# Teac

Twitch Elixir API Client
For Twitch's REST and Websocket api. 

## Hex docs

https://hexdocs.pm/teac/readme.html

## Installation

This is currently a work in progress.
While in development its highly recomended to use the github mix package as there are rapid changes coming in.

```elixir
def deps do
  [
    {:teac, "~> 0.8.0"}
  ]
end
```

### .env
```bash
export TWITCH_CLIENT_ID=""
export TWITCH_CLIENT_SECRET=""
export TWITCH_API_URI="https://api.twitch.tv/helix/"
export TWITCH_AUTH_URI="https://id.twitch.tv/oauth2/"
export TWITCH_OAUTH_CALLBACK_URI="http://example.com:4000/oauth/callbacks/twitch/"
```

### config.ex

```elixir
config :teac,
  client_id: System.get_env("TWITCH_CLIENT_ID"),
  client_secret: System.get_env("TWITCH_CLIENT_SECRET"),
  api_uri: System.get_env("TWITCH_API_URI"),
  auth_uri: System.get_env("TWITCH_AUTH_URI"),
  oauth_callback_uri: System.get_env("TWITCH_OAUTH_CALLBACK_URI")
```

## Basic Usage

Create a client with your credentials, then pass it to any endpoint:

```elixir
client = Teac.new(token: "some_auth_token", client_id: "your_client_id")

Teac.Api.Bits.Leaderboard.get(client)
Teac.Api.Chat.Color.get(client, user_id: "some_users_id")
Teac.Api.Polls.post(client, broadcaster_id: "123", title: "Best game?", choices: [...], duration: 300)
```

The `client_id` defaults to the value in your config if omitted:

```elixir
client = Teac.new(token: "some_auth_token")
```

Check the endpoint documentation to determine whether it requires a user or app access token — some accept either, some are exclusive.
https://dev.twitch.tv/docs/api/reference/

## Example Application using this lib.
https://codeberg.org/FullStacking/teac_example

## Using App Flow Auth token.

A genserver that fetches and mantains a valid auth token for Client Credential is provided.
IE: Server To Server or noted as on any endpoint as `Requires an app access token`

```elixir
def start(_type, _args) do
  children = [
    ...
    Teac.Oauth.ClientCredentialManager,
    ...
  ]
  opts = [strategy: :one_for_one, name: TeacExample.Supervisor]
  Supervisor.start_link(children, opts)
end
```

Assuming you provided your `.env` vars and have a running server, retrieve a token and build a client:

```elixir
token = Teac.Oauth.ClientCredentialManager.get_token()
client = Teac.new(token: token)
```

`get_token/0` always returns a valid app token. Pass the resulting client to any endpoint that accepts an app access token.


## Developing
You will need the twitch cli tool.
https://dev.twitch.tv/docs/cli/

* Generate some mock data
  `twitch mock-api generate -c 6`

* Set Env Variables from mock output
  `export TWITCH_CLIENT_ID=your_client_id`
  `export TWITCH_CLIENT_SECRET=your_client_secret`
  `export TWITCH_API_URI="http://localhost:8080"`

* Start a mock twitch server.
  `twitch mock-api serve`

Assuming you have a Twitch mock server running to get the auth:

```elixir
{:ok, [%{"ID" => client_id, "Secret" => client_secret}]} = Teac.MockApi.clients()

{:ok, %{"access_token" => access_token}} =
  Teac.MockAuth.fetch_app_access_token(client_id: client_id, client_secret: client_secret)

client = Teac.new(token: access_token, client_id: client_id)
{:ok, data} = Teac.Api.Bits.Cheermotes.get(client)
```

All endpoints take a `%Teac.Client{}` as the first argument, followed by an optional keyword list of endpoint-specific parameters.