import React, { useState, useEffect } from 'react'
import { Box, Newline, Spacer, Text, useInput } from 'ink'
import TextInput from 'ink-text-input'

/**
 * Command input component with autocomplete suggestions like Claude Code
 */
const CommandInput = ({
  value,
  onChange,
  onSubmit,
  placeholder = 'Type a command or message...',
  commands = [],
  exitPrompt = false,
  onClearInput = null,
  onExit = null,
}) => {
  const [suggestions, setSuggestions] = useState([])
  const [showSuggestions, setShowSuggestions] = useState(false)
  const [selectedIndex, setSelectedIndex] = useState(0)

  // Handle keyboard input for autocomplete and Ctrl+C
  useInput((input, key) => {
    // Handle Ctrl+C
    if (key.ctrl && input === 'c') {
      if (value.length > 0 && onClearInput) {
        onClearInput()
        return
      }
      if (onExit) {
        onExit()
        return
      }
    }

    // Handle autocomplete when suggestions are shown
    if (showSuggestions && suggestions.length > 0) {
      if (key.upArrow) {
        setSelectedIndex(prev => Math.max(0, prev - 1))
        return
      }
      if (key.downArrow) {
        setSelectedIndex(prev => Math.min(suggestions.length - 1, prev + 1))
        return
      }
      if (key.tab) {
        // Auto-complete with selected suggestion
        const selectedCmd = suggestions[selectedIndex]
        if (selectedCmd) {
          onChange(`/${selectedCmd.name}`)
          setShowSuggestions(false)
        }
        return
      }
    }
  })

  // Update suggestions when input value changes
  useEffect(() => {
    if (value.startsWith('/')) {
      const query = value.substring(1).toLowerCase()
      const filteredCommands = commands.filter(
        cmd =>
          cmd.name.toLowerCase().includes(query) || cmd.description.toLowerCase().includes(query)
      )
      setSuggestions(filteredCommands)
      setShowSuggestions(filteredCommands.length > 0)
      setSelectedIndex(0) // Reset selection
    } else {
      setSuggestions([])
      setShowSuggestions(false)
      setSelectedIndex(0)
    }
  }, [value, commands])

  const handleSubmit = inputValue => {
    // If there are suggestions showing and user presses Enter,
    // auto-complete with the selected suggestion
    if (showSuggestions && suggestions.length > 0) {
      const selectedCmd = suggestions[selectedIndex]
      if (selectedCmd) {
        setShowSuggestions(false)
        onSubmit(`/${selectedCmd.name}`)
        return
      }
    }

    // Normal submit
    setShowSuggestions(false)
    onSubmit(inputValue)
  }

  return (
    <Box flexDirection='column' width='100%'>
      {/* Input field */}
      <Box paddingX={1} paddingY={0} borderColor='whiteBright' borderStyle='round' width={'100%'}>
        <Text color='blue'>{'> '}</Text>
        <TextInput
          value={value}
          onChange={onChange}
          onSubmit={handleSubmit}
          placeholder={placeholder}
          focus={true}
        />
      </Box>

      {/* Autocomplete suggestions */}
      {showSuggestions && suggestions.length > 0 && (
        <Box flexDirection='column' marginTop={1} marginBottom={1} paddingLeft={2}>
          {suggestions.map((cmd, index) => (
            <Box flexDirection='row' flexWrap='wrap' key={index}>
              <Box width={16}>
                <Text color={index === selectedIndex ? 'blueBright' : 'gray'}>
                  <Text color={index === selectedIndex ? 'blueBright' : 'gray'}>/{cmd.name}</Text>
                </Text>
              </Box>
              <Box paddingLeft={3}>
                <Text color={index === selectedIndex ? 'blueBright' : 'gray'}>
                  {cmd.description}
                </Text>
              </Box>
            </Box>
          ))}
        </Box>
      )}

      {/* Help text with integrated Ctrl+C status */}
      <Box width='100%'>
        <Text dimColor>
          {exitPrompt ? (
            <Text color='yellow'>Press Ctrl+C again to exit</Text>
          ) : value.startsWith('/') ? (
            <>Press Enter to continue</>
          ) : (
            <>Type / for commands</>
          )}
        </Text>
        <Spacer />
        <Text dimColor>{!exitPrompt && <> Ctrl+C to {value ? 'clear input' : 'exit'}</>}</Text>
      </Box>
    </Box>
  )
}

export default CommandInput