const UserError = require('vn-loopback/util/user-error');
const fs = require('fs-extra');

module.exports = Self => {
    Self.remoteMethodCtx('download', {
        description: 'Download a document',
        accessType: 'READ',
        accepts: [
            {
                arg: 'id',
                type: 'String',
                description: 'The document id',
                http: {source: 'path'}
            }
        ],
        returns: [
            {
                arg: 'body',
                type: 'file',
                root: true
            }, {
                arg: 'Content-Type',
                type: 'String',
                http: {target: 'header'}
            }, {
                arg: 'Content-Disposition',
                type: 'String',
                http: {target: 'header'}
            }
        ],
        http: {
            path: `/:id/download`,
            verb: 'GET'
        }
    });

    Self.download = async function(ctx, id) {
        const userId = ctx.req.accessToken.userId;
        const env = process.env.NODE_ENV;
        const document = await Self.findById(id, {
            include: {
                relation: 'dmsType',
                scope: {
                    fields: ['path', 'readRoleFk'],
                    include: {
                        relation: 'readRole'
                    }
                }
            }
        });
        const readRole = document.dmsType().readRole().name;
        const hasRequiredRole = await Self.app.models.Account.hasRole(userId, readRole);

        if (!hasRequiredRole)
            throw new UserError(`You don't have enough privileges`);

        if (env && env != 'development') {
            const path = `/${document.companyFk}/${document.dmsType().path}/${document.file}`;
            file = {
                path: `/var/lib/salix/dms/${path}`,
                contentType: 'application/octet-stream',
                name: document.file
            };
        } else {
            file = {
                path: `${process.cwd()}/README.md`,
                contentType: 'text/plain',
                name: `README.md`
            };
        }

        await fs.access(file.path);
        let stream = fs.createReadStream(file.path);
        return [stream, file.contentType, `filename="${file.name}"`];
    };
};