# API Reference

BetterCurseForge exposes a global runtime object on `window.BetterCurseForge` within the CurseForge Electron renderer process. This API allows themes, plugins, and developer scripts to inject styles, monkey-patch methods, manage settings, and listen to application events.

---

## TypeScript Definition

For TypeScript development and autocompletion:

```typescript
declare global {
  interface Window {
    BetterCurseForge: BetterCurseForgeAPI;
  }
}

export interface BetterCurseForgeAPI {
  /** Active BetterCurseForge runtime version */
  readonly version: string;

  /** Injects CSS dynamically into <head>. Returns an unmount callback. */
  injectCSS(css: string): () => void;

  /** Persistent settings storage */
  settings: {
    get(key?: string): Promise<any>;
    set(key: string, value: any): Promise<boolean>;
  };

  /** Runtime method interception and monkey-patching */
  patcher: {
    before(obj: any, method: string, callback: (args: any[]) => void): () => void;
    after(obj: any, method: string, callback: (args: any[], result: any) => any): () => void;
    instead(obj: any, method: string, callback: (args: any[], original: Function) => any): () => void;
  };

  /** Event bus */
  on(event: string, callback: (...args: any[]) => void): void;
  off(event: string, callback: (...args: any[]) => void): void;
  emit(event: string, ...args: any[]): void;

  /** Internal subsystem managers */
  themes: ThemeManager;
  plugins: PluginManager;
  ads: AdBlocker;
}
```

---

## Core API

### `BetterCurseForge.version`

- **Type**: `string`
- **Description**: The currently running BetterCurseForge runtime version.

```javascript
console.log(BetterCurseForge.version); // "1.0.0"
```

---

### `BetterCurseForge.injectCSS(css)`

Dynamically injects CSS rules into the document `<head>`.

- **Parameters**:
  - `css` *(string)*: Raw CSS string to inject.
- **Returns**: `() => void` — Function that removes the injected `<style>` tag when called.

```javascript
// Inject styles
const uninject = BetterCurseForge.injectCSS(`
  .some-container {
    background-color: #1a102f !important;
  }
`);

// Later, remove the styles
uninject();
```

---

## Settings API (`BetterCurseForge.settings`)

Manages persistent configuration stored in `%APPDATA%\CurseForge\BetterCurseForge\settings.json`.

### `settings.get(key?)`

Retrieves a setting by key, or returns the entire settings object if no key is specified.

- **Parameters**:
  - `key` *(string, optional)*: Setting key name.
- **Returns**: `Promise<any>` — Value of the setting, or `null`.

```javascript
// Retrieve a specific value
const activeTheme = await BetterCurseForge.settings.get('activeCustomTheme');

// Retrieve all settings
const allSettings = await BetterCurseForge.settings.get();
```

### `settings.set(key, value)`

Stores a setting value and writes it asynchronously to disk.

- **Parameters**:
  - `key` *(string)*: Setting key name.
  - `value` *(any)*: JSON-serializable value.
- **Returns**: `Promise<boolean>` — `true` if saved successfully.

```javascript
await BetterCurseForge.settings.set('myPlugin.fontSize', 14);
```

---

## Patcher API (`BetterCurseForge.patcher`)

Provides monkey-patching utilities to inspect, modify, or replace methods on JavaScript objects and modules safely.

### `patcher.before(obj, method, callback)`

Executes `callback(args)` **before** the target method is invoked.

- **Parameters**:
  - `obj` *(object)*: Target object.
  - `method` *(string)*: Method name on `obj`.
  - `callback` *(Function)*: Function receiving arguments: `(args) => void`.
- **Returns**: `() => void` — Unpatch function that restores the original method.

```javascript
const unpatch = BetterCurseForge.patcher.before(console, 'warn', (args) => {
  console.log('[Warn Interceptor]', ...args);
});

// Revert patch:
unpatch();
```

---

### `patcher.after(obj, method, callback)`

Executes `callback(args, result)` **after** the target method runs. You can return a new value to replace the method's return value.

- **Parameters**:
  - `obj` *(object)*: Target object.
  - `method` *(string)*: Method name on `obj`.
  - `callback` *(Function)*: `(args, result) => any`.
- **Returns**: `() => void` — Unpatch function.

```javascript
const unpatch = BetterCurseForge.patcher.after(service, 'getTitle', (args, result) => {
  return `Prefix: ${result}`;
});

unpatch();
```

---

### `patcher.instead(obj, method, callback)`

Completely overrides the target method. Receives both the incoming arguments and a reference to the original method.

- **Parameters**:
  - `obj` *(object)*: Target object.
  - `method` *(string)*: Method name on `obj`.
  - `callback` *(Function)*: `(args, originalFn) => any`.
- **Returns**: `() => void` — Unpatch function.

```javascript
const unpatch = BetterCurseForge.patcher.instead(target, 'openExternalUrl', (args, originalFn) => {
  const url = args[0];
  if (url.startsWith('https://safe-domain.com')) {
    return originalFn(...args);
  }
  console.warn('Blocked external URL navigation:', url);
});

unpatch();
```

---

## Event System (`BetterCurseForge.on / off / emit`)

BetterCurseForge includes an event bus for inter-plugin and lifecycle communication.

### `BetterCurseForge.on(event, callback)`
Subscribes a listener to an event.

```javascript
const onReady = () => console.log('BetterCurseForge is ready!');
BetterCurseForge.on('ready', onReady);
```

### `BetterCurseForge.off(event, callback)`
Unsubscribes a listener.

```javascript
BetterCurseForge.off('ready', onReady);
```

### `BetterCurseForge.emit(event, ...args)`
Emits an event to all registered listeners.

```javascript
BetterCurseForge.emit('custom-event', { detail: 123 });
```

---

## Subsystem Managers

### `BetterCurseForge.themes` (`ThemeManager`)
Provides programmatic control over custom themes:

```javascript
// Get all discovered themes
const themes = BetterCurseForge.themes.getThemes();

// Get active theme filename (or null)
const currentTheme = BetterCurseForge.themes.getActiveThemeName();

// Preview a theme temporarily on screen
BetterCurseForge.themes.previewTheme(themes[0]);

// Revert preview back to active theme
BetterCurseForge.themes.cancelPreview();

// Apply and save a theme permanently
BetterCurseForge.themes.applyTheme(themes[0], true);

// Remove custom theme and revert to native CurseForge skin
BetterCurseForge.themes.removeTheme(true);
```

### `BetterCurseForge.plugins` (`PluginManager`)
Provides programmatic control over plugins:

```javascript
// Get all installed plugins
const plugins = BetterCurseForge.plugins.getPlugins();

// Toggle a plugin by folder name
await BetterCurseForge.plugins.togglePlugin('compact-mode');
```

### `BetterCurseForge.ads` (`AdBlocker`)
Internal ad blocker runtime:

```javascript
// Contains zero-ad CSS rules and ad container cleanup handlers
console.log(BetterCurseForge.ads);
```