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

module.exports = Self => {
    Self.remoteMethodCtx('upload', {
        description: 'Uploads a file and inserts into dms model',
        accessType: 'WRITE',
        accepts: [
            {
                arg: 'id',
                type: 'Number',
                description: 'The entity id',
                required: true
            },
            {
                arg: 'collection',
                type: 'string',
                description: 'The collection name',
                required: true
            }],
        returns: {
            type: 'Object',
            root: true
        },
        http: {
            path: `/upload`,
            verb: 'POST'
        }
    });

    Self.upload = async ctx => {
        const models = Self.app.models;
        const fileOptions = {};
        const args = ctx.args;

        const hasWriteRole = await models.ImageCollection.hasWriteRole(ctx, args.collection);
        if (!hasWriteRole)
            throw new UserError(`You don't have enough privileges`);

        if (process.env.NODE_ENV == 'test')
            throw new UserError(`You can't upload images on the test instance`);

        // Upload file to temporary path
        const container = await getContainer(args.collection);
        const uploaded = await models.ImageContainer.upload(container.name, ctx.req, ctx.result, fileOptions);
        const [uploadedFile] = Object.values(uploaded.files).map(file => {
            return file[0];
        });

        const file = await models.ImageContainer.getFile(container.name, uploadedFile.name);
        const srcFile = `${file.client.root}/${file.container}/${file.name}`;
        await models.Image.registerImage(container.name, srcFile, args.id);
    };

    /**
     * Returns a container instance
     * If doesn't exists creates a new one
     *
     * @param {String} name Container name
     * @return {Object} Container instance
     */
    async function getContainer(name) {
        const models = Self.app.models;
        let container;
        try {
            container = await models.ImageContainer.getContainer(name);
        } catch (err) {
            if (err.code === 'ENOENT') {
                container = await models.ImageContainer.createContainer({
                    name: name
                });
            } else throw err;
        }

        return container;
    }
};