import { useState } from 'react'
import {
  View, Text, TextInput, TouchableOpacity, StyleSheet,
  KeyboardAvoidingView, Platform, ActivityIndicator, Alert, ScrollView,
} from 'react-native'
import { useAuth } from '../../hooks/useAuth'
import { COLORS } from '../../constants/Config'

export default function LoginScreen() {
  const { login } = useAuth()
  const [username, setUsername] = useState('')
  const [password, setPassword] = useState('')
  const [loading,  setLoading]  = useState(false)

  const handleLogin = async () => {
    if (!username.trim() || !password.trim()) {
      Alert.alert('입력 오류', '아이디와 비밀번호를 입력해주세요.')
      return
    }
    setLoading(true)
    try {
      await login(username.trim(), password)
    } catch (e: any) {
      const msg = e.response?.data?.detail ?? '로그인에 실패했습니다.'
      Alert.alert('로그인 실패', msg)
    } finally {
      setLoading(false)
    }
  }

  return (
    <KeyboardAvoidingView
      style={s.container}
      behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
    >
      <ScrollView contentContainerStyle={s.inner} keyboardShouldPersistTaps="handled">
        {/* 로고 영역 */}
        <View style={s.logoBox}>
          <Text style={s.logoIcon}>🛡️</Text>
          <Text style={s.logoTitle}>GUARDiA</Text>
          <Text style={s.logoSub}>AI 인프라 자율 운영 플랫폼</Text>
          <View style={s.badge}>
            <Text style={s.badgeText}>(주)지오정보기술</Text>
          </View>
        </View>

        {/* 로그인 카드 */}
        <View style={s.card}>
          <Text style={s.cardTitle}>로그인</Text>

          <View style={s.field}>
            <Text style={s.label}>아이디</Text>
            <TextInput
              style={s.input}
              value={username}
              onChangeText={setUsername}
              placeholder="관리자 아이디"
              placeholderTextColor={COLORS.muted}
              autoCapitalize="none"
              autoCorrect={false}
              returnKeyType="next"
            />
          </View>

          <View style={s.field}>
            <Text style={s.label}>비밀번호</Text>
            <TextInput
              style={s.input}
              value={password}
              onChangeText={setPassword}
              placeholder="비밀번호"
              placeholderTextColor={COLORS.muted}
              secureTextEntry
              returnKeyType="done"
              onSubmitEditing={handleLogin}
            />
          </View>

          <TouchableOpacity
            style={[s.btn, loading && s.btnDisabled]}
            onPress={handleLogin}
            disabled={loading}
          >
            {loading
              ? <ActivityIndicator color="#fff" />
              : <Text style={s.btnText}>로그인</Text>
            }
          </TouchableOpacity>

          <Text style={s.hint}>GUARDiA ITSM 계정으로 로그인합니다</Text>
        </View>

        <Text style={s.version}>v1.0.0 · zioinfo.co.kr</Text>
      </ScrollView>
    </KeyboardAvoidingView>
  )
}

const s = StyleSheet.create({
  container: { flex: 1, backgroundColor: COLORS.primary },
  inner:     { flexGrow: 1, justifyContent: 'center', padding: 24 },
  logoBox:   { alignItems: 'center', marginBottom: 32 },
  logoIcon:  { fontSize: 56, marginBottom: 8 },
  logoTitle: { fontSize: 32, fontWeight: '800', color: '#fff', letterSpacing: 2 },
  logoSub:   { fontSize: 13, color: '#aac4e8', marginTop: 4 },
  badge:     { marginTop: 10, backgroundColor: 'rgba(255,255,255,.15)',
               paddingHorizontal: 14, paddingVertical: 4, borderRadius: 20 },
  badgeText: { color: '#fff', fontSize: 11, fontWeight: '600' },
  card:      { backgroundColor: '#fff', borderRadius: 16, padding: 24,
               shadowColor: '#000', shadowOffset: { width: 0, height: 8 },
               shadowOpacity: 0.15, shadowRadius: 24, elevation: 8 },
  cardTitle: { fontSize: 18, fontWeight: '700', color: COLORS.primary,
               marginBottom: 20, textAlign: 'center' },
  field:     { marginBottom: 14 },
  label:     { fontSize: 12, fontWeight: '600', color: COLORS.muted,
               marginBottom: 6, textTransform: 'uppercase', letterSpacing: .5 },
  input:     { borderWidth: 1.5, borderColor: COLORS.border, borderRadius: 10,
               padding: 13, fontSize: 15, color: COLORS.text, backgroundColor: '#fafafa' },
  btn:       { backgroundColor: COLORS.primary, borderRadius: 10, padding: 15,
               alignItems: 'center', marginTop: 8 },
  btnDisabled: { opacity: .6 },
  btnText:   { color: '#fff', fontSize: 16, fontWeight: '700' },
  hint:      { textAlign: 'center', color: COLORS.muted, fontSize: 12, marginTop: 16 },
  version:   { textAlign: 'center', color: 'rgba(255,255,255,.4)', fontSize: 11, marginTop: 24 },
})