ds-chat/frontend/src/context/AuthContext.tsx

import { createContext, useContext, useEffect, useState, type ReactNode } from 'react'
import * as authApi from '../api/auth'
import { ApiError } from '../api/client'
import type { User } from '../types'

interface AuthContextValue {
  user: User | null
  loading: boolean
  login: (usernameOrEmail: string, password: string) => Promise<void>
  logout: () => Promise<void>
}

const AuthContext = createContext<AuthContextValue | undefined>(undefined)

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<User | null>(null)
  const [loading, setLoading] = useState(true)

  useEffect(() => {
    authApi
      .me()
      .then(setUser)
      .catch((err) => {
        if (!(err instanceof ApiError && err.status === 401)) {
          console.error('Failed to load current user', err)
        }
      })
      .finally(() => setLoading(false))
  }, [])

  async function login(usernameOrEmail: string, password: string) {
    setUser(await authApi.login(usernameOrEmail, password))
  }

  async function logout() {
    await authApi.logout()
    setUser(null)
  }

  return (
    <AuthContext.Provider value={{ user, loading, login, logout }}>
      {children}
    </AuthContext.Provider>
  )
}

export function useAuth(): AuthContextValue {
  const ctx = useContext(AuthContext)
  if (!ctx) throw new Error('useAuth must be used within an AuthProvider')
  return ctx
}