change": {"type": "string", "minLength": 1},
              "preserve": {"type": "array", "items": {"type": "string"}}
            }
          }
        },
        "thresholds": {"type": "object"}
      }
    },
    "compiled_surface_provenance": {
      "type": "object",
      "required": [
        "source",
        "teacher_geometry_used",
        "semantic_layer_authoritative"
      ],
      "properties": {
        "source": {"const": "generated_step"},
        "teacher_geometry_used": {"const": false},
        "semantic_layer_authoritative": {"const": true}
      }
    }
  },
  "allOf": [
    {
      "if": {
        "properties": {"reconstruction_mode": {"const": "surface_parametric"}}
      },
      "then": {"required": ["surface_layer"]}
    },
    {
      "if": {
        "properties": {
          "reconstruction_mode": {
            "enum": [
              "fully_semantic_parametric",
              "hybrid_semantic_surface_parametric"
            ]
          }
        }
      },
      "then": {
        "required": ["family", "authoring_mode"],
        "properties": {
          "semantic_layer": {
            "required": [
              "reconstruction_status",
              "coordinate_system",
              "parameters",
              "datums",
              "expressions",
              "sketches",
              "features",
              "constraints",
              "patterns",
              "attachments",
              "construction_stages"
            ]
          }
        }
      }
    },
    {
      "if": {
        "properties": {
          "reconstruction_mode": {
            "const": "hybrid_semantic_surface_parametric"
          }
        }
      },
      "then": {"required": ["surface_layer", "compiled_surface_provenance"]}
    }
  ],
  "$defs": {
    "point3": {
      "type": "array",
      "prefixItems": [
        {"type": "number"},
        {"type": "number"},
        {"type": "number"}
      ],
      "minItems": 3,
      "maxItems": 3
    },
    "coordinateSystem": {
      "type": "object",
      "required": ["origin", "x_axis", "y_axis", "z_axis"],
      "properties": {
        "origin": {"$ref": "#/$defs/point3"},
        "x_axis": {"$ref": "#/$defs/point3"},
        "y_axis": {"$ref": "#/$defs/point3"},
        "z_axis": {"$ref": "#/$defs/point3"}
      }
    },
    "face": {
      "type": "object",
      "required": ["id", "orientation", "surface", "uv_bounds", "wires"],
      "properties": {
        "id": {"type": "string"},
        "orientation": {"type": "integer"},
        "area": {"type": "number", "minimum": 0},
        "volume_contribution": {"type": "number"},
        "surface": {"type": "object"},
        "uv_bounds": {
          "type": "array",
          "items": {"type": "number"},
          "minItems": 4,
          "maxItems": 4
        },
        "wires": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["id", "orientation", "edges"],
            "properties": {
              "id": {"type": "string"},
              "orientation": {"type": "integer"},
              "edges": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "id",
                    "topology_edge_id",
                    "vertex_ids",
                    "orientation",
                    "curve"
                  ],
                  "properties": {
                    "id": {"type": "string"},
                    "topology_edge_id": {"type": "string"},
                    "vertex_ids": {
                      "type": "array",
                      "items": {"type": "string"},
                      "maxItems": 2
                    },
                    "orientation": {"type": "integer"},
                    "curve": {"type": "object"}
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}