{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "ScenarioConfig",
  "description": "Root configuration for a simulation scenario.",
  "type": "object",
  "required": [
    "fluid"
  ],
  "properties": {
    "circuits": {
      "description": "Circuit configurations.",
      "default": [],
      "type": "array",
      "items": {
        "$ref": "#/definitions/CircuitConfig"
      }
    },
    "connections": {
      "description": "External connections between instance ports (and/or literal `component:port` endpoints). Resolved and routed into the appropriate circuit during flattening.",
      "default": [],
      "type": "array",
      "items": {
        "$ref": "#/definitions/EdgeConfig"
      }
    },
    "controls": {
      "description": "Steady-state control loops (co-solved saturated-PI controllers).",
      "default": [],
      "type": "array",
      "items": {
        "$ref": "#/definitions/ControlConfig"
      }
    },
    "fluid": {
      "description": "Fluid name (e.g., \"R134a\", \"R410A\", \"R744\").",
      "type": "string"
    },
    "fluid_backend": {
      "description": "Fluid backend to use (e.g., \"CoolProp\", \"Test\"). Defaults to \"Test\".",
      "default": null,
      "type": [
        "string",
        "null"
      ]
    },
    "instances": {
      "description": "Instantiations of `subsystems` templates. Each instance is expanded into concrete, name-prefixed components/edges in its target circuit.",
      "default": [],
      "type": "array",
      "items": {
        "$ref": "#/definitions/InstanceConfig"
      }
    },
    "metadata": {
      "description": "Optional metadata.",
      "default": null,
      "type": [
        "object",
        "null"
      ],
      "additionalProperties": true
    },
    "name": {
      "description": "Scenario name.",
      "default": null,
      "type": [
        "string",
        "null"
      ]
    },
    "schema_version": {
      "description": "Model IR schema version (`\"1\"` legacy flat graph, `\"2\"` adds controls/subsystems/instances/connections). Absent ⇒ `\"1\"`.",
      "default": "1",
      "type": "string"
    },
    "solver": {
      "description": "Solver configuration.",
      "default": {
        "max_iterations": 100,
        "strategy": "fallback",
        "timeout_ms": 0,
        "tolerance": 1e-6,
        "verbose": false
      },
      "allOf": [
        {
          "$ref": "#/definitions/SolverConfig"
        }
      ]
    },
    "subsystems": {
      "description": "Reusable subsystem templates (parameterized assemblies of components + internal edges, exposing a reduced external port set). Flattened into `circuits` at load time — the solver never sees the hierarchy.",
      "default": {},
      "type": "object",
      "additionalProperties": {
        "$ref": "#/definitions/SubsystemTemplate"
      }
    },
    "thermal_couplings": {
      "description": "Thermal couplings between circuits.",
      "default": [],
      "type": "array",
      "items": {
        "$ref": "#/definitions/ThermalCouplingConfig"
      }
    }
  },
  "definitions": {
    "ActuatorConfig": {
      "description": "Reference to a manipulated actuator on a component.",
      "type": "object",
      "required": [
        "component",
        "factor",
        "max",
        "min"
      ],
      "properties": {
        "component": {
          "description": "Name of the component carrying the actuator.",
          "type": "string"
        },
        "factor": {
          "description": "Calibration Z-factor to manipulate: `z_flow`, `z_dp`, `z_ua`, `z_power`, or `z_etav` (BOLT `Z_flow_suc`, `Z_dpc`, `Z_UA`, `Z_power`; legacy `f_*` names accepted).",
          "type": "string"
        },
        "initial": {
          "description": "Initial actuator value (nominal, e.g. 1.0).",
          "default": 1.0,
          "type": "number",
          "format": "double"
        },
        "max": {
          "description": "Upper bound for the actuator.",
          "type": "number",
          "format": "double"
        },
        "min": {
          "description": "Lower bound for the actuator.",
          "type": "number",
          "format": "double"
        }
      }
    },
    "CircuitConfig": {
      "description": "Configuration for a single circuit.",
      "type": "object",
      "required": [
        "components"
      ],
      "properties": {
        "components": {
          "description": "Components in this circuit.",
          "type": "array",
          "items": {
            "$ref": "#/definitions/ComponentConfig"
          }
        },
        "edges": {
          "description": "Edge connections between components.",
          "default": [],
          "type": "array",
          "items": {
            "$ref": "#/definitions/EdgeConfig"
          }
        },
        "id": {
          "description": "Circuit ID (default: 0).",
          "default": 0,
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        },
        "initial_state": {
          "description": "Initial state for edges.",
          "default": null,
          "anyOf": [
            {
              "$ref": "#/definitions/InitialStateConfig"
            },
            {
              "type": "null"
            }
          ]
        }
      }
    },
    "ComponentConfig": {
      "description": "Configuration for a component.",
      "type": "object",
      "required": [
        "name",
        "type"
      ],
      "properties": {
        "air_inlet_temp_c": {
          "description": "Air inlet temperature in Celsius.",
          "default": null,
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        },
        "condenser_bank": {
          "description": "Condenser bank spec identifier (used for creating multiple instances).",
          "default": null,
          "anyOf": [
            {
              "$ref": "#/definitions/CondenserBankConfig"
            },
            {
              "type": "null"
            }
          ]
        },
        "fan_speed": {
          "description": "Fan speed ratio (0.0 to 1.0).",
          "default": null,
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        },
        "n_air_exponent": {
          "description": "Air side heat transfer exponent.",
          "default": null,
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        },
        "name": {
          "description": "Component name for referencing in edges.",
          "type": "string"
        },
        "type": {
          "description": "Component type (e.g., \"Compressor\", \"Condenser\", \"Evaporator\", \"ExpansionValve\", \"HeatExchanger\").",
          "type": "string"
        },
        "ua_nominal_kw_k": {
          "description": "Nominal UA value (kW/K). Maps to ua_nominal_kw_k.",
          "default": null,
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        }
      },
      "additionalProperties": true
    },
    "CondenserBankConfig": {
      "description": "Configuration for a condenser bank (multi-circuit, multi-coil).",
      "type": "object",
      "required": [
        "circuits",
        "coils_per_circuit"
      ],
      "properties": {
        "circuits": {
          "description": "Number of circuits.",
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        },
        "coils_per_circuit": {
          "description": "Number of coils per circuit.",
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        }
      }
    },
    "ControlConfig": {
      "description": "A steady-state control loop declaration.\n\nCurrently supports the `SaturatedController` type: a saturated-PI loop with anti-windup that is co-solved inside the Newton system. It drives a measured plant output (`measure`) to `target` by manipulating an actuator factor (`actuator`) within `[min, max]` bounds.",
      "type": "object",
      "required": [
        "actuator",
        "id",
        "measure",
        "target"
      ],
      "properties": {
        "actuator": {
          "description": "The manipulated actuator.",
          "allOf": [
            {
              "$ref": "#/definitions/ActuatorConfig"
            }
          ]
        },
        "band": {
          "description": "Saturation band half-width `Q > 0`.",
          "default": 1.0,
          "type": "number",
          "format": "double"
        },
        "gain": {
          "description": "Loop gain `K` (sign must match actuator→output sensitivity).",
          "default": 1.0,
          "type": "number",
          "format": "double"
        },
        "id": {
          "description": "Unique identifier for this control loop.",
          "type": "string"
        },
        "measure": {
          "description": "The measured plant output to regulate.",
          "allOf": [
            {
              "$ref": "#/definitions/MeasureConfig"
            }
          ]
        },
        "smooth_eps": {
          "description": "If set, uses the C¹ smooth saturation with this `eps`; otherwise hard clamp.",
          "default": null,
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        },
        "target": {
          "description": "Target value for the measured output (SI units: W, K, Pa, kg/s).",
          "type": "number",
          "format": "double"
        },
        "type": {
          "description": "Controller type. Only `\"SaturatedController\"` is supported today.",
          "default": "SaturatedController",
          "type": "string"
        }
      }
    },
    "EdgeConfig": {
      "description": "Configuration for an edge between components.",
      "type": "object",
      "required": [
        "from",
        "to"
      ],
      "properties": {
        "from": {
          "description": "Source component and port (e.g., \"comp1:outlet\").",
          "type": "string"
        },
        "to": {
          "description": "Target component and port (e.g., \"cond1:inlet\").",
          "type": "string"
        }
      }
    },
    "InitialStateConfig": {
      "description": "Initial state configuration.",
      "type": "object",
      "properties": {
        "enthalpy_kj_kg": {
          "description": "Initial enthalpy in kJ/kg.",
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        },
        "pressure_bar": {
          "description": "Initial pressure in bar.",
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        },
        "temperature_k": {
          "description": "Initial temperature in Kelvin.",
          "type": [
            "number",
            "null"
          ],
          "format": "double"
        }
      }
    },
    "InstanceConfig": {
      "description": "An instantiation of a [`SubsystemTemplate`].",
      "type": "object",
      "required": [
        "name",
        "of"
      ],
      "properties": {
        "circuit": {
          "description": "Target circuit id the expanded components/edges are placed into (default 0).",
          "default": 0,
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        },
        "name": {
          "description": "Unique instance name; becomes the `\"{name}.\"` prefix on expanded components.",
          "type": "string"
        },
        "of": {
          "description": "Name of the template to instantiate (key in `subsystems`).",
          "type": "string"
        },
        "params": {
          "description": "Parameter overrides for this instance (override template defaults).",
          "default": {},
          "type": "object",
          "additionalProperties": true
        }
      }
    },
    "MeasureConfig": {
      "description": "Reference to a measurable component output.",
      "type": "object",
      "required": [
        "component",
        "output"
      ],
      "properties": {
        "component": {
          "description": "Name of the component whose output is measured.",
          "type": "string"
        },
        "output": {
          "description": "Output kind: one of `capacity`, `heatTransferRate`, `superheat`, `subcooling`, `saturationTemperature`, `massFlowRate`, `pressure`, `temperature`.",
          "type": "string"
        }
      }
    },
    "SolverConfig": {
      "description": "Solver configuration.",
      "type": "object",
      "properties": {
        "max_iterations": {
          "description": "Maximum iterations.",
          "default": 100,
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        },
        "strategy": {
          "description": "Solver strategy: \"newton\", \"picard\", or \"fallback\".",
          "default": "fallback",
          "type": "string"
        },
        "timeout_ms": {
          "description": "Timeout in milliseconds (0 = no timeout).",
          "default": 0,
          "type": "integer",
          "format": "uint64",
          "minimum": 0.0
        },
        "tolerance": {
          "description": "Convergence tolerance.",
          "default": 1e-6,
          "type": "number",
          "format": "double"
        },
        "verbose": {
          "description": "Enable verbose output.",
          "default": false,
          "type": "boolean"
        }
      }
    },
    "SubsystemTemplate": {
      "description": "A reusable subsystem template: a parameterized assembly of components and internal edges, exposing a reduced set of external ports.\n\nThis is Modelica-style `model` composition. Templates are declared once under `subsystems` and instantiated any number of times via `instances`, each with its own parameter overrides. At load time every instance is **flattened** into the flat `circuits/components/edges` graph (component names prefixed by `\"{instance}.\"`), so the solver and every downstream consumer are unchanged.\n\n# Parameter substitution Any component parameter whose JSON value is a string of the form `\"$name\"` is replaced by the resolved value of parameter `name` (instance override, falling back to the template default in `params`). Because `ua`, `secondary_*`, `isentropic_efficiency`, `t_cond_k`, … all flow through the component `params` catch-all, this covers essentially every physical knob.",
      "type": "object",
      "required": [
        "components"
      ],
      "properties": {
        "components": {
          "description": "Components inside the template (names are local to the template).",
          "type": "array",
          "items": {
            "$ref": "#/definitions/ComponentConfig"
          }
        },
        "edges": {
          "description": "Internal edges between the template's own components.",
          "default": [],
          "type": "array",
          "items": {
            "$ref": "#/definitions/EdgeConfig"
          }
        },
        "params": {
          "description": "Default parameter values, overridable per instance.",
          "default": {},
          "type": "object",
          "additionalProperties": true
        },
        "ports": {
          "description": "External ports: maps an exposed port name to an internal `\"component:port\"` endpoint. `connections` reference these as `\"{instance}.{external_port}\"`.",
          "default": {},
          "type": "object",
          "additionalProperties": {
            "type": "string"
          }
        }
      }
    },
    "ThermalCouplingConfig": {
      "description": "Thermal coupling configuration between two circuits.",
      "type": "object",
      "required": [
        "cold_circuit",
        "hot_circuit",
        "ua"
      ],
      "properties": {
        "cold_circuit": {
          "description": "Cold circuit ID.",
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        },
        "efficiency": {
          "description": "Heat exchanger efficiency (0.0 to 1.0).",
          "default": 0.95,
          "type": "number",
          "format": "double"
        },
        "hot_circuit": {
          "description": "Hot circuit ID.",
          "type": "integer",
          "format": "uint",
          "minimum": 0.0
        },
        "ua": {
          "description": "Thermal conductance in W/K.",
          "type": "number",
          "format": "double"
        }
      }
    }
  }
}