{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://xzbt.org/schemas/0.1/exhibit.json",
  "title": "XZBT Exhibit Schema 0.1",
  "description": "Authoritative structural schema for XZBT 0.1 declarative exhibits.",
  "type": "object",
  "required": [
    "xzbt",
    "meta"
  ],
  "additionalProperties": false,
  "properties": {
    "xzbt": {
      "type": "string",
      "const": "0.1",
      "description": "XZBT format specification version. Must be '0.1'."
    },
    "meta": {
      "type": "object",
      "description": "Exhibit metadata and descriptive properties.",
      "required": [
        "id",
        "name"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "pattern": "^[a-z][a-z0-9_-]*$",
          "maxLength": 64,
          "description": "Unique exhibit identifier."
        },
        "name": {
          "type": "string",
          "minLength": 1,
          "maxLength": 128,
          "description": "Human-readable exhibit title."
        },
        "version": {
          "type": "string",
          "description": "Exhibit author semantic version string."
        },
        "author": {
          "type": "string",
          "maxLength": 128,
          "description": "Author or entity attribution."
        },
        "description": {
          "type": "string",
          "maxLength": 1024,
          "description": "Short description of exhibit behavior and theme."
        },
        "license": {
          "type": "string",
          "description": "License or rights attribution."
        },
        "tags": {
          "type": "array",
          "maxItems": 16,
          "items": {
            "type": "string",
            "maxLength": 32
          }
        }
      }
    },
    "runtime": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "seed": {
          "oneOf": [
            {
              "type": "integer"
            },
            {
              "type": "string",
              "const": "random"
            }
          ],
          "description": "PRNG seed: integer for deterministic reproduction, or 'random'."
        }
      }
    },
    "parameters": {
      "type": "object",
      "description": "User-tunable exhibit parameters.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "$ref": "#/definitions/ParameterSpec"
        }
      },
      "additionalProperties": false
    },
    "state": {
      "type": "object",
      "description": "Simulation-owned runtime state variables.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "$ref": "#/definitions/StateSpec"
        }
      },
      "additionalProperties": false
    },
    "signals": {
      "type": "object",
      "description": "Read-only environmental and input signals.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "type": "object"
        }
      },
      "additionalProperties": false
    },
    "ui": {
      "type": "object",
      "description": "Generated UI grouping and presentation preferences.",
      "additionalProperties": true
    },
    "components": {
      "type": "object",
      "description": "Modular audio and visual reusable components.",
      "additionalProperties": false,
      "properties": {
        "audio": {
          "type": "object"
        },
        "visual": {
          "type": "object"
        }
      }
    },
    "visuals": {
      "type": "object",
      "description": "Procedural rendering systems, canvas, and cameras.",
      "additionalProperties": false,
      "properties": {
        "camera": {
          "type": "object"
        },
        "systems": {
          "type": "object"
        },
        "passes": {
          "type": "array"
        }
      }
    },
    "audio": {
      "type": "object",
      "description": "Synthesizer graphs, buses, and routing.",
      "additionalProperties": false,
      "properties": {
        "master": {
          "type": "object"
        },
        "buses": {
          "type": "object"
        },
        "recipes": {
          "type": "object"
        }
      }
    },
    "sounds": {
      "type": "object",
      "description": "One-shot sound event templates.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "type": "object"
        }
      },
      "additionalProperties": false
    },
    "cadence": {
      "type": "object",
      "description": "Procedural rhythm clocks and pulse pools.",
      "additionalProperties": false,
      "properties": {
        "clocks": {
          "type": "object"
        },
        "pools": {
          "type": "object"
        }
      }
    },
    "modulators": {
      "type": "object",
      "description": "Continuous LFOs, noise generators, and sample-and-hold signals.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "type": "object"
        }
      },
      "additionalProperties": false
    },
    "bindings": {
      "type": "array",
      "description": "Directed value propagation links.",
      "items": {
        "$ref": "#/definitions/BindingSpec"
      }
    },
    "events": {
      "type": "object",
      "description": "Discrete lifecycle and state change event triggers.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "type": "object"
        }
      },
      "additionalProperties": false
    },
    "scenarios": {
      "type": "object",
      "description": "Autonomous orchestrated scenarios and timelines.",
      "patternProperties": {
        "^[a-z][a-z0-9_-]*$": {
          "type": "object"
        }
      },
      "additionalProperties": false
    }
  },
  "definitions": {
    "ParameterSpec": {
      "type": "object",
      "required": [
        "type",
        "default"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "type": "string",
          "enum": [
            "number",
            "integer",
            "boolean",
            "string",
            "color",
            "enum"
          ]
        },
        "default": {},
        "min": {
          "type": "number"
        },
        "max": {
          "type": "number"
        },
        "step": {
          "type": "number",
          "exclusiveMinimum": 0
        },
        "values": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "label": {
          "type": "string",
          "maxLength": 128
        },
        "unit": {
          "type": "string",
          "maxLength": 16
        }
      }
    },
    "StateSpec": {
      "type": "object",
      "required": [
        "type",
        "initial"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "type": "string",
          "enum": [
            "number",
            "integer",
            "boolean",
            "string"
          ]
        },
        "initial": {},
        "min": {
          "type": "number"
        },
        "max": {
          "type": "number"
        }
      }
    },
    "BindingSpec": {
      "type": "object",
      "required": [
        "source",
        "target"
      ],
      "additionalProperties": false,
      "properties": {
        "source": {
          "type": "string",
          "description": "Source reference path (e.g. 'parameters.activity')."
        },
        "target": {
          "type": "string",
          "description": "Target reference path (e.g. 'audio.buses.ambient.gain')."
        },
        "scale": {
          "type": "number",
          "description": "Numeric source multiplier. Defaults to 1."
        },
        "offset": {
          "type": "number",
          "description": "Numeric offset applied after scaling. Defaults to 0."
        },
        "clamp": {
          "type": "array",
          "minItems": 2,
          "maxItems": 2,
          "items": {
            "type": "number"
          },
          "description": "Inclusive [minimum, maximum] clamp applied to the transformed binding value."
        },
        "smoothing": {
          "$ref": "#/definitions/DurationSpec",
          "description": "Optional smoothing low-pass duration."
        },
        "when": {
          "$ref": "#/definitions/ConditionSpec",
          "description": "Optional condition; defaults to true."
        }
      }
    },
    "ValueSpec": {
      "description": "Universal value expression (literal, reference, random, weighted choice, or operation).",
      "oneOf": [
        {
          "type": "number",
          "description": "Literal numeric constant."
        },
        {
          "type": "boolean",
          "description": "Literal boolean constant."
        },
        {
          "type": "string",
          "description": "Literal string or color constant."
        },
        {
          "type": "object",
          "required": [
            "ref"
          ],
          "additionalProperties": false,
          "properties": {
            "ref": {
              "type": "string",
              "pattern": "^[a-z][a-z0-9_-]*(\\.[a-z][a-z0-9_-]*)+$",
              "description": "Dot-separated reference path."
            }
          }
        },
        {
          "type": "object",
          "required": [
            "random"
          ],
          "additionalProperties": false,
          "properties": {
            "random": {
              "type": "object",
              "required": [
                "min",
                "max"
              ],
              "additionalProperties": false,
              "properties": {
                "min": {
                  "type": "number"
                },
                "max": {
                  "type": "number"
                },
                "integer": {
                  "type": "boolean"
                },
                "distribution": {
                  "type": "string",
                  "enum": [
                    "uniform",
                    "gaussian"
                  ]
                }
              }
            }
          }
        },
        {
          "type": "object",
          "required": [
            "choose"
          ],
          "additionalProperties": false,
          "properties": {
            "choose": {
              "type": "array",
              "minItems": 1,
              "items": {
                "type": "object",
                "required": [
                  "value",
                  "weight"
                ],
                "additionalProperties": false,
                "properties": {
                  "value": {},
                  "weight": {
                    "type": "number",
                    "exclusiveMinimum": 0
                  }
                }
              }
            }
          }
        },
        {
          "type": "object",
          "required": [
            "op",
            "args"
          ],
          "additionalProperties": false,
          "properties": {
            "op": {
              "type": "string",
              "enum": [
                "abs",
                "negate",
                "round",
                "floor",
                "ceil",
                "add",
                "subtract",
                "multiply",
                "divide",
                "min",
                "max",
                "clamp",
                "lerp"
              ]
            },
            "args": {
              "type": "array",
              "items": {
                "$ref": "#/definitions/ValueSpec"
              }
            }
          }
        }
      ]
    },
    "ConditionSpec": {
      "description": "Boolean condition expression (comparison, and, or, not).",
      "oneOf": [
        {
          "type": "object",
          "required": [
            "op",
            "left",
            "right"
          ],
          "additionalProperties": false,
          "properties": {
            "op": {
              "type": "string",
              "enum": [
                "eq",
                "ne",
                "gt",
                "gte",
                "lt",
                "lte"
              ]
            },
            "left": {
              "$ref": "#/definitions/ValueSpec"
            },
            "right": {
              "$ref": "#/definitions/ValueSpec"
            }
          }
        },
        {
          "type": "object",
          "required": [
            "and"
          ],
          "additionalProperties": false,
          "properties": {
            "and": {
              "type": "array",
              "minItems": 1,
              "items": {
                "$ref": "#/definitions/ConditionSpec"
              }
            }
          }
        },
        {
          "type": "object",
          "required": [
            "or"
          ],
          "additionalProperties": false,
          "properties": {
            "or": {
              "type": "array",
              "minItems": 1,
              "items": {
                "$ref": "#/definitions/ConditionSpec"
              }
            }
          }
        },
        {
          "type": "object",
          "required": [
            "not"
          ],
          "additionalProperties": false,
          "properties": {
            "not": {
              "$ref": "#/definitions/ConditionSpec"
            }
          }
        }
      ]
    },
    "DurationSpec": {
      "type": "string",
      "pattern": "^([0-9]+(\\.[0-9]+)?)(ms|s|m|h)$",
      "description": "Normalized duration literal string (e.g. '250ms', '4s', '1.5m', '1h')."
    }
  }
}