<table>
  <tr><th colspan="2"><h3>🎲 Community plugins</h3></th></tr>
  <tr><td colspan="2" align="center">Additional plugins maintained by community for even more features!</td></tr>
<% {
  let cell = 0
  const elements = Object.entries(plugins).filter(([key, value]) => (value)&&(value.category === "community"))
  if (elements.length%2)
    elements.push(["", {readme:{demo:`<td align="center"><img width="900" height="1" alt=""></td>`}}])
  for (let i = 0; i < elements.length; i+=2) {
    const cells = [["even", elements[i]], ["odd", elements[i+1]]]
    for (const [cell, [plugin, {name, readme}]] of cells) {
      if (cell === "even") { %>  <tr><% } %>
    <th><% if (plugin) { %><a href="source/plugins/community/<%= plugin %>/README.md"><%= name -%></a><% } %></th><%
    if (cell === "odd") { %>
  </tr>
<% }}
    for (const [cell, [plugin, {name, readme}]] of cells) {
      if (cell === "even") { %>  <tr><% } %>
<%- readme.demo.replace(/<img src=/g, `<img alt="" width="400" src=`) %><%
      if (cell === "odd") { %>
  </tr><% }}}} %>
</table>

## 📪 Creating community plugins

Plugins creation requires you to be comfortable with JavaScript, HTML, CSS and [EJS](https://github.com/mde/ejs).

### 💬 Before creating a new plugin

Be sure to read [contribution guide](/CONTRIBUTING.md) and [architecture](/ARCHITECTURE.md) first.

> ℹ️ *metrics* maintainers have no obligation towards community plugins support and may redirect any help, feature or fix requests from other users to you. Of course you are not bound to work on it, but it would be great if you plan to merge a plugin in the main repository

Please respect the following guidelines:

- A plugin should be independant and should not rely on other plugins
  - [🧱 core](/source/plugins/core/README.md) and [🗃️ base](/source/plugins/base/README.md) output can be reused though
- A plugin should never edit its original arguments, as it is shared amongst other plugins and would create unattended side effects
- Use `imports.metadata.plugins.{plugin-name}.inputs()` to automatically typecheck and default user inputs through defined `metadata.yml`
- Plugin options should respect the "lexical field" of existing option to keep consistency
- Plugin errors should be handled gracefully by partials with error message
- New dependencies should be avoided, consider using existing `imports`
- Spawning sub-process should be avoided, unless absolute necessity
  - Use `imports.which()` to detect whether a command is available
  - Use `imports.run()` to run a command
    - Pass `{prefixed: true}` to wrap automatically command with [WSL](https://docs.microsoft.com/windows/wsl/about) on Windows
  - It is required to work on Linux Ubuntu (as the GitHub action run on it)

> 💡 While the following guide intend to explain the creation process of new plugin, it may also be a good idea to see what existing plugins looks like and see if you want to embark on the adventure!

### 💬 Quick-start

To create a new plugin, clone and setup this repository first:
```shell
git clone https://github.com/lowlighter/metrics.git
cd metrics/
npm install
```

Find a cool name and an [unused emoji](https://emojipedia.org) for your new plugin and run the following:
```shell
npm run quickstart plugin <plugin_name>
```

> ⚠️ Community plugins cannot have the same name as official plugins. *metrics* maintainers may also reserve a plugin name for future usage and may ask you to rename it in case of conflicts

It will create a new directory in `/source/plugins/community` with the following file structure:
* `/source/plugins/community/{plugin-name}`
  * `README.md`
  * `metadata.yml`
  * `examples.mjs`
  * `index.mjs`

Plugins are auto-loaded based on their folder existence, so there's no need to register them somewhere.

### 💬 Filling `metadata.yml`

`metadata.yml` is a required file which describes supported account types, output formats, scopes, etc.

The default file looks like below:
```yaml
name: "🧩 Plugin name"
category: community
description: Short description
examples:
  default: https://via.placeholder.com/468x60?text=No%20preview%20available
authors:
  - octocat
supports:
  - user
  - organization
  - repository
scopes: []
inputs:

  plugin_{name}:
    description: Enable {name} plugin
    type: boolean
    default: no
```

> 💡 It is important to correctly define `metadata.yml` because *metrics* will use its content for various usage

[`🧱 core`](/source/plugins/core/README.md) plugin (which is always called) will automatically verify user inputs against `supports` and `inputs` values and throw an error in case of incompatibility.

`name`, `description`, `scopes`, `examples` are used to auto-generate documentation in the `README.md`. For community plugins, `examples` should be set with auto-generated examples of your own profile.

`authors` should contain your GitHub username

`category` should be set to `community`.

Because of GitHub Actions original limitations, only strings, numbers and boolean were actually supported by `action.yml`. *metrics* implemented its own `inputs` validator to circumvent this. It should be pretty simple to use.

*Example: boolean type, defaults to `false`*
```yml
  plugin_{name}_{option}:
    description: Boolean type
    type: boolean
    default: no
```

```yml
  plugin_{name}_{option}:
    description: String type
    type: string
    default: .user.login
```

> 💡 `.user.login`, `.user.twitter` and `.user.website` are special default values that will be respectively replaced by user's login, Twitter username and attached website. Note that these are not available if `token: NOT_NEEDED` is set by user

*Example: string type, defaults to `foo` with `foo` or `bar` as allowed values*
```yml
  plugin_{name}_{option}:
    description: Select type
    type: string
    values:
      - foo
      - bar
    default: foo
```

> 💡 `values` restricts what can be passed by user

*Example: number type, defaults to `1` and expected to be between `0` and `100`*
```yml
  plugin_{name}_{option}:
    description: Number type
    type: number
    default: 1
    min: 0
    max: 100
```

> 💡 `min` and `max` restricts what can be passed by user. Omit these to respectively remove lower and upper limits.

> 💡 Zero may have a special behaviour (usually to disable limitations), if that's the case add a `zero` attribute (e.g. `zero: disable`) to reference this in documentation

*Example: array type, with comma-separated elements*
```yml
  plugin_{name}_{option}:
    description: Array type
    type: array
    format: comma-separated
    values:
      - foo
      - bar
    default: foo, bar
```

> 💡 An array can be either `comma-separated` or `space-separated`, and will split user input by mentioned separator. Each value is trimmed and lowercased.

*Example: json type*
```yml
  plugin_{name}_{option}:
    description: JSON type
    type: json
    default: |
      {
        "foo": "bar"
      }
```

> 💡 JSON types should be avoided when possible, as they're usually kind of unpractical to write within a YAML document

For complex inputs, pass an `example` that will be displayed as a placeholder on web instances.

When calling `imports.metadata.plugins.{plugin-name}.inputs({data, account, q})`, an object with verified user inputs and correct typing will be returned.

Any invalid input will use have the `default` value instead.

> ⚠️ Returned object will use the web syntax for options rather than the action one. It means that `plugin_` prefix is dropped, and all underscores (`_`) are replaced by dots (`.`)

*Example: validating user inputs*
```javascript
let {limit, "limit.field":limit_field} = imports.metadata.plugins.myplugin.inputs({data, account, q})
console.assert(limit === true)
```

### 💬 Filling `index.mjs`

Plugins use [JavaScript modules](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules).

The default exported module of `index.mjs` will be auto-loaded when *metrics* start.

Below is a breakdown of basic `index.mjs` content
```js
export default async function(
  //Shared inputs
  {
    login, //GitHub username
    q, //Raw user inputs (dot notation without plugin_ prefix, don't use it directly)
    imports, //Various utilitaires (axios, puppeteer, fs, etc., see /source/app/metrics/utils.mjs)
    data, //Raw data from core/base plugin
    computed, //Computed data from core/base plugin
    rest, //Rest authenticated GitHub octokit
    graphql, //Graph QL authenticated GitHub octokit
    queries, //Autoloaded queries from ./queries
    account, //Account type ("user" or "organization")
  },
  //Settings and tokens
  {
    enabled = false
  } = {}) {
    //Plugin execution
    try {
      //Check if plugin is enabled and requirements are met
      if ((!enabled)||(!q.my_plugin))
        return null

      //Automatically validate user inputs
      //An error will be thrown if `account` type is not supported
      //Inputs will have correct typing from `metadata.yml` and unset or invalid options will be set to default
      let {option} = imports.metadata.plugins.my_plugin.inputs({data, account, q})

      //Automatically template query from /source/plugins/myplugin/queries/myquery.graph ql
      const {[account]:stuff} = await graphql(queries.myplugin.myquery({login, account, option}))

      //Results
      return {stuff}
    }
    //Handle errors
    catch (error) {
      throw {error:{message:"An error occured", instance:error}}
    }
}
```

> ⚠️ Remember, a plugin should never edit its original arguments, as it is shared amongst other plugins and would create unattended side effects

### 💬 Creating partials

Just create a new `.ejs` file in `partials` folder from templates you wish to support, and reference it into their `partials/_.json`.

Plugin partials should be able to handle gracefully their own state and errors.

Below is a minimal snippet of a partial:
```ejs
<<%= "%" %> if (plugins.{plugin_name}) { <%= "%" %>>
  <<%= "%" %> if (plugins.{plugin_name}.error) { <%= "%" %>>
    <<%= "%=" %> plugins.{plugin_name}.error.message <%= "%" %>>
  <<%= "%" %> } else { <%= "%" %>>
    <<%= "%#" %> content <%= "%" %>>
  <<%= "%" %> } <%= "%" %>>
<<%= "%" %> } <%= "%" %>>
```

Partials should have the match the same name as plugin handles, as they're used to display plugin compatibility in auto-generated header.

[EJS](https://github.com/mde/ejs) framework is used to template content through templating tags (`<% %>`).

### 💬 Filling `README.md`

`README.md` is used as documentation.

Most of it will is auto-generated by `metadata.yml` and `examples.yml` content, so usually it is not required to manually edit it.

The default content looks like below:
```markdown
<ǃ--header-->
<ǃ--/header-->

## ➡️ Available options

<ǃ--options-->
<ǃ--/options-->

## ℹ️ Examples workflows

<ǃ--examples-->
<ǃ--/examples-->
```

- `<ǃ--header-->` will be replaced by an auto-generated header containing plugin name, supported features and output examples based on `metadata.yml`
- `<ǃ--options-->` will be replaced by an auto-generated table containing all referenced option from `metadata.yml`
- `<ǃ--examples-->` will be replaced by workflows from `examples.yml`

> ⚠️ Do not replace these auto-generated placeholder yet! They will be built by the ci workflow and will help making your pull request easier to read

When a plugin requires a token, please add a `## 🗝️ Obtaining a {service} token` section after the available options section.

Complex features may also be documented in additional sections after available options section options if required.

Try to respect current format of `README.md` from other plugins and use a neutral and impersonal writing style if possible.

### 💬 Filling `examples.yml`

Workflow examples from `examples.yml` are used as unit testing and to auto-generate documentation in the `README.md`.

It uses the same syntax as GitHub action and looks like below:
```yml
- name: Test name
  uses: lowlighter/metrics@latest
  with:
    filename: metrics.plugin.{name}.svg
    token: ${{ secrets.METRICS_TOKEN }}
    base: ""
    plugin_{name}: yes
  prod:
    skip: true
  test:
    timeout: 1800000
    modes:
      - action
      - web
      - placeholder
```

> 💡 Tests are executed in a mocked environment to avoid causing charges on external services. It may be required to create mock testing files.

`test` is usually not needed and optional but can be set to set a custom timeout (for plugins with a high execution time) and `modes` can be used to restrict which environment should be used.

`prod` should keep `skip: true` as you should use your own render outputs as examples.

### 💬 Testing locally and creating mocked data

The easiest way to test a new plugin is to setup a web instance locally ([see documentation](.github/readme/partials/documentation/setup/local.md)).

Once server is started, open a browser and try to generate an output with your new plugin enabled and check if it works as expected:
```
http://localhost:3000/username?base=0&my-plugin=1
```

> 💡 You may need to configure your server first by editing `settings.json`. Ensure that:
> - `token` is correctly set when working with GitHub APIs
> - `plugins.default` is set to `true` as plugins are disabled by default
>   - or enable your plugins by manually in `plugins`.`my-plugin`.`enabled`
> -  `debug` is set to `true` for more verbose output

When your plugin is finalized, you may need to create mocked data if it either uses GitHub APIs or any external service.

They must be created in `tests/mocks/api`:
- use `github` directory for all related GitHub APIs data
- use `axios` directory for all external service that you call using `imports.axios`

> 💡 Files from these directories are auto-loaded, so it is just required to create them with faked data.

Finally [/source/app/web/statics/app.placeholder.js](/source/app/web/statics/app.placeholder.js) to add mocked placeholder data to make users using the shared instance able to preview a render locally without any server computation.

### 💬 Submitting a pull request

If you made it until there, congratulations 🥳!

You're almost done, review the following checklist before submitting a pull request:
- [x] I have correctly filled `metadata.yml`
  - [x] `name` is set with an unused emoji and plugin name
  - [x] `category` is set to `community`
  - [x] `examples` contains links towards a rendered output hosted by you
  - [x] `authors` contains my GitHub username
  - [x] `supports` list which account type are supported
  - [x] `scopes` are correctly listed with their associated names on GitHub (leave an empty array if not applicable)
  - [x] `inputs` are correctly filled
- [x] I have implemented my plugin
  - [x] `index.mjs` respects the plugins guidelines
- [x] I have tested my plugin locally
  - [x] `tests/mocks` ... have been created
  - [x] `app.placeholder.js` has been updated for preview from web instances
  - [x] `examples.yml` contains workflows examples (at least one is required)
    - [x] `skip: true` has been set for `prod` attribute in each test
  - [x] `npm run linter` yields no errors
- [x] I have documented my plugin
  - [x] `README.md` eventually describes complex setup or options (if applicable)
- [x] I am ready!
  - [x] Checkout any generated files (in fact, don't run `npm run build`)
  - [x] Commit and push your changes (commits are squashed, no need to rebase)
  - [x] Open a new [pull request](https://github.com/lowlighter/metrics/pulls)
  - [x] Post a screenshot or a render in the pull request so it can be previewed

> 💡 A pull request **will need** to have passing builds and an example screenshot if you want to get it merged.
> Maintainers may request changes in some cases

> 🎊 Thanks a lot for your contribution!

