"use client";

import { useState, useTransition, useEffect, useCallback } from "react";
import { createPortal } from "react-dom";
import { useRouter } from "next/navigation";
import { BookDto } from "@/lib/api";
import { FormField, FormLabel, FormInput } from "./ui/Form";

interface EditBookFormProps {
  book: BookDto;
}

export function EditBookForm({ book }: EditBookFormProps) {
  const router = useRouter();
  const [isPending, startTransition] = useTransition();
  const [isOpen, setIsOpen] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const [title, setTitle] = useState(book.title);
  const [authors, setAuthors] = useState<string[]>(book.authors ?? []);
  const [authorInput, setAuthorInput] = useState("");
  const [authorInputEl, setAuthorInputEl] = useState<HTMLInputElement | null>(null);
  const [series, setSeries] = useState(book.series ?? "");
  const [volume, setVolume] = useState(book.volume?.toString() ?? "");
  const [language, setLanguage] = useState(book.language ?? "");

  const addAuthor = () => {
    const v = authorInput.trim();
    if (v && !authors.includes(v)) {
      setAuthors([...authors, v]);
    }
    setAuthorInput("");
    authorInputEl?.focus();
  };

  const removeAuthor = (idx: number) => {
    setAuthors(authors.filter((_, i) => i !== idx));
  };

  const handleAuthorKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === "Enter") {
      e.preventDefault();
      addAuthor();
    }
  };

  const handleClose = useCallback(() => {
    setTitle(book.title);
    setAuthors(book.authors ?? []);
    setAuthorInput("");
    setSeries(book.series ?? "");
    setVolume(book.volume?.toString() ?? "");
    setLanguage(book.language ?? "");
    setError(null);
    setIsOpen(false);
  }, [book]);

  useEffect(() => {
    if (!isOpen) return;
    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === "Escape" && !isPending) handleClose();
    };
    document.addEventListener("keydown", handleKeyDown);
    return () => document.removeEventListener("keydown", handleKeyDown);
  }, [isOpen, isPending, handleClose]);

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (!title.trim()) return;
    setError(null);

    const finalAuthors = authorInput.trim()
      ? [...new Set([...authors, authorInput.trim()])]
      : authors;

    startTransition(async () => {
      try {
        const res = await fetch(`/api/books/${book.id}`, {
          method: "PATCH",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({
            title: title.trim(),
            author: finalAuthors[0] ?? null,
            authors: finalAuthors,
            series: series.trim() || null,
            volume: volume.trim() ? parseInt(volume.trim(), 10) : null,
            language: language.trim() || null,
          }),
        });
        if (!res.ok) {
          const data = await res.json();
          setError(data.error ?? "Erreur lors de la sauvegarde");
          return;
        }
        setIsOpen(false);
        router.refresh();
      } catch {
        setError("Erreur réseau");
      }
    });
  };

  const modal = isOpen ? createPortal(
    <>
      {/* Backdrop */}
      <div
        className="fixed inset-0 bg-black/30 backdrop-blur-sm z-50"
        onClick={() => !isPending && handleClose()}
      />

      {/* Modal */}
      <div className="fixed inset-0 flex items-center justify-center z-50 p-4">
        <div className="bg-card border border-border/50 rounded-xl shadow-2xl w-full max-w-2xl max-h-[90vh] overflow-y-auto animate-in fade-in zoom-in-95 duration-200">
          {/* Header */}
          <div className="flex items-center justify-between px-5 py-4 border-b border-border/50 bg-muted/30 sticky top-0 z-10">
            <h3 className="font-semibold text-foreground">Modifier les métadonnées</h3>
            <button
              type="button"
              onClick={handleClose}
              disabled={isPending}
              className="text-muted-foreground hover:text-foreground transition-colors p-1 hover:bg-accent rounded"
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
              </svg>
            </button>
          </div>

          {/* Body */}
          <form onSubmit={handleSubmit} className="p-5 space-y-5">
            <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
              <FormField className="sm:col-span-2">
                <FormLabel required>Titre</FormLabel>
                <FormInput
                  value={title}
                  onChange={(e) => setTitle(e.target.value)}
                  disabled={isPending}
                  placeholder="Titre du livre"
                />
              </FormField>

              {/* Auteurs — multi-valeur */}
              <FormField className="sm:col-span-2">
                <FormLabel>Auteur(s)</FormLabel>
                <div className="space-y-2">
                  {authors.length > 0 && (
                    <div className="flex flex-wrap gap-1.5">
                      {authors.map((a, i) => (
                        <span
                          key={i}
                          className="inline-flex items-center gap-1 px-2.5 py-1 rounded-full bg-primary/10 text-primary text-xs font-medium"
                        >
                          {a}
                          <button
                            type="button"
                            onClick={() => removeAuthor(i)}
                            disabled={isPending}
                            className="hover:text-destructive transition-colors ml-0.5"
                            aria-label={`Supprimer ${a}`}
                          >
                            ×
                          </button>
                        </span>
                      ))}
                    </div>
                  )}
                  <div className="flex gap-2">
                    <input
                      ref={setAuthorInputEl}
                      value={authorInput}
                      onChange={(e) => setAuthorInput(e.target.value)}
                      onKeyDown={handleAuthorKeyDown}
                      disabled={isPending}
                      placeholder="Ajouter un auteur (Entrée pour valider)"
                      className="flex h-10 flex-1 rounded-md border border-input bg-background px-3 py-2 text-sm shadow-sm transition-colors placeholder:text-muted-foreground/90 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50"
                    />
                    <button
                      type="button"
                      onClick={addAuthor}
                      disabled={isPending || !authorInput.trim()}
                      className="px-3 py-1.5 rounded-lg border border-border bg-card text-sm font-medium text-muted-foreground hover:text-foreground disabled:opacity-40 transition-colors"
                    >
                      +
                    </button>
                  </div>
                </div>
              </FormField>

              <FormField>
                <FormLabel>Langue</FormLabel>
                <FormInput
                  value={language}
                  onChange={(e) => setLanguage(e.target.value)}
                  disabled={isPending}
                  placeholder="ex : fr, en, jp"
                />
              </FormField>

              <FormField>
                <FormLabel>Série</FormLabel>
                <FormInput
                  value={series}
                  onChange={(e) => setSeries(e.target.value)}
                  disabled={isPending}
                  placeholder="Nom de la série"
                />
              </FormField>

              <FormField>
                <FormLabel>Volume</FormLabel>
                <FormInput
                  type="number"
                  min="1"
                  value={volume}
                  onChange={(e) => setVolume(e.target.value)}
                  disabled={isPending}
                  placeholder="Numéro de volume"
                />
              </FormField>
            </div>

            {error && (
              <p className="text-xs text-destructive">{error}</p>
            )}

            {/* Footer */}
            <div className="flex items-center justify-end gap-2 pt-2 border-t border-border/50">
              <button
                type="button"
                onClick={handleClose}
                disabled={isPending}
                className="px-4 py-1.5 rounded-lg border border-border bg-card text-sm font-medium text-muted-foreground hover:text-foreground transition-colors"
              >
                Annuler
              </button>
              <button
                type="submit"
                disabled={isPending || !title.trim()}
                className="px-4 py-1.5 rounded-lg bg-primary text-white text-sm font-medium hover:bg-primary/90 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
              >
                {isPending ? "Sauvegarde…" : "Sauvegarder"}
              </button>
            </div>
          </form>
        </div>
      </div>
    </>,
    document.body
  ) : null;

  return (
    <>
      <button
        onClick={() => setIsOpen(true)}
        className="inline-flex items-center gap-1.5 px-3 py-1.5 rounded-lg border border-border bg-card text-sm font-medium text-muted-foreground hover:text-foreground hover:border-primary transition-colors"
      >
        <span>✏️</span> Modifier
      </button>
      {modal}
    </>
  );
}