<?php

namespace Kanboard\Plugin\OrganonTweaks\Filter;

use Kanboard\Core\Filter\FilterInterface;
use Kanboard\Filter\BaseFilter;
use Kanboard\Model\TaskModel;

/**
 * Filter tasks by a whole calendar month, optionally padded.
 *
 * Registered twice by the plugin (via $container->extend('taskLexer', ...)):
 *   - `duemonth:VALUE`    -- padDays 0: due within the target month.
 *   - `aroundmonth:VALUE` -- padDays 10: the month minus 10 days .. plus 10 days (i.e. the last
 *     10 days of the previous month, the whole month, and the first 10 days of the next month).
 *
 * VALUE is `this` (also `next` / `last`) or an explicit month such as `2026-01` or `january-2026`
 * (anything strtotime() can parse). Bounds are computed with mktime (correct for any month length)
 * at search time, so the filter auto-rolls.
 *
 * Both bounds (gte start, lte end) are added inside this single apply() on the single-value path,
 * so they AND -- the range Kanboard's saved-filter string syntax cannot express (repeating the
 * same attribute ORs via OrCriteria, and there is no AND keyword).
 */
class TaskMonthRangeFilter extends BaseFilter implements FilterInterface
{
    private $attribute = 'duemonth';
    private $padDays = 0;

    public function setAttribute($attribute)
    {
        $this->attribute = $attribute;
        return $this;
    }

    public function setPadDays($days)
    {
        $this->padDays = (int) $days;
        return $this;
    }

    public function getAttributes()
    {
        return array($this->attribute);
    }

    public function apply()
    {
        $reference = $this->resolveMonthTimestamp((string) $this->value);

        if ($reference === false) {
            return $this; // unknown/typo value -> no-op (matches nothing added)
        }

        $month = (int) date('n', $reference);
        $year = (int) date('Y', $reference);
        $first = mktime(0, 0, 0, $month, 1, $year);
        $last = mktime(23, 59, 59, $month + 1, 0, $year); // day 0 of next month = last day of this
        $pad = $this->padDays * 86400;

        $this->query->neq(TaskModel::TABLE.'.date_due', 0);
        $this->query->gte(TaskModel::TABLE.'.date_due', $first - $pad);
        $this->query->lte(TaskModel::TABLE.'.date_due', $last + $pad);

        return $this;
    }

    /**
     * Resolve the filter value to any timestamp inside the target month (or false if unparseable).
     *
     * @param  string $value
     * @return int|false
     */
    private function resolveMonthTimestamp($value)
    {
        $value = strtolower(trim($value));

        if ($value === '' || $value === 'this') {
            return strtotime('first day of this month');
        }

        if ($value === 'next') {
            return strtotime('first day of next month');
        }

        if ($value === 'last' || $value === 'prev' || $value === 'previous') {
            return strtotime('first day of last month');
        }

        return strtotime($value); // 2026-01, january-2026, "last day of january 2026", ...
    }
}