"use server";

import { getServerSession } from "next-auth";
import { authOptions } from "@/app/api/auth/[...nextauth]/route";

export interface DiscordRole {
  id: string;
  name: string;
  color: number;
  position: number;
}

// --- In-memory caches with TTL ---
interface CacheEntry<T> { data: T; expiresAt: number }
const rolesCache: { entry: CacheEntry<DiscordRole[]> | null } = { entry: null };
const profileCache = new Map<string, CacheEntry<any>>();
const CACHE_TTL = 60_000; // 60 seconds

function getCached<T>(entry: CacheEntry<T> | null | undefined): T | null {
  if (entry && Date.now() < entry.expiresAt) return entry.data;
  return null;
}

/** Internal: fetch guild roles without auth check (for use by other server functions). */
async function getGuildRolesInternal(): Promise<DiscordRole[]> {
  const cached = getCached(rolesCache.entry);
  if (cached) return cached;

  const token = process.env.DISCORD_BOT_TOKEN;
  const guildId = process.env.DISCORD_GUILD_ID;
  if (!token || !guildId) return [];

  try {
    const res = await fetch(`https://discord.com/api/v10/guilds/${guildId}/roles`, {
      headers: { Authorization: `Bot ${token}` },
      signal: AbortSignal.timeout(5000),
    });
    
    if (!res.ok) return [];
    
    const roles: any[] = await res.json();
    const result = roles.map(r => ({
      id: r.id,
      name: r.name,
      color: r.color,
      position: r.position,
    })).sort((a, b) => b.position - a.position);

    rolesCache.entry = { data: result, expiresAt: Date.now() + CACHE_TTL };
    return result;
  } catch {
    return [];
  }
}

/** Public: fetch guild roles with admin auth check. */
export async function getGuildRoles(): Promise<DiscordRole[]> {
  const session = await getServerSession(authOptions);
  const discordId = (session?.user as any)?.discordId;
  const admins = (process.env.ADMIN_DISCORD_IDS || "").split(",");
  if (!discordId || !admins.includes(discordId)) {
    throw new Error("Unauthorized");
  }

  return getGuildRolesInternal();
}

export async function getGuildMemberRoles(discordId: string): Promise<string[]> {
  const token = process.env.DISCORD_BOT_TOKEN;
  const guildId = process.env.DISCORD_GUILD_ID;
  if (!token || !guildId || !discordId) return [];

  try {
    const res = await fetch(`https://discord.com/api/v10/guilds/${guildId}/members/${discordId}`, {
      headers: { Authorization: `Bot ${token}` },
      cache: "no-store", // Always fresh for access control
      signal: AbortSignal.timeout(5000),
    });
    
    if (!res.ok) return [];

    const member = await res.json();
    return member.roles || [];
  } catch {
    return [];
  }
}

export async function getDiscordMemberProfile(discordId: string) {
  const cached = getCached(profileCache.get(discordId));
  if (cached) return cached;

  const token = process.env.DISCORD_BOT_TOKEN;
  const guildId = process.env.DISCORD_GUILD_ID;
  if (!token || !guildId || !discordId) return null;

  try {
    const [memberRes, allRoles] = await Promise.all([
      fetch(`https://discord.com/api/v10/guilds/${guildId}/members/${discordId}`, {
        headers: { Authorization: `Bot ${token}` },
        cache: "no-store",
        signal: AbortSignal.timeout(5000),
      }),
      getGuildRolesInternal(),
    ]);
    
    if (!memberRes.ok) return null;
    const member = await memberRes.json();
    
    // Map member role IDs to actual role objects
    const memberRoleIds = member.roles || [];
    const roles = memberRoleIds
      .map((id: string) => allRoles.find(r => r.id === id))
      .filter(Boolean);

    // Sort roles by position (descending)
    roles.sort((a: any, b: any) => (b?.position || 0) - (a?.position || 0));

    const user = member.user;
    
    let avatarUrl = null;
    if (user.avatar) {
      const ext = user.avatar.startsWith("a_") ? "gif" : "png";
      avatarUrl = `https://cdn.discordapp.com/avatars/${user.id}/${user.avatar}.${ext}?size=128`;
    }

    let bannerUrl = null;
    if (user.banner) {
      const ext = user.banner.startsWith("a_") ? "gif" : "png";
      bannerUrl = `https://cdn.discordapp.com/banners/${user.id}/${user.banner}.${ext}?size=512`;
    }

    const result = {
      id: user.id,
      username: user.username,
      globalName: user.global_name || null,
      avatarUrl,
      bannerUrl,
      accentColor: user.accent_color || null,
      roles,
    };

    profileCache.set(discordId, { data: result, expiresAt: Date.now() + CACHE_TTL });
    return result;
  } catch (e) {
    console.error("Failed to fetch member profile", e);
    return null;
  }
}