<?php
declare(strict_types=1);

include_once __DIR__ . '/libs/vendor/autoload.php'; // TCPDF via Composer

class Abrechnung extends IPSModule
{
    public function Create()
    {
        parent::Create();

        // Eigenschaften
        $this->RegisterPropertyString('Users', '[]');
        $this->RegisterPropertyString('PowerMeters', '[]');
        $this->RegisterPropertyString('WaterMeters', '[]');
        $this->RegisterPropertyString('Tariffs', '[]');

        // Variablen
        $this->RegisterVariableInteger('FromDate', 'Startdatum', '~UnixTimestamp', 1);
        $this->RegisterVariableInteger('ToDate', 'Enddatum', '~UnixTimestamp', 2);
        $this->RegisterVariableString('LastResult', 'Letzte Abrechnung', '', 3);
        $this->EnableAction('FromDate');
        $this->EnableAction('ToDate');

        // Abrechnungs-Button
        $this->RegisterScript('StartBilling', 'Abrechnung starten', "<?php IPS_RequestAction(" . $this->InstanceID . ", 'StartBilling', ''); ?>");

        // 🧾 Media-Objekt für PDF-Ergebnis
        $this->RegisterMediaDocument('InvoicePDF', 'Letzte Rechnung', 'pdf');
    }

    public function ApplyChanges()
    {
        parent::ApplyChanges();
        IPS_LogMessage('Abrechnung', 'Modul geladen');
    }

    private function RegisterMediaDocument($Ident, $Name, $Extension, $Position = 0)
    {
        $mid = @IPS_GetObjectIDByIdent($Ident, $this->InstanceID);
        if ($mid === false) {
            $mid = IPS_CreateMedia(5); // 5 = Document
            IPS_SetParent($mid, $this->InstanceID);
            IPS_SetIdent($mid, $Ident);
            IPS_SetName($mid, $Name);
            IPS_SetPosition($mid, $Position);
            IPS_SetMediaFile($mid, 'media/' . $mid . '.' . $Extension, false);
            IPS_LogMessage('Abrechnung', 'Media-Datei erstellt: media/' . $mid . '.' . $Extension);
        }
    }

public function RequestAction($Ident, $Value)
{
    IPS_LogMessage('Abrechnung', "RequestAction: $Ident");

    switch ($Ident) {
        case 'FromDate':
        case 'ToDate':
            SetValue($this->GetIDForIdent($Ident), $Value);
            break;

        case 'StartBilling':
            IPS_LogMessage('Abrechnung', 'Starte Abrechnung...');
            try {
                $pdfContent = $this->GenerateInvoices();
                if ($pdfContent === false) {
                    IPS_LogMessage('Abrechnung', '❌ GenerateInvoices() lieferte false zurück');
                    echo "❌ Fehler bei der PDF-Erstellung (GenerateInvoices)";
                    return;
                }
                if ($pdfContent === null) {
                    IPS_LogMessage('Abrechnung', '❌ GenerateInvoices() gab null zurück');
                    echo "❌ Fehler bei der PDF-Erstellung (leer)";
                    return;
                }
                if (strlen($pdfContent) < 100) {
                    IPS_LogMessage('Abrechnung', '❌ PDF-Inhalt zu kurz: ' . strlen($pdfContent));
                    echo "❌ Fehler bei der PDF-Erstellung (leeres PDF)";
                    return;
                }

                $mediaID = $this->GetIDForIdent('InvoicePDF');
                if (!$mediaID) {
                    IPS_LogMessage('Abrechnung', '❌ Media-ID nicht gefunden');
                    echo "❌ Kein Media-Objekt vorhanden";
                    return;
                }

                IPS_SetMediaContent($mediaID, base64_encode($pdfContent));
                SetValue($this->GetIDForIdent('LastResult'), 'Abrechnung vom ' . date('d.m.Y H:i'));
                IPS_LogMessage('Abrechnung', '✅ Abrechnung erfolgreich gespeichert (' . strlen($pdfContent) . ' Bytes)');
                echo "✅ PDF erfolgreich erstellt.";

            } catch (Throwable $e) {
                IPS_LogMessage('Abrechnung', '💥 Exception in StartBilling: ' . $e->getMessage());
                echo "❌ Ausnahmefehler: " . $e->getMessage();
            }
            break;
    }
}


    // ====================== PDF-Logik ======================

public function GenerateInvoices()
{
    $from = GetValue($this->GetIDForIdent('FromDate'));
    $to   = GetValue($this->GetIDForIdent('ToDate'));

    IPS_LogMessage('Abrechnung', '🕒 Starte GenerateInvoices()');
    IPS_LogMessage('Abrechnung', 'Zeitraum von ' . date('d.m.Y H:i', $from) . ' bis ' . date('d.m.Y H:i', $to));

    $users   = json_decode($this->ReadPropertyString('Users'), true);
    $power   = json_decode($this->ReadPropertyString('PowerMeters'), true);
    $water   = json_decode($this->ReadPropertyString('WaterMeters'), true);
    $tariffs = json_decode($this->ReadPropertyString('Tariffs'), true);

    if (!class_exists('TCPDF')) {
        IPS_LogMessage('Abrechnung', '❌ TCPDF fehlt – prüfe libs/vendor/autoload.php');
        return false;
    }

    try {
        $pdf = new TCPDF('P', 'mm', 'A4', true, 'UTF-8', false);
        $pdf->SetCreator('IPSymcon Abrechnung');
        $pdf->SetMargins(15, 15, 15);
        $pdf->SetAutoPageBreak(true, 20);
        $pdf->SetFont('dejavusans', '', 10);

    foreach ($users as $user) {
        IPS_LogMessage('Abrechnung', '→ Erstelle Seite für Benutzer: ' . $user['name']);
        $pdf->AddPage();

        // 🔽 Hier fügst du den neuen HTML-Block ein:
        $html = "
        <h2>Rechnung für {$user['name']}</h2>
        <p>{$user['address']}<br>{$user['city']}</p>
        <table border='1' cellpadding='3' style='font-size:8px;'>
        <tr style='background-color:#e0e0e0;'>
            <th>Zähler</th>
            <th>Typ</th>
            <th>Startzeit</th>
            <th>Endzeit</th>
            <th>Zählerstand Start</th>
            <th>Zählerstand Ende</th>
            <th>Verbrauch</th>
            <th>Tarif (Rp)</th>
            <th>Kosten (CHF)</th>
        </tr>
        ";

        $total = 0.0;
        foreach ($power as $m) {
            if ($m['user_id'] != $user['id']) continue;
            $cost = $this->AddMeterToPDFRow($m, $tariffs, $from, $to, 'Strombezug');
            $html .= $cost['row'];
            $total += $cost['value'];
        }
        foreach ($water as $m) {
            if ($m['user_id'] != $user['id']) continue;
            $type = $m['meter_type'] ?? 'Warmwasser';
            $cost = $this->AddMeterToPDFRow($m, $tariffs, $from, $to, $type);
            $html .= $cost['row'];
            $total += $cost['value'];
        }

        $html .= "</table><h3>Gesamtsumme: " . number_format($total, 2) . " CHF</h3>";
        $pdf->writeHTML($html);
    }

        
        IPS_LogMessage('Abrechnung', '✅ PDF-Daten fertiggestellt');
        return $pdf->Output('Abrechnung.pdf', 'S');
        
    } catch (Throwable $e) {
        IPS_LogMessage('Abrechnung', '💥 Exception in TCPDF: ' . $e->getMessage());
        return false;
    }
}


    private function AddMeterToPDF($pdf, $meter, $tariffs, $from, $to, $type)
    {
        $start = $this->GetValueAt($meter['var_consumption'], $from);
        $end   = $this->GetValueAt($meter['var_consumption'], $to);
        if ($start === null || $end === null) return 0;

        $diff  = max(0, $end - $start);
        $tariffRp = $this->GetTariff($tariffs, $type, $from, $to);
        $cost  = ($tariffRp / 100) * $diff;

        $pdf->writeHTML("
            <tr>
                <td>{$meter['name']}</td>
                <td>$type</td>
                <td>$start</td>
                <td>$end</td>
                <td>$diff</td>
                <td>$tariffRp</td>
                <td>" . number_format($cost, 2) . "</td>
            </tr>", false, false, false, false, '');

        return $cost;
    }

    private function GetTariff(array $tariffs, string $type, int $from, int $to): float
    {
        foreach ($tariffs as $t) {
            $start = strtotime($t['start']);
            $end   = strtotime($t['end']);
            if ($from >= $start && $to <= $end && strtolower($t['unit_type']) == strtolower($type)) {
                return floatval($t['price']);
            }
        }
        // Kein passender Tarif gefunden
        return 0.0;
    }

private function GetValueAt(int $varId, int $timestamp, bool $nearestAfter = true)
{
    $archiveID = @IPS_GetInstanceListByModuleID('{43192F0B-135B-4CE7-A0A7-1475603F3060}')[0];
    if (!$archiveID || !IPS_VariableExists($varId)) {
        IPS_LogMessage('Abrechnung', "❌ Variable $varId oder Archiv $archiveID nicht gefunden");
        return null;
    }

    $maxDays = 365;     // maximal 1 Jahr suchen
    $stepDays = 30;     // in 30-Tage-Blöcken durchsuchen
    $valueFound = null;

    if ($nearestAfter) {
        // 🔹 Suche den ersten Wert NACH dem gewünschten Zeitpunkt
        for ($offset = 0; $offset < $maxDays; $offset += $stepDays) {
            $from = $timestamp + $offset * 86400;
            $to   = $from + $stepDays * 86400;
            $values = @AC_GetLoggedValues($archiveID, $varId, $from, $to, 0);
            if (!empty($values)) {
                // ersten Wert nach Timestamp nehmen
                foreach ($values as $v) {
                    if ($v['TimeStamp'] >= $timestamp) {
                        $valueFound = floatval($v['Value']);
                        break 2;
                    }
                }
            }
        }
    } else {
        // 🔹 Suche den letzten Wert VOR dem gewünschten Zeitpunkt
        for ($offset = 0; $offset < $maxDays; $offset += $stepDays) {
            $from = $timestamp - ($offset + $stepDays) * 86400;
            $to   = $timestamp - $offset * 86400;
            $values = @AC_GetLoggedValues($archiveID, $varId, $from, $to, 0);
            if (!empty($values)) {
                // letzten Wert vor Timestamp nehmen
                $last = null;
                foreach ($values as $v) {
                    if ($v['TimeStamp'] <= $timestamp) {
                        $last = $v;
                    } else {
                        break;
                    }
                }
                if ($last !== null) {
                    $valueFound = floatval($last['Value']);
                    break;
                }
            }
        }
    }

    // 🔹 Falls nichts im Archiv: aktuellen Variablenwert nehmen
    if ($valueFound === null) {
        $fallback = floatval(GetValue($varId));
        IPS_LogMessage('Abrechnung', "⚠ Kein Archivwert für $varId gefunden – nutze aktuellen Wert ($fallback)");
        return $fallback;
    }

    return $valueFound;
}


private function AddMeterToPDFRow($meter, $tariffs, $from, $to, $type)
{
    $rows = '';
    $totalCost = 0.0;
    $varId = $meter['var_consumption'];

    IPS_LogMessage('Abrechnung', "🔧 [AddMeterToPDFRow] Starte Berechnung für {$meter['name']} ($type) von " . date('d.m.Y H:i', $from) . " bis " . date('d.m.Y H:i', $to));

    if (!IPS_VariableExists($varId)) {
        IPS_LogMessage('Abrechnung', "❌ Variable {$varId} für {$meter['name']} nicht gefunden");
        return ['row' => '', 'value' => 0];
    }

    // --- 1. Relevante Tarife filtern ---
    $filteredTariffs = array_filter($tariffs, function ($t) use ($type) {
        $typeNorm = strtolower(trim($type));
        $tariffType = strtolower(trim($t['unit_type'] ?? ''));
        $map = [
            'strombezug' => ['strom', 'strombezug', 'stromzähler', 'stromverbrauch'],
            'warmwasser' => ['warmwasser', 'wasser', 'hww'],
            'kaltwasser' => ['kaltwasser', 'wasser', 'kww'],
            'wärme'      => ['wärme', 'heizung', 'heat']
        ];
        return in_array($tariffType, $map[$typeNorm] ?? []) || $tariffType === $typeNorm;
    });

    IPS_LogMessage('Abrechnung', "🔹 Gefundene Tarife für Typ '$type': " . count($filteredTariffs));

    if (empty($filteredTariffs)) {
        IPS_LogMessage('Abrechnung', "⚠ Keine passenden Tarife gefunden → alles 0 Rp");
        return ['row' => '', 'value' => 0];
    }

    // --- 2. Zeitstempel normalisieren & sortieren ---
    foreach ($filteredTariffs as &$t) {
        $t['start_ts'] = is_numeric($t['start']) ? intval($t['start']) : strtotime($t['start']);
        $t['end_ts']   = is_numeric($t['end'])   ? intval($t['end'])   : strtotime($t['end']);
        IPS_LogMessage('Abrechnung', sprintf(
            "   🕓 Tarif: %s - %s @ %.3f Rp",
            date('d.m.Y H:i', $t['start_ts']),
            date('d.m.Y H:i', $t['end_ts']),
            floatval($t['price'])
        ));
    }
    unset($t);
    usort($filteredTariffs, fn($a, $b) => $a['start_ts'] <=> $b['start_ts']);

    // --- 3. Iteration über Tarifabschnitte ---
    $current = $from;
    $segIndex = 1;

    while ($current < $to) {
        IPS_LogMessage('Abrechnung', "➡️ [Segment $segIndex] Start: " . date('d.m.Y H:i', $current));

        // Aktiven Tarif finden
        $active = null;
        foreach ($filteredTariffs as $t) {
            if ($t['start_ts'] <= $current && $current < $t['end_ts']) {
                $active = $t;
                break;
            }
        }

        if ($active) {
            $segmentEnd = min($active['end_ts'], $to);
            $tariffPrice = floatval($active['price']);
            $tariffLabel = number_format($tariffPrice, 2);
            IPS_LogMessage('Abrechnung', sprintf("   ✅ Aktiver Tarif gefunden: %.3f Rp (gültig bis %s)", $tariffPrice, date('d.m.Y H:i', $active['end_ts'])));
        } else {
            // Kein aktiver Tarif gefunden → Nulltarif
            $nextStart = $to;
            foreach ($filteredTariffs as $t) {
                if ($t['start_ts'] > $current && $t['start_ts'] < $nextStart) {
                    $nextStart = $t['start_ts'];
                }
            }
            $segmentEnd = min($nextStart, $to);
            $tariffPrice = 0.0;
            $tariffLabel = 'kein Tarif';
            IPS_LogMessage('Abrechnung', sprintf("   ⚠ Kein Tarif aktiv – verwende 0 Rp bis %s", date('d.m.Y H:i', $segmentEnd)));
        }

        if ($segmentEnd <= $current) {
            IPS_LogMessage('Abrechnung', "   ⚠ SegmentEnd <= current – Abbruch (Ende erreicht oder Tariflücke fehlerhaft)");
            break;
        }

        // --- 4. Werte holen ---
        $startVal = $this->GetValueAt($varId, $current, false);
        $endVal   = $this->GetValueAt($varId, $segmentEnd, true);
        $diff = max(0, $endVal - $startVal);
        $costCHF = round(($tariffPrice / 100) * $diff, 2);
        $totalCost += $costCHF;

        IPS_LogMessage('Abrechnung', sprintf(
            "   📊 Werte: Start=%.3f (%.s), Ende=%.3f (%.s), Verbrauch=%.3f, Tarif=%.3f Rp, Kosten=%.3f CHF",
            $startVal,
            date('d.m.Y H:i', $current),
            $endVal,
            date('d.m.Y H:i', $segmentEnd),
            $diff,
            $tariffPrice,
            $costCHF
        ));

        // --- 5. HTML-Zeile erstellen ---
        $rows .= "
        <tr>
            <td>{$meter['name']}</td>
            <td>{$type}</td>
            <td>" . date('d.m.Y H:i', $current) . "</td>
            <td>" . date('d.m.Y H:i', $segmentEnd) . "</td>
            <td>" . number_format($startVal, 2) . "</td>
            <td>" . number_format($endVal, 2) . "</td>
            <td>" . number_format($diff, 2) . "</td>
            <td>{$tariffLabel}</td>
            <td>" . number_format($costCHF, 2) . "</td>
        </tr>";

        $segIndex++;
        $current = $segmentEnd + 1;
    }

    // --- 6. Falls keine Zeilen ---
    if ($rows === '') {
        IPS_LogMessage('Abrechnung', "⚠ Keine Tarifabschnitte oder Werte berechnet – Erstelle Nullzeile");
        $startVal = $this->GetValueAt($varId, $from, false);
        $endVal   = $this->GetValueAt($varId, $to, true);
        $diff = max(0, $endVal - $startVal);
        $rows = "
        <tr>
            <td>{$meter['name']}</td>
            <td>{$type}</td>
            <td>" . date('d.m.Y H:i', $from) . "</td>
            <td>" . date('d.m.Y H:i', $to) . "</td>
            <td>" . number_format($startVal, 2) . "</td>
            <td>" . number_format($endVal, 2) . "</td>
            <td>" . number_format($diff, 2) . "</td>
            <td>0</td>
            <td>0.00</td>
        </tr>";
    }

    IPS_LogMessage('Abrechnung', sprintf("✅ [AddMeterToPDFRow] Fertig: %.3f CHF total (%d Segmente)", $totalCost, $segIndex - 1));

    return ['row' => $rows, 'value' => $totalCost];
}

}