// Discord OAuth2 Service
const DISCORD_API = 'https://discord.com/api/v10';

export function getDiscordAuthUrl() {
  const params = new URLSearchParams({
    client_id: process.env.DISCORD_CLIENT_ID,
    redirect_uri: process.env.DISCORD_REDIRECT_URI,
    response_type: 'code',
    scope: 'identify guilds.members.read'
  });
  return `https://discord.com/oauth2/authorize?${params}`;
}

export async function exchangeCode(code) {
  const response = await fetch(`${DISCORD_API}/oauth2/token`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    },
    body: new URLSearchParams({
      client_id: process.env.DISCORD_CLIENT_ID,
      client_secret: process.env.DISCORD_CLIENT_SECRET,
      grant_type: 'authorization_code',
      code,
      redirect_uri: process.env.DISCORD_REDIRECT_URI
    })
  });

  if (!response.ok) {
    const error = await response.text();
    throw new Error(`Failed to exchange code: ${error}`);
  }

  return response.json();
}

export async function getDiscordUser(accessToken) {
  const response = await fetch(`${DISCORD_API}/users/@me`, {
    headers: {
      Authorization: `Bearer ${accessToken}`
    }
  });

  if (!response.ok) {
    throw new Error('Failed to get Discord user');
  }

  return response.json();
}

export async function getGuildMember(userId) {
  const response = await fetch(
    `${DISCORD_API}/guilds/${process.env.DISCORD_GUILD_ID}/members/${userId}`,
    {
      headers: {
        Authorization: `Bot ${process.env.DISCORD_BOT_TOKEN}`
      }
    }
  );

  if (!response.ok) {
    if (response.status === 404) {
      return null; // User not in guild
    }
    throw new Error('Failed to get guild member');
  }

  return response.json();
}

export function getUserRole(memberRoles) {
  const adminRoleId = process.env.DISCORD_ADMIN_ROLE_ID;
  const modRoleId = process.env.DISCORD_MOD_ROLE_ID;

  if (memberRoles.includes(adminRoleId)) {
    return 'superadmin';
  }
  if (memberRoles.includes(modRoleId)) {
    return 'moderator';
  }
  return 'user';
}