import React, { useState, useRef, useEffect } from 'react'
import { Text, Box, useApp, Newline, Static } from 'ink'
import { Alert } from '@inkjs/ui'
import fs from 'fs/promises'
import CommandInput from './components/CommandInput.jsx'
import InitPage from './init/page.jsx'
import SettingsPage from './settings/page.jsx'
import EmojiSpinner from './init/components/EmojiSpinner.jsx'
import chatService from './services/chatService.js'

/**
 * Main App - Command Router
 */
const App = () => {
  const [inputValue, setInputValue] = useState('')
  const [exitPrompt, setExitPrompt] = useState(false)
  const [currentRoute, setCurrentRoute] = useState('home')
  const [hasAuraConfig, setHasAuraConfig] = useState(false)
  const [settings, setSettings] = useState({
    avatars: { aura: '🌀', user: '>' }
  })
  const lastCtrlC = useRef(0)
  const { exit } = useApp()

  // 使用本地狀態管理聊天
  const [messages, setMessages] = useState([])
  const [isLoading, setIsLoading] = useState(false)
  const [error, setError] = useState(null)

  // 檢查 aura.md 是否存在 & 載入設定
  useEffect(() => {
    const checkAuraConfig = async () => {
      try {
        await fs.access('./aura.md')
        setHasAuraConfig(true)
      } catch {
        setHasAuraConfig(false)
      }
    }
    
    const loadSettings = async () => {
      try {
        const data = await fs.readFile('./.aura.json', 'utf-8')
        setSettings(JSON.parse(data))
      } catch {
        // 使用預設值
      }
    }
    
    checkAuraConfig()
    loadSettings()
  }, [])

  // Available commands (removed chat)
  const availableCommands = [
    {
      name: 'init',
      description: 'Analyze my product and generate a marketing strategy',
    },
    {
      name: 'today',
      description: "[DEMO] Check today's marketing report and recommended actions",
    },
    { name: 'post', description: '[DEMO] Tweet, blog post, email, short video, etc' },
    { name: 'settings', description: 'Manage your Aura settings' },
    {
      name: 'claude-setup',
      description: 'Make Aura a sub-agent of Claude',
    },
  ]

  // Handle Ctrl+C logic
  const handleClearInput = () => {
    setInputValue('')
    setExitPrompt(false)
  }

  const handleExit = () => {
    const now = Date.now()
    if (now - lastCtrlC.current < 2000) {
      exit()
    } else {
      setExitPrompt(true)
      lastCtrlC.current = now
      setTimeout(() => {
        setExitPrompt(false)
      }, 2000)
    }
  }

  const handleSubmit = value => {
    if (value.trim()) {
      const trimmedValue = value.trim()
      
      // 檢查是否為命令
      if (trimmedValue.startsWith('/')) {
        const command = trimmedValue.substring(1).toLowerCase()
        if (command === 'init') {
          setCurrentRoute('init')
        } else if (command === 'settings') {
          setCurrentRoute('settings')
        }
        // 可以在這裡處理其他命令
        setInputValue('')
      } else {
        // 非命令文字 - 發送到聊天
        // 添加用戶訊息
        const userMessage = { 
          id: Date.now().toString(), 
          role: 'user', 
          content: trimmedValue 
        }
        setMessages(prev => [...prev, userMessage])
        setError(null)
        
        // 呼叫真實 AI API
        setIsLoading(true)
        chatService.sendMessage([...messages, userMessage])
          .then(async (stream) => {
            let fullContent = ''
            const assistantMessageId = (Date.now() + 1).toString()
            
            // 初始化助手訊息
            setMessages(prev => [...prev, {
              id: assistantMessageId,
              role: 'assistant',
              content: ''
            }])
            
            // 處理串流回應
            for await (const chunk of stream.textStream) {
              fullContent += chunk
              // 更新助手訊息內容
              setMessages(prev => prev.map(msg => 
                msg.id === assistantMessageId 
                  ? { ...msg, content: fullContent }
                  : msg
              ))
            }
            setIsLoading(false)
          })
          .catch((err) => {
            console.error('Chat error:', err)
            setError(err.message)
            
            // 如果 API 失敗，使用備用回應
            if (err.message.includes('API key not configured')) {
              setMessages(prev => [...prev, {
                id: (Date.now() + 1).toString(),
                role: 'assistant',
                content: '⚠️ OpenAI API key not configured. Please set OPENAI_API_KEY in your .env file to enable AI chat.'
              }])
            } else {
              setMessages(prev => [...prev, {
                id: (Date.now() + 1).toString(),
                role: 'assistant',
                content: hasAuraConfig 
                  ? 'Based on your product analysis, I recommend focusing on content marketing to build authority in your niche. Start with educational blog posts that solve your target audience\'s pain points.'
                  : 'I\'m using demo analysis results. Run /init to analyze your product for personalized marketing insights! Meanwhile, I can help with general marketing strategies.'
              }])
            }
            setIsLoading(false)
          })
        
        setInputValue('')
      }
      setExitPrompt(false)
    }
  }

  const handleBack = () => {
    setCurrentRoute('home')
  }

  // Route to different pages
  if (currentRoute === 'init') {
    return <InitPage onBack={handleBack} />
  }
  
  if (currentRoute === 'settings') {
    return <SettingsPage onBack={() => {
      // 重新載入設定
      const loadSettings = async () => {
        try {
          const data = await fs.readFile('./.aura.json', 'utf-8')
          setSettings(JSON.parse(data))
        } catch {
          // 使用預設值
        }
      }
      loadSettings()
      handleBack()
    }} />
  }

  // Home page
  return (
    <Box flexDirection='column' padding={1}>
      <Box paddingY={1} paddingX={2} borderColor='blue' borderStyle='round' width={'100%'}>
        {/* Header */}
        <Text>
          🌀 Welcome to <Text bold>Aura!</Text>
          <Newline />
          <Newline />
          <Text color={'white'} dimColor>
            Your AI marketing companion
          </Text>
        </Text>
      </Box>

      {/* Tips for getting started */}
      <Box marginTop={1} paddingLeft={1} flexDirection='column'>
        <Text color='gray'>Tips for getting started:</Text>
        <Newline />
        <Text color='gray'> 1. Run /init to analyze your product and create a marketing strategy</Text>
        <Text color='gray'> 2. Chat directly with Aura for marketing insights and recommendations</Text>
        <Text color='gray'> 3. Be as specific as you would with a marketing expert for best results</Text>
        <Text color='gray'> 4. ✓ View available commands by typing /</Text>
      </Box>

      {/* Demo 警告 - 使用 Static 和 Alert */}
      {!hasAuraConfig && messages.length > 0 && (
        <Static items={[{id: 'demo-alert'}]}>
          {() => (
            <Box marginTop={1} marginBottom={1}>
              <Alert variant="warning">
                You're chatting with demo analysis results. Run /init for personalized insights.
              </Alert>
            </Box>
          )}
        </Static>
      )}
      
      {/* API 錯誤警告 */}
      {error && (
        <Static items={[{id: 'error-alert'}]}>
          {() => (
            <Box marginTop={1} marginBottom={1}>
              <Alert variant="error">
                {error}
              </Alert>
            </Box>
          )}
        </Static>
      )}

      {/* 聊天歷史 */}
      {messages.length > 0 && (
        <Box flexDirection='column' marginTop={2} marginBottom={1} paddingLeft={1}>
          {messages.filter(m => m.role !== 'system').map((msg) => (
            <Box key={msg.id} marginBottom={1}>
              <Text>
                {msg.role === 'user' ? `${settings.avatars.user} ` : `${settings.avatars.aura} `}
                {msg.role === 'user' ? (
                  <Text>{msg.content}</Text>
                ) : (
                  <Text color='white'>{msg.content}</Text>
                )}
              </Text>
            </Box>
          ))}
          {isLoading && <EmojiSpinner label="Aura is thinking..." />}
        </Box>
      )}

      {/* Command Input with integrated Ctrl+C status */}
      <Box marginTop={messages.length === 0 ? 2 : 1}>
        <CommandInput
          value={inputValue}
          onChange={setInputValue}
          onSubmit={handleSubmit}
          placeholder='Type a command or message...'
          commands={availableCommands}
          exitPrompt={exitPrompt}
          onClearInput={handleClearInput}
          onExit={handleExit}
        />
      </Box>
    </Box>
  )
}

export default App