// MGC planner — real-time CONVERGENCE diagnostic.
//
// Where planner-rendezvous.integration.test.js intercepts _fireCommand to
// only assert schedule SHAPE, this test lets the executor REALLY run on
// real pumps with non-zero startup/warmup times, and asks two questions:
//
//   (a) does sum-of-pump-flows converge to the demand setpoint?
//   (b) do all pumps reach their individual flow target at roughly the
//       same wall-clock instant (the rendezvous)?
//
// Realistic scenario: ONE pump already operational, TWO pumps idle. A new
// demand requires (i) the two idle pumps to start (slow, ~3.5s) AND (ii)
// the running pump to retarget. Per the planner code, only flow-DECREASING
// moves get delayed to land at t*; flow-INCREASING moves on running pumps
// fire at tick 0 and land at their own eta. So the running pump's landing
// time should NOT match the two idle pumps unless its target equals its
// current flow (an unusual coincidence). This test surfaces that.

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

const MachineGroup = require('../../src/specificClass');
const Machine = require('../../../rotatingMachine/src/specificClass');

const HEAD_MBAR_UP = 0;
const HEAD_MBAR_DOWN = 1100;
const N_PUMPS = 3;

const LOG_DEBUG = process.env.LOG_DEBUG === '1';
const logCfg = { enabled: LOG_DEBUG, logLevel: LOG_DEBUG ? 'debug' : 'error' };

const stateConfig = {
    general: { logging: logCfg },
    state: { current: 'idle' },
    movement: { mode: 'staticspeed', speed: 200, maxSpeed: 200, interval: 50 },
    // REAL ladder times — this is the whole point of the test.
    time: { starting: 1, warmingup: 2, stopping: 1, coolingdown: 2 },
};

function machineConfig(id) {
    return {
        general: { logging: logCfg, name: id, id, unit: 'm3/h' },
        functionality: { softwareType: 'machine', role: 'rotationaldevicecontroller' },
        asset: { model: 'hidrostal-H05K-S03R', unit: 'm3/h' },
        mode: {
            current: 'auto',
            allowedActions: { auto: ['execsequence', 'execmovement', 'flowmovement', 'statuscheck'] },
            allowedSources: { auto: ['parent', 'GUI'] },
        },
        sequences: {
            startup:       ['starting', 'warmingup', 'operational'],
            shutdown:      ['stopping', 'coolingdown', 'idle'],
            emergencystop: ['emergencystop', 'off'],
        },
    };
}

function groupConfig() {
    return {
        general: { logging: logCfg, name: 'mgc', id: 'mgc' },
        functionality: { softwareType: 'machinegroup', role: 'groupcontroller', positionVsParent: 'atEquipment' },
        mode: { current: 'optimalcontrol' },
    };
}

function pctToCanonical(mgc, pct) {
    if (pct < 0) return -1;
    const dt = mgc.calcDynamicTotals();
    return mgc.interpolation.interpolate_lin_single_point(pct, 0, 100, dt.flow.min, dt.flow.max);
}

const NON_RUNNING = new Set(['idle', 'off', 'stopping', 'coolingdown', 'emergencystop']);
function pumpFlow_m3h(pump) {
    const state = pump.state.getCurrentState();
    if (NON_RUNNING.has(state)) return 0;
    return Number(pump.predictFlow?.outputY ?? 0) * 3600;
}

function buildGroup() {
    const mgc = new MachineGroup(groupConfig());
    const ids = Array.from({ length: N_PUMPS }, (_, i) => `pump_${String.fromCharCode(97 + i)}`);
    const pumps = ids.map((id) => new Machine(machineConfig(id), stateConfig));
    for (const m of pumps) {
        m.updateMeasuredPressure(HEAD_MBAR_UP,   'upstream',   { timestamp: Date.now(), unit: 'mbar', childName: 'up', childId: `up-${m.config.general.id}` });
        m.updateMeasuredPressure(HEAD_MBAR_DOWN, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'dn', childId: `dn-${m.config.general.id}` });
        mgc.childRegistrationUtils.registerChild(m, 'downstream');
    }
    mgc.calcAbsoluteTotals();
    mgc.calcDynamicTotals();
    return { mgc, pumps };
}

const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

// Sample per-pump flow at fixed intervals and return a trajectory: an array
// of {tMs, perPump:[...], sum}.
async function sampleFlows(pumps, durationMs, intervalMs = 200) {
    const t0 = Date.now();
    const out = [];
    while (Date.now() - t0 < durationMs) {
        const perPump = pumps.map(pumpFlow_m3h);
        out.push({ tMs: Date.now() - t0, perPump, sum: perPump.reduce((a, b) => a + b, 0) });
        await sleep(intervalMs);
    }
    return out;
}

// Find the wall-clock instant (in ms from t0) at which a given series
// REACHES and STAYS within `tol` of `target` for the rest of the run. If
// never reached, returns null.
function arrivalTimeMs(series, target, tol) {
    for (let i = 0; i < series.length; i++) {
        const v = series[i];
        if (Math.abs(v - target) <= tol) {
            // require it to stay close
            let stayed = true;
            for (let j = i + 1; j < series.length; j++) {
                if (Math.abs(series[j] - target) > tol * 1.5) { stayed = false; break; }
            }
            if (stayed) return i;
        }
    }
    return null;
}

function printTrace(label, traj, demand_m3h) {
    console.log(`\n${label}  (demand=${demand_m3h.toFixed(1)} m³/h)`);
    const head = ['  t(s)'.padStart(7), 'pump_a'.padStart(8), 'pump_b'.padStart(8), 'pump_c'.padStart(8), 'Σ m³/h'.padStart(8), 'err'.padStart(7)];
    console.log(head.join(' '));
    console.log('─'.repeat(head.join(' ').length));
    for (const s of traj) {
        const err = s.sum - demand_m3h;
        console.log([
            (s.tMs / 1000).toFixed(2).padStart(7),
            s.perPump[0].toFixed(1).padStart(8),
            s.perPump[1].toFixed(1).padStart(8),
            s.perPump[2].toFixed(1).padStart(8),
            s.sum.toFixed(1).padStart(8),
            err.toFixed(1).padStart(7),
        ].join(' '));
    }
}

// ── The diagnostic ──────────────────────────────────────────────────────

test('planner-convergence: mixed-state dispatch — sum reaches demand AND lands together', async () => {
    const { mgc, pumps } = buildGroup();
    const dyn = mgc.calcDynamicTotals();
    const flowMin_m3h = dyn.flow.min * 3600;
    const flowMax_m3h = dyn.flow.max * 3600;
    console.log(`\nStation envelope at head ${HEAD_MBAR_DOWN} mbar (${N_PUMPS} pumps): ${flowMin_m3h.toFixed(1)} .. ${flowMax_m3h.toFixed(1)} m³/h`);

    // Phase 1: bring pump_a (only) to operational at a low setpoint via a
    // direct child command. This bypasses the optimizer and gives us a
    // deterministic mixed state: 1 running, 2 idle. We then drive a global
    // demand to ramp up — the planner must coordinate one in-flight retarget
    // with two startups.
    const pumpA = pumps[0];
    await pumpA.handleInput('parent', 'execsequence', 'startup');
    // wait for warmup to complete
    for (let i = 0; i < 200 && pumpA.state.getCurrentState() !== 'operational'; i++) await sleep(50);
    assert.equal(pumpA.state.getCurrentState(), 'operational', 'pre-condition: pump_a should be operational');

    // Put pump_a at ~30% of its per-pump flow range. This guarantees the
    // optimizer's later combination will want pump_a to MOVE (either up to
    // share work with the new pumps, or down to balance them) — either
    // direction surfaces a rendezvous concern.
    const sample = pumpA.groupPredictFlow ?? pumpA.predictFlow;
    const perPumpMin_m3h = sample.currentFxyYMin * 3600;
    const perPumpMax_m3h = sample.currentFxyYMax * 3600;
    const initialFlow_m3h = perPumpMin_m3h + 0.30 * (perPumpMax_m3h - perPumpMin_m3h);
    await pumpA.handleInput('parent', 'flowmovement', initialFlow_m3h);
    await sleep(500); // let pump_a settle

    const initialSnap = pumps.map((p) => ({ state: p.state.getCurrentState(), q: pumpFlow_m3h(p) }));
    console.log('\nInitial state (1 running, 2 idle):');
    for (let i = 0; i < pumps.length; i++) {
        console.log(`  ${pumps[i].config.general.id}: ${initialSnap[i].state.padEnd(13)} Q=${initialSnap[i].q.toFixed(1)} m³/h`);
    }
    assert.equal(initialSnap[0].state, 'operational', 'pump_a operational at start');
    assert.equal(initialSnap[1].state, 'idle', 'pump_b idle at start');
    assert.equal(initialSnap[2].state, 'idle', 'pump_c idle at start');

    // Phase 2: drive 90% demand — needs all 3 pumps.
    const demandPct = 90;
    const demand_m3s = pctToCanonical(mgc, demandPct);
    const demand_m3h = demand_m3s * 3600;
    console.log(`\nDispatching ${demandPct}% → ${demand_m3h.toFixed(1)} m³/h demand…`);

    // Fire-and-don't-wait so we can sample DURING the move.
    mgc.handleInput('parent', demand_m3s).catch(() => {});

    // Give the dispatcher a microtask + tick to plan, then dump the
    // schedule so we can see WHAT the planner produced (vs. what the
    // executor actually does).
    await sleep(60);
    const sched = mgc.movementExecutor.schedule();
    console.log(`\nPlanner schedule (tStar=${sched?.tStarS?.toFixed(2)}s, ${sched?.commands?.length} cmds):`);
    for (const c of (sched?.commands || [])) {
        console.log(`  ${c.machineId.padEnd(8)} ${c.action.padEnd(13)} ${c.sequence ?? ('flow=' + (c.flow?.toFixed(1) ?? 'n/a')).padEnd(12)}  fireAtTickN=${c.fireAtTickN}  eta=${c.eta?.toFixed(2)}s`);
    }

    // Sample for 8 seconds at 200 ms — long enough for tStar ≈ 3.5 s + ramp.
    const traj = await sampleFlows(pumps, 8000, 200);

    printTrace('Per-pump flow trajectory', traj, demand_m3h);

    // ── Question (a): does sum-of-flows converge to demand? ────────────
    const finalSum = traj[traj.length - 1].sum;
    const tolAbs = demand_m3h * 0.05; // 5% tolerance
    console.log(`\nFinal ΣQ = ${finalSum.toFixed(1)} m³/h vs demand ${demand_m3h.toFixed(1)} m³/h  (tol ±${tolAbs.toFixed(1)})`);
    assert.ok(
        Math.abs(finalSum - demand_m3h) <= tolAbs,
        `(a) CONVERGENCE FAILED: final ΣQ=${finalSum.toFixed(1)} m³/h, demand=${demand_m3h.toFixed(1)} m³/h, err=${(finalSum - demand_m3h).toFixed(1)} m³/h (>${tolAbs.toFixed(1)})`,
    );

    // ── Question (b): same-time landing? ───────────────────────────────
    //
    // For each pump, find when its flow first reached a stable value (its
    // own steady-state target). Compare the spread across the three pumps:
    // if they "land together", all arrival indices are within ~1 sample.
    const sampleTargets = pumps.map((_, i) => {
        // Use the LAST sample's flow as that pump's actual landing value.
        // We're measuring "when did this pump stop moving" not "did it hit
        // some externally-specified target" — that's what same-time-landing
        // is about.
        return traj[traj.length - 1].perPump[i];
    });
    const arrivalIdx = pumps.map((_, i) => {
        const series = traj.map((s) => s.perPump[i]);
        const tgt = sampleTargets[i];
        const tol = Math.max(2.0, Math.abs(tgt) * 0.05); // 5% or 2 m³/h, whichever larger
        return arrivalTimeMs(series, tgt, tol);
    });
    console.log('\nArrival index per pump (sample # where flow stabilises within 5%):');
    for (let i = 0; i < pumps.length; i++) {
        const idx = arrivalIdx[i];
        const t = idx == null ? 'NEVER' : `${(traj[idx].tMs / 1000).toFixed(2)} s`;
        console.log(`  ${pumps[i].config.general.id}: idx=${idx}, t=${t}, finalQ=${sampleTargets[i].toFixed(1)} m³/h`);
    }
    const validIdx = arrivalIdx.filter((x) => x != null);
    assert.equal(validIdx.length, N_PUMPS, '(b) one or more pumps never landed on a stable flow');

    const spreadSamples = Math.max(...validIdx) - Math.min(...validIdx);
    const spreadMs = spreadSamples * 200;
    console.log(`Same-time-landing spread: ${spreadSamples} samples = ${spreadMs} ms`);
    // Loose bound: within 1.5 s. A bigger spread means the schedule did
    // NOT bring the pumps to their setpoints together.
    assert.ok(
        spreadMs <= 1500,
        `(b) SAME-TIME LANDING FAILED: pumps landed ${spreadMs} ms apart (>1500 ms tolerance). ` +
        `This means flow-INCREASING moves on running pumps land BEFORE startup pumps reach operational.`,
    );
});