<?php

namespace Model;

use DateTime;
use Eluceo\iCal\Component\Calendar;
use Eluceo\iCal\Component\Event;
use Eluceo\iCal\Property\Event\Attendees;

/**
 * Task Filter
 *
 * @package  model
 * @author   Frederic Guillot
 */
class TaskFilter extends Base
{
    /**
     * Query
     *
     * @access public
     * @var \PicoDb\Table
     */
    public $query;

    /**
     * Apply filters according to the search input
     *
     * @access public
     * @param  string   $input
     * @return TaskFilter
     */
    public function search($input)
    {
        $tree = $this->lexer->map($this->lexer->tokenize($input));
        $this->query = $this->taskFinder->getExtendedQuery();

        if (empty($tree)) {
            $this->query->addCondition('1 = 0');
        }

        foreach ($tree as $filter => $value) {
            switch ($filter) {
                case 'T_ASSIGNEE':
                    $this->filterByAssignee($value);
                    break;
                case 'T_COLOR':
                    $this->filterByColors($value);
                    break;
                case 'T_DUE':
                    $this->filterByDueDate($value);
                    break;
                case 'T_TITLE':
                    $this->filterByTitle($value);
                    break;
                case 'T_STATUS':
                    $this->filterByStatusName($value);
                    break;
                case 'T_DESCRIPTION':
                    $this->filterByDescription($value);
                    break;
                case 'T_CATEGORY':
                    $this->filterByCategoryName($value);
                    break;
                case 'T_PROJECT':
                    $this->filterByProjectName($value);
                    break;
                case 'T_COLUMN':
                    $this->filterByColumnName($value);
                    break;
                case 'T_REFERENCE':
                    $this->filterByReference($value);
                    break;
            }
        }

        return $this;
    }

    /**
     * Create a new query
     *
     * @access public
     * @return TaskFilter
     */
    public function create()
    {
        $this->query = $this->db->table(Task::TABLE);
        $this->query->left(User::TABLE, 'ua', 'id', Task::TABLE, 'owner_id');
        $this->query->left(User::TABLE, 'uc', 'id', Task::TABLE, 'creator_id');

        $this->query->columns(
            Task::TABLE.'.*',
            'ua.email AS assignee_email',
            'ua.username AS assignee_username',
            'uc.email AS creator_email',
            'uc.username AS creator_username'
        );

        return $this;
    }

    /**
     * Clone the filter
     *
     * @access public
     * @return TaskFilter
     */
    public function copy()
    {
        $filter = clone($this);
        $filter->query = clone($this->query);
        $filter->query->condition = clone($this->query->condition);
        return $filter;
    }

    /**
     * Exclude a list of task_id
     *
     * @access public
     * @param  array  $task_ids
     * @return TaskFilter
     */
    public function excludeTasks(array $task_ids)
    {
        $this->query->notin(Task::TABLE.'.id', $task_ids);
        return $this;
    }

    /**
     * Filter by id
     *
     * @access public
     * @param  integer  $task_id
     * @return TaskFilter
     */
    public function filterById($task_id)
    {
        if ($task_id > 0) {
            $this->query->eq(Task::TABLE.'.id', $task_id);
        }

        return $this;
    }

    /**
     * Filter by reference
     *
     * @access public
     * @param  string  $reference
     * @return TaskFilter
     */
    public function filterByReference($reference)
    {
        if (! empty($reference)) {
            $this->query->eq(Task::TABLE.'.reference', $reference);
        }

        return $this;
    }

    /**
     * Filter by title
     *
     * @access public
     * @param  string  $title
     * @return TaskFilter
     */
    public function filterByDescription($title)
    {
        $this->query->ilike(Task::TABLE.'.description', '%'.$title.'%');
        return $this;
    }

    /**
     * Filter by title or id if the string is like #123 or an integer
     *
     * @access public
     * @param  string  $title
     * @return TaskFilter
     */
    public function filterByTitle($title)
    {
        if (strlen($title) > 1 && $title{0} === '#' && ctype_digit(substr($title, 1))) {
            $this->query->eq(Task::TABLE.'.id', substr($title, 1));
        }
        else if (ctype_digit($title)) {
            $this->query->eq(Task::TABLE.'.id', $title);
        }
        else {
            $this->query->ilike(Task::TABLE.'.title', '%'.$title.'%');
        }

        return $this;
    }

    /**
     * Filter by a list of project id
     *
     * @access public
     * @param  array  $project_ids
     * @return TaskFilter
     */
    public function filterByProjects(array $project_ids)
    {
        $this->query->in(Task::TABLE.'.project_id', $project_ids);
        return $this;
    }

    /**
     * Filter by project id
     *
     * @access public
     * @param  integer  $project_id
     * @return TaskFilter
     */
    public function filterByProject($project_id)
    {
        if ($project_id > 0) {
            $this->query->eq(Task::TABLE.'.project_id', $project_id);
        }

        return $this;
    }

    /**
     * Filter by project name
     *
     * @access public
     * @param  array    $values   List of project name
     * @return TaskFilter
     */
    public function filterByProjectName(array $values)
    {
        $this->query->beginOr();

        foreach ($values as $project) {
            if (ctype_digit($project)) {
                $this->query->eq(Task::TABLE.'.project_id', $project);
            }
            else {
                $this->query->ilike(Project::TABLE.'.name', $project);
            }
        }

        $this->query->closeOr();
    }

    /**
     * Filter by category id
     *
     * @access public
     * @param  integer  $category_id
     * @return TaskFilter
     */
    public function filterByCategory($category_id)
    {
        if ($category_id >= 0) {
            $this->query->eq(Task::TABLE.'.category_id', $category_id);
        }

        return $this;
    }

    /**
     * Filter by category
     *
     * @access public
     * @param  array    $values   List of assignees
     * @return TaskFilter
     */
    public function filterByCategoryName(array $values)
    {
        $this->query->beginOr();

        foreach ($values as $category) {
            if ($category === 'none') {
                $this->query->eq(Task::TABLE.'.category_id', 0);
            }
            else {
                $this->query->eq(Category::TABLE.'.name', $category);
            }
        }

        $this->query->closeOr();
    }

    /**
     * Filter by assignee
     *
     * @access public
     * @param  integer  $owner_id
     * @return TaskFilter
     */
    public function filterByOwner($owner_id)
    {
        if ($owner_id >= 0) {
            $this->query->eq(Task::TABLE.'.owner_id', $owner_id);
        }

        return $this;
    }

    /**
     * Filter by assignee names
     *
     * @access public
     * @param  array    $values   List of assignees
     * @return TaskFilter
     */
    public function filterByAssignee(array $values)
    {
        $this->query->beginOr();

        foreach ($values as $assignee) {
            $subtaskQuery = $this->buildSubtaskQuery();
            switch ($assignee) {
                case 'me':
                    $this->query->eq(Task::TABLE.'.owner_id', $this->userSession->getId());
                    $subtaskQuery->eq(Subtask::TABLE.'user_id',$this->userSession->getId() );
                    break;
                case 'nobody':
                    $this->query->eq(Task::TABLE.'.owner_id', 0);
                    break;
                default:
                    $this->query->ilike(User::TABLE.'.username', '%'.$assignee.'%');
                    $this->query->ilike(User::TABLE.'.name', '%'.$assignee.'%');
                    $subtaskQuery->ilike(User::TABLE.'.username', '%'.$assignee.'%');
                    $subtaskQuery->ilike(User::TABLE.'.name', '%'.$assignee.'%');
            }
            if ($assignee != 'nobody'){
                $subtasks = $subtaskQuery->findAll();
                $this->addTasksWithFoundSubtask($subtasks);
            }
        }

        $this->query->closeOr();
    }

    /**
     * Filter by color
     *
     * @access public
     * @param  string  $color_id
     * @return TaskFilter
     */
    public function filterByColor($color_id)
    {
        if ($color_id !== '') {
            $this->query->eq(Task::TABLE.'.color_id', $color_id);
        }

        return $this;
    }

    /**
     * Filter by colors
     *
     * @access public
     * @param  array   $colors
     * @return TaskFilter
     */
    public function filterByColors(array $colors)
    {
        $this->query->beginOr();

        foreach ($colors as $color) {
            $this->filterByColor($this->color->find($color));
        }

        $this->query->closeOr();

        return $this;
    }

    /**
     * Filter by column
     *
     * @access public
     * @param  integer $column_id
     * @return TaskFilter
     */
    public function filterByColumn($column_id)
    {
        if ($column_id >= 0) {
            $this->query->eq(Task::TABLE.'.column_id', $column_id);
        }

        return $this;
    }

    /**
     * Filter by column name
     *
     * @access public
     * @param  array    $values   List of column name
     * @return TaskFilter
     */
    public function filterByColumnName(array $values)
    {
        $this->query->beginOr();

        foreach ($values as $project) {
            $this->query->ilike(Board::TABLE.'.title', $project);
        }

        $this->query->closeOr();
    }

    /**
     * Filter by swimlane
     *
     * @access public
     * @param  integer  $swimlane_id
     * @return TaskFilter
     */
    public function filterBySwimlane($swimlane_id)
    {
        if ($swimlane_id >= 0) {
            $this->query->eq(Task::TABLE.'.swimlane_id', $swimlane_id);
        }

        return $this;
    }

    /**
     * Filter by status name
     *
     * @access public
     * @param  string  $status
     * @return TaskFilter
     */
    public function filterByStatusName($status)
    {
        if ($status === 'open' || $status === 'closed') {
            $this->filterByStatus($status === 'open' ? Task::STATUS_OPEN : Task::STATUS_CLOSED);
        }

        return $this;
    }

    /**
     * Filter by status
     *
     * @access public
     * @param  integer  $is_active
     * @return TaskFilter
     */
    public function filterByStatus($is_active)
    {
        if ($is_active >= 0) {
            $this->query->eq(Task::TABLE.'.is_active', $is_active);
        }

        return $this;
    }

    /**
     * Filter by due date
     *
     * @access public
     * @param  string      $date      ISO8601 date format
     * @return TaskFilter
     */
    public function filterByDueDate($date)
    {
        $this->query->neq(Task::TABLE.'.date_due', 0);
        $this->query->notNull(Task::TABLE.'.date_due');
        return $this->filterWithOperator(Task::TABLE.'.date_due', $date, true);
    }

    /**
     * Filter by due date (range)
     *
     * @access public
     * @param  string  $start
     * @param  string  $end
     * @return TaskFilter
     */
    public function filterByDueDateRange($start, $end)
    {
        $this->query->gte('date_due', $this->dateParser->getTimestampFromIsoFormat($start));
        $this->query->lte('date_due', $this->dateParser->getTimestampFromIsoFormat($end));

        return $this;
    }

    /**
     * Filter by start date (range)
     *
     * @access public
     * @param  string  $start
     * @param  string  $end
     * @return TaskFilter
     */
    public function filterByStartDateRange($start, $end)
    {
        $this->query->addCondition($this->getCalendarCondition(
            $this->dateParser->getTimestampFromIsoFormat($start),
            $this->dateParser->getTimestampFromIsoFormat($end),
            'date_started',
            'date_completed'
        ));

        return $this;
    }

    /**
     * Filter by creation date
     *
     * @access public
     * @param  string  $start
     * @param  string  $end
     * @return TaskFilter
     */
    public function filterByCreationDateRange($start, $end)
    {
        $this->query->addCondition($this->getCalendarCondition(
            $this->dateParser->getTimestampFromIsoFormat($start),
            $this->dateParser->getTimestampFromIsoFormat($end),
            'date_creation',
            'date_completed'
        ));

        return $this;
    }

    /**
     * Get all results of the filter
     *
     * @access public
     * @return array
     */
    public function findAll()
    {
        return $this->query->asc(Task::TABLE.'.id')->findAll();
    }

    /**
     * Get the PicoDb query
     *
     * @access public
     * @return \PicoDb\Table
     */
    public function getQuery()
    {
        return $this->query;
    }

    /**
     * Get swimlanes and tasks to display the board
     *
     * @access public
     * @return array
     */
    public function getBoard($project_id)
    {
        $tasks = $this->filterByProject($project_id)->query->asc(Task::TABLE.'.position')->findAll();

        return $this->board->getBoard($project_id, function ($project_id, $column_id, $swimlane_id) use ($tasks) {
            return array_filter($tasks, function(array $task) use ($column_id, $swimlane_id) {
                return $task['column_id'] == $column_id && $task['swimlane_id'] == $swimlane_id;
            });
        });
    }

    /**
     * Format the results to the ajax autocompletion
     *
     * @access public
     * @return array
     */
    public function toAutoCompletion()
    {
        return $this->query->columns(Task::TABLE.'.id', Task::TABLE.'.title')->callback(function(array $results) {

            foreach ($results as &$result) {
                $result['value'] = $result['title'];
                $result['label'] = '#'.$result['id'].' - '.$result['title'];
            }

            return $results;

        })->findAll();
    }

    /**
     * Transform results to calendar events
     *
     * @access public
     * @param  string  $start_column    Column name for the start date
     * @param  string  $end_column      Column name for the end date
     * @return array
     */
    public function toDateTimeCalendarEvents($start_column, $end_column)
    {
        $events = array();

        foreach ($this->query->findAll() as $task) {

            $events[] = array_merge(
                $this->getTaskCalendarProperties($task),
                array(
                    'start' => date('Y-m-d\TH:i:s', $task[$start_column]),
                    'end' => date('Y-m-d\TH:i:s', $task[$end_column] ?: time()),
                    'editable' => false,
                )
            );
        }

        return $events;
    }

    /**
     * Transform results to all day calendar events
     *
     * @access public
     * @param  string    $column   Column name for the date
     * @return array
     */
    public function toAllDayCalendarEvents($column = 'date_due')
    {
        $events = array();

        foreach ($this->query->findAll() as $task) {

            $events[] = array_merge(
                $this->getTaskCalendarProperties($task),
                array(
                    'start' => date('Y-m-d', $task[$column]),
                    'end' => date('Y-m-d', $task[$column]),
                    'allday' => true,
                )
            );
        }

        return $events;
    }

    /**
     * Transform results to ical events
     *
     * @access public
     * @param  string                           $start_column    Column name for the start date
     * @param  string                           $end_column      Column name for the end date
     * @param  Eluceo\iCal\Component\Calendar   $vCalendar       Calendar object
     * @return Eluceo\iCal\Component\Calendar
     */
    public function addDateTimeIcalEvents($start_column, $end_column, Calendar $vCalendar = null)
    {
        if ($vCalendar === null) {
            $vCalendar = new Calendar('Kanboard');
        }

        foreach ($this->query->findAll() as $task) {

            $start = new DateTime;
            $start->setTimestamp($task[$start_column]);

            $end = new DateTime;
            $end->setTimestamp($task[$end_column] ?: time());

            $vEvent = $this->getTaskIcalEvent($task, 'task-#'.$task['id'].'-'.$start_column.'-'.$end_column);
            $vEvent->setDtStart($start);
            $vEvent->setDtEnd($end);

            $vCalendar->addComponent($vEvent);
        }

        return $vCalendar;
    }

    /**
     * Transform results to all day ical events
     *
     * @access public
     * @param  string                             $column        Column name for the date
     * @param  Eluceo\iCal\Component\Calendar     $vCalendar     Calendar object
     * @return Eluceo\iCal\Component\Calendar
     */
    public function addAllDayIcalEvents($column = 'date_due', Calendar $vCalendar = null)
    {
        if ($vCalendar === null) {
            $vCalendar = new Calendar('Kanboard');
        }

        foreach ($this->query->findAll() as $task) {

            $date = new DateTime;
            $date->setTimestamp($task[$column]);

            $vEvent = $this->getTaskIcalEvent($task, 'task-#'.$task['id'].'-'.$column);
            $vEvent->setDtStart($date);
            $vEvent->setDtEnd($date);
            $vEvent->setNoTime(true);

            $vCalendar->addComponent($vEvent);
        }

        return $vCalendar;
    }

    /**
     * Get common events for task ical events
     *
     * @access protected
     * @param  array   $task
     * @param  string  $uid
     * @return Eluceo\iCal\Component\Event
     */
    protected function getTaskIcalEvent(array &$task, $uid)
    {
        $dateCreation = new DateTime;
        $dateCreation->setTimestamp($task['date_creation']);

        $dateModif = new DateTime;
        $dateModif->setTimestamp($task['date_modification']);

        $vEvent = new Event($uid);
        $vEvent->setCreated($dateCreation);
        $vEvent->setModified($dateModif);
        $vEvent->setUseTimezone(true);
        $vEvent->setSummary(t('#%d', $task['id']).' '.$task['title']);
        $vEvent->setUrl($this->helper->url->base().$this->helper->url->to('task', 'show', array('task_id' => $task['id'], 'project_id' => $task['project_id'])));

        if (! empty($task['creator_id'])) {
            $vEvent->setOrganizer('MAILTO:'.($task['creator_email'] ?: $task['creator_username'].'@kanboard.local'));
        }

        if (! empty($task['owner_id'])) {
            $attendees = new Attendees;
            $attendees->add('MAILTO:'.($task['creator_email'] ?: $task['creator_username'].'@kanboard.local'));
            $vEvent->setAttendees($attendees);
        }

        return $vEvent;
    }

    /**
     * Filter with an operator
     *
     * @access public
     * @param  string    $field
     * @param  string    $value
     * @param  boolean   $is_date
     * @return TaskFilter
     */
    private function filterWithOperator($field, $value, $is_date)
    {
        $operators = array(
            '<=' => 'lte',
            '>=' => 'gte',
            '<' => 'lt',
            '>' => 'gt',
        );

        foreach ($operators as $operator => $method) {

            if (strpos($value, $operator) === 0) {
                $value = substr($value, strlen($operator));
                $this->query->$method($field, $is_date ? $this->dateParser->getTimestampFromIsoFormat($value) : $value);
                return $this;
            }
        }

        $this->query->eq($field, $is_date ? $this->dateParser->getTimestampFromIsoFormat($value) : $value);

        return $this;
    }
    
    private function buildSubtaskQuery(){
        return $this->db->table(Subtask::TABLE)
                ->columns(
                    Subtask::TABLE.'.user_id',
                    Subtask::TABLE.'.task_id',
                    User::TABLE.'.name',
                    User::TABLE.'.username')
                ->join(User::TABLE, 'id', 'user_id', Subtask::TABLE)
                ->beginOr()
                ->eq(Subtask::TABLE.'.status', Subtask::STATUS_TODO)
                ->eq(Subtask::TABLE.'.status', Subtask::STATUS_INPROGRESS)
                ->closeOr();
    }

    private function addTasksWithFoundSubtask($subtasks) {
        foreach ($subtasks as $subtask) {
            $this->query->eq(Task::TABLE.'.id',$subtask['task_id']);
        }
    }

}