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

// Local stub for groupCurves — replace once ../groupOps/groupCurves lands.
const groupCurves = {
    groupFlow: (m) => m.predictFlow,
    groupPower: (m) => m.predictPower,
    groupNCog: (m) => m.NCog ?? 0,
    groupCalcPower: (m, f) => m.inputFlowCalcPower(f),
};

const { validPumpCombinations, checkSpecialCases } =
    require('../../src/combinatorics/pumpCombinations');

function makeMachine({ id, state = 'off', mode = 'auto',
                       fMin = 0, fMax = 100, pMax = 100,
                       NCog = 0.5, validAction = true } = {}) {
    return {
        config: { general: { id } },
        state: { getCurrentState: () => state },
        currentMode: mode,
        NCog,
        predictFlow: { currentFxyYMin: fMin, currentFxyYMax: fMax },
        predictPower: { currentFxyYMin: 0, currentFxyYMax: pMax },
        inputFlowCalcPower: (flow) => flow * 0.5,
        isValidActionForMode: () => validAction,
    };
}

const POSITIONS = { DOWNSTREAM: 'downstream' };
const baseCtx = (extra = {}) => ({
    groupCurves,
    logger: { warn: () => {}, debug: () => {}, error: () => {} },
    readChildMeasurement: () => undefined,
    POSITIONS,
    unitPolicy: { canonical: { flow: 'm3/s' } },
    ...extra,
});

test('validPumpCombinations: 3 idle machines + Qd in range returns subsets that can deliver', () => {
    const machines = {
        a: makeMachine({ id: 'a', state: 'idle', fMin: 10, fMax: 50 }),
        b: makeMachine({ id: 'b', state: 'idle', fMin: 10, fMax: 50 }),
        c: makeMachine({ id: 'c', state: 'idle', fMin: 10, fMax: 50 }),
    };
    const combos = validPumpCombinations(machines, 40, baseCtx());
    assert.ok(combos.length > 0, 'expected at least one combination');
    // every combination must be able to deliver Qd
    for (const subset of combos) {
        const maxF = subset.reduce((s, id) => s + machines[id].predictFlow.currentFxyYMax, 0);
        const minF = subset.reduce((s, id) => s + machines[id].predictFlow.currentFxyYMin, 0);
        assert.ok(maxF >= 40);
        assert.ok(minF <= 40);
    }
});

test('validPumpCombinations: excludes machines in off/coolingdown/stopping/emergencystop', () => {
    const machines = {
        a: makeMachine({ id: 'a', state: 'off', fMin: 10, fMax: 50 }),
        b: makeMachine({ id: 'b', state: 'coolingdown', fMin: 10, fMax: 50 }),
        c: makeMachine({ id: 'c', state: 'stopping', fMin: 10, fMax: 50 }),
        d: makeMachine({ id: 'd', state: 'emergencystop', fMin: 10, fMax: 50 }),
        e: makeMachine({ id: 'e', state: 'idle', fMin: 10, fMax: 50 }),
    };
    const combos = validPumpCombinations(machines, 30, baseCtx());
    // Only "e" can be in a combination
    for (const subset of combos) {
        for (const id of subset) assert.equal(id, 'e');
    }
});

test('checkSpecialCases: reduces Qd by flow of manually controlled operational machines', () => {
    const machines = {
        a: makeMachine({ id: 'a', state: 'operational', mode: 'virtualControl' }),
        b: makeMachine({ id: 'b', state: 'idle' }),
    };
    const ctx = baseCtx({
        readChildMeasurement: (m, type, variant) => {
            if (m.config.general.id === 'a' && variant === 'measured') return 12;
            return undefined;
        },
    });
    const adjusted = checkSpecialCases(machines, 50, ctx);
    assert.equal(adjusted, 38);
});

test('validPumpCombinations: no machines returns empty array', () => {
    const combos = validPumpCombinations({}, 10, baseCtx());
    assert.deepEqual(combos, []);
});