'use client';

import { useEffect, useRef, useState, useTransition } from 'react';
import { useFormState, useFormStatus } from 'react-dom';
import { Button } from '@/components/ui/button';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
  DialogClose,
} from '@/components/ui/dialog';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Textarea } from '@/components/ui/textarea';
import { createPrompt, suggestPromptTags } from '@/lib/actions';
import { useToast } from '@/hooks/use-toast';
import { PlusCircle, Loader2, Sparkles, XIcon } from 'lucide-react';
import { Badge } from './ui/badge';

const initialState = {
  message: '',
  errors: {},
  success: false,
};

function SubmitButton() {
  const { pending } = useFormStatus();
  return (
    <Button type="submit" disabled={pending}>
      {pending && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
      Create Prompt
    </Button>
  );
}

export function CreatePromptDialog() {
  const [open, setOpen] = useState(false);
  const [state, formAction] = useFormState(createPrompt, initialState);
  const { toast } = useToast();
  const formRef = useRef<HTMLFormElement>(null);

  const [promptContent, setPromptContent] = useState('');
  const [tags, setTags] = useState<string[]>([]);
  const [tagInput, setTagInput] = useState('');
  const [isSuggesting, startSuggestionTransition] = useTransition();

  const handleSuggestTags = async () => {
    startSuggestionTransition(async () => {
      const result = await suggestPromptTags(promptContent);
      if (result.error) {
        toast({ title: 'Suggestion Failed', description: result.error, variant: 'destructive' });
      } else if (result.tags) {
        setTags((prev) => [...new Set([...prev, ...result.tags!])]);
        toast({ title: 'Tags Suggested!', description: 'AI-powered tags have been added.' });
      }
    });
  };

  const handleTagInputKeyDown = (e: React.KeyboardEvent<HTMLInputElement>) => {
    if (e.key === 'Enter' && tagInput.trim()) {
      e.preventDefault();
      setTags((prev) => [...new Set([...prev, tagInput.trim().toLowerCase()])]);
      setTagInput('');
    }
  };

  const removeTag = (tagToRemove: string) => {
    setTags((prev) => prev.filter((tag) => tag !== tagToRemove));
  };


  useEffect(() => {
    if (state.success) {
      toast({
        title: 'Success!',
        description: state.message,
      });
      setOpen(false);
      formRef.current?.reset();
      setTags([]);
      setPromptContent('');
    } else if (state.message && !state.success && Object.keys(state.errors ?? {}).length > 0) {
      toast({
        title: 'Error',
        description: state.message,
        variant: 'destructive',
      });
    }
  }, [state, toast]);

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        <Button>
          <PlusCircle className="mr-2 h-4 w-4" />
          New Prompt
        </Button>
      </DialogTrigger>
      <DialogContent className="sm:max-w-[625px]">
        <DialogHeader>
          <DialogTitle>Create a new prompt</DialogTitle>
          <DialogDescription>
            Craft your next masterpiece. Add notes and tags to keep it organized.
          </DialogDescription>
        </DialogHeader>
        <form ref={formRef} action={formAction} className="space-y-4">
          <div className="space-y-2">
            <Label htmlFor="title">Title</Label>
            <Input id="title" name="title" placeholder="e.g., Blog Post Ideas" required />
             {state.errors?.title && <p className="text-sm text-destructive">{state.errors.title[0]}</p>}
          </div>
          <div className="space-y-2">
            <Label htmlFor="content">Prompt</Label>
            <Textarea
              id="content"
              name="content"
              placeholder="Your prompt text here..."
              className="min-h-[120px]"
              onChange={(e) => setPromptContent(e.target.value)}
              required
            />
            {state.errors?.content && <p className="text-sm text-destructive">{state.errors.content[0]}</p>}
          </div>
          <div className="space-y-2">
            <Label htmlFor="notes">Notes (Optional)</Label>
            <Textarea
              id="notes"
              name="notes"
              placeholder="Add context or notes about this prompt..."
            />
          </div>
          <div className="space-y-2">
            <div className="flex justify-between items-center">
                <Label htmlFor="tags">Tags</Label>
                <Button type="button" size="sm" variant="ghost" onClick={handleSuggestTags} disabled={isSuggesting || promptContent.length < 20}>
                    {isSuggesting ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Sparkles className="mr-2 h-4 w-4" />}
                    Suggest
                </Button>
            </div>
            <div className="flex flex-wrap gap-2 p-2 border rounded-md min-h-[40px] bg-muted/50">
                {tags.map(tag => (
                    <Badge key={tag} variant="secondary">
                        {tag}
                        <button type="button" onClick={() => removeTag(tag)} className="ml-1 rounded-full hover:bg-destructive/80 p-0.5">
                            <XIcon className="h-3 w-3" />
                        </button>
                    </Badge>
                ))}
            </div>
            <Input id="tags-input" value={tagInput} onChange={(e) => setTagInput(e.target.value)} onKeyDown={handleTagInputKeyDown} placeholder="Type a tag and press Enter" />
            <input type="hidden" name="tags" value={JSON.stringify(tags)} />
          </div>

          <DialogFooter>
            <DialogClose asChild>
                <Button type="button" variant="outline">Cancel</Button>
            </DialogClose>
            <SubmitButton />
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}