// apps/mobile/app/(tabs)/talk.tsx
// AI Chat tab — text+voice chat
// Design ref: docs/v3/designs/talk.html

import { useState, useRef } from 'react'
import {
  View,
  ScrollView,
  TextInput,
  StyleSheet,
  Pressable,
  KeyboardAvoidingView,
  Platform
} from 'react-native'
import { useSafeAreaInsets } from 'react-native-safe-area-context'
import {
  PhosphorText,
  Led,
  Header,
  AppStatusBar,
  d3roNativePalette,
  d3roNativeFonts
} from '@d3ro/ui-native'
import { useI18n } from '@d3ro/i18n'

interface ChatMessage {
  id: string
  role: 'user' | 'assistant'
  content: string
}

export default function TalkScreen(): React.ReactElement {
  const insets = useSafeAreaInsets()
  const { t } = useI18n()
  const scrollRef = useRef<ScrollView>(null)
  const [messages, setMessages] = useState<ChatMessage[]>([
    {
      id: '1',
      role: 'assistant',
      content: t('mobile.talk.greeting')
    }
  ])
  const [input, setInput] = useState('')

  function handleSend(): void {
    if (!input.trim()) return
    const userMsg: ChatMessage = {
      id: String(Date.now()),
      role: 'user',
      content: input.trim()
    }
    setMessages((prev) => [...prev, userMsg])
    setInput('')
    // Phase M-5: actual AI response
    setTimeout(() => {
      scrollRef.current?.scrollToEnd({ animated: true })
    }, 100)
  }

  return (
    <KeyboardAvoidingView
      style={styles.container}
      behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
      keyboardVerticalOffset={80}
    >
      <Header
        title={t('mobile.talk.title')}
        paddingTop={insets.top}
        rightContent={
          <View style={styles.headerRight}>
            <PhosphorText variant="label" color="amber">{t('mobile.talk.live')}</PhosphorText>
            <Led color="green" size={6} />
          </View>
        }
      />

      {/* Chat Messages */}
      <ScrollView
        ref={scrollRef}
        style={styles.chatArea}
        contentContainerStyle={styles.chatContent}
      >
        {/* Date Badge */}
        <View style={styles.dateBadge}>
          <PhosphorText variant="label" color="muted">
            {new Date().toLocaleDateString(undefined, {
              month: 'short',
              day: 'numeric'
            }).toUpperCase()}
          </PhosphorText>
        </View>

        {messages.map((msg) => (
          <View
            key={msg.id}
            style={[
              styles.bubble,
              msg.role === 'user' ? styles.userBubble : styles.aiBubble
            ]}
          >
            <PhosphorText
              variant="body"
              color={msg.role === 'user' ? 'amber' : 'primary'}
              style={styles.bubbleText}
            >
              {msg.content}
            </PhosphorText>
            <PhosphorText variant="label" color="muted" style={styles.bubbleLabel}>
              {msg.role === 'user' ? t('mobile.talk.you') : t('mobile.talk.claude')}
            </PhosphorText>
          </View>
        ))}
      </ScrollView>

      {/* Input Area */}
      <View style={styles.inputArea}>
        <View style={styles.inputRow}>
          <TextInput
            style={styles.textInput}
            placeholder={t('mobile.talk.placeholder')}
            placeholderTextColor={d3roNativePalette.text.muted}
            value={input}
            onChangeText={setInput}
            onSubmitEditing={handleSend}
            returnKeyType="send"
          />
          <Pressable style={styles.sendBtn} onPress={handleSend}>
            <View style={styles.sendArrow} />
          </Pressable>
        </View>
        <AppStatusBar style={styles.inputStatus} />
      </View>
    </KeyboardAvoidingView>
  )
}

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: d3roNativePalette.bg.app },
  headerRight: { flexDirection: 'row', alignItems: 'center', gap: 8 },
  chatArea: { flex: 1 },
  chatContent: { padding: 20, paddingBottom: 20, gap: 16 },
  dateBadge: {
    alignSelf: 'center',
    backgroundColor: d3roNativePalette.bg.card,
    borderWidth: 1,
    borderColor: d3roNativePalette.border.default,
    borderRadius: 999,
    paddingHorizontal: 12,
    paddingVertical: 4,
    marginBottom: 8
  },
  bubble: {
    maxWidth: '85%',
    padding: 16,
    borderRadius: 16,
    marginBottom: 20
  },
  aiBubble: {
    alignSelf: 'flex-start',
    backgroundColor: d3roNativePalette.bg.card,
    borderWidth: 1,
    borderColor: d3roNativePalette.border.default,
    borderTopLeftRadius: 4
  },
  userBubble: {
    alignSelf: 'flex-end',
    backgroundColor: d3roNativePalette.accent.dim,
    borderWidth: 1,
    borderColor: 'rgba(255, 92, 53, 0.3)',
    borderTopRightRadius: 4
  },
  bubbleText: { fontFamily: d3roNativeFonts.sans },
  bubbleLabel: {
    position: 'absolute',
    bottom: -16,
    fontSize: 9,
    letterSpacing: 1
  },
  inputArea: {
    backgroundColor: 'rgba(25, 25, 27, 0.95)',
    borderTopWidth: 1,
    borderTopColor: d3roNativePalette.border.default,
    paddingHorizontal: 12,
    paddingTop: 12,
    paddingBottom: 8
  },
  inputRow: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: d3roNativePalette.bg.inset,
    borderRadius: 12,
    borderWidth: 1,
    borderColor: d3roNativePalette.border.default,
    padding: 8
  },
  textInput: {
    flex: 1,
    color: d3roNativePalette.text.primary,
    fontSize: 14,
    paddingHorizontal: 8,
    fontFamily: d3roNativeFonts.sans
  },
  sendBtn: {
    width: 32,
    height: 32,
    borderRadius: 16,
    backgroundColor: d3roNativePalette.accent.dim,
    borderWidth: 1,
    borderColor: 'rgba(255, 92, 53, 0.3)',
    justifyContent: 'center',
    alignItems: 'center'
  },
  sendArrow: {
    width: 0,
    height: 0,
    borderLeftWidth: 5,
    borderRightWidth: 5,
    borderBottomWidth: 8,
    borderLeftColor: 'transparent',
    borderRightColor: 'transparent',
    borderBottomColor: d3roNativePalette.accent.main
  },
  inputStatus: { paddingVertical: 4 }
})