<?php

class Ticket extends \DB\SQL\Mapper {
    function __construct($db){
        parent::__construct($db, 'tickets');
        
    }

    /**
     * Return all tickets in descending order of creation
     */
    public function findAll(): array
    {
        $tickets = $this->db->exec(
            'SELECT t.id, t.title, t.created_at, 
                tp.name AS priority_name, ts.name AS status_name, u.display_name
            FROM tickets  t
            LEFT JOIN ticket_priorities tp ON t.priority_id = tp.id
            LEFT JOIN ticket_statuses ts ON t.status_id = ts.id
            LEFT JOIN users u ON t.created_by = u.id
            WHERE t.recycled = 0
            ORDER BY t.created_at DESC'
        );
        $result = $this->getTagsForTickets($tickets);
        return $result;
    }

    public function findFiltered(string $filter): array
    {
        $sql = '
            SELECT t.*, tp.name AS priority_name, ts.name AS status_name, u.display_name
            FROM tickets t
            LEFT JOIN ticket_priorities tp ON t.priority_id = tp.id
            LEFT JOIN ticket_statuses ts ON t.status_id = ts.id
            LEFT JOIN users u ON t.created_by = u.id
            WHERE t.recycled = 0
        ';
        $params = [];
        switch($filter){
            case 'open':
                $sql .= ' AND status_id = ?';
                $params[] = 1;
            break;
            case 'in_progress':
                $sql .= ' AND status_id = ?';
                $params[] = 2;
            break;
            case 'on_hold':
                $sql .= ' AND status_id = ?';
                $params[] = 3;
            break;
            case 'completed':
                $sql .= ' AND status_id = ?';
                $params[] = 4;
            break;
        }

        $sql .= ' ORDER BY t.created_at DESC';
        $tickets = $this->db->exec($sql, $params);
        $result = $this->getTagsForTickets($tickets);
        return $result;
    }

    public function getTagsForTickets(array $tickets)
    {
        if(empty($tickets)) return [];
        $tag_mapper = new Tag($this->db, 'ticket');
        $tickets = $tag_mapper->getTagsFor($tickets);

        return $tickets;
    }

    public function findById($id): ?Ticket
    {
        $this->status_name = 'SELECT name FROM ticket_statuses WHERE tickets.status_id = ticket_statuses.id';
        $this->priority_name = 'SELECT name FROM ticket_priorities WHERE tickets.priority_id = ticket_priorities.id';
        $this->load(['id = ?', $id]);
        if($this->dry()){
            return null;
        }
        $tag_model = new Tag($this->db, 'ticket');
        $this->tags = $tag_model->getTagsForID($this->id, 'ticket_id');
        return $this;
    }

    public function setTags(array $tags_ids):void {
        if($this->dry() || !$this->id){
            // can't set tags for a ticket that hasn't been saved or loaded
            return;
        }

        // remove existing tags - TODO: shouldn't this be in the tag model?
        $this->db->exec('DELETE FROM ticket_tags WHERE ticket_id = ?', [$this->id]);

        if(!empty($tags_ids)){
            $sql_insert_tag = 'INSERT INTO ticket_tags (ticket_id, tag_id) VALUES (?,?)';
            foreach($tags_ids as $tag_id){
                if(filter_var($tag_id, FILTER_VALIDATE_INT)){
                    $this->db->exec($sql_insert_tag, [$this->id, (int)$tag_id]);
                }
            }
        }
        // refresh tags
        $tag_model = new Tag($this->db, 'ticket');
        $this->tags = $tag_model->getTagsForID($this->id, 'ticket_id');
    }

    public function createTicket(array $data): int
    {
        $this->reset();

        $this->title = $data['title'] ?? '';
        $this->description = $data['description'] ?? '';
        // 
        $this->priority_id = $data['priority_id'] ?? null;
        $this->status_id = $data['status_id'] ?? null;
        //
        $this->created_by = $data['created_by'] ?? null;
        $this->created_at = ($data['created_at'] == '' ? date('Y-m-d H:i:s') : $data['created_at']) ?? date('Y-m-d H:i:s');
        $this->updated_at = date('Y-m-d H:i:s');

        $this->save();
        $this->logCreate();
        return (int)$this->id;
    }

    public function updateTicket(array $data): void
    {

        $this->logDiff($data);

        if(isset($data['title'])){ $this->title = $data['title']; }
        if(isset($data['description'])) { $this->description = $data['description']; }
        if(isset($data['priority_id'])) { $this->priority_id = $data['priority_id']; }
        if(isset($data['status_id'])) { $this->status_id = $data['status_id']; } 
        if(isset($data['updated_by'])) { $this->updated_by = $data['updated_by']; }
        if(isset($data['assigned_to'])) { 
            if($data['assigned_to'] == '-1'){
                $this->assigned_to = null;
            } else {
                $this->assigned_to = $data['assigned_to'];
            }
        }
        $this->created_at = ($data['created_at'] == '' ? date('Y-m-d H:i:s') : $data['created_at']) ?? date('Y-m-d H:i:s');
        $this->updated_at = date('Y-m-d H:i:s');

        $this->save();
    }

    public function softDelete():void {
        $this->recycled = 1;
        $this->save();
    }

    public function attachments(){
        $attachment = new Attachment($this->db);
        return $attachment->findWithUserByTicketId($this->id);
    }

    public function comments(){
        $comment = new Comment($this->db);
        return $comment->findWithUserByTicketId($this->id);
    }

    public function getParentTickets()
    {
        return $this->db->exec(
            'SELECT p.*
            FROM ticket_relations r
            INNER JOIN tickets p ON r.parent_ticket_id = p.id
            WHERE r.child_ticket_id = ?',
            [$this->id]
        );
    }

    public function getChildTickets()
    {
        return $this->db->exec(
            'SELECT c.*
            FROM ticket_relations r
            INNER JOIN tickets c ON r.child_ticket_id = c.id
            WHERE r.parent_ticket_id = ?',
            [$this->id]
        );
    }

    public function addChildTicket(int $childId)
    {
        $this->db->exec(
            'INSERT IGNORE INTO ticket_relations (parent_ticket_id, child_ticket_id)
            VALUES (?, ?)',
            [$this->id, $childId]
        );
    }

    // meta data
    public function getMeta()
    {
        return $this->db->exec(
            'SELECT id, meta_key, meta_value
            FROM ticket_meta
            WHERE ticket_id = ?',
            [$this->id]
        );
    }

    public function getMetaAssoc()
    {
        $rows = $this->getMeta();
        $assoc = [];
        foreach($rows as $row){
            $assoc[$row['meta_key']] = $row['meta_value'];
        }
        return $assoc;
    }

    public function assocExistingMeta($meta_ids, $meta_keys, $meta_values){
        if(is_array($meta_ids) && is_array($meta_keys) && is_array($meta_values)){
            $field_assoc = [];
            foreach($meta_ids as $i => $m_id){
                $key = $meta_keys[$i] ?? '';
                $value = $meta_values[$i] ?? '';
                if(!empty($key) && $value !== ''){
                    $field_assoc[$key] = $value;
                }
            }
            return $field_assoc;
        }
        return [];
    }

    public function assocMetaFromKeyValue($meta_keys, $meta_values)
    {
        if(is_array($meta_keys) && is_array($meta_values)){
            $field_assoc = [];
            foreach($meta_keys as $i => $key){
                $val = $meta_values[$i] ?? '';
                if(!empty($key) && $val != ''){
                    $field_assoc[$key] = $val;
                }
            }
            return $field_assoc;
        }
        return [];
    }

    public function setCustomFields(array $fields)
    {
        $this->db->exec(
            'DELETE FROM ticket_meta WHERE ticket_id = ?', [$this->id]
        );

        foreach($fields as $key => $value){
            $this->db->exec(
                'INSERT INTO ticket_meta (ticket_id, meta_key, meta_value)
                VALUES (?, ?, ?)',
                [$this->id, $key, $value]
            );
        }
    }

    public function getAssignedUser()
    {
        if(!$this->assigned_to){
            return null;
        }

        $sql = '
            SELECT id, username, display_name 
            FROM users
            WHERE id =?
        ';
        $user = $this->db->exec($sql, [$this->assigned_to]);
        return $user[0];
    }


    /**
     * Logs a change to the ticket history.
     * @param int $user_id - the ID of the user making the change.
     * @param string $field_changed - the name of the field that was changed.
     * @param string|null $old_value - the old value
     * @param string|null $new_value - the new value
     */
    public function logHistory(int $user_id, string $field_changed, 
        $old_value = null, $new_value = null, 
        $changed_at = null): void
    {
        if($this->dry() || !$this->id) return;

        $history = new \DB\SQL\Mapper($this->db, 'ticket_history');
        $history->ticket_id = $this->id;
        $history->user_id = $user_id;
        $history->field_changed = $field_changed;
        $history->old_value = $old_value === null ? null : (string)$old_value;
        $history->new_value = $new_value === null ? null : (string)$new_value;
        if($changed_at == null){
            $history->changed_at = date('Y-m-d H:i:s');
        } else {
            $history->changed_at = $changed_at;
        }
        $history->save();
    }

    public function getHistory(): array {
        if($this->dry() || !$this->id) return[];

        $sql = 'SELECT th.*, u.display_name as user_display_name
        FROM ticket_history th
        JOIN users u ON th.user_id = u.id
        WHERE th.ticket_id = ?
        ORDER BY th.changed_at DESC';
        return $this->db->exec($sql, [$this->id]);
    }

    /**
     * called from create
     */
    public function logCreate(){
        $changed_at = date('Y-m-d H:i:s');
        $user_making_change = \Base::instance()->get('SESSION.user.id');
        $this->logHistory($user_making_change, 'ticket_created', null, $this->title, $changed_at);
        if($this->status_id) $this->logHistory($user_making_change, 'status_id', null, $this->status_id, $changed_at);
        if($this->priority_id) $this->logHistory($user_making_change, 'priority_id', null, $this->priority_id, $changed_at);
        if($this->assigned_to) $this->logHistory($user_making_change, 'assigned_to', null, $this->assigned_to, $changed_at);
    }

    /**
     * called from update
     */
    public function logDiff($data){
        $user_making_change = \Base::instance()->get('SESSION.user.id');
        $changed_at = date('Y-m-d H:i:s');

        $checks = ['title', 'description', 'priority_id', 'status_id', 'assigned_to', 'updated_by'];

        // loop instead
        foreach($checks as $check){
            if(isset($data[$check]) && $this->$check != $data[$check]){
                if($check == 'description'){
                    $old_hash = hash('sha256', $this->$check);
                    $new_hash = hash('sha256', $data[$check]);
                    $this->logHistory($user_making_change, $check, $old_hash, $new_hash, $changed_at);
                } else {
                    $this->logHistory($user_making_change, $check, $this->$check, $data[$check], $changed_at);
                }
            }
        }
    }
    
}