"use client";

import { useState, useTransition } from "react";
import { useRouter } from "next/navigation";
import { FormField, FormLabel, FormInput } from "./ui/Form";

interface EditSeriesFormProps {
  libraryId: string;
  seriesName: string;
  currentAuthors: string[];
  currentPublishers: string[];
  currentBookAuthor: string | null;
  currentBookLanguage: string | null;
  currentDescription: string | null;
  currentStartYear: number | null;
}

export function EditSeriesForm({
  libraryId,
  seriesName,
  currentAuthors,
  currentPublishers,
  currentBookAuthor,
  currentBookLanguage,
  currentDescription,
  currentStartYear,
}: EditSeriesFormProps) {
  const router = useRouter();
  const [isPending, startTransition] = useTransition();
  const [isEditing, setIsEditing] = useState(false);
  const [error, setError] = useState<string | null>(null);

  // Champs propres à la série
  const [newName, setNewName] = useState(seriesName === "unclassified" ? "" : seriesName);
  const [authors, setAuthors] = useState<string[]>(currentAuthors);
  const [authorInput, setAuthorInput] = useState("");
  const [authorInputEl, setAuthorInputEl] = useState<HTMLInputElement | null>(null);
  const [publishers, setPublishers] = useState<string[]>(currentPublishers);
  const [publisherInput, setPublisherInput] = useState("");
  const [publisherInputEl, setPublisherInputEl] = useState<HTMLInputElement | null>(null);
  const [description, setDescription] = useState(currentDescription ?? "");
  const [startYear, setStartYear] = useState(currentStartYear?.toString() ?? "");

  // Propagation aux livres — opt-in via bouton
  const [bookAuthor, setBookAuthor] = useState(currentBookAuthor ?? "");
  const [bookLanguage, setBookLanguage] = useState(currentBookLanguage ?? "");
  const [showApplyToBooks, setShowApplyToBooks] = useState(false);

  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 addPublisher = () => {
    const v = publisherInput.trim();
    if (v && !publishers.includes(v)) {
      setPublishers([...publishers, v]);
    }
    setPublisherInput("");
    publisherInputEl?.focus();
  };

  const removePublisher = (idx: number) => {
    setPublishers(publishers.filter((_, i) => i !== idx));
  };

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

  const handleCancel = () => {
    setNewName(seriesName === "unclassified" ? "" : seriesName);
    setAuthors(currentAuthors);
    setAuthorInput("");
    setPublishers(currentPublishers);
    setPublisherInput("");
    setDescription(currentDescription ?? "");
    setStartYear(currentStartYear?.toString() ?? "");
    setShowApplyToBooks(false);
    setBookAuthor(currentBookAuthor ?? "");
    setBookLanguage(currentBookLanguage ?? "");
    setError(null);
    setIsEditing(false);
  };

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (!newName.trim() && seriesName !== "unclassified") return;
    setError(null);

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

    const finalPublishers = publisherInput.trim()
      ? [...new Set([...publishers, publisherInput.trim()])]
      : publishers;

    startTransition(async () => {
      try {
        const effectiveName = newName.trim() || "unclassified";
        const body: Record<string, unknown> = {
          new_name: effectiveName,
          authors: finalAuthors,
          publishers: finalPublishers,
          description: description.trim() || null,
          start_year: startYear.trim() ? parseInt(startYear.trim(), 10) : null,
        };
        if (showApplyToBooks) {
          body.author = bookAuthor.trim() || null;
          body.language = bookLanguage.trim() || null;
        }

        const res = await fetch(
          `/api/libraries/${libraryId}/series/${encodeURIComponent(seriesName)}`,
          {
            method: "PATCH",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify(body),
          }
        );
        if (!res.ok) {
          const data = await res.json();
          setError(data.error ?? "Erreur lors de la sauvegarde");
          return;
        }
        setIsEditing(false);

        if (effectiveName !== seriesName) {
          router.push(`/libraries/${libraryId}/series/${encodeURIComponent(effectiveName)}` as any);
        } else {
          router.refresh();
        }
      } catch {
        setError("Erreur réseau");
      }
    });
  };

  if (!isEditing) {
    return (
      <button
        onClick={() => setIsEditing(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 la série
      </button>
    );
  }

  return (
    <form onSubmit={handleSubmit} className="w-full p-4 border border-border rounded-xl bg-muted/30 space-y-5">
      <h3 className="text-sm font-semibold text-foreground">Modifier les métadonnées de la série</h3>

      <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
        <FormField>
          <FormLabel required>Nom</FormLabel>
          <FormInput
            value={newName}
            onChange={(e) => setNewName(e.target.value)}
            disabled={isPending}
            placeholder="Nom de la série"
          />
        </FormField>

        <FormField>
          <FormLabel>Année de début</FormLabel>
          <FormInput
            type="number"
            min="1900"
            max="2100"
            value={startYear}
            onChange={(e) => setStartYear(e.target.value)}
            disabled={isPending}
            placeholder="ex : 1990"
          />
        </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>
              <button
                type="button"
                onClick={() => setShowApplyToBooks(!showApplyToBooks)}
                disabled={isPending}
                className={`px-3 py-1.5 rounded-lg border text-sm font-medium transition-colors ${
                  showApplyToBooks
                    ? "border-primary bg-primary/10 text-primary"
                    : "border-border bg-card text-muted-foreground hover:text-foreground"
                }`}
                title="Appliquer auteur et langue à tous les livres de la série"
              >
                → livres
              </button>
            </div>
          </div>
        </FormField>

        {showApplyToBooks && (
          <div className="sm:col-span-2 grid grid-cols-1 sm:grid-cols-2 gap-3 pl-4 border-l-2 border-primary/30">
            <FormField>
              <FormLabel>Auteur (livres)</FormLabel>
              <FormInput
                value={bookAuthor}
                onChange={(e) => setBookAuthor(e.target.value)}
                disabled={isPending}
                placeholder="Écrase le champ auteur de chaque livre"
              />
            </FormField>
            <FormField>
              <FormLabel>Langue (livres)</FormLabel>
              <FormInput
                value={bookLanguage}
                onChange={(e) => setBookLanguage(e.target.value)}
                disabled={isPending}
                placeholder="ex : fr, en, jp"
              />
            </FormField>
          </div>
        )}

        {/* Éditeurs — multi-valeur */}
        <FormField className="sm:col-span-2">
          <FormLabel>Éditeur(s)</FormLabel>
          <div className="space-y-2">
            {publishers.length > 0 && (
              <div className="flex flex-wrap gap-1.5">
                {publishers.map((p, i) => (
                  <span
                    key={i}
                    className="inline-flex items-center gap-1 px-2.5 py-1 rounded-full bg-secondary/50 text-secondary-foreground text-xs font-medium"
                  >
                    {p}
                    <button
                      type="button"
                      onClick={() => removePublisher(i)}
                      disabled={isPending}
                      className="hover:text-destructive transition-colors ml-0.5"
                      aria-label={`Supprimer ${p}`}
                    >
                      ×
                    </button>
                  </span>
                ))}
              </div>
            )}
            <div className="flex gap-2">
              <input
                ref={setPublisherInputEl}
                value={publisherInput}
                onChange={(e) => setPublisherInput(e.target.value)}
                onKeyDown={handlePublisherKeyDown}
                disabled={isPending}
                placeholder="Ajouter un éditeur (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={addPublisher}
                disabled={isPending || !publisherInput.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 className="sm:col-span-2">
          <FormLabel>Description</FormLabel>
          <textarea
            value={description}
            onChange={(e) => setDescription(e.target.value)}
            disabled={isPending}
            rows={3}
            placeholder="Synopsis ou description de la série…"
            className="flex w-full 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 resize-none"
          />
        </FormField>
      </div>

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

      <div className="flex items-center gap-2">
        <button
          type="submit"
          disabled={isPending || (!newName.trim() && seriesName !== "unclassified")}
          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>
        <button
          type="button"
          onClick={handleCancel}
          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>
      </div>
    </form>
  );
}