"use client";

import { useEffect, useId, useMemo, useState } from "react";
import CategoryTreeSelect from "@/components/CategoryTreeSelect";
import {
  searchMeshkeeCategories,
  type MeshkeeCategory,
} from "@/services/meshkee-categories";
import styles from "./WebsiteLinkGenerator.module.css";

export type WebsiteLinkKind = "businesses" | "blog";

function buildCategoryLink(kind: WebsiteLinkKind, category: MeshkeeCategory) {
  const path = kind === "blog" ? "/blog" : "/businesses";
  const query = category.slug
    ? `category=${encodeURIComponent(category.slug)}`
    : `categoryId=${encodeURIComponent(category.id)}`;
  return `${path}?${query}`;
}

function LinkIcon() {
  return (
    <svg
      width="16"
      height="16"
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.75"
      strokeLinecap="round"
      strokeLinejoin="round"
      aria-hidden
    >
      <path d="M10 13a5 5 0 0 0 7.54.54l1.92-1.92a5 5 0 0 0-7.07-7.07l-1.72 1.71" />
      <path d="M14 11a5 5 0 0 0-7.54-.54L4.54 12.38a5 5 0 0 0 7.07 7.07l1.71-1.71" />
    </svg>
  );
}

export default function WebsiteLinkGenerator({
  onPick,
  disabled = false,
}: {
  onPick: (url: string) => void;
  disabled?: boolean;
}) {
  const titleId = useId();
  const [open, setOpen] = useState(false);
  const [kind, setKind] = useState<WebsiteLinkKind>("businesses");
  const [categories, setCategories] = useState<MeshkeeCategory[]>([]);
  const [categoryId, setCategoryId] = useState("");
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState("");

  useEffect(() => {
    if (!open) return;
    setKind("businesses");
    setCategoryId("");
    setError("");
  }, [open]);

  useEffect(() => {
    if (!open) return;
    const previousOverflow = document.body.style.overflow;
    document.body.style.overflow = "hidden";
    const onKey = (event: KeyboardEvent) => {
      if (event.key === "Escape") setOpen(false);
    };
    window.addEventListener("keydown", onKey);
    return () => {
      document.body.style.overflow = previousOverflow;
      window.removeEventListener("keydown", onKey);
    };
  }, [open]);

  useEffect(() => {
    if (!open) return;
    const controller = new AbortController();
    setLoading(true);
    setError("");
    void searchMeshkeeCategories("", controller.signal)
      .then((items) => {
        if (controller.signal.aborted) return;
        setCategories(items);
      })
      .catch((err) => {
        if (controller.signal.aborted) return;
        setCategories([]);
        setError(
          err instanceof Error ? err.message : "Could not load categories.",
        );
      })
      .finally(() => {
        if (!controller.signal.aborted) setLoading(false);
      });

    return () => controller.abort();
  }, [open]);

  const selected = useMemo(
    () => categories.find((item) => item.id === categoryId) ?? null,
    [categories, categoryId],
  );
  const preview = selected ? buildCategoryLink(kind, selected) : "";

  return (
    <>
      <button
        type="button"
        className={styles.trigger}
        aria-label="Generate link"
        title="Generate link"
        disabled={disabled}
        onClick={() => setOpen(true)}
      >
        <LinkIcon />
      </button>

      {open ? (
        <div
          className={styles.overlay}
          role="presentation"
          onClick={() => setOpen(false)}
        >
          <div
            className={styles.modal}
            role="dialog"
            aria-modal="true"
            aria-labelledby={titleId}
            onClick={(event) => event.stopPropagation()}
          >
            <div className={styles.head}>
              <div>
                <p className={styles.kicker}>Link generator</p>
                <h3 id={titleId} className={styles.title}>
                  Build category link
                </h3>
              </div>
              <button
                type="button"
                className={styles.closeBtn}
                aria-label="Close"
                onClick={() => setOpen(false)}
              >
                ×
              </button>
            </div>

            <div className={styles.kindSwitch} role="tablist" aria-label="Link type">
              <button
                type="button"
                role="tab"
                aria-selected={kind === "businesses"}
                className={`${styles.kindBtn} ${
                  kind === "businesses" ? styles.kindBtnActive : ""
                }`}
                onClick={() => setKind("businesses")}
              >
                Businesses category
              </button>
              <button
                type="button"
                role="tab"
                aria-selected={kind === "blog"}
                className={`${styles.kindBtn} ${
                  kind === "blog" ? styles.kindBtnActive : ""
                }`}
                onClick={() => setKind("blog")}
              >
                Blog category
              </button>
            </div>

            {loading ? (
              <p className={styles.status}>Loading categories…</p>
            ) : error ? (
              <p className={styles.error}>{error}</p>
            ) : (
              <CategoryTreeSelect
                categories={categories}
                value={categoryId ? [categoryId] : []}
                onChange={(ids) => setCategoryId(ids[0] ?? "")}
                selection="single"
                dropdownVariant="inFlow"
                label="Category"
                placeholder="Search categories…"
              />
            )}

            <div className={styles.preview}>
              <span>Preview</span>
              <code dir="ltr">{preview || "Select a category"}</code>
            </div>

            <div className={styles.actions}>
              <button
                type="button"
                className={`outline-btn ${styles.secondaryBtn}`}
                onClick={() => setOpen(false)}
              >
                Cancel
              </button>
              <button
                type="button"
                className={`outline-btn ${styles.primaryBtn}`}
                disabled={!preview}
                onClick={() => {
                  if (!preview) return;
                  onPick(preview);
                  setOpen(false);
                }}
              >
                Use link
              </button>
            </div>
          </div>
        </div>
      ) : null}
    </>
  );
}