"use client";

import { createContext, useContext, useEffect, useState } from "react";
import { onAuthStateChanged, signOut as firebaseSignOut, User } from "firebase/auth";
import { auth } from "@/lib/firebase";
import type { UserRole } from "@/lib/types";

export type OrgRole = "owner" | "member";

interface AuthContextType {
  user: User | null;
  loading: boolean;
  role: UserRole | null;
  isAdmin: boolean;
  isOperator: boolean;
  ownedNodeIds: string[];
  /** Tenant claim — null means this account isn't provisioned into an org yet. */
  orgId: string | null;
  orgRole: OrgRole | null;
  isOrgOwner: boolean;
  signOut: () => Promise<void>;
  /** Force-refetch the ID token's claims — call after POST /auth/signup so orgId picks up immediately. */
  refreshClaims: () => Promise<void>;
}

const AuthContext = createContext<AuthContextType>({
  user: null,
  loading: true,
  role: null,
  isAdmin: false,
  isOperator: false,
  ownedNodeIds: [],
  orgId: null,
  orgRole: null,
  isOrgOwner: false,
  signOut: async () => {},
  refreshClaims: async () => {},
});

export function AuthProvider({ children }: { children: React.ReactNode }) {
  const [user, setUser] = useState<User | null>(null);
  const [loading, setLoading] = useState(true);
  const [role, setRole] = useState<UserRole | null>(null);
  const [ownedNodeIds, setOwnedNodeIds] = useState<string[]>([]);
  const [orgId, setOrgId] = useState<string | null>(null);
  const [orgRole, setOrgRole] = useState<OrgRole | null>(null);

  async function applyClaims(u: User, forceRefresh: boolean) {
    const result = await u.getIdTokenResult(forceRefresh);
    const claims = result.claims;

    // Derive role: prefer granular "role" claim, fall back to legacy "admin" boolean
    let effectiveRole: UserRole = "viewer";
    if (claims.role === "admin" || claims.admin) {
      effectiveRole = "admin";
    } else if (claims.role === "operator") {
      effectiveRole = "operator";
    } else if (claims.role === "viewer") {
      effectiveRole = "viewer";
    }

    setRole(effectiveRole);
    setOwnedNodeIds((claims.owned_node_ids as string[]) ?? []);

    // org_id/org_role are set by POST /auth/signup. No org_id claim means
    // this account was created (e.g. via Google sign-in's implicit account
    // creation) but never provisioned — see the no-claim guard below, which
    // is what stops that from being a live data exposure.
    const claimOrgId = typeof claims.org_id === "string" ? claims.org_id : null;
    const claimOrgRole = claims.org_role === "owner" || claims.org_role === "member" ? claims.org_role : null;
    setOrgId(claimOrgId);
    setOrgRole(claimOrgRole);

    // drb_session is only a UX redirect signal (middleware.ts), not a
    // security boundary (see CLAUDE.md) — but it must not be set for an
    // unprovisioned account, or the middleware will wave them straight into
    // /dashboard instead of /onboarding.
    if (claimOrgId) {
      document.cookie = "drb_session=1; path=/; SameSite=Strict";
    } else {
      document.cookie = "drb_session=; path=/; max-age=0";
    }
  }

  useEffect(() => {
    return onAuthStateChanged(auth, async (u) => {
      setUser(u);

      if (u) {
        await applyClaims(u, true);
      } else {
        document.cookie = "drb_session=; path=/; max-age=0";
        setRole(null);
        setOwnedNodeIds([]);
        setOrgId(null);
        setOrgRole(null);
      }
      setLoading(false);
    });
  }, []);

  async function signOut() {
    await firebaseSignOut(auth);
    document.cookie = "drb_session=; path=/; max-age=0";
  }

  async function refreshClaims() {
    if (auth.currentUser) await applyClaims(auth.currentUser, true);
  }

  const isAdmin = role === "admin";
  const isOperator = role === "operator";
  const isOrgOwner = orgRole === "owner";

  return (
    <AuthContext.Provider
      value={{ user, loading, role, isAdmin, isOperator, ownedNodeIds, orgId, orgRole, isOrgOwner, signOut, refreshClaims }}
    >
      {children}
    </AuthContext.Provider>
  );
}

export function useAuth() {
  return useContext(AuthContext);
}