<?php

declare(strict_types=1);

class EnergyPie extends IPSModule
{
    // Attribute keys for UI state
    private const ATTR_RANGE = 'Range';
    private const ATTR_DATE  = 'Date';

    public function Create(): void
    {
        parent::Create();

        // Source variables (logged counters, kWh)
        $this->RegisterPropertyInteger('VarProduction', 0);
        $this->RegisterPropertyInteger('VarConsumption', 0);
        $this->RegisterPropertyInteger('VarFeedIn', 0);
        $this->RegisterPropertyInteger('VarGrid', 0);

        // Default range for first startup
        $this->RegisterPropertyString('DefaultRange', 'day');

        // Persisted UI state
        $this->RegisterAttributeString(self::ATTR_RANGE, 'day');
        $this->RegisterAttributeString(self::ATTR_DATE, date('Y-m-d'));

        // Enable individual visualization (HTML-SDK)
        $this->SetVisualizationType(1);
    }

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

        // First-time init: if range is empty, set it to property default
        $range = $this->ReadAttributeString(self::ATTR_RANGE);
        if ($range === '') {
            $this->WriteAttributeString(self::ATTR_RANGE, $this->ReadPropertyString('DefaultRange'));
        }

        // Push initial view data
        $this->RecalculateAndPush();
    }

    public function GetVisualizationTile(): string
    {
        $path = __DIR__ . '/module.html';
        if (!file_exists($path)) {
            return '<div style="padding:12px;font-family:sans-serif;">module.html fehlt</div>';
        }
        return file_get_contents($path);
    }

    public function RequestAction($Ident, $Value): void
    {
        switch ($Ident) {
            case 'SetRange':
                $range = (string)$Value;
                if (!in_array($range, ['day', 'week', 'month', 'total'], true)) {
                    throw new Exception('Invalid range: ' . $range);
                }
                $this->WriteAttributeString(self::ATTR_RANGE, $range);
                $this->RecalculateAndPush();
                break;

            case 'SetDate':
                // Expect YYYY-MM-DD from HTML <input type="date">
                $date = (string)$Value;
                if (!$this->isValidDate($date)) {
                    throw new Exception('Invalid date: ' . $date);
                }
                $this->WriteAttributeString(self::ATTR_DATE, $date);
                $this->RecalculateAndPush();
                break;

            case 'Prev':
            case 'Next':
            case 'Today':
                $this->ShiftDate($Ident);
                $this->RecalculateAndPush();
                break;

            case 'Refresh':
                $this->RecalculateAndPush();
                break;

            default:
                throw new Exception('Unknown Ident: ' . $Ident);
        }
    }

    /**
     * Compute values (later from archive), then push to tile via UpdateVisualizationValue.
     */
    private function RecalculateAndPush(): void
    {
        $range = $this->ReadAttributeString(self::ATTR_RANGE);
        $date  = $this->ReadAttributeString(self::ATTR_DATE);

        [$tStart, $tEnd] = $this->getRange($range, $date);

        // --- PLACEHOLDER CALCULATION ---
        // Replace these with your later delta calculation from logged data:
        // $prod = $this->readDelta($this->ReadPropertyInteger('VarProduction'),  $tStart, $tEnd);
        // etc.
        $prod = 12.3;
        $cons = 8.7;
        $feed = 3.1;
        $grid = 5.6;

        // If you prefer, you can already set them to 0.0 for "no calc yet"
        // $prod = $cons = $feed = $grid = 0.0;

        $payload = [
            'range' => $range,
            'date'  => $date,
            'tStart' => $tStart,
            'tEnd'   => $tEnd,
            'values' => [
                'Produktion'  => (float)$prod,
                'Verbrauch'   => (float)$cons,
                'Einspeisung' => (float)$feed,
                'Netz'        => (float)$grid
            ]
        ];

        $this->UpdateVisualizationValue($payload);
    }

    /**
     * Range rules:
     * - day: chosen date 00:00:00 .. next day 00:00:00
     * - week: Monday 00:00:00 .. next Monday 00:00:00   (Mo–So)
     * - month: first of month 00:00:00 .. first of next month 00:00:00
     * - total: 0 .. now (placeholder)
     */
    private function getRange(string $range, string $dateYmd): array
    {
        $now = time();

        if ($range === 'total') {
            // Later: use oldest log timestamp as start
            return [0, $now];
        }

        $base = strtotime($dateYmd . ' 00:00:00');
        if ($base === false) {
            // fallback to today
            $base = strtotime(date('Y-m-d') . ' 00:00:00');
        }

        switch ($range) {
            case 'day':
                $start = $base;
                $end   = $start + 86400;
                return [$start, $end];

            case 'week':
                // date('N'): 1=Mon .. 7=Sun
                $dow = (int)date('N', $base);
                $start = $base - (($dow - 1) * 86400); // Monday
                $end   = $start + (7 * 86400);         // next Monday
                return [$start, $end];

            case 'month':
                $start = strtotime(date('Y-m-01 00:00:00', $base));
                $end   = strtotime(date('Y-m-01 00:00:00', strtotime('+1 month', $start)));
                return [$start, $end];

            default:
                return [$base, $base + 86400];
        }
    }

    /**
     * Buttons for quick navigation.
     */
    private function ShiftDate(string $action): void
    {
        $range = $this->ReadAttributeString(self::ATTR_RANGE);

        if ($range === 'total') {
            // total ignores date
            return;
        }

        if ($action === 'Today') {
            $this->WriteAttributeString(self::ATTR_DATE, date('Y-m-d'));
            return;
        }

        $date = $this->ReadAttributeString(self::ATTR_DATE);
        $base = strtotime($date . ' 00:00:00');
        if ($base === false) {
            $base = strtotime(date('Y-m-d') . ' 00:00:00');
        }

        $sign = ($action === 'Prev') ? -1 : 1;

        switch ($range) {
            case 'day':
                $base = strtotime(($sign === -1 ? '-1 day' : '+1 day'), $base);
                break;

            case 'week':
                $base = strtotime(($sign === -1 ? '-7 day' : '+7 day'), $base);
                break;

            case 'month':
                $base = strtotime(($sign === -1 ? '-1 month' : '+1 month'), $base);
                break;
        }

        $this->WriteAttributeString(self::ATTR_DATE, date('Y-m-d', $base));
    }

    private function isValidDate(string $ymd): bool
    {
        // expects YYYY-MM-DD
        if (!preg_match('/^\d{4}-\d{2}-\d{2}$/', $ymd)) {
            return false;
        }
        [$y, $m, $d] = array_map('intval', explode('-', $ymd));
        return checkdate($m, $d, $y);
    }

    // Optional helper for the "actions" test button in form.json
    public function TestPush(): void
    {
        $this->RecalculateAndPush();
    }
}

?>