<?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', ''); ?>");

        // PDF-Media-Objekt
        $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);
        }
    }

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

            case 'StartBilling':
                try {
                    $pdfContent = $this->GenerateInvoices();
                    if ($pdfContent && strlen($pdfContent) > 100) {
                        $mediaID = $this->GetIDForIdent('InvoicePDF');
                        IPS_SetMediaContent($mediaID, base64_encode($pdfContent));
                        SetValue($this->GetIDForIdent('LastResult'), 'Abrechnung vom ' . date('d.m.Y H:i'));
                        echo "✅ PDF erfolgreich erstellt.";
                    } else {
                        echo "❌ Fehler bei der PDF-Erstellung.";
                    }
                } catch (Throwable $e) {
                    echo "❌ Ausnahmefehler: " . $e->getMessage();
                }
                break;
        }
    }

    // ===========================================================
    // 🧾 Hauptlogik: Rechnungserstellung für alle Benutzer
    // ===========================================================
    public function GenerateInvoices()
    {
        $from = GetValue($this->GetIDForIdent('FromDate'));
        $to   = GetValue($this->GetIDForIdent('ToDate'));

        $users   = json_decode($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')) return false;

        $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', '', 9);

        foreach ($users as $user) {
            $pdf->AddPage();
            $html = $this->BuildUserInvoice($user, $power, $water, $tariffs, $from, $to);
            $pdf->writeHTML($html);
        }

        return $pdf->Output('Abrechnung.pdf', 'S');
    }

    // ===========================================================
    // 🧱 Layout / PDF-Aufbau pro Benutzerseite
    // ===========================================================
    private function BuildUserInvoice($user, $power, $water, $tariffs, $from, $to)
    {
        $stromRows = '';
        $stromTotal = 0.0;
        $stromTariffsUsed = [];

        $nebenRows = '';
        $nebenTotal = 0.0;
        $nebenTariffsUsed = [];

        // ---------- Stromkosten ----------
        foreach ($power as $m) {
            if ($m['user_id'] != $user['id']) continue;
            $res = $this->AddMeterToPDFRow($m, $tariffs, $from, $to, 'Strombezug');
            $stromRows .= $res['row'];
            $stromTotal += $res['value'];

            foreach ($tariffs as $t) {
                if (strtolower($t['unit_type']) == 'strombezug') {
                    $sTs = $this->toUnixTs($t['start'], false);
                    $eTs = $this->toUnixTs($t['end'], true);
                    if ($sTs && $eTs) {
                        $period = date('d.m.Y', $sTs) . ' - ' . date('d.m.Y', $eTs);
                        $stromTariffsUsed[$period] = number_format(floatval($t['price']), 2);
                    }
                }
            }
        }

        // ---------- Nebenkosten ----------
        foreach ($water as $m) {
            if ($m['user_id'] != $user['id']) continue;
            $type = $m['meter_type'] ?? 'Warmwasser';
            $res = $this->AddMeterToPDFRow($m, $tariffs, $from, $to, $type);
            $nebenRows .= $res['row'];
            $nebenTotal += $res['value'];

            foreach ($tariffs as $t) {
                $u = strtolower($t['unit_type'] ?? '');
                if (in_array($u, ['warmwasser', 'kaltwasser', 'wärme'])) {
                    $sTs = $this->toUnixTs($t['start'], false);
                    $eTs = $this->toUnixTs($t['end'], true);
                    if ($sTs && $eTs) {
                        $period = date('d.m.Y', $sTs) . ' - ' . date('d.m.Y', $eTs);
                        $nebenTariffsUsed[$period] = number_format(floatval($t['price']), 2);
                    }
                }
            }
        }

        $gesamtTotal = $stromTotal + $nebenTotal;
        $tableStyle = "border-collapse:collapse;width:100%;font-size:8px;";
        $cellStyle = "border:0.3px solid #999;padding:2px;";

        $html = "
        <h2 style='text-align:center;'>Rechnung für {$user['name']}</h2>
        <p>{$user['address']}<br>{$user['city']}</p>
        <p><b>Abrechnungszeitraum:</b> " . date('d.m.Y', $from) . " – " . date('d.m.Y', $to) . "</p>

        <h3 style='margin-top:10px;color:#004085;'>⚡ Stromkosten</h3>
        <table style='{$tableStyle}'>
            <tr style='background-color:#e0e0e0;text-align:center;'>
                <th style='{$cellStyle}'>Zähler</th>
                <th style='{$cellStyle}'>Typ</th>
                <th style='{$cellStyle}'>Startzeit</th>
                <th style='{$cellStyle}'>Endzeit</th>
                <th style='{$cellStyle}'>Start</th>
                <th style='{$cellStyle}'>Ende</th>
                <th style='{$cellStyle}'>Verbrauch</th>
                <th style='{$cellStyle}'>Tarif (Rp)</th>
                <th style='{$cellStyle}'>Kosten (CHF)</th>
            </tr>
            {$stromRows}
            <tr style='border-top:1px solid black;font-weight:bold;'>
                <td colspan='8' style='text-align:right;{$cellStyle}'>Total Stromkosten:</td>
                <td style='{$cellStyle}'>" . number_format($stromTotal, 2) . "</td>
            </tr>
        </table>";

        if (!empty($stromTariffsUsed)) {
            $html .= "<p style='font-size:7px;'><b>Angewendete Tarife:</b><br>";
            foreach ($stromTariffsUsed as $period => $price) {
                $html .= "&nbsp;&nbsp;{$period}: {$price} Rp/kWh<br>";
            }
            $html .= "</p>";
        }

        $html .= "
        <h3 style='margin-top:15px;color:#6c757d;'>💧 Nebenkosten (Wasser & Wärme)</h3>
        <table style='{$tableStyle}'>
            <tr style='background-color:#e0e0e0;text-align:center;'>
                <th style='{$cellStyle}'>Zähler</th>
                <th style='{$cellStyle}'>Typ</th>
                <th style='{$cellStyle}'>Startzeit</th>
                <th style='{$cellStyle}'>Endzeit</th>
                <th style='{$cellStyle}'>Start</th>
                <th style='{$cellStyle}'>Ende</th>
                <th style='{$cellStyle}'>Verbrauch</th>
                <th style='{$cellStyle}'>Tarif (Rp)</th>
                <th style='{$cellStyle}'>Kosten (CHF)</th>
            </tr>
            {$nebenRows}
            <tr style='border-top:1px solid black;font-weight:bold;'>
                <td colspan='8' style='text-align:right;{$cellStyle}'>Total Nebenkosten:</td>
                <td style='{$cellStyle}'>" . number_format($nebenTotal, 2) . "</td>
            </tr>
        </table>";

        if (!empty($nebenTariffsUsed)) {
            $html .= "<p style='font-size:7px;'><b>Angewendete Tarife:</b><br>";
            foreach ($nebenTariffsUsed as $period => $price) {
                $html .= "&nbsp;&nbsp;{$period}: {$price} Rp/m³ oder kWh<br>";
            }
            $html .= "</p>";
        }

        $html .= "<h3 style='text-align:right;margin-top:10px;'>💰 <u>Gesamttotal:</u> " . number_format($gesamtTotal, 2) . " CHF</h3>";

        return $html;
    }

    // ===========================================================
    // 🧮 Datumskonvertierung – robust für JSON, String, Timestamp
    // ===========================================================
    private function toUnixTs($val, bool $endOfDay = false): ?int
    {
        if (is_int($val)) return $val;
        if (is_numeric($val)) return intval($val);

        if (is_string($val)) {
            $s = trim($val);
            if ($s !== '' && $s[0] === '{') {
                $obj = json_decode($s, true);
                if (is_array($obj) && isset($obj['year'], $obj['month'], $obj['day'])) {
                    $time = $endOfDay ? '23:59:59' : '00:00:00';
                    return strtotime(sprintf('%04d-%02d-%02d %s', $obj['year'], $obj['month'], $obj['day'], $time));
                }
            }
            $ts = strtotime($s);
            return $ts === false ? null : $ts;
        }
        return null;
    }

    // ===========================================================
    // 🔍 Archivwertsuche (deine getestete Version)
    // ===========================================================
    private function GetValueAt(int $varId, int $timestamp, bool $nearestAfter = true)
    {
        $archiveID = @IPS_GetInstanceListByModuleID('{43192F0B-135B-4CE7-A0A7-1475603F3060}')[0];
        if (!$archiveID || !IPS_VariableExists($varId)) return null;

        $maxDays = 365;
        $stepDays = 30;
        $valueFound = null;

        if ($nearestAfter) {
            for ($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)) {
                    foreach ($values as $v) {
                        if ($v['TimeStamp'] >= $timestamp) {
                            return floatval($v['Value']);
                        }
                    }
                }
            }
        } else {
            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)) {
                    $last = end($values);
                    return floatval($last['Value']);
                }
            }
        }

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

    IPS_LogMessage('Abrechnung', "🔧 [AddMeterToPDFRow] Starte für '{$meter['name']}' (Typ: {$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];
    }

    // Zeitzone setzen, um strtotime()-Abweichungen zu vermeiden
    date_default_timezone_set('Europe/Zurich');

    // 1️⃣ Relevante Tarife nach Typ filtern
    $filteredTariffs = array_filter($tariffs, function ($t) use ($type) {
        return strtolower(trim($t['unit_type'] ?? '')) === strtolower(trim($type));
    });

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

    // 2️⃣ Zeitstempel konvertieren, JSON-Objekte erkennen & sortieren
    foreach ($filteredTariffs as &$t) {
        // JSON-Fix: Start/Ende evtl. verschachtelt
        if (is_string($t['start']) && str_starts_with(trim($t['start']), '{')) {
            $s = json_decode($t['start'], true);
            if (is_array($s)) {
                $t['start'] = sprintf('%04d-%02d-%02d 00:00:00', $s['year'], $s['month'], $s['day']);
            }
        }
        if (is_string($t['end']) && str_starts_with(trim($t['end']), '{')) {
            $e = json_decode($t['end'], true);
            if (is_array($e)) {
                $t['end'] = sprintf('%04d-%02d-%02d 23:59:59', $e['year'], $e['month'], $e['day']);
            }
        }

        $t['start_ts'] = is_numeric($t['start']) ? intval($t['start']) : strtotime($t['start']);
        $t['end_ts']   = is_numeric($t['end'])   ? intval($t['end'])   : strtotime($t['end']);

        if (!$t['start_ts'] || !$t['end_ts']) {
            IPS_LogMessage('Abrechnung', "⚠ Ungültiger Tarifzeitraum: " . json_encode($t));
        } else {
            IPS_LogMessage('Abrechnung', sprintf(
                "   🕓 Tarif gültig von %s bis %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']);

    // 3️⃣ Abrechnungslogik
    $currentStart = $from;
    $segmentIndex = 1;

    while ($currentStart < $to) {
        IPS_LogMessage('Abrechnung', "➡️ Segment {$segmentIndex} Startzeit: " . date('d.m.Y H:i', $currentStart));

        // 🔹 Aktiven Tarif bestimmen (FIX: <= auch am Ende erlaubt)
        $activeTariff = null;
        foreach ($filteredTariffs as $t) {
            $startTs = intval($t['start_ts']);
            $endTs   = intval($t['end_ts']);
            if ($startTs === 0 || $endTs === 0) continue;

            if ($startTs <= $currentStart && $currentStart <= $endTs) {
                $activeTariff = $t;
                IPS_LogMessage('Abrechnung', sprintf(
                    "   ✅ Tarif erkannt: %.2f Rp gültig %s → %s",
                    floatval($t['price']),
                    date('d.m.Y H:i', $startTs),
                    date('d.m.Y H:i', $endTs)
                ));
                break;
            }
        }

        // 🔹 Falls kein aktiver Tarif → 0 Rp
        if (!$activeTariff) {
            IPS_LogMessage('Abrechnung', "⚠ Kein Tarif aktiv bei " . date('d.m.Y H:i', $currentStart) . " → 0 Rp");
            $activeTariff = [
                'start_ts' => $currentStart,
                'end_ts'   => $to,
                'price'    => 0.0,
                'unit_type'=> $type
            ];
        }

        $tariffEnd   = intval($activeTariff['end_ts']);
        $tariffPrice = floatval($activeTariff['price']);
        $tariffLabel = number_format($tariffPrice, 2, ',', '');

        // 🔹 Start- & Endwerte aus Archiv
        $startValue = $this->GetValueAt($varId, $currentStart, true);
        if ($startValue === null) {
            IPS_LogMessage('Abrechnung', "⚠ Kein Startwert für " . date('d.m.Y H:i', $currentStart));
            break;
        }

        $segmentEnd = ($tariffEnd < $to) ? $tariffEnd : $to;
        $endValue = $this->GetValueAt($varId, $segmentEnd, true);
        if ($endValue === null) {
            IPS_LogMessage('Abrechnung', "⚠ Kein Endwert für " . date('d.m.Y H:i', $segmentEnd));
            break;
        }

        // 🔹 Verbrauch & Kosten
        $verbrauch = max(0, $endValue - $startValue);
        $kosten = round(($tariffPrice / 100) * $verbrauch, 2);
        $totalCost += $kosten;

        IPS_LogMessage('Abrechnung', sprintf(
            "   📊 Segment %d: %.3f → %.3f (Δ=%.3f) | Tarif=%.3f Rp | Kosten=%.2f CHF",
            $segmentIndex, $startValue, $endValue, $verbrauch, $tariffPrice, $kosten
        ));

        // 🔹 Tabellenzeile
        $rows .= "
        <tr>
            <td>{$meter['name']}</td>
            <td>{$type}</td>
            <td>" . date('d.m.Y H:i', $currentStart) . "</td>
            <td>" . date('d.m.Y H:i', $segmentEnd) . "</td>
            <td>" . number_format($startValue, 2) . "</td>
            <td>" . number_format($endValue, 2) . "</td>
            <td>" . number_format($verbrauch, 2) . "</td>
            <td>{$tariffLabel}</td>
            <td>" . number_format($kosten, 2) . "</td>
        </tr>";

        // 🔹 Neuen Startpunkt setzen (FIX: +1 Sekunde nach Tarifende)
        if ($tariffEnd < $to) {
            $currentStart = $tariffEnd + 1;
        } else {
            break;
        }

        $segmentIndex++;
    }

    // Fallback, falls keine Segmente erzeugt wurden
    if ($rows === '') {
        IPS_LogMessage('Abrechnung', "⚠ Keine Segmente erzeugt, Fallback auf Gesamtzeitraum");
        $startValue = $this->GetValueAt($varId, $from, false);
        $endValue   = $this->GetValueAt($varId, $to, true);
        $verbrauch = max(0, $endValue - $startValue);
        $rows = "
        <tr>
            <td>{$meter['name']}</td>
            <td>{$type}</td>
            <td>" . date('d.m.Y H:i', $from) . "</td>
            <td>" . date('d.m.Y H:i', $to) . "</td>
            <td>" . number_format($startValue, 2) . "</td>
            <td>" . number_format($endValue, 2) . "</td>
            <td>" . number_format($verbrauch, 2) . "</td>
            <td>0</td>
            <td>0.00</td>
        </tr>";
    }

    IPS_LogMessage('Abrechnung', sprintf("✅ [AddMeterToPDFRow] Fertig: %.2f CHF total, %d Segmente", $totalCost, $segmentIndex - 1));

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

}