Refactor Bake CLI

[jmickey]

Description

Currently, the bake CLI is both out-of-date with the current state of the repo (see #171), and rather difficult to maintain. In order to improve the situation I have some suggestions and ideas.

App Structure

Moving to the hexagonal architecture pattern for structuring the app. Inspiration and more info can be found in this great talk by @katzien:

Video
Slides
golang-standards/project-layout

I propose moving to the following structure:

bake/
├── cmd/
│   ├── root.go
│   └── other-commands.go
└── pkg/
    ├── creators/
    │   └── creator.go
    └── providers/
        ├── provider.go
        ├── youtube.go
        └── some-other-provider.go

API Design

APIs should provide clear and generic interfaces. In the case of a provider, each provider should have a common set of functions that ensures it conforms to the provider interface. E.g. <provider>.Load(), <provider>.Add(), <provider>.Delete() etc.

Creator will consume providers, with config passed from cmd into the creator.
Example of the code workflow (I haven't tested this code, it's just an idea):

package cmd

import (
  "github.com/breadtubetv/breadtubetv/bake/pkg/creators"
  "github.com/spf13/viper
)

var creator creators.Creator
creator.AddConfig(viper.GetViper())
if creator = creators.Get('slug') == nil {
  // Add a creator if not found
  creator = creator.Create('slug', 'initial-provider', 'url')
}

creator.Providers.Add('twitter')
creator.Provider['twitter'].Update(("followers", 1200000))

...and so on.

This will provide us with an easy way of adding new providers, which can easily be added to creators, which in term can easily be consumed by the CLI.

Implementation

WIP