'use client'

import { useState } from 'react'
import { useRouter } from 'next/navigation'
import Link from 'next/link'
import { createClient } from '@/lib/supabase/client'
import { Mail, Lock, User, Code2, Loader2 } from 'lucide-react'

interface AuthFormProps {
  mode: 'login' | 'signup'
}

export function AuthForm({ mode }: AuthFormProps) {
  const router = useRouter()
  const supabase = createClient()
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)
  const [formData, setFormData] = useState({
    email: '',
    password: '',
    fullName: '',
  })

  const isSignup = mode === 'signup'

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    setLoading(true)
    setError(null)

    try {
      if (isSignup) {
        const { error } = await supabase.auth.signUp({
          email: formData.email,
          password: formData.password,
          options: {
            data: {
              full_name: formData.fullName,
            },
            emailRedirectTo: `${process.env.NEXT_PUBLIC_APP_URL}/auth/callback`,
          },
        })
        if (error) throw error
      } else {
        const { error } = await supabase.auth.signInWithPassword({
          email: formData.email,
          password: formData.password,
        })
        if (error) throw error
        
        router.push('/dashboard')
        router.refresh()
      }
    } catch (err: any) {
      setError(err.message || 'An error occurred')
    } finally {
      setLoading(false)
    }
  }

  const handleOAuthLogin = async (provider: 'google' | 'github') => {
    try {
      const { error } = await supabase.auth.signInWithOAuth({
        provider,
        options: {
          redirectTo: `${process.env.NEXT_PUBLIC_APP_URL}/auth/callback`,
        },
      })
      if (error) throw error
    } catch (err: any) {
      setError(err.message)
    }
  }

  return (
    <div className="bg-dark-900/50 p-6 rounded-2xl border border-dark-700">
      <form onSubmit={handleSubmit} className="space-y-4">
        {error && (
          <div className="p-3 rounded-lg bg-red-500/10 border border-red-500/20 text-red-400 text-sm">
            {error}
          </div>
        )}

        {isSignup && (
          <div className="relative">
            <User className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-dark-500" />
            <input
              type="text"
              placeholder="Full name"
              value={formData.fullName}
              onChange={(e) => setFormData({ ...formData, fullName: e.target.value })}
              className="w-full pl-10 pr-4 py-3 rounded-xl bg-dark-800 border border-dark-600 focus:border-primary-500 focus:outline-none transition-colors"
              required
            />
          </div>
        )}

        <div className="relative">
          <Mail className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-dark-500" />
          <input
            type="email"
            placeholder="Email address"
            value={formData.email}
            onChange={(e) => setFormData({ ...formData, email: e.target.value })}
            className="w-full pl-10 pr-4 py-3 rounded-xl bg-dark-800 border border-dark-600 focus:border-primary-500 focus:outline-none transition-colors"
            required
          />
        </div>

        <div className="relative">
          <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-dark-500" />
          <input
            type="password"
            placeholder="Password"
            value={formData.password}
            onChange={(e) => setFormData({ ...formData, password: e.target.value })}
            className="w-full pl-10 pr-4 py-3 rounded-xl bg-dark-800 border border-dark-600 focus:border-primary-500 focus:outline-none transition-colors"
            required
            minLength={6}
          />
        </div>

        <button
          type="submit"
          disabled={loading}
          className="w-full py-3 rounded-xl bg-primary-600 hover:bg-primary-500 disabled:opacity-50 disabled:cursor-not-allowed font-semibold flex items-center justify-center gap-2 transition-colors"
        >
          {loading ? (
            <Loader2 className="w-5 h-5 animate-spin" />
          ) : isSignup ? (
            'Create Account'
          ) : (
            'Sign In'
          )}
        </button>
      </form>

      <div className="mt-6">
        <div className="relative">
          <div className="absolute inset-0 flex items-center">
            <div className="w-full border-t border-dark-600" />
          </div>
          <div className="relative flex justify-center text-sm">
            <span className="px-4 bg-dark-900/50 text-dark-400">Or continue with</span>
          </div>
        </div>

        <div className="mt-6 grid grid-cols-2 gap-3">
          <button
            onClick={() => handleOAuthLogin('google')}
            className="flex items-center justify-center gap-2 py-2.5 rounded-xl bg-dark-800 hover:bg-dark-700 border border-dark-600 transition-colors"
          >
            <svg className="w-5 h-5" viewBox="0 0 24 24">
              <path
                fill="currentColor"
                d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92c-.26 1.37-1.04 2.53-2.21 3.31v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.09z"
              />
              <path
                fill="currentColor"
                d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z"
              />
              <path
                fill="currentColor"
                d="M5.84 14.09c-.22-.66-.35-1.36-.35-2.09s.13-1.43.35-2.09V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l2.85-2.22.81-.62z"
              />
              <path
                fill="currentColor"
                d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z"
              />
            </svg>
            Google
          </button>
          <button
            onClick={() => handleOAuthLogin('github')}
            className="flex items-center justify-center gap-2 py-2.5 rounded-xl bg-dark-800 hover:bg-dark-700 border border-dark-600 transition-colors"
          >
            <Code2 className="w-5 h-5" />
            GitHub
          </button>
        </div>
      </div>

      {isSignup && (
        <p className="mt-4 text-xs text-dark-500 text-center">
          By signing up, you agree to our{' '}
          <Link href="/terms" className="text-primary-400 hover:underline">Terms</Link>
          {' '}and{' '}
          <Link href="/privacy" className="text-primary-400 hover:underline">Privacy Policy</Link>
        </p>
      )}

      {/* Dev Mode: Skip Auth */}
      {process.env.NODE_ENV === 'development' && (
        <>
          <div className="mt-6 relative">
            <div className="absolute inset-0 flex items-center">
              <div className="w-full border-t border-yellow-500/20" />
            </div>
            <div className="relative flex justify-center text-sm">
              <span className="px-4 bg-dark-900/50 text-yellow-500/70">⚡ Dev Mode</span>
            </div>
          </div>

          <button
            type="button"
            onClick={async () => {
              setLoading(true)
              setError(null)
              try {
                const devUser = JSON.stringify({
                  id: 'dev-user-' + Date.now(),
                  email: 'dev@codeview.local',
                  full_name: 'Dev User',
                })
                // Set cookie so middleware can see it
                document.cookie = `dev_user=${encodeURIComponent(devUser)}; path=/; max-age=86400; SameSite=Lax`
                localStorage.setItem('dev_user', devUser)
                router.push('/dashboard')
                router.refresh()
              } catch (err: any) {
                setError(err.message || 'Failed to skip auth')
              } finally {
                setLoading(false)
              }
            }}
            disabled={loading}
            className="mt-4 w-full py-3 rounded-xl bg-yellow-500/10 hover:bg-yellow-500/20 border border-yellow-500/30 text-yellow-400 font-semibold flex items-center justify-center gap-2 transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
          >
            {loading ? (
              <Loader2 className="w-5 h-5 animate-spin" />
            ) : (
              <>
                <span>🚀</span> Continue as Guest (Dev)
              </>
            )}
          </button>
        </>
      )}
    </div>
  )
}