const test = require('node:test');
const assert = require('node:assert/strict');
const { MeasurementContainer, POSITIONS } = require('generalFunctions');
const GroupOperatingPoint = require('../../src/groupOps/groupOperatingPoint');

const unitPolicy = {
    canonical: { pressure: 'Pa', flow: 'm3/s', power: 'W', temperature: 'K' },
    output:    { pressure: 'Pa', flow: 'm3/s', power: 'W', temperature: 'K' },
};

const silentLogger = { debug() {}, info() {}, warn() {}, error() {} };

function makeContainer() {
    return new MeasurementContainer({
        defaultUnits:   unitPolicy.output,
        preferredUnits: unitPolicy.output,
        canonicalUnits: unitPolicy.canonical,
        storeCanonical: true,
        autoConvert: true,
    });
}

function makeMachine(id, pressures = {}) {
    // pressures: { down?: Pa, up?: Pa }  — written into a real container
    const m = {
        config: { general: { id } },
        measurements: makeContainer(),
        setGroupOperatingPointCalls: [],
        setGroupOperatingPoint(down, up) {
            this.setGroupOperatingPointCalls.push({ down, up });
        },
    };
    const now = Date.now();
    if (pressures.down != null) {
        m.measurements.type('pressure').variant('measured').position(POSITIONS.DOWNSTREAM).value(pressures.down, now, 'Pa');
    }
    if (pressures.up != null) {
        m.measurements.type('pressure').variant('measured').position(POSITIONS.UPSTREAM).value(pressures.up, now, 'Pa');
    }
    return m;
}

test('readChild returns value in requested unit when present', () => {
    const machines = {};
    const m = makeMachine('m1', { down: 150000 });
    machines[m.config.general.id] = m;
    const gop = new GroupOperatingPoint({ measurements: makeContainer(), machines, unitPolicy, logger: silentLogger });

    const v = gop.readChild(m, 'pressure', 'measured', POSITIONS.DOWNSTREAM, 'Pa');
    assert.equal(v, 150000);
});

test('readChild returns null when measurement missing', () => {
    const m = makeMachine('m1');
    const gop = new GroupOperatingPoint({ measurements: makeContainer(), machines: { m1: m }, unitPolicy, logger: silentLogger });

    const v = gop.readChild(m, 'pressure', 'measured', POSITIONS.UPSTREAM, 'Pa');
    assert.equal(v, null);
});

test("writeOwn writes to the group's measurements container", () => {
    const ownC = makeContainer();
    const gop = new GroupOperatingPoint({ measurements: ownC, machines: {}, unitPolicy, logger: silentLogger });

    gop.writeOwn('flow', 'predicted', POSITIONS.AT_EQUIPMENT, 0.1, 'm3/s');
    const v = ownC.type('flow').variant('predicted').position(POSITIONS.AT_EQUIPMENT).getCurrentValue('m3/s');
    assert.equal(v, 0.1);
});

test('writeOwn skips non-finite values', () => {
    const ownC = makeContainer();
    const gop = new GroupOperatingPoint({ measurements: ownC, machines: {}, unitPolicy, logger: silentLogger });

    gop.writeOwn('flow', 'predicted', POSITIONS.AT_EQUIPMENT, NaN, 'm3/s');
    const v = ownC.type('flow').variant('predicted').position(POSITIONS.AT_EQUIPMENT).getCurrentValue('m3/s');
    assert.equal(v, null);
});

test('equalize() pushes the worst-case header onto each machine when 3 pressures differ', () => {
    // No group header → max child downstream, min positive child upstream.
    // max(120k, 140k, 100k) = 140000, min(80k, 90k, 70k) = 70000.
    const machines = {
        a: makeMachine('a', { down: 120000, up: 80000 }),
        b: makeMachine('b', { down: 140000, up: 90000 }),
        c: makeMachine('c', { down: 100000, up: 70000 }),
    };
    const gop = new GroupOperatingPoint({ measurements: makeContainer(), machines, unitPolicy, logger: silentLogger });

    gop.equalize();

    for (const id of ['a', 'b', 'c']) {
        const last = machines[id].setGroupOperatingPointCalls.at(-1);
        assert.ok(last, `machine ${id} should have been called`);
        assert.equal(last.down, 140000);
        assert.equal(last.up,   70000);
    }
});

test('equalize() is a no-op when there is no pressure data', () => {
    const machines = { a: makeMachine('a'), b: makeMachine('b') };
    const gop = new GroupOperatingPoint({ measurements: makeContainer(), machines, unitPolicy, logger: silentLogger });

    gop.equalize();

    assert.equal(machines.a.setGroupOperatingPointCalls.length, 0);
    assert.equal(machines.b.setGroupOperatingPointCalls.length, 0);
});

test('equalize() is a no-op when machines map is empty', () => {
    const gop = new GroupOperatingPoint({ measurements: makeContainer(), machines: {}, unitPolicy, logger: silentLogger });
    assert.doesNotThrow(() => gop.equalize());
});

test('equalize() falls back to direct fDimension when setGroupOperatingPoint is missing', () => {
    const m = {
        config: { general: { id: 'old' } },
        measurements: makeContainer(),
        predictFlow:  { fDimension: 0 },
        predictPower: { fDimension: 0 },
        predictCtrl:  { fDimension: 0 },
    };
    m.measurements.type('pressure').variant('measured').position(POSITIONS.DOWNSTREAM).value(200000, Date.now(), 'Pa');
    m.measurements.type('pressure').variant('measured').position(POSITIONS.UPSTREAM).value(100000, Date.now(), 'Pa');

    const gop = new GroupOperatingPoint({ measurements: makeContainer(), machines: { old: m }, unitPolicy, logger: silentLogger });
    gop.equalize();

    assert.equal(m.predictFlow.fDimension,  100000);
    assert.equal(m.predictPower.fDimension, 100000);
    assert.equal(m.predictCtrl.fDimension,  100000);
});