### Initialize Yahoo Fantasy Module (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Demonstrates how to initialize the Yahoo Fantasy module with application credentials and optional callback functions for token refreshes and redirect URIs. This setup is essential for authenticating API requests.

```javascript
const YahooFantasy = require('yahoo-fantasy');

const yf = new YahooFantasy(
  Y!APPLICATION_KEY, // Yahoo! Application Key
  Y!APPLICATION_SECRET, // Yahoo! Application Secret
  tokenCallbackFunction, // callback function when user token is refreshed (optional)
  redirectUri // redirect endpoint when user authenticates (optional)
);
```

--------------------------------

### Handle Yahoo API Authentication Callback (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Illustrates the setup of the callback route to handle the authentication code received from Yahoo!. This function automatically sets the user and refresh tokens upon successful retrieval.

```javascript
yf.authCallback(
  request, // the request will contain the auth code from Yahoo!
  callback // callback function that will be called after the token has been retrieved
)
```

--------------------------------

### Update League Resource for Player Stats

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

A 'players' subresource has been added to the 'league' resource. This allows for fetching weekly or season stats for a player based on league settings. This also includes fixes for data format shifts affecting starting status.

```javascript
async function getLeaguePlayerStats(leagueKey, playerKey, seasonType = 'season', week = null) {
  let url = `/league/${leagueKey}/players;{playerKey}/stats`;
  if (seasonType === 'week' && week) {
    url += `?week=${week}`;
  } else if (seasonType === 'season') {
    // Default season stats query
  }
  // Assuming 'this' context is the API client with a 'request' method
  return this.request(url);
}
```

--------------------------------

### Query Resource/Subresource with Promises (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Shows how to query Yahoo Fantasy API resources and subresources using a promise chain, available from v3.1.0. This allows for cleaner asynchronous code with `.then()` for success and `.catch()` for errors.

```javascript
yf.{resource}.{subresource} (
  {possible argument(s)}
)
.then(data => // do your thing)
.catch(err => // handle error)
```

--------------------------------

### Query Resource/Subresource with Async/Await (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Illustrates querying Yahoo Fantasy API resources and subresources using the `async/await` syntax, supported in newer versions of Node.js. This provides a synchronous-like way to handle asynchronous operations, including robust error handling with `try...catch`.

```javascript
try {
  let data = await yf.{resource}.{subresource} (
    {possible argument(s)}
  )

  // do your thing
} catch(err) {
  // handle error
}
```

--------------------------------

### Query Resource/Subresource with Callback (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Demonstrates how to query specific resources and subresources of the Yahoo Fantasy API using a traditional callback pattern. It includes error handling and processing of the returned data.

```javascript
yf.{resource}.{subresource} (
  {possible argument(s)},
  function cb(err, data) {
    // handle error
    // callback function
    // do your thing
  }
);
```

--------------------------------

### Authenticate User with Yahoo API (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Shows how to initiate the user authentication process by redirecting the user to Yahoo!'s login screen. This is typically done by calling the `auth` method with the response object.

```javascript
yf.auth(
  response // response object to redirect the user to the Yahoo! login screen
)
```

--------------------------------

### Use Promise-Based Flow for Endpoints

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

This update introduces a promise-based flow for all API endpoints, offering an alternative to traditional callbacks. This improves asynchronous code handling and readability.

```javascript
class YahooFantasyApiClient {
  // ... constructor and other methods ...

  request(endpoint) {
    return new Promise((resolve, reject) => {
      // Replace with actual fetch or axios implementation
      fetch(`https://fantasysports.yahooapis.com/fantasy/v2${endpoint}`)
        .then(response => {
          if (!response.ok) {
            throw new Error(`HTTP error! status: ${response.status}`);
          }
          return response.json();
        })
        .then(data => resolve(data))
        .catch(error => reject(error));
    });
  }

  // Example usage of a promise-based endpoint
  getGameLeagues(gameKey) {
    return this.request(`/game/${gameKey}/leagues`);
  }
}

// Usage:
const yahooApi = new YahooFantasyApiClient(/* ... */);
yahooApi.getGameLeagues('397')
  .then(leagues => console.log(leagues))
  .catch(error => console.error('Error fetching leagues:', error));
```

--------------------------------

### Add Authentication Functions (auth, authCallback, setRefreshToken)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

This version introduces new functions for authentication: `auth()` for initiating the OAuth flow, `authCallback()` for handling the redirect response, and `setRefreshToken()` for managing refresh tokens. It also adds automatic token refreshing and a callback for when the token expires.

```javascript
class YahooFantasyAuth {
  constructor(clientId, clientSecret, redirectUri) {
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.redirectUri = redirectUri;
    this.refreshToken = null;
    this.accessToken = null;
  }

  auth() {
    const authUrl = `https://api.login.yahoo.com/oauth2/request_auth?client_id=${this.clientId}&redirect_uri=${this.redirectUri}&response_type=code`;
    window.location.href = authUrl;
  }

  async authCallback(code) {
    const tokenEndpoint = 'https://api.login.yahoo.com/oauth2/get_token';
    const params = new URLSearchParams();
    params.append('client_id', this.clientId);
    params.append('client_secret', this.clientSecret);
    params.append('redirect_uri', this.redirectUri);
    params.append('code', code);
    params.append('grant_type', 'authorization_code');

    const response = await fetch(tokenEndpoint, {
      method: 'POST',
      body: params
    });
    const data = await response.json();
    this.accessToken = data.access_token;
    this.refreshToken = data.refresh_token;
    return data;
  }

  setRefreshToken(refreshToken) {
    this.refreshToken = refreshToken;
  }

  // Method to automatically refresh token (implementation details omitted)
  async refreshTokenIfNeeded() {
    // ... logic to check expiration and refresh using this.refreshToken ...
  }
}
```

--------------------------------

### Set Yahoo User Token Manually (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Provides a method to manually set the Yahoo! user token if authentication is not handled directly by the library. This is useful for pre-authenticated sessions or custom auth flows.

```javascript
yf.setUserToken(
  Y!CLIENT_TOKEN
);
```

--------------------------------

### Refactor to ES Modules (mjs)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

The library has undergone a major refactor using ES Modules (mjs) where possible. This modernization aims to improve code organization and compatibility with modern JavaScript environments.

```javascript
// Example of an ES Module file (e.g., './auth.mjs')

// Import other modules if needed
// import { someUtil } from './utils.mjs';

export async function auth(clientId, redirectUri) {
  const authUrl = `https://api.login.yahoo.com/oauth2/request_auth?client_id=${clientId}&redirect_uri=${redirectUri}&response_type=code`;
  window.location.href = authUrl;
}

export async function authCallback(clientId, clientSecret, redirectUri, code) {
  const tokenEndpoint = 'https://api.login.yahoo.com/oauth2/get_token';
  const params = new URLSearchParams();
  params.append('client_id', clientId);
  params.append('client_secret', clientSecret);
  params.append('redirect_uri', redirectUri);
  params.append('code', code);
  params.append('grant_type', 'authorization_code');

  const response = await fetch(tokenEndpoint, {
    method: 'POST',
    body: params
  });
  return await response.json();
}

// Usage in another ES Module file (e.g., './main.mjs')
// import { auth, authCallback } from './auth.mjs';

// async function initiateAuth() {
//   const clientId = 'YOUR_CLIENT_ID';
//   const redirectUri = 'YOUR_REDIRECT_URI';
//   auth(clientId, redirectUri);
// }

// async function handleCallback() {
//   const urlParams = new URLSearchParams(window.location.search);
//   const code = urlParams.get('code');
//   if (code) {
//     const clientId = 'YOUR_CLIENT_ID';
//     const clientSecret = 'YOUR_CLIENT_SECRET';
//     const redirectUri = 'YOUR_REDIRECT_URI';
//     const tokenData = await authCallback(clientId, clientSecret, redirectUri, code);
//     console.log('Access Token:', tokenData.access_token);
//     console.log('Refresh Token:', tokenData.refresh_token);
//   }
// }
```

--------------------------------

### Update mapScoreboard Function for League Resource

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

This update simplifies the `stat_winners` array within the `mapScoreboard` function, which is used by the league resource. It now directly shows the winning `stat_id` and `team_key` (or `is_tied`) instead of nesting them within a `stat_winner` object.

```javascript
function mapScoreboard() {
  // ... existing code ...
  const simplifiedStatWinners = league.scoreboard.stats.map(stat => {
    // Assuming stat_winners is an array of objects like [{ stat_winner: { stat_id: '...', team_key: '...' } }]
    // The change implies it might now be an array of objects like [{ stat_id: '...', team_key: '...' }]
    return stat.stat_winners.map(winnerWrapper => {
      if (winnerWrapper.stat_winner.is_tied) {
        return { stat_id: winnerWrapper.stat_winner.stat_id, is_tied: true };
      } else {
        return { stat_id: winnerWrapper.stat_winner.stat_id, team_key: winnerWrapper.stat_winner.team_key };
      }
    });
  });
  // ... rest of the function potentially using simplifiedStatWinners ...
}
```

--------------------------------

### Update authCallback Function Return Value

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

The `authCallback()` function now returns an object containing both the user's `access_token` and `refresh_token`. This provides more comprehensive authentication information upon successful callback.

```javascript
async function handleAuthCallback(authCode) {
  // ... authentication logic ...
  const response = await fetch('/oauth2/token', {
    method: 'POST',
    // ... other options ...
    body: `code=${authCode}&grant_type=authorization_code`
  });
  const data = await response.json();
  return {
    accessToken: data.access_token,
    refreshToken: data.refresh_token
  };
}
```

--------------------------------

### Set Yahoo Refresh Token Manually (Node.js)

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

Enables manual setting of the Yahoo! refresh token. When set, the library can automatically refresh the access token if it expires, utilizing the provided `tokenCallbackFunction` to persist the new token.

```javascript
yf.setRefreshToken(
  Y!CLIENT_REFRESH_TOKEN
);
```

--------------------------------

### Update player.stats Function for Week or Date Input

Source: https://github.com/whatadewitt/yahoo-fantasy-sports-api/blob/master/README.md

The `player.stats` function has been updated to accept either a week number or a date string in 'yyyy-mm-dd' format as the second parameter. This enhances flexibility when querying player statistics. Note: For non-NFL players, manual week fetching and multiple queries might be necessary.

```javascript
async function getPlayerStats(playerKey, weekOrDate) {
  let queryParams = '';
  if (typeof weekOrDate === 'number') {
    queryParams = `?week=${weekOrDate}`;
  } else if (typeof weekOrDate === 'string' && /\\d{4}-\\d{2}-\\d{2}/.test(weekOrDate)) {
    queryParams = `?date=${weekOrDate}`;
  } else {
    throw new Error('Invalid week or date format');
  }
  // Assuming 'this' context is the API client with a 'request' method
  return this.request(`/players;{playerKey}/stats${queryParams}`);
}
```

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