import React, { useState, useMemo } from 'react';
import {
  Modal,
  ModalOverlay,
  ModalContent,
  ModalHeader,
  ModalBody,
  ModalFooter,
  Button,
  Input,
  InputGroup,
  InputLeftElement,
  VStack,
  HStack,
  Text,
  Icon,
  useToast,
  Box,
} from '@chakra-ui/react';
import { SearchIcon } from '@chakra-ui/icons';
import { FiMusic } from 'react-icons/fi';
import type { PlaylistNode } from '../types/interfaces';

interface PlaylistSelectionModalProps {
  isOpen: boolean;
  onClose: () => void;
  playlists: PlaylistNode[];
  onPlaylistSelect: (playlistName: string) => void;
  selectedSongCount: number;
}

export const PlaylistSelectionModal: React.FC<PlaylistSelectionModalProps> = ({
  isOpen,
  onClose,
  playlists,
  onPlaylistSelect,
  selectedSongCount,
}) => {
  const [searchQuery, setSearchQuery] = useState('');
  const toast = useToast();

  // Flatten all playlists (including nested ones) for search
  const allPlaylists = useMemo(() => {
    const flattenPlaylists = (nodes: PlaylistNode[]): PlaylistNode[] => {
      const result: PlaylistNode[] = [];
      for (const node of nodes) {
        if (node.type === 'playlist') {
          result.push(node);
        } else if (node.type === 'folder' && node.children) {
          result.push(...flattenPlaylists(node.children));
        }
      }
      return result;
    };
    return flattenPlaylists(playlists);
  }, [playlists]);

  // Filter playlists based on search query
  const filteredPlaylists = useMemo(() => {
    if (!searchQuery.trim()) return allPlaylists;
    
    const query = searchQuery.toLowerCase();
    return allPlaylists.filter(playlist => 
      playlist.name.toLowerCase().includes(query)
    );
  }, [allPlaylists, searchQuery]);

  const handlePlaylistSelect = (playlistName: string) => {
    onPlaylistSelect(playlistName);
    onClose();
    setSearchQuery('');
    
    toast({
      title: 'Songs Added',
      description: `${selectedSongCount} song${selectedSongCount !== 1 ? 's' : ''} added to "${playlistName}"`,
      status: 'success',
      duration: 3000,
      isClosable: true,
    });
  };

  const handleClose = () => {
    onClose();
    setSearchQuery('');
  };

  return (
    <Modal isOpen={isOpen} onClose={handleClose} size="md">
      <ModalOverlay />
      <ModalContent bg="gray.800" borderColor="gray.700" borderWidth="1px">
        <ModalHeader color="white">
          Add to Playlist
          <Text fontSize="sm" color="gray.400" fontWeight="normal" mt={1}>
            Select a playlist to add {selectedSongCount} song{selectedSongCount !== 1 ? 's' : ''}
          </Text>
        </ModalHeader>
        
        <ModalBody>
          <VStack spacing={4} align="stretch">
            {/* Search Input */}
            <InputGroup>
              <InputLeftElement pointerEvents="none">
                <SearchIcon color="gray.400" />
              </InputLeftElement>
              <Input
                placeholder="Search playlists..."
                value={searchQuery}
                onChange={(e) => setSearchQuery(e.target.value)}
                bg="gray.700"
                borderColor="gray.600"
                color="white"
                _placeholder={{ color: 'gray.400' }}
                _focus={{ borderColor: 'blue.400', boxShadow: 'none' }}
                _hover={{ borderColor: 'gray.500' }}
              />
            </InputGroup>

            {/* Playlist List */}
            <Box maxH="300px" overflowY="auto">
              {filteredPlaylists.length === 0 ? (
                <Text color="gray.400" textAlign="center" py={4}>
                  {searchQuery ? 'No playlists found' : 'No playlists available'}
                </Text>
              ) : (
                <VStack spacing={1} align="stretch">
                  {filteredPlaylists.map((playlist) => (
                    <Box
                      key={playlist.id}
                      p={3}
                      borderRadius="md"
                      bg="gray.700"
                      cursor="pointer"
                      _hover={{ bg: 'gray.600' }}
                      onClick={() => handlePlaylistSelect(playlist.name)}
                      transition="background-color 0.2s"
                    >
                      <HStack spacing={3}>
                        <Icon as={FiMusic} color="blue.400" />
                        <VStack align="start" spacing={0} flex={1}>
                          <Text fontWeight="medium" color="white">
                            {playlist.name}
                          </Text>
                          <Text fontSize="sm" color="gray.400">
                            {playlist.trackCount || playlist.tracks?.length || 0} tracks
                          </Text>
                        </VStack>
                      </HStack>
                    </Box>
                  ))}
                </VStack>
              )}
            </Box>
          </VStack>
        </ModalBody>

        <ModalFooter>
          <Button variant="ghost" onClick={handleClose} color="gray.400">
            Cancel
          </Button>
        </ModalFooter>
      </ModalContent>
    </Modal>
  );
};