This commit refactors the whole package gateway as well as utils/ws
(formerly utils/wsutil) and voice/voicegateway. The new refactor
utilizes a design pattern involving a concurrent loop and an arriving
event channel.
An additional change was made to the way gateway events are typed.
Before, pretty much any type will satisfy a gateway event type, since
the actual type was just interface{}. The new refactor defines a
concrete interface that events can implement:
type Event interface {
Op() OpCode
EventType() EventType
}
Using this interface, the user can easily add custom gateway events
independently of the library without relying on string maps. This adds a
lot of type safety into the library and makes type-switching on Event
types much more reasonable.
Gateway error callbacks are also almost entirely removed in favor of
custom gateway events. A catch-all can easily be added like this:
s.AddHandler(func(err error) {
log.Println("gateway error:, err")
})
This commit refactors the Store interface in State into smaller
interfaces in package store. These interfaces are combined into one
structure called a "Cabinet". The default implementation of those
interfaces have been rewritten in package defaultstore, while the old
no-op implementation stays with the store package.
This commit also omitted several state handlers for user events, as it
is unclear what they are actually structured like.
This commit refactored several structures from package discord to be in
package gateway. Those structures are mostly presence ones, which per
official documentation has a lot more to do with the Gateway API than
the REST API or anything else.
This commit also renamed several global variables to have a more
consistent and obvious name.
As of v8, the user API has had a lot of minor and some major changes,
especially regarding its Ready event API. The most significant change is
the addition of the ReadySupplemental event as well as several changes
to the Ready field itself.
All of these changes above are breaking, and they have already broken
the state package. These breaking changes will be addressed in other
packages by the next commit.