'use client'

import { createContext, useContext, useState, useEffect, useCallback, useRef, ReactNode } from 'react'

export interface AuthUser {
  id: string
  name: string
  email: string
  role: 'admin' | 'standard'
}

interface AuthContextValue {
  user: AuthUser | null
  isLoading: boolean
  isAdmin: boolean
  login: (email: string, password: string) => Promise<{ error?: string }>
  logout: () => Promise<void>
}

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

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<AuthUser | null>(null)
  const [isLoading, setIsLoading] = useState(true)
  const hydrated = useRef(false)

  // Hydrate session once on mount
  useEffect(() => {
    if (hydrated.current) return
    hydrated.current = true

    fetch('/api/auth/me')
      .then(res => (res.ok ? res.json() : null))
      .then(data => {
        if (data?.id) setUser(data)
      })
      .catch(() => {})
      .finally(() => setIsLoading(false))
  }, [])

  const login = useCallback(async (email: string, password: string) => {
    const res = await fetch('/api/auth/login', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ email, password }),
    })

    if (!res.ok) {
      const data = await res.json()
      return { error: data.error || 'Login failed' }
    }

    const data = await res.json()
    setUser(data)
    return {}
  }, [])

  const logout = useCallback(async () => {
    await fetch('/api/auth/logout', { method: 'POST' })
    setUser(null)
    window.location.href = '/login'
  }, [])

  return (
    <AuthContext.Provider
      value={{
        user,
        isLoading,
        isAdmin: user?.role === 'admin',
        login,
        logout,
      }}
    >
      {children}
    </AuthContext.Provider>
  )
}

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