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

const { makeMeasurementInstance } = require('../helpers/factories');

/**
 * Covers the scaling / offset / interpolation primitives and the min/max
 * tracking side effects that are not exercised by the existing
 * scaling-and-output test.
 */

test("applyOffset adds configured offset to the input", () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: false, inputMin: 0, inputMax: 1, absMin: 0, absMax: 100, offset: 7 },
  });
  assert.equal(m.applyOffset(10), 17);
  assert.equal(m.applyOffset(-3), 4);
});

test("interpolateLinear maps within range", () => {
  const m = makeMeasurementInstance();
  assert.equal(m.interpolateLinear(50, 0, 100, 0, 10), 5);
  assert.equal(m.interpolateLinear(0,  0, 100, 0, 10), 0);
  assert.equal(m.interpolateLinear(100, 0, 100, 0, 10), 10);
});

test("interpolateLinear warns and returns input when ranges collapse", () => {
  const m = makeMeasurementInstance();
  // iMin == iMax -> invalid
  assert.equal(m.interpolateLinear(42, 0, 0, 0, 10), 42);
  // oMin > oMax -> invalid
  assert.equal(m.interpolateLinear(42, 0, 100, 10, 0), 42);
});

test("constrain clamps below, inside, and above range", () => {
  const m = makeMeasurementInstance();
  assert.equal(m.constrain(-5, 0, 10), 0);
  assert.equal(m.constrain(5, 0, 10), 5);
  assert.equal(m.constrain(15, 0, 10), 10);
});

test("handleScaling falls back when inputRange is invalid", () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: true, inputMin: 5, inputMax: 5, absMin: 0, absMax: 10, offset: 0 },
  });
  // Before the call, inputRange is 0 (5-5). handleScaling should reset
  // inputMin/inputMax to defaults [0, 1] and still return a finite number.
  const result = m.handleScaling(0.5);
  assert.ok(Number.isFinite(result), `expected finite result, got ${result}`);
  assert.equal(m.config.scaling.inputMin, 0);
  assert.equal(m.config.scaling.inputMax, 1);
});

test("handleScaling constrains out-of-range inputs before interpolating", () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: true, inputMin: 0, inputMax: 100, absMin: 0, absMax: 10, offset: 0 },
  });
  // Input above inputMax is constrained to inputMax then mapped to absMax.
  assert.equal(m.handleScaling(150), 10);
  // Input below inputMin is constrained to inputMin then mapped to absMin.
  assert.equal(m.handleScaling(-20), 0);
});

test("calculateInput updates raw min/max from the unfiltered input", () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: false, inputMin: 0, inputMax: 1, absMin: 0, absMax: 1000, offset: 0 },
    smoothing: { smoothWindow: 1, smoothMethod: 'none' },
  });
  m.calculateInput(10);
  m.calculateInput(30);
  m.calculateInput(5);
  assert.equal(m.totalMinValue, 5);
  assert.equal(m.totalMaxValue, 30);
});

test("updateOutputPercent falls back to observed min/max when processRange <= 0", () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: false, inputMin: 0, inputMax: 1, absMin: 5, absMax: 5, offset: 0 },
    smoothing: { smoothWindow: 1, smoothMethod: 'none' },
  });
  // processRange starts at 0 so updateOutputPercent uses totalMinValue/Max.
  m.totalMinValue = 0;
  m.totalMaxValue = 100;
  const pct = m.updateOutputPercent(50);
  // Linear interp: (50 - 0) / (100 - 0) * 100 = 50.
  assert.ok(Math.abs(pct - 50) < 0.01, `expected ~50, got ${pct}`);
});

test("updateOutputAbs only emits MeasurementContainer update when value changes", async () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: false, inputMin: 0, inputMax: 1, absMin: 0, absMax: 100, offset: 0 },
    smoothing: { smoothWindow: 1, smoothMethod: 'none' },
  });
  let emitCount = 0;
  // MeasurementContainer normalizes positions to lowercase, so the
  // event name uses 'atequipment' not the camelCase config value.
  m.measurements.emitter.on('pressure.measured.atequipment', () => { emitCount += 1; });

  m.calculateInput(10);
  await new Promise((r) => setImmediate(r));
  m.calculateInput(10);  // same value -> no emit
  await new Promise((r) => setImmediate(r));
  m.calculateInput(20);  // new value -> emit
  await new Promise((r) => setImmediate(r));

  assert.equal(emitCount, 2, `expected 2 emits (two distinct values), got ${emitCount}`);
});

test("getOutput returns the full tracked state object", () => {
  const m = makeMeasurementInstance({
    scaling: { enabled: false, inputMin: 0, inputMax: 1, absMin: 0, absMax: 100, offset: 0 },
    smoothing: { smoothWindow: 1, smoothMethod: 'none' },
  });
  m.calculateInput(15);
  const out = m.getOutput();
  assert.equal(typeof out.mAbs, 'number');
  assert.equal(typeof out.mPercent, 'number');
  assert.equal(typeof out.totalMinValue, 'number');
  assert.equal(typeof out.totalMaxValue, 'number');
  assert.equal(typeof out.totalMinSmooth, 'number');
  assert.equal(typeof out.totalMaxSmooth, 'number');
});