# Plugin API Reference

This document provides detailed technical information about BetterSEQTA+'s plugin APIs. For a beginner-friendly introduction, see [Creating Your First Plugin](./README.md).

## Plugin Structure

Here's how a plugin is structured:

```typescript
import type { Plugin } from '@/plugins/core/types';
import { BasePlugin } from '@/plugins/core/settings';
import { booleanSetting, defineSettings, Setting } from '@/plugins/core/settingsHelpers';

// First, define your settings
const settings = defineSettings({
  enabled: booleanSetting({
    default: true,
    title: "Enable Feature",
    description: "Turn this feature on or off",
  })
});

// Create a class to handle your settings
class MyPluginClass extends BasePlugin<typeof settings> {
  @Setting(settings.enabled)
  enabled!: boolean;
}

// Create an instance of your settings
const settingsInstance = new MyPluginClass();

// Create your plugin
const myPlugin: Plugin<typeof settings> = {
  id: 'my-plugin',
  name: 'My Plugin',
  description: 'A cool plugin that does things',
  version: '1.0.0',
  settings: settingsInstance.settings,
  disableToggle: true,

  run: async (api) => {
    console.log('Plugin is running!');
    
    // Do stuff when settings change
    api.settings.onChange('enabled', (enabled) => {
      if (enabled) {
        console.log('Feature enabled!');
      }
    });

    // Return a cleanup function
    return () => {
      console.log('Plugin cleanup');
    };
  }
};

export default myPlugin;
```

## SEQTA API

The SEQTA API helps you interact with SEQTA's pages:

```typescript
import type { Plugin } from '@/plugins/core/types';

const seqtaPlugin: Plugin<typeof settings> = {
  id: 'seqta-example',
  name: 'SEQTA Example',
  description: 'Shows how to use the SEQTA API',
  version: '1.0.0',
  settings: {},
  disableToggle: true,

  run: async (api) => {
    // Wait for elements to appear
    const { unregister: timetableUnregister } = api.seqta.onMount('.timetable', (timetable) => {
      const button = document.createElement('button');
      button.textContent = 'Export';
      timetable.appendChild(button);
    });

    // Track page changes
    const { unregister: pageUnregister } = api.seqta.onPageChange((page) => {
      console.log('User went to:', page);
    });

    // Clean up when disabled
    return () => {
      timetableUnregister();
      pageUnregister();
    };
  }
};

export default seqtaPlugin;
```

## Settings API

Here's how to add settings to your plugin:

```typescript
import type { Plugin } from '@/plugins/core/types';
import { BasePlugin } from '@/plugins/core/settings';
import { booleanSetting, stringSetting, numberSetting, selectSetting, defineSettings, Setting } from '@/plugins/core/settingsHelpers';

// Define your settings
const settings = defineSettings({
  darkMode: booleanSetting({
    default: false,
    title: "Dark Mode",
    description: "Enable dark mode"
  }),
  userName: stringSetting({
    default: "",
    title: "User Name",
    description: "Your display name",
    placeholder: "Enter your name..."
  }),
  theme: selectSetting({
    default: "light",
    title: "Theme",
    description: "Choose your theme",
    options: [
      { value: "light", label: "Light" },
      { value: "dark", label: "Dark" }
    ]
  })
});

// Create your settings class
class ThemePluginClass extends BasePlugin<typeof settings> {
  @Setting(settings.darkMode)
  darkMode!: boolean;

  @Setting(settings.userName)
  userName!: string;

  @Setting(settings.theme)
  theme!: string;
}

// Create the plugin
const themePlugin: Plugin<typeof settings> = {
  id: 'theme-example',
  name: 'Theme Example',
  description: 'Shows how to use settings',
  version: '1.0.0',
  settings: new ThemePluginClass().settings,
  disableToggle: true,

  run: async (api) => {
    // Apply initial settings
    if (api.settings.darkMode) {
      document.body.classList.add('dark');
    }

    // Listen for changes
    const { unregister } = api.settings.onChange('darkMode', (enabled) => {
      document.body.classList.toggle('dark', enabled);
    });

    return () => {
      unregister();
      document.body.classList.remove('dark');
    };
  }
};

export default themePlugin;
```

## Storage API

Here's how to use storage in your plugin:

```typescript
import type { Plugin } from '@/plugins/core/types';

const storagePlugin: Plugin<typeof settings> = {
  id: 'storage-example',
  name: 'Storage Example',
  description: 'Shows how to use storage',
  version: '1.0.0',
  settings: {},
  disableToggle: true,

  run: async (api) => {
    // Wait for storage to be ready
    await api.storage.loaded;

    // Save some data
    await api.storage.set('lastVisit', new Date().toISOString());
    
    // Get saved data
    const lastVisit = await api.storage.get('lastVisit');
    console.log('Last visit:', lastVisit);

    // Listen for changes
    const { unregister } = api.storage.onChange('lastVisit', (newValue) => {
      console.log('Last visit updated:', newValue);
    });

    return () => {
      unregister();
    };
  }
};

export default storagePlugin;
```

## Events API

Here's how to use events in your plugin:

```typescript
import type { Plugin } from '@/plugins/core/types';

const eventsPlugin: Plugin<typeof settings> = {
  id: 'events-example',
  name: 'Events Example',
  description: 'Shows how to use events',
  version: '1.0.0',
  settings: {},
  disableToggle: true,

  run: async (api) => {
    // Listen for theme changes
    const { unregister: themeListener } = api.events.on('theme.changed', (theme) => {
      console.log('Theme changed to:', theme);
    });

    // Listen for notifications
    const { unregister: notifyListener } = api.events.on('notification.new', (notification) => {
      console.log('New notification:', notification);
    });

    // Clean up listeners
    return () => {
      themeListener();
      notifyListener();
    };
  }
};

export default eventsPlugin;
```

## Performance Tips

Here's how to write efficient plugins:

```typescript
import type { Plugin } from '@/plugins/core/types';

const efficientPlugin: Plugin<typeof settings> = {
  id: 'efficient-example',
  name: 'Efficient Example',
  description: 'Shows performance best practices',
  version: '1.0.0',
  settings: {},
  disableToggle: true,

  run: async (api) => {
    // ✅ Good: Use onMount
    const { unregister } = api.seqta.onMount('.timetable', (el) => {
      el.classList.add('enhanced');
    });

    // ❌ Bad: Don't use intervals
    // const interval = setInterval(() => {
    //   const el = document.querySelector('.timetable');
    //   if (el) el.classList.add('enhanced');
    // }, 100);

    // ✅ Good: Cache DOM elements
    const header = document.querySelector('.header');
    if (header) {
      // Reuse header instead of querying again
    }

    // ✅ Good: Batch DOM updates
    const fragment = document.createDocumentFragment();
    for (let i = 0; i < 10; i++) {
      const div = document.createElement('div');
      fragment.appendChild(div);
    }
    document.body.appendChild(fragment);

    return () => {
      unregister();
      // clearInterval(interval); // If you used the bad approach
    };
  }
};

export default efficientPlugin;
```

Each plugin should be in its own file and exported as the default export. The plugin should:
1. Import necessary types and helpers
2. Define settings if needed
3. Create a settings class if using settings
4. Create the plugin object with proper type annotation
5. Export the plugin as default

Remember to always:
- Use proper TypeScript types
- Clean up when your plugin is disabled
- Handle errors gracefully
- Follow the plugin structure shown above