<?php

namespace Kanboard\Plugin\RecoReco\Controller;

use Kanboard\Controller\BaseController;
use Kanboard\Model\TaskModel;

/**
 * The "Recurring schedule" modal: configure a card's calendar recurrence and store it in task
 * metadata. The CLI engine (RecoRecoModel) does the actual spawning.
 *
 * Gate: a card can only be enabled when it has a due date (the recurrence anchor), is not already a
 * native-recurring card (mutually exclusive), and the board has a column other than the card's own
 * (the copy must land elsewhere).
 */
class RecurrenceController extends BaseController
{
    public function edit(array $values = array(), array $errors = array())
    {
        $task = $this->getTask();
        $columns = $this->targetColumns($task);
        $meta = $this->taskMetadataModel->getAll($task['id']);

        if (empty($values)) {
            $values = $this->getStoredValues($meta, $task, $columns);
        }

        $this->response->html($this->template->render('recoReco:recurrence/edit', array(
            'task' => $task,
            'values' => $values,
            'errors' => $errors,
            'columns_list' => $columns,
            'frequency_list' => $this->getFrequencyList(),
            'has_due_date' => ! empty($task['date_due']),
            'is_native' => $task['recurrence_status'] != TaskModel::RECURRING_STATUS_NONE,
            'has_target' => ! empty($columns),
            'is_clone' => isset($meta['recoreco_clone']) && $meta['recoreco_clone'] == 1,
            'source_id' => isset($meta['recoreco_source']) ? (int) $meta['recoreco_source'] : 0,
        )));
    }

    public function save()
    {
        $task = $this->getTask();
        $input = $this->request->getValues();
        $columns = $this->targetColumns($task);

        // A clone can never be made recurring (that would recurse). Guard even though the modal
        // hides the form for clones.
        $is_clone = (int) $this->taskMetadataModel->get($task['id'], 'recoreco_clone', 0) === 1;

        // Only a plain card (a due date, not native-recurring, not a clone, a valid target) may enable.
        $can_recur = ! empty($task['date_due'])
            && $task['recurrence_status'] == TaskModel::RECURRING_STATUS_NONE
            && ! $is_clone
            && ! empty($columns);
        $enabled = ($can_recur && isset($input['recoreco_enabled']) && $input['recoreco_enabled'] == 1) ? 1 : 0;

        $frequency = isset($input['recoreco_frequency']) && array_key_exists($input['recoreco_frequency'], $this->getFrequencyList())
            ? $input['recoreco_frequency']
            : 'monthly_day';

        // Keep the lead time under one period (else a copy's fire time crosses the prior occurrence).
        $daysBefore = isset($input['recoreco_days_before']) && ctype_digit((string) $input['recoreco_days_before']) ? (int) $input['recoreco_days_before'] : 0;
        $daysBefore = min($daysBefore, $this->maxDaysBefore($frequency));

        $values = array(
            'recoreco_enabled' => $enabled,
            'recoreco_target_column' => $this->resolveTarget(isset($input['recoreco_target_column']) ? $input['recoreco_target_column'] : 0, $columns),
            'recoreco_frequency' => $frequency,
            'recoreco_last_day' => isset($input['recoreco_last_day']) ? 1 : 0,
            'recoreco_days_before' => $daysBefore,
            'recoreco_link_copies' => isset($input['recoreco_link_copies']) ? 1 : 0,
        );

        // Capture the anchor (the due date at enable time) -- the drift-free pattern.
        if ($enabled) {
            $values['recoreco_anchor'] = (int) $task['date_due'];
        }

        $this->taskMetadataModel->save($task['id'], $values);

        // Reconcile the template's duplicate links with the setting right away.
        $model = new \Kanboard\Plugin\RecoReco\Model\RecoRecoModel($this->container);
        $model->syncCloneLinks($task['id'], $values['recoreco_link_copies'] == 1);

        $this->flash->success(t('Recurring schedule saved.'));

        return $this->response->redirect($this->helper->url->to('TaskViewController', 'show', array('task_id' => $task['id'])), true);
    }

    // Columns the copy can land in: every column except the template's own (the copy must move).
    private function targetColumns(array $task)
    {
        $columns = $this->columnModel->getList($task['project_id']);
        unset($columns[$task['column_id']]);

        return $columns;
    }

    // A stored/posted target, if still a valid non-current column; otherwise the first one (or 0).
    private function resolveTarget($candidate, array $columns)
    {
        $candidate = (int) $candidate;

        if (array_key_exists($candidate, $columns)) {
            return $candidate;
        }

        $keys = array_keys($columns);

        return empty($keys) ? 0 : (int) $keys[0];
    }

    private function getStoredValues(array $meta, array $task, array $columns)
    {
        return array(
            'recoreco_enabled' => isset($meta['recoreco_enabled']) ? (int) $meta['recoreco_enabled'] : 0,
            'recoreco_target_column' => $this->resolveTarget(isset($meta['recoreco_target_column']) ? $meta['recoreco_target_column'] : 0, $columns),
            'recoreco_frequency' => isset($meta['recoreco_frequency']) ? $meta['recoreco_frequency'] : 'monthly_day',
            'recoreco_last_day' => isset($meta['recoreco_last_day']) ? (int) $meta['recoreco_last_day'] : 0,
            'recoreco_days_before' => isset($meta['recoreco_days_before']) ? (int) $meta['recoreco_days_before'] : 0,
            'recoreco_link_copies' => isset($meta['recoreco_link_copies']) ? (int) $meta['recoreco_link_copies'] : 0,
        );
    }

    private function getFrequencyList()
    {
        return array(
            'yearly' => t('Yearly'),
            'monthly_day' => t('Monthly by day'),
            'monthly_dow' => t('Monthly by weekday'),
            'weekly' => t('Weekly'),
            'daily' => t('Daily'),
        );
    }

    /**
     * The largest allowed "days before" for a frequency -- kept strictly under one period so a
     * copy's fire time never crosses the previous occurrence. Daily = 0 (disabled).
     */
    private function maxDaysBefore($frequency)
    {
        switch ($frequency) {
            case 'daily':
                return 0;
            case 'weekly':
                return 6;
            case 'yearly':
                return 364;
            default: // monthly_day, monthly_dow
                return 27;
        }
    }
}