Graph Schema

-- The MOSFET is thermally coupled to the heatsink
MATCH (mosfet:DesignElement {name: 'Q1_MOSFET'})-[:THERMALLY_COUPLED_TO]->(heatsink:DesignElement {name: 'HS1'})

-- The MOSFET is electrically connected to the motor rail
MATCH (mosfet)-[:ELECTRICALLY_CONNECTED_TO]->(rail:DesignElement {name: 'VMOTOR_RAIL'})

-- The MOSFET is controlled by the MCU via PWM
MATCH (mosfet)-[:CONTROLLED_BY]->(mcu:DesignElement {name: 'MCU_STM32'})

-- The MCU firmware controls the PWM output
MATCH (mcu)-[:CONTROLLED_BY]->(pwm_driver:DesignElement {domain: 'firmware', name: 'pwm_driver'})

-- Core graph uniqueness
CREATE CONSTRAINT req_id IF NOT EXISTS FOR (r:Requirement) REQUIRE r.id IS UNIQUE;
CREATE CONSTRAINT bom_id IF NOT EXISTS FOR (b:BOMItem) REQUIRE b.id IS UNIQUE;
CREATE CONSTRAINT design_id IF NOT EXISTS FOR (d:DesignElement) REQUIRE d.id IS UNIQUE;
CREATE CONSTRAINT test_proc_id IF NOT EXISTS FOR (t:TestProcedure) REQUIRE t.id IS UNIQUE;
CREATE CONSTRAINT gate_id IF NOT EXISTS FOR (g:Gate) REQUIRE g.id IS UNIQUE;
CREATE CONSTRAINT session_id IF NOT EXISTS FOR (s:Session) REQUIRE s.id IS UNIQUE;

CREATE CONSTRAINT device_serial IF NOT EXISTS FOR (d:DeviceInstance) REQUIRE d.serialNumber IS UNIQUE;
CREATE CONSTRAINT twin_model_id IF NOT EXISTS FOR (t:TwinModel) REQUIRE t.id IS UNIQUE;
CREATE CONSTRAINT sim_run_id IF NOT EXISTS FOR (s:SimulationRun) REQUIRE s.id IS UNIQUE;

-- Digital Thread indexes
CREATE INDEX req_status IF NOT EXISTS FOR (r:Requirement) ON (r.status);
CREATE INDEX bom_lifecycle IF NOT EXISTS FOR (b:BOMItem) ON (b.lifecycle);
CREATE INDEX bom_mpn IF NOT EXISTS FOR (b:BOMItem) ON (b.mpn);
CREATE INDEX gate_type IF NOT EXISTS FOR (g:Gate) ON (g.type);
CREATE INDEX evidence_status IF NOT EXISTS FOR (e:Evidence) ON (e.status);

-- Twin Instance indexes
CREATE INDEX device_status IF NOT EXISTS FOR (d:DeviceInstance) ON (d.status);
CREATE INDEX device_model IF NOT EXISTS FOR (d:DeviceInstance) ON (d.twinModelId);
CREATE INDEX sim_run_type IF NOT EXISTS FOR (s:SimulationRun) ON (s.type);

MATCH path = (r:Requirement)-[:SATISFIED_BY]->(d:DesignElement)
             -[:MANUFACTURED_BY]->(b:BOMItem)
             -[:TESTED_BY]->(tp:TestProcedure)
             -[:PRODUCES]->(e:Evidence)
WHERE r.id = $requirementId
RETURN path

MATCH (g:Gate {type: 'EVT'})
OPTIONAL MATCH (risk:RiskItem)-[:BLOCKS]->(g)
WHERE risk.severity = 'critical'
OPTIONAL MATCH (r:Requirement {status: 'active'})
WHERE NOT (r)-[:SATISFIED_BY]->()
RETURN g, collect(risk) AS blockers, collect(r) AS unmetRequirements

MATCH (d:DeviceInstance)-[:INSTANCE_OF]->(tm:TwinModel {name: $modelName})
WHERE d.status = 'active'
OPTIONAL MATCH (d)<-[:FEEDS]-(ts:TelemetrySource)
OPTIONAL MATCH (sr:SimulationRun {instanceId: d.id})
WHERE sr.timestamp > datetime() - duration('P1D')
RETURN d.serialNumber, d.lastSyncAt, collect(ts.sensorType) AS sensors,
       collect(sr.results) AS recentSimulations