/*
 This file is part of GNU Taler
 (C) 2021-2023 Taler Systems S.A.

 GNU Taler is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

/**
 *
 * @author Sebastian Javier Marchano (sebasjm)
 */

import { buildCodecForObject, codecForMap, codecForString, codecForTimestamp } from "@gnu-taler/taler-util";
import { buildStorageKey, useLocalStorage } from "@gnu-taler/web-util/browser";
import { StateUpdater, useEffect, useState } from "preact/hooks";
import { LoginToken } from "../declaration.js";
import { ValueOrFunction } from "../utils/types.js";
import { useMatchMutate } from "./backend.js";

const calculateRootPath = () => {
  const rootPath =
    typeof window !== undefined
      ? window.location.origin + window.location.pathname
      : "/";

  /**
   * By default, merchant backend serves the html content
   * from the /webui root. This should cover most of the 
   * cases and the rootPath will be the merchant backend
   * URL where the instances are
   */
  return rootPath.replace("/webui/", "");
};

const loginTokenCodec = buildCodecForObject<LoginToken>()
  .property("token", codecForString())
  .property("expiration", codecForTimestamp)
  .build("loginToken")
const TOKENS_KEY = buildStorageKey("merchant-token", codecForMap(loginTokenCodec));


export function useBackendURL(
  url?: string,
): [string, StateUpdater<string>] {
  const [value, setter] = useSimpleLocalStorage(
    "merchant-base-url",
    url || calculateRootPath(),
  );

  const checkedSetter = (v: ValueOrFunction<string>) => {
    return setter((p) => (v instanceof Function ? v(p ?? "") : v).replace(/\/$/, ""));
  };

  return [value!, checkedSetter];
}

export function useBackendDefaultToken(
): [LoginToken | undefined, ((d: LoginToken | undefined) => void)] {
  const { update: setToken, value: tokenMap, reset } = useLocalStorage(TOKENS_KEY, {})

  // const tokenOfDefaultInstance = tokenMap["default"]
  // const clearCache = useMatchMutate()
  // useEffect(() => {
  //   clearCache()
  // }, [tokenOfDefaultInstance])

  function updateToken(
    value: (LoginToken | undefined)
  ): void {
    if (value === undefined) {
      reset()
    } else {
      const res = { ...tokenMap, "default": value }
      setToken(res)
    }
  }
  return [tokenMap["default"], updateToken];
}

export function useBackendInstanceToken(
  id: string,
): [LoginToken | undefined, ((d: LoginToken | undefined) => void)] {
  const { update: setToken, value: tokenMap, reset } = useLocalStorage(TOKENS_KEY, {})
  const [defaultToken, defaultSetToken] = useBackendDefaultToken();

  // instance named 'default' use the default token
  if (id === "default") {
    return [defaultToken, defaultSetToken];
  }
  function updateToken(
    value: (LoginToken | undefined)
  ): void {
    if (value === undefined) {
      reset()
    } else {
      const res = { ...tokenMap, [id]: value }
      setToken(res)
    }
  }

  return [tokenMap[id], updateToken];
}

export function useLang(initial?: string): [string, StateUpdater<string>] {
  const browserLang =
    typeof window !== "undefined"
      ? navigator.language || (navigator as any).userLanguage
      : undefined;
  const defaultLang = (browserLang || initial || "en").substring(0, 2);
  return useSimpleLocalStorage("lang-preference", defaultLang) as [string, StateUpdater<string>];
}

export function useSimpleLocalStorage(
  key: string,
  initialValue?: string,
): [string | undefined, StateUpdater<string | undefined>] {
  const [storedValue, setStoredValue] = useState<string | undefined>(
    (): string | undefined => {
      return typeof window !== "undefined"
        ? window.localStorage.getItem(key) || initialValue
        : initialValue;
    },
  );

  const setValue = (
    value?: string | ((val?: string) => string | undefined),
  ) => {
    setStoredValue((p) => {
      const toStore = value instanceof Function ? value(p) : value;
      if (typeof window !== "undefined") {
        if (!toStore) {
          window.localStorage.removeItem(key);
        } else {
          window.localStorage.setItem(key, toStore);
        }
      }
      return toStore;
    });
  };

  return [storedValue, setValue];
}