'use client';

import { useState, useCallback, useRef } from 'react';
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogDescription,
  DialogFooter,
} from '@/components/ui/dialog';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Download, Upload } from 'lucide-react';
import { TermEditor } from './TermEditor';
import { exportGlossaryToCsv, parseCsvToTerms } from './csvUtils';
import { useToast } from '@/components/ui/toast';
import type { Glossary, GlossaryTermInput } from './types';
import { MAX_TERMS_PER_GLOSSARY } from './types';

interface EditGlossaryDialogProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  glossary: Glossary | null;
  onSave: (id: string, data: { name: string; terms: GlossaryTermInput[] }) => Promise<void>;
  isSaving: boolean;
}

export function EditGlossaryDialog({
  open,
  onOpenChange,
  glossary,
  onSave,
  isSaving,
}: EditGlossaryDialogProps) {
  const [name, setName] = useState('');
  const [terms, setTerms] = useState<GlossaryTermInput[]>([]);
  const fileInputRef = useRef<HTMLInputElement>(null);

  const isInitialized = useRef(false);

  if (glossary && !isInitialized.current) {
    setName(glossary.name);
    setTerms(glossary.terms.map(t => ({ source: t.source, target: t.target })));
    isInitialized.current = true;
  }

  if (!open && isInitialized.current) {
    isInitialized.current = false;
  }

  const handleSave = useCallback(async () => {
    if (!glossary || !name.trim()) return;
    
    const validTerms = terms.filter(t => t.source.trim() && t.target.trim());
    
    await onSave(glossary.id, {
      name: name.trim(),
      terms: validTerms,
    });
  }, [glossary, name, terms, onSave]);

  const handleExport = useCallback(() => {
    if (!glossary) return;
    
    const glossaryWithCurrentTerms: Glossary = {
      ...glossary,
      name,
      terms: terms.map((t, i) => ({
        id: `temp-${i}`,
        source: t.source,
        target: t.target,
        translations: t.translations || {},
        created_at: null,
      })),
    };
    
    exportGlossaryToCsv(glossaryWithCurrentTerms);
  }, [glossary, name, terms]);

  const handleImportClick = useCallback(() => {
    fileInputRef.current?.click();
  }, []);

  const { toast } = useToast();

  const handleFileChange = useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;

    const reader = new FileReader();
    reader.onload = (event) => {
      const text = event.target?.result;
      if (typeof text === 'string') {
        const importedTerms = parseCsvToTerms(text);
        if (importedTerms.length > 0) {
          if (importedTerms.length > MAX_TERMS_PER_GLOSSARY) {
            toast({
              variant: 'destructive',
              title: 'Import failed',
              description: `CSV contains ${importedTerms.length} terms, but maximum is ${MAX_TERMS_PER_GLOSSARY}. Please reduce the number of terms.`,
            });
            e.target.value = '';
            return;
          }
          setTerms(importedTerms);
          toast({
            title: 'Import successful',
            description: `${importedTerms.length} terms imported successfully.`,
          });
        } else {
          toast({
            variant: 'destructive',
            title: 'Import failed',
            description: 'No valid terms found in CSV file.',
          });
        }
      }
    };
    reader.onerror = () => {
      toast({
        variant: 'destructive',
        title: 'Import failed',
        description: 'Failed to read CSV file.',
      });
    };
    reader.readAsText(file);
    
    e.target.value = '';
  }, [toast]);

  const validTermsCount = terms.filter(t => t.source.trim() && t.target.trim()).length;

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="sm:max-w-2xl max-h-[90vh] overflow-y-auto">
        <DialogHeader>
          <DialogTitle>Edit Glossary</DialogTitle>
          <DialogDescription>
            Update the glossary name and term pairs.
          </DialogDescription>
        </DialogHeader>

        <div className="space-y-6 py-4">
          <div className="space-y-2">
            <Label htmlFor="glossary-name">Glossary Name</Label>
            <Input
              id="glossary-name"
              value={name}
              onChange={(e) => setName(e.target.value)}
              placeholder="Enter glossary name..."
              disabled={isSaving}
            />
          </div>

          <div className="space-y-2">
            <Label>Terms ({validTermsCount} valid)</Label>
            <TermEditor
              terms={terms}
              onChange={setTerms}
              disabled={isSaving}
            />
          </div>

          <div className="flex items-center gap-2 pt-2">
            <Button
              type="button"
              variant="outline"
              size="sm"
              onClick={handleExport}
              disabled={isSaving || validTermsCount === 0}
              className="gap-1.5"
            >
              <Download className="size-3.5" />
              Export CSV
            </Button>
            <Button
              type="button"
              variant="outline"
              size="sm"
              onClick={handleImportClick}
              disabled={isSaving}
              className="gap-1.5"
            >
              <Upload className="size-3.5" />
              Import CSV
            </Button>
            <input
              ref={fileInputRef}
              type="file"
              accept=".csv"
              onChange={handleFileChange}
              className="hidden"
            />
          </div>
        </div>

        <DialogFooter>
          <Button
            variant="outline"
            onClick={() => onOpenChange(false)}
            disabled={isSaving}
          >
            Cancel
          </Button>
          <Button
            onClick={handleSave}
            disabled={isSaving || !name.trim()}
          >
            {isSaving ? 'Saving...' : 'Save Changes'}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}