const test = require('node:test');
const assert = require('node:assert/strict');

const Machine = require('../../src/specificClass');
const { makeMachineConfig, makeStateConfig } = require('../helpers/factories');

test('getOutput contains all required fields in idle state', () => {
  const machine = new Machine(makeMachineConfig(), makeStateConfig());

  const output = machine.getOutput();

  // Core state fields
  assert.equal(output.state, 'idle');
  assert.ok('runtime' in output);
  assert.ok('ctrl' in output);
  assert.ok('moveTimeleft' in output);
  assert.ok('mode' in output);
  assert.ok('maintenanceTime' in output);

  // Efficiency fields
  assert.ok('cog' in output);
  assert.ok('NCog' in output);
  assert.ok('NCogPercent' in output);
  assert.ok('effDistFromPeak' in output);
  assert.ok('effRelDistFromPeak' in output);

  // Prediction health fields
  assert.ok('predictionQuality' in output);
  assert.ok('predictionConfidence' in output);
  assert.ok('predictionPressureSource' in output);
  assert.ok('predictionFlags' in output);

  // Pressure drift fields
  assert.ok('pressureDriftLevel' in output);
  assert.ok('pressureDriftSource' in output);
  assert.ok('pressureDriftFlags' in output);
});

test('getOutput flow drift fields appear after sufficient measured flow samples', async () => {
  const machine = new Machine(makeMachineConfig(), makeStateConfig());

  await machine.handleInput('parent', 'execSequence', 'startup');
  machine.updateMeasuredPressure(1000, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt' });
  await machine.handleInput('parent', 'execMovement', 50);

  // Provide multiple measured flow samples to trigger valid drift assessment
  const baseTime = Date.now();
  for (let i = 0; i < 12; i++) {
    machine.updateMeasuredFlow(100 + i, 'downstream', {
      timestamp: baseTime + (i * 1000),
      unit: 'm3/h',
      childId: 'flow-sensor',
      childName: 'FT-1',
    });
  }

  const output = machine.getOutput();

  // Drift fields should appear once enough samples provide a valid assessment
  if ('flowNrmse' in output) {
    assert.ok(typeof output.flowNrmse === 'number');
    assert.ok('flowDriftValid' in output);
  }
  // At minimum, prediction health fields should always be present
  assert.ok('predictionQuality' in output);
  assert.ok('predictionConfidence' in output);
});

test('getOutput prediction confidence is 0 in non-operational state', () => {
  const machine = new Machine(makeMachineConfig(), makeStateConfig());

  const output = machine.getOutput();

  assert.equal(output.predictionConfidence, 0);
});

test('getOutput prediction confidence reflects differential pressure', () => {
  const machine = new Machine(makeMachineConfig(), makeStateConfig({ state: { current: 'operational' } }));

  // Differential pressure → high confidence
  machine.updateMeasuredPressure(800, 'upstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt-up' });
  machine.updateMeasuredPressure(1200, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt-down' });

  const output = machine.getOutput();

  assert.ok(output.predictionConfidence >= 0.8, `Confidence ${output.predictionConfidence} should be >= 0.8 with differential pressure`);
  assert.equal(output.predictionPressureSource, 'differential');
});

test('getOutput values are in configured output units not canonical', () => {
  const machine = new Machine(makeMachineConfig(), makeStateConfig({ state: { current: 'operational' } }));

  machine.updateMeasuredPressure(1000, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt' });
  machine.updatePosition();

  const output = machine.getOutput();

  // Flow keys should contain values in m3/h (configured), not m3/s (canonical)
  // Predicted flow at minimum pressure should be in a reasonable m3/h range, not ~0.003 m3/s
  const flowKey = Object.keys(output).find(k => k.startsWith('flow.predicted.downstream'));
  if (flowKey) {
    const flowVal = output[flowKey];
    assert.ok(typeof flowVal === 'number', 'Flow output should be a number');
    // m3/h values are typically 0-300, m3/s values are 0-0.08
    // If in canonical units it would be very small
    if (flowVal > 0) {
      assert.ok(flowVal > 0.1, `Flow value ${flowVal} looks like canonical m3/s, should be m3/h`);
    }
  }
});

test('getOutput NCogPercent is correctly derived from NCog', () => {
  const machine = new Machine(makeMachineConfig(), makeStateConfig({ state: { current: 'operational' } }));

  machine.updateMeasuredPressure(1000, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt' });
  machine.updatePosition();

  const output = machine.getOutput();
  const expected = Math.round(output.NCog * 100 * 100) / 100;
  assert.equal(output.NCogPercent, expected, 'NCogPercent should be NCog * 100, rounded to 2 decimals');
});