<?php

use dokuwiki\Extension\SyntaxPlugin;
use dokuwiki\plugin\luxtools\ChronologicalCalendarWidget;

require_once(__DIR__ . '/../autoload.php');

/**
 * luxtools Plugin: Calendar widget syntax.
 *
 * Syntax:
 * - {{calendar>}}            current month
 * - {{calendar>YYYY-MM}}     specific month
 * - {{calendar>YYYY-MM&base=chronological}} custom base namespace (optional)
 */
class syntax_plugin_luxtools_calendar extends SyntaxPlugin
{
    /** @inheritdoc */
    public function getType()
    {
        return 'substition';
    }

    /** @inheritdoc */
    public function getPType()
    {
        return 'block';
    }

    /** @inheritdoc */
    public function getSort()
    {
        return 224;
    }

    /** @inheritdoc */
    public function connectTo($mode)
    {
        $this->Lexer->addSpecialPattern('\{\{calendar>.*?\}\}', $mode, 'plugin_luxtools_calendar');
    }

    /** @inheritdoc */
    public function handle($match, $state, $pos, Doku_Handler $handler)
    {
        $match = substr($match, strlen('{{calendar>'), -2);
        [$target, $flags] = array_pad(explode('&', $match, 2), 2, '');

        $target = trim((string)$target);
        $params = $this->parseFlags($flags);
        $baseNs = $params['base'] ?? 'chronological';

        $resolved = $this->resolveTargetMonth($target);
        if ($resolved === null) {
            return [
                'ok' => false,
                'error' => 'calendar_err_badmonth',
            ];
        }

        return [
            'ok' => true,
            'year' => $resolved['year'],
            'month' => $resolved['month'],
            'base' => $baseNs,
        ];
    }

    /** @inheritdoc */
    public function render($format, Doku_Renderer $renderer, $data)
    {
        if ($data === false || !is_array($data)) return false;
        if ($format !== 'xhtml') return false;
        if (!($renderer instanceof Doku_Renderer_xhtml)) return false;

        if (!($data['ok'] ?? false)) {
            $message = (string)$this->getLang((string)($data['error'] ?? 'calendar_err_badmonth'));
            if ($message === '') $message = 'Invalid calendar month. Use YYYY-MM.';
            $renderer->doc .= '<div class="luxtools-plugin luxtools-calendar"><div class="luxtools-empty">' . hsc($message) . '</div></div>';
            return true;
        }

        $year = (int)$data['year'];
        $month = (int)$data['month'];
        $baseNs = (string)$data['base'];

        $renderer->doc .= ChronologicalCalendarWidget::render($year, $month, $baseNs);

        return true;
    }

    /**
     * @param string $flags
     * @return array<string,string>
     */
    protected function parseFlags(string $flags): array
    {
        $params = [];
        foreach (explode('&', $flags) as $flag) {
            if (trim($flag) === '') continue;
            [$name, $value] = array_pad(explode('=', $flag, 2), 2, '');
            $name = strtolower(trim($name));
            $value = trim($value);
            if ($name === '') continue;
            $params[$name] = $value;
        }

        if (!isset($params['base']) || trim($params['base']) === '') {
            $params['base'] = 'chronological';
        }

        return $params;
    }

    /**
     * Resolve target string to year/month.
     *
     * Accepted formats:
     * - '' (current month)
     * - YYYY-MM
     *
     * @param string $target
     * @return array{year:int,month:int}|null
     */
    protected function resolveTargetMonth(string $target): ?array
    {
        if ($target === '') {
            return [
                'year' => (int)date('Y'),
                'month' => (int)date('m'),
            ];
        }

        if (!preg_match('/^(\d{4})-(\d{2})$/', $target, $matches)) {
            return null;
        }

        $year = (int)$matches[1];
        $month = (int)$matches[2];
        if ($year < 1) return null;
        if ($month < 1 || $month > 12) return null;

        return [
            'year' => $year,
            'month' => $month,
        ];
    }
}