<?php

declare(strict_types=1);

namespace Belevo\EnelixEMS;

use DateTimeImmutable;
use DateTimeZone;
use InvalidArgumentException;

require_once __DIR__ . '/Nachrichtenvertrag.php';
require_once __DIR__ . '/NetzfahrplanV4Planpruefung.php';
require_once __DIR__ . '/NetzfahrplanV4Rueckmeldung.php';

/** Pure correction of an ordinary Manager allocation. No commands or permissions.
 * The caller separately enforces licence, user consent and healthy model readiness.
 */
final class NetzfahrplanV4Regelung
{
    private static function number($value, string $label): float
    {
        if ((!is_int($value) && !is_float($value)) || !is_finite((float) $value) || abs($value) > 1.0e9) {
            throw new InvalidArgumentException($label . ': endlicher Zahlenwert erforderlich.');
        }
        return (float) $value;
    }

    private static function objectId($value): int
    {
        if (!is_int($value) || $value < 1 || $value > 99999) {
            throw new InvalidArgumentException('Eindeutige Instanzzuordnung erforderlich.');
        }
        return $value;
    }

    /** A legal interval or singleton is selected, never a gap between offers. */
    private static function offeredTarget(array $offers, float $desired, float $lower, float $upper): int
    {
        $best = null;
        foreach ($offers as $offer) {
            $from = is_int($offer) ? $offer : $offer['Von_W'];
            $until = is_int($offer) ? $offer : $offer['Bis_W'];
            $low = (int) ceil(max($lower, $from));
            $high = (int) floor(min($upper, $until));
            if ($low > $high) {
                continue;
            }
            $candidate = max($low, min($high, (int) $desired));
            if ($best === null || [abs($candidate - $desired), abs($candidate), $candidate]
                < [abs($best - $desired), abs($best), $best]) {
                $best = $candidate;
            }
        }
        if ($best === null || !Nachrichtenvertrag::enthaeltLeistungswert($offers, $best)) {
            throw new InvalidArgumentException('Kein angebotener Batteriesollwert innerhalb aller Schutzgrenzen.');
        }
        return $best;
    }

    /** Read-only readiness checks. Consumer synchronization and offers are checked at allocation time.
     * @return array{checked:array,feedback:array,preview:array}
     */
    public static function pruefen(
        array $envelope,
        string $installationId,
        int $managerId,
        array $operation,
        array $actual,
        array $binding,
        int $now
    ): array {
        self::objectId($managerId);
        $batteryId = self::objectId($binding['batteryInstanceId'] ?? null);
        $assetId = $binding['assetId'] ?? null;
        $watchdog = $binding['watchdogEvidence'] ?? null;
        if ($now < 1 || $batteryId === $managerId
            || !is_string($assetId) || $assetId === '' || strlen($assetId) > 100
            || !is_string($watchdog) || strlen(trim($watchdog)) < 8 || strlen($watchdog) > 256
            || strcasecmp(trim($watchdog), 'explicit_test_plant_watchdog_waiver') === 0) {
            throw new InvalidArgumentException('Batteriezuordnung oder Geraete-Watchdog fehlen.');
        }
        foreach (['installationId' => $installationId, 'managerId' => $managerId] as $key => $value) {
            if (isset($binding[$key]) && $binding[$key] !== $value) {
                throw new InvalidArgumentException('Widerspruechliche lokale Anlagenzuordnung.');
            }
            $binding[$key] = $value;
        }
        if (!is_array($envelope['response'] ?? null) || !is_int($envelope['receivedAt'] ?? null)
            || !is_array($operation['batteries'] ?? null)
            || array_keys($operation['batteries']) !== array_keys(array_values($operation['batteries']))
            || count($operation['batteries']) !== 1 || ($operation['batteries'][0]['id'] ?? null) !== $assetId
            || count($actual) !== 1 || !array_key_exists($assetId, $actual)
            || array_key_exists('localPredictedOtherDeltaW', $operation)) {
            throw new InvalidArgumentException('Vollstaendiger unveraenderter Einzelbatterie-Kontext erforderlich.');
        }
        $feedback = $operation['localFeedback'][$assetId] ?? [];
        if (!is_array($feedback)) {
            throw new InvalidArgumentException('Bestaetigte physische Batterierueckmeldung fehlt.');
        }
        NetzfahrplanV4Rueckmeldung::requireTrial($feedback, $binding, $now);
        if (($feedback['estimated'] ?? null) !== false || ($feedback['separatelyMeasured'] ?? null) !== true
            || abs(self::number($actual[$assetId], 'Batterie-Istleistung') - $feedback['batteryW']) > 0.000001
            || abs(self::number($operation['gridW'] ?? null, 'Netz-Istleistung') - $feedback['gridW']) > 0.001) {
            throw new InvalidArgumentException('Direkt gemessene Batterie- und Netzleistung aus derselben Aufnahme erforderlich.');
        }
        $checked = NetzfahrplanV4Planpruefung::pruefen(
            $envelope['response'], $installationId, $operation, $now, $envelope['receivedAt']
        );
        $quality = $checked['plan']['inputQuality'] ?? [];
        if (($quality['loadBasis'] ?? null) !== 'base_load'
            || !is_string($quality['accountingEvidenceId'] ?? null) || strlen($quality['accountingEvidenceId']) < 8) {
            throw new InvalidArgumentException('Nachvollziehbare physische Verbrauchsbilanz fehlt.');
        }
        $preview = NetzfahrplanV4Planpruefung::vorschau($checked, $operation, $actual, $now);
        if ($preview['unmetGridLimitW'] > 1) {
            throw new InvalidArgumentException('Netzgrenze durch Batterie allein nicht erreichbar.');
        }
        return ['checked' => $checked, 'feedback' => $feedback, 'preview' => $preview];
    }

    /** @return array{allocation:array,report:array} */
    public static function korrigieren(
        array $envelope,
        string $installationId,
        int $managerId,
        array $operation,
        array $actual,
        array $allocation,
        array $consumers,
        bool $synchronized,
        array $binding,
        int $now
    ): array {
        $verified = self::pruefen($envelope, $installationId, $managerId, $operation, $actual, $binding, $now);
        $checked = $verified['checked'];
        $feedback = $verified['feedback'];
        $batteryId = $binding['batteryInstanceId'];
        $assetId = $binding['assetId'];
        if (!$synchronized || !is_array($allocation['Sollwerte'] ?? null)
            || !array_key_exists($batteryId, $allocation['Sollwerte'])) {
            throw new InvalidArgumentException('Verbraucher nicht synchronisiert oder Batterie nicht in Zuteilung.');
        }
        if (array_keys($consumers) !== array_keys(array_values($consumers)) || count($consumers) > 500) {
            throw new InvalidArgumentException('Ungueltige Verbraucherliste.');
        }
        $byId = [];
        foreach ($consumers as $consumer) {
            if (!is_array($consumer) || !is_array($consumer['Daten'] ?? null)) {
                throw new InvalidArgumentException('Verbraucherdaten fehlen.');
            }
            $id = self::objectId($consumer['InstanzID'] ?? null);
            if (isset($byId[$id])) {
                throw new InvalidArgumentException('Doppelte Verbraucherzuordnung.');
            }
            Nachrichtenvertrag::pruefeVerbraucherdaten($consumer['Daten']);
            $d = $consumer['Daten'];
            if ($d['Kopf']['AbsenderID'] !== $id || $d['Kopf']['EmpfaengerID'] !== $managerId
                || $d['Kopf']['Zeitpunkt'] > $now || $now - $d['Kopf']['Zeitpunkt'] > 60) {
                throw new InvalidArgumentException('Verbrauchermeldung falsch zugeordnet oder veraltet.');
            }
            $byId[$id] = $d;
        }
        $battery = $byId[$batteryId] ?? null;
        if ($battery === null || !$battery['Verfuegbar'] || !$battery['AenderungMoeglich']) {
            throw new InvalidArgumentException('Batterie fehlt oder bietet keine Aenderung an.');
        }
        $delta = 0.0;
        foreach ($allocation['Sollwerte'] as $id => $target) {
            if (!is_int($id) || !isset($byId[$id]) || !is_int($target)) {
                throw new InvalidArgumentException('Sollwert ohne eindeutigen Verbraucher.');
            }
            if ($id === $batteryId) {
                continue;
            }
            if ($byId[$id]['Leistungsquelle'] !== Nachrichtenvertrag::LEISTUNGSQUELLE_GEMESSEN) {
                throw new InvalidArgumentException('Istleistung anderer zugeteilter Verbraucher muss gemessen sein.');
            }
            $delta += self::number($target, 'Anderer Sollwert') - self::number($byId[$id]['Istleistung_W'], 'Andere Istleistung');
        }
        $delta = self::number($delta, 'Andere Verbraucherabweichung');
        $operation['gridW'] = self::number($feedback['gridW'] + $delta, 'Prognostizierte Netzleistung');
        $preview = NetzfahrplanV4Planpruefung::vorschau($checked, $operation, $actual, $now);
        if ($preview['unmetGridLimitW'] > 1) {
            throw new InvalidArgumentException('Netzgrenze durch Batterie allein nicht erreichbar.');
        }
        $lower = -self::number($preview['maxDischargeW'] ?? null, 'Vorschau-Entladegrenze');
        $upper = self::number($preview['maxChargeW'] ?? null, 'Vorschau-Ladegrenze');
        $desired = self::number($preview['previewBatteryW'], 'Vorschau-Sollwert');
        $residual = $operation['gridW'] - $actual[$assetId];
        $import = $operation['limits']['importW'];
        $export = $operation['limits']['exportW'];
        $month = (int) (new DateTimeImmutable('@' . $now))->setTimezone(new DateTimeZone('Europe/Zurich'))->format('n');
        $monthly = $operation['limits']['managerMonthLimitsW'][$month] ?? null;
        foreach ([$monthly, $checked['point']['importLimitW']] as $limit) {
            if ($limit !== null) {
                $import = $import === null ? $limit : min($import, $limit);
            }
        }
        if ($checked['point']['exportLimitW'] !== null) {
            $export = $export === null ? $checked['point']['exportLimitW'] : min($export, $checked['point']['exportLimitW']);
        }
        if ($import !== null) {
            $upper = min($upper, $import - $residual);
        }
        if ($export !== null) {
            $lower = max($lower, -$export - $residual);
        }
        // An offer gap must not turn hold into charging or reverse the computed intent.
        if ($desired >= 0) {
            $lower = max($lower, 0.0);
        }
        if ($desired <= 0) {
            $upper = min($upper, 0.0);
        }
        $target = self::offeredTarget($battery['Leistungswerte_W'], $desired, $lower, $upper);
        $old = self::number($allocation['Sollwerte'][$batteryId], 'Bisheriger Batteriesollwert');
        $allocation['Sollwerte'][$batteryId] = $target;
        if (array_key_exists('Restabweichung_W', $allocation)) {
            $allocation['Restabweichung_W'] = (int) (self::number($allocation['Restabweichung_W'], 'Restabweichung') - ($target - $old));
        }
        return ['allocation' => $allocation, 'report' => [
            'status' => 'allocation_corrected', 'installationId' => $installationId, 'managerId' => $managerId,
            'batteryInstanceId' => $batteryId, 'assetId' => $assetId, 'planId' => $checked['plan']['planId'],
            'checkedAt' => gmdate('c', $now), 'stepValidUntil' => $checked['point']['validUntil'],
            'targetW' => $target, 'gridTargetW' => $preview['gridTargetW'], 'expectedGridW' => $residual + $target,
            'otherConsumerPredictedDeltaW' => $delta, 'physicalResponseVerified' => false,
        ]];
    }
}