/*
 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 { useTranslationContext } from "@gnu-taler/web-util/browser";
import { ComponentChildren, h, VNode } from "preact";
import { useCallback, useEffect, useState } from "preact/hooks";
import { useBackendContext } from "../../context/backend.js";
import { useInstanceContext } from "../../context/instance.js";
import { AccessToken, LoginToken } from "../../declaration.js";
import { useCredentialsChecker } from "../../hooks/backend.js";

interface Props {
  onConfirm: (token: LoginToken | undefined) => void;
}

function normalizeToken(r: string): AccessToken {
  return `secret-token:${r}` as AccessToken;
}

export function LoginPage({ onConfirm }: Props): VNode {
  const { url: backendURL } = useBackendContext();
  const { admin, id } = useInstanceContext();
  const { requestNewLoginToken } = useCredentialsChecker();
  const [token, setToken] = useState("");

  const { i18n } = useTranslationContext();


  const doLogin = useCallback(async function doLoginImpl() {
    const secretToken = normalizeToken(token);
    const baseUrl = id === undefined ? backendURL : `${backendURL}/instances/${id}`
    const result = await requestNewLoginToken(baseUrl, secretToken);
    if (result.valid) {
      const { token, expiration } = result
      onConfirm({ token, expiration });
    } else {
      onConfirm(undefined);
    }
  }, [id, token])

  if (admin && id !== "default") {
    //admin trying to access another instance
    return (<div class="columns is-centered" style={{ margin: "auto" }}>
      <div class="column is-two-thirds ">
        <div class="modal-card" style={{ width: "100%", margin: 0 }}>
          <header
            class="modal-card-head"
            style={{ border: "1px solid", borderBottom: 0 }}
          >
            <p class="modal-card-title">{i18n.str`Login required`}</p>
          </header>
          <section
            class="modal-card-body"
            style={{ border: "1px solid", borderTop: 0, borderBottom: 0 }}
          >
            <p>
              <i18n.Translate>Need the access token for the instance.</i18n.Translate>
            </p>
            <div class="field is-horizontal">
              <div class="field-label is-normal">
                <label class="label">
                  <i18n.Translate>Access Token</i18n.Translate>
                </label>
              </div>
              <div class="field-body">
                <div class="field">
                  <p class="control is-expanded">
                    <input
                      class="input"
                      type="password"
                      placeholder={"current access token"}
                      name="token"
                      onKeyPress={(e) =>
                        e.keyCode === 13
                          ? doLogin()
                          : null
                      }
                      value={token}
                      onInput={(e): void => setToken(e?.currentTarget.value)}
                    />
                  </p>
                </div>
              </div>
            </div>
          </section>
          <footer
            class="modal-card-foot "
            style={{
              justifyContent: "flex-end",
              border: "1px solid",
              borderTop: 0,
            }}
          >
            <AsyncButton
              onClick={doLogin}
            >
              <i18n.Translate>Confirm</i18n.Translate>
            </AsyncButton>
          </footer>
        </div>
      </div>
    </div>)
  }

  return (
    <div class="columns is-centered" style={{ margin: "auto" }}>
      <div class="column is-two-thirds ">
        <div class="modal-card" style={{ width: "100%", margin: 0 }}>
          <header
            class="modal-card-head"
            style={{ border: "1px solid", borderBottom: 0 }}
          >
            <p class="modal-card-title">{i18n.str`Login required`}</p>
          </header>
          <section
            class="modal-card-body"
            style={{ border: "1px solid", borderTop: 0, borderBottom: 0 }}
          >
            <i18n.Translate>Please enter your access token.</i18n.Translate>

            <div class="field is-horizontal">
              <div class="field-label is-normal">
                <label class="label">
                  <i18n.Translate>Access Token</i18n.Translate>
                </label>
              </div>
              <div class="field-body">
                <div class="field">
                  <p class="control is-expanded">
                    <input
                      class="input"
                      type="password"
                      placeholder={"current access token"}
                      name="token"
                      onKeyPress={(e) =>
                        e.keyCode === 13
                          ? doLogin()
                          : null
                      }
                      value={token}
                      onInput={(e): void => setToken(e?.currentTarget.value)}
                    />
                  </p>
                </div>
              </div>
            </div>
          </section>
          <footer
            class="modal-card-foot "
            style={{
              justifyContent: "space-between",
              border: "1px solid",
              borderTop: 0,
            }}
          >
            <div />
            <AsyncButton
              type="is-info"
              onClick={doLogin}
            >
              <i18n.Translate>Confirm</i18n.Translate>
            </AsyncButton>
          </footer>
        </div>
      </div>
    </div>
  );
}

function AsyncButton({ onClick, disabled, type = "", children }: { type?: string, disabled?: boolean, onClick: () => Promise<void>, children: ComponentChildren }): VNode {
  const [running, setRunning] = useState(false)
  return <button class={"button " + type} disabled={disabled || running} onClick={() => {
    setRunning(true)
    onClick().then(() => {
      setRunning(false)
    }).catch(() => {
      setRunning(false)
    })
  }}>
    {children}
  </button>
}