import { useEnvironment } from "@keycloak/keycloak-ui-shared";
import {
  ActionList,
  ActionListItem,
  List,
  ListItem,
  MenuToggle,
  MenuToggleElement,
  PageSection,
  PageSectionVariants,
  Select,
  SelectList,
  SelectOption,
} from "@patternfly/react-core";
import { useEffect, useMemo, useState } from "react";
import { useTranslation } from "react-i18next";
import { getIssuer, requestVCOffer } from "../api";
import { CredentialsIssuer } from "../api/representations";
import { Page } from "../components/page/Page";
import { usePromise } from "../utils/usePromise";

export const Oid4Vci = () => {
  const context = useEnvironment();

  const { t } = useTranslation();

  const initialSelected = t("verifiableCredentialsSelectionDefault");

  const [selected, setSelected] = useState<string>(initialSelected);
  const [qrCode, setQrCode] = useState<string>("");
  const [isOpen, setIsOpen] = useState<boolean>(false);
  const [offerQRVisible, setOfferQRVisible] = useState<boolean>(false);
  const [credentialsIssuer, setCredentialsIssuer] =
    useState<CredentialsIssuer>();

  usePromise(() => getIssuer(context), setCredentialsIssuer);

  const selectOptions = useMemo(() => {
    if (typeof credentialsIssuer !== "undefined") {
      return credentialsIssuer.credential_configurations_supported;
    }
    return {};
  }, [credentialsIssuer]);

  const dropdownItems = useMemo(() => {
    if (typeof selectOptions !== "undefined") {
      return Array.from(Object.keys(selectOptions));
    }
    return [];
  }, [selectOptions]);

  useEffect(() => {
    if (initialSelected !== selected && credentialsIssuer !== undefined) {
      requestVCOffer(context, selectOptions[selected], credentialsIssuer).then(
        (blob) => {
          const reader = new FileReader();
          reader.readAsDataURL(blob);
          reader.onloadend = function () {
            const result = reader.result;
            if (typeof result === "string") {
              setQrCode(result);
              setOfferQRVisible(true);
              setIsOpen(false);
            }
          };
        },
      );
    }
  }, [selected]);

  const onToggleClick = () => {
    setIsOpen(!isOpen);
  };

  const toggle = (toggleRef: React.Ref<MenuToggleElement>) => (
    <MenuToggle
      ref={toggleRef}
      onClick={onToggleClick}
      isExpanded={isOpen}
      data-testid="menu-toggle"
    >
      {selected}
    </MenuToggle>
  );

  return (
    <Page
      title={t("verifiableCredentialsTitle")}
      description={t("verifiableCredentialsDescription")}
    >
      <PageSection isFilled variant={PageSectionVariants.light}>
        <List isPlain>
          <ListItem>
            <Select
              data-testid="credential-select"
              onOpenChange={(isOpen) => setIsOpen(isOpen)}
              onSelect={(_event, val) => setSelected(val as string)}
              isOpen={isOpen}
              selected={selected}
              toggle={toggle}
              shouldFocusToggleOnSelect={true}
            >
              <SelectList>
                {dropdownItems.map((option) => (
                  <SelectOption
                    key={option}
                    value={option}
                    data-testid={option}
                  >
                    {option}
                  </SelectOption>
                ))}
              </SelectList>
            </Select>
          </ListItem>
          <ListItem>
            <ActionList>
              {offerQRVisible && (
                <ActionListItem>
                  <img
                    width="500"
                    height="500"
                    src={qrCode}
                    data-testid="qr-code"
                  />
                </ActionListItem>
              )}
            </ActionList>
          </ListItem>
        </List>
      </PageSection>
    </Page>
  );
};

export default Oid4Vci;