<?php
declare(strict_types=1);


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

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

        // Variablen für Zeitraum und Status
        $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 das PDF
        $this->RegisterMediaDocument('InvoicePDF', 'Letzte Rechnung', 'pdf');
    }

    public function ApplyChanges()
    {
        parent::ApplyChanges();

    }

    private function RegisterMediaDocument($Ident, $Name, $Extension, $Position = 0)
    {
        $this->RegisterMedia(5, $Ident, $Name, $Extension, $Position);
    }

    private function RegisterMedia($Type, $Ident, $Name, $Extension, $Position)
    {
        $mid = @IPS_GetObjectIDByIdent($Ident, $this->InstanceID);
        if ($mid === false) {
            $mid = IPS_CreateMedia(5 /* Document */);
            IPS_SetParent($mid, $this->InstanceID);
            IPS_SetIdent($mid, $Ident);
            IPS_SetName($mid, $Name);
            IPS_SetPosition($mid, $Position);
            IPS_SetMediaFile($mid, 'media/' . $mid . '.' . $Extension, false);
        }
    }

    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...');
                $pdfContent = $this->GenerateInvoices();

                if ($pdfContent && strlen($pdfContent) > 100) {
                    $mediaID = $this->GetIDForIdent('InvoicePDF');
                    IPS_SetMediaContent($mediaID, base64_encode($pdfContent));
                    IPS_LogMessage('Abrechnung', '✅ PDF erfolgreich im Media-Objekt gespeichert');

                    SetValue($this->GetIDForIdent('LastResult'), 'Abrechnung ' . date('Y-m-d H:i'));
                    echo "✅ Abrechnung erfolgreich erstellt.";
                } else {
                    IPS_LogMessage('Abrechnung', '❌ Fehler bei der PDF-Erstellung oder leeres PDF');
                    echo "❌ Fehler bei der PDF-Erstellung";
                }
                break;
        }
    }

    // 🧾 Hauptfunktion: PDF erzeugen (wie SymconReport)
    public function GenerateInvoices()
    {
        $from = GetValue($this->GetIDForIdent('FromDate'));
        $to = GetValue($this->GetIDForIdent('ToDate'));

        if ($from >= $to) {
            IPS_LogMessage('Abrechnung', '❌ Ungültiger Zeitraum');
            return false;
        }

        $users = json_decode($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);

        IPS_LogMessage('Abrechnung', 'Starte PDF-Erstellung mit TCPDF...');

        // TCPDF initialisieren
        $pdf = new TCPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false);
        $pdf->SetCreator(PDF_CREATOR);
        $pdf->SetAuthor('IPSymcon Abrechnung');
        $pdf->SetTitle('Zählerabrechnung');
        $pdf->SetSubject('Automatische Abrechnung');

        $pdf->setPrintHeader(false);
        $pdf->setFooterFont([PDF_FONT_NAME_DATA, '', PDF_FONT_SIZE_DATA]);
        $pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);
        $pdf->SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP - 15, PDF_MARGIN_RIGHT);
        $pdf->SetAutoPageBreak(true, PDF_MARGIN_BOTTOM);
        $pdf->SetFont('dejavusans', '', 10);

        // Jede Seite = Benutzer
        foreach ($users as $user) {
            $pdf->AddPage();

            $pdf->writeHTML("<h2>Rechnung für {$user['name']}</h2>", true, false, true, false, '');
            $pdf->writeHTML("<p>{$user['address']}<br>{$user['city']}</p>", true, false, true, false, '');

            $pdf->writeHTML("<table border=\"1\" cellpadding=\"4\">
                <tr style=\"background-color:#eee;\">
                    <th>Zähler</th><th>Start</th><th>Ende</th><th>Verbrauch</th><th>Kosten (CHF)</th>
                </tr>", false, false, false, false, '');

            $userMeters = array_merge(
                array_filter($power, fn($m) => $m['user_id'] == $user['id']),
                array_filter($water, fn($m) => $m['user_id'] == $user['id'])
            );

            $total = 0.0;
            foreach ($userMeters as $m) {
                $start = $this->GetValueAt($m['var_consumption'], $from);
                $end = $this->GetValueAt($m['var_consumption'], $to);
                if ($start === null || $end === null) continue;

                $diff = max(0, $end - $start);
                $price = $this->GetTariffForMeter($tariffs, $from, $to, $m);
                $cost = $diff * $price;
                $total += $cost;

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

            $pdf->writeHTML("</table><br><h3>Gesamt: " . number_format($total, 2) . " CHF</h3>", true, false, true, false, '');
        }

        // Rückgabe als String
        return $pdf->Output('Abrechnung.pdf', 'S');
    }

    private function GetValueAt(int $varId, int $timestamp)
    {
        $archiveID = @IPS_GetInstanceListByModuleID('{43192F0B-135B-4CE7-A0A7-1475603F3060}')[0];
        if (!$archiveID) return GetValue($varId);

        $values = AC_GetLoggedValues($archiveID, $varId, $timestamp - 3600, $timestamp + 3600, 1);
        if (count($values) > 0) return floatval($values[0]['Value']);
        return GetValue($varId);
    }

    private function GetTariffForMeter(array $tariffs, int $from, int $to, array $meter): float
    {
        $type = $meter['meter_type'] ?? 'Wärme';
        $tariff = 0.0;
        foreach ($tariffs as $t) {
            $start = strtotime($t['start']);
            $end = strtotime($t['end']);
            if ($from >= $start && $to <= $end && $t['unit_type'] == $type) {
                $tariff = floatval($t['price']) / 100.0;
            }
        }
        return $tariff;
    }
}