<?php

class AttachmentController {

    private function check_access($f3){
        if(!$f3->exists('SESSION.user')){
            $f3->reroute('/login');
        }
    }

    // list attachments
    public function index($f3){
        $this->check_access($f3);

        $ticket_id = (int) $f3->get('PARAMS.id');
        $db = $f3->get('DB');

        // fetch attachments

        $attachments = $db->exec(
            'SELECT a.*, u.username
            FROM attachments a
            LEFT JOIN users u ON u.id = a.uploaded_by
            WHERE a.ticket_id = ? 
            ORDER BY a.created_at DESC', 
            [$ticket_id]
        );

        $f3->set('ticket_id', $ticket_id);
        $f3->set('attachments', $attachments);
        
        $f3->set('content', '../ui/views/attachment/index.html');
        // echo \Template::instance()->render('../ui/templates/layout.html');
        echo \Template::instance()->render($f3->get('content'));
    }

    // handle file upload
    public function upload($f3){
        $this->check_access($f3);

        $ticket_id = (int) $f3->get('PARAMS.id');
        $uploaded_by = $f3->get('SESSION.user.id');

        if(!isset($_FILES['attachment']) || $_FILES['attachment']['error'] !== UPLOAD_ERR_OK){
            $f3->reroute('/ticket/'.$ticket_id.'/attachments');
        }

        $file_info = $_FILES['attachment'];
        $original_name = $file_info['name'];
        $tmp_path = $file_info['tmp_name'];

        // create a unique file path
        $upload_dir = '../storage/attachments/tickets/'.$ticket_id.'/';
        if(!is_dir($upload_dir)){
            mkdir($upload_dir, 0777, true);
        }

        // if file exists increment version
        $db = $f3->get('DB');
        $existing = $db->exec(
            'SELECT * FROM attachments
            WHERE ticket_id =? AND file_name = ?
            ORDER BY version_number DESC
            LIMIT 1',
            [$ticket_id, $original_name]
        );

        $new_version = 1;
        if($existing){
            $new_version = $existing[0]['version_number'] + 1;
        }

        $final_path = $upload_dir.$new_version.'_'.$original_name;

        // move file
        move_uploaded_file($tmp_path, $final_path);

        // store meta data in DB
        $db->exec(
            'INSERT INTO attachments
            (ticket_id, path, file_name, version_number, uploaded_by, created_at)
            VALUES (?,?,?,?,?,NOW())', 
            [$ticket_id, $final_path, $original_name, $new_version, $uploaded_by]
        );

        $f3->reroute('/ticket/'.$ticket_id.'');
    }

    // download attachment
    public function download($f3){
        $this->check_access($f3);

        $attachment_id = (int) $f3->get('PARAMS.id');
        $db = $f3->get('DB');

        $rows = $db->exec('SELECT * FROM attachments WHERE id = ?', [$attachment_id]);

        if(!$rows){
            $f3->error(404, "File not found");
            return;
        }

        $attachment = $rows[0];
        $file_path = $attachment['path'];
        $file_name = $attachment['file_name'];

        // validate file exists
        if(!file_exists($file_path)){
            $f3->error(404, "File not found");
            return;
        }

        // output headers for download
        header('Content-Description: File Transfer');
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
        header('Content-Length: '. filesize($file_path));

        // flush headers
        flush();

        // read file
        readfile($file_path);
        exit;
    }

    // delete an attachment
    public function delete($f3){
        $this->check_access($f3);

        $attachment_id = (int) $f3->get('PARAMS.id');
        $current_user = $f3->get('SESSION.user');

        $db = $f3->get('DB');

        $rows = $db->exec('SELECT * FROM attachments WHERE id =? LIMIT 1', [$attachment_id]);
        if(!$rows){
            $f3->error(404, "Attachment not found");
            return;
        }

        $attachment = $rows[0];
        // TODO: role or ownership

        if(file_exists($attachment['path'])){
            unlink($attachment['path']);
        }

        // remove DB row
        $db->exec('DELETE FROM attachments WHERE id =?', [$attachment_id]);
    }
}