import { Icon } from "./components/Icon";
// In-app dialogs and toasts instead of the browser's alert/confirm/prompt.
import { useEffect, useRef, useState, useSyncExternalStore } from "react";
import { t } from "./i18n";

interface ConfirmOpts {
  title?: string;
  message: string;
  confirmLabel?: string;
  /** Destructive action: red button. */
  danger?: boolean;
}

interface PromptOpts {
  title?: string;
  message: string;
  defaultValue?: string;
  placeholder?: string;
  password?: boolean;
  confirmLabel?: string;
}

type Dialog =
  | ({ kind: "confirm"; id: number; resolve: (v: boolean) => void } & ConfirmOpts)
  | ({ kind: "prompt"; id: number; resolve: (v: string | null) => void } & PromptOpts);

interface Toast {
  id: number;
  message: string;
  kind: "error" | "info" | "success";
}

let dialogs: Dialog[] = [];
let toasts: Toast[] = [];
let seq = 0;
const listeners = new Set<() => void>();
const emit = () => listeners.forEach((l) => l());
const subscribe = (l: () => void) => (listeners.add(l), () => listeners.delete(l));

export function confirmDialog(opts: ConfirmOpts | string): Promise<boolean> {
  const o = typeof opts === "string" ? { message: opts } : opts;
  return new Promise((resolve) => {
    dialogs = [...dialogs, { kind: "confirm", id: ++seq, resolve, ...o }];
    emit();
  });
}

export function promptDialog(opts: PromptOpts | string): Promise<string | null> {
  const o = typeof opts === "string" ? { message: opts } : opts;
  return new Promise((resolve) => {
    dialogs = [...dialogs, { kind: "prompt", id: ++seq, resolve, ...o }];
    emit();
  });
}

export function toast(message: unknown, kind: Toast["kind"] = "error") {
  const text = message instanceof Error ? message.message : typeof message === "string" ? message : String((message as any)?.message ?? message);
  const id = ++seq;
  toasts = [...toasts, { id, message: text, kind }];
  emit();
  setTimeout(() => {
    toasts = toasts.filter((x) => x.id !== id);
    emit();
  }, kind === "error" ? 7000 : 3500);
}

function close(d: Dialog, value: any) {
  dialogs = dialogs.filter((x) => x.id !== d.id);
  emit();
  (d.resolve as (v: any) => void)(value);
}

function DialogView({ d }: { d: Dialog }) {
  const [value, setValue] = useState(d.kind === "prompt" ? d.defaultValue ?? "" : "");
  const input = useRef<HTMLInputElement>(null);
  const ok = useRef<HTMLButtonElement>(null);
  const cancelValue = d.kind === "confirm" ? false : null;
  useEffect(() => {
    if (d.kind === "prompt") {
      input.current?.focus();
      input.current?.select();
    } else ok.current?.focus();
    const h = (e: KeyboardEvent) => e.key === "Escape" && close(d, cancelValue);
    window.addEventListener("keydown", h);
    return () => window.removeEventListener("keydown", h);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);
  const submit = () => close(d, d.kind === "confirm" ? true : value);
  return (
    <div className="modal-backdrop" onClick={() => close(d, cancelValue)}>
      <form
        className="modal dialog"
        role={d.kind === "confirm" ? "alertdialog" : "dialog"}
        aria-label={d.title ?? d.message}
        onClick={(e) => e.stopPropagation()}
        onSubmit={(e) => (e.preventDefault(), submit())}
      >
        {d.title && <h3>{d.title}</h3>}
        <p className="dialog-message">{d.message}</p>
        {d.kind === "prompt" && (
          <input
            ref={input}
            type={d.password ? "password" : "text"}
            value={value}
            placeholder={d.placeholder}
            onChange={(e) => setValue(e.target.value)}
            autoComplete={d.password ? "new-password" : "off"}
            style={{ width: "100%" }}
          />
        )}
        <div className="row dialog-actions">
          <button type="button" onClick={() => close(d, cancelValue)}>
            {t("common.cancel")}
          </button>
          <button ref={ok} type="submit" className={d.kind === "confirm" && d.danger ? "danger-solid" : "primary"}>
            {d.confirmLabel ?? t("common.ok")}
          </button>
        </div>
      </form>
    </div>
  );
}

/** Renders open dialogs and toasts; mounted once in App. */
export function DialogHost() {
  const state = useSyncExternalStore(subscribe, () => dialogs);
  const ts = useSyncExternalStore(subscribe, () => toasts);
  return (
    <>
      {state.map((d) => (
        <DialogView key={d.id} d={d} />
      ))}
      <div className="toasts" role="status" aria-live="polite">
        {ts.map((x) => (
          <div key={x.id} className={`toast ${x.kind}`} onClick={() => ((toasts = toasts.filter((y) => y.id !== x.id)), emit())}>
            {x.kind === "error" ? <Icon name="warning" /> : x.kind === "success" ? <Icon name="check" /> : null}
            {x.message}
          </div>
        ))}
      </div>
    </>
  );
}