/*
 This file is part of GNU Taler
 (C) 2021-2024 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 {
  AmountString,
  Amounts,
  Duration,
  TalerError,
  TalerMerchantApi,
  assertUnreachable,
} from "@gnu-taler/taler-util";
import {
  useTranslationContext
} from "@gnu-taler/web-util/browser";
import { VNode, h } from "preact";
import { useState } from "preact/hooks";
import { AsyncButton } from "../../../../components/exception/AsyncButton.js";
import {
  FormErrors,
  FormProvider,
} from "../../../../components/form/FormProvider.js";
import { Input } from "../../../../components/form/Input.js";
import { InputCurrency } from "../../../../components/form/InputCurrency.js";
import { InputDuration } from "../../../../components/form/InputDuration.js";
import { InputNumber } from "../../../../components/form/InputNumber.js";
import { InputSearchOnList } from "../../../../components/form/InputSearchOnList.js";
import { InputTab } from "../../../../components/form/InputTab.js";
import { InputWithAddon } from "../../../../components/form/InputWithAddon.js";
import { useSessionContext } from "../../../../context/session.js";
import { useInstanceOtpDevices } from "../../../../hooks/otp.js";

enum Steps {
  BOTH_FIXED,
  FIXED_PRICE,
  FIXED_SUMMARY,
  NON_FIXED,
}

// type Entity = TalerMerchantApi.TemplateAddDetails & { type: Steps };
type Entity = {
  id?: string;
  description?: string;
  otpId?: string;
  summary?: string;
  amount?: AmountString;
  minimum_age?: number;
  pay_duration?: Duration;
  type: Steps;
};

interface Props {
  onCreate: (d: TalerMerchantApi.TemplateAddDetails) => Promise<void>;
  onBack?: () => void;
}

export function CreatePage({ onCreate, onBack }: Props): VNode {
  const { i18n } = useTranslationContext();
  const {
    state: { backendUrl },
  } = useSessionContext();
  const devices = useInstanceOtpDevices();

  const [state, setState] = useState<Partial<Entity>>({
    minimum_age: 0,
    pay_duration: {
      d_ms: 1000 * 60 * 30, //30 min
    },
    type: Steps.NON_FIXED,
  });

  const parsedPrice = !state.amount ? undefined : Amounts.parse(state.amount);

  const errors: FormErrors<Entity> = {
    id: !state.id
      ? i18n.str`should not be empty`
      : !/[a-zA-Z0-9]*/.test(state.id)
        ? i18n.str`no valid. only characters and numbers`
        : undefined,
    description: !state.description ? i18n.str`should not be empty` : undefined,
    amount: !(
      state.type === Steps.FIXED_PRICE || state.type === Steps.BOTH_FIXED
    )
      ? undefined
      : !state.amount
        ? i18n.str`required`
        : !parsedPrice
          ? i18n.str`not valid`
          : Amounts.isZero(parsedPrice)
            ? i18n.str`must be greater than 0`
            : undefined,
    summary: !(
      state.type === Steps.FIXED_SUMMARY || state.type === Steps.BOTH_FIXED
    )
      ? undefined
      : !state.summary
        ? i18n.str`required`
        : undefined,
    minimum_age:
      state.minimum_age && state.minimum_age < 0
        ? i18n.str`should be greater that 0`
        : undefined,
    pay_duration: !state.pay_duration
      ? i18n.str`can't be empty`
      : state.pay_duration.d_ms === "forever"
        ? undefined
        : state.pay_duration.d_ms < 1000 //less than one second
          ? i18n.str`to short`
          : undefined,
  };

  const hasErrors = Object.keys(errors).some(
    (k) => (errors as Record<string,unknown>)[k] !== undefined,
  );

  const submitForm = () => {
    if (hasErrors || state.type === undefined) return Promise.reject();
    switch (state.type) {
      case Steps.FIXED_PRICE:
        return onCreate({
          template_id: state.id!,
          template_description: state.description!,
          template_contract: {
            minimum_age: state.minimum_age!,
            pay_duration: Duration.toTalerProtocolDuration(state.pay_duration!),
            amount: state.amount!,
            // summary: state.summary,
          },
          otp_id: state.otpId!,
        });
      case Steps.FIXED_SUMMARY:
        return onCreate({
          template_id: state.id!,
          template_description: state.description!,
          template_contract: {
            minimum_age: state.minimum_age!,
            pay_duration: Duration.toTalerProtocolDuration(state.pay_duration!),
            // amount: state.amount!,
            summary: state.summary,
          },
          otp_id: state.otpId!,
        });
      case Steps.NON_FIXED:
        return onCreate({
          template_id: state.id!,
          template_description: state.description!,
          template_contract: {
            minimum_age: state.minimum_age!,
            pay_duration: Duration.toTalerProtocolDuration(state.pay_duration!),
            // amount: state.amount!,
            // summary: state.summary,
          },
          otp_id: state.otpId!,
        });
      case Steps.BOTH_FIXED:
        return onCreate({
          template_id: state.id!,
          template_description: state.description!,
          template_contract: {
            minimum_age: state.minimum_age!,
            pay_duration: Duration.toTalerProtocolDuration(state.pay_duration!),
            amount: state.amount!,
            summary: state.summary,
          },
          otp_id: state.otpId!,
        });
      default:
        assertUnreachable(state.type);
      // return onCreate(state);
    }
  };
  const deviceList = !devices || devices instanceof TalerError || devices.type === "fail" ? [] : devices.body;

  return (
    <div>
      <section class="section is-main-section">
        <div class="columns">
          <div class="column" />
          <div class="column is-four-fifths">
            <FormProvider
              object={state}
              valueHandler={setState}
              errors={errors}
            >
              <InputWithAddon<Entity>
                name="id"
                help={new URL(`templates/${state.id ?? ""}`, backendUrl).href}
                label={i18n.str`Identifier`}
                tooltip={i18n.str`Name of the template in URLs.`}
              />
              <Input<Entity>
                name="description"
                label={i18n.str`Description`}
                help=""
                tooltip={i18n.str`Describe what this template stands for`}
              />
              <InputTab<Entity>
                name="type"
                label={i18n.str`Type`}
                help={(() => {
                  if (state.type === undefined) return "";
                  switch (state.type) {
                    case Steps.NON_FIXED:
                      return i18n.str`User will be able to input price and summary before payment.`;
                    case Steps.FIXED_PRICE:
                      return i18n.str`User will be able to add a summary before payment.`;
                    case Steps.FIXED_SUMMARY:
                      return i18n.str`User will be able to set the price before payment.`;
                    case Steps.BOTH_FIXED:
                      return i18n.str`User will not be able to change the price or the summary.`;
                  }
                })()}
                tooltip={i18n.str`Define what the user be allowed to modify`}
                values={[
                  Steps.NON_FIXED,
                  Steps.FIXED_PRICE,
                  Steps.FIXED_SUMMARY,
                  Steps.BOTH_FIXED,
                ]}
                toStr={(v: Steps): string => {
                  switch (v) {
                    case Steps.NON_FIXED:
                      return i18n.str`Simple`;
                    case Steps.FIXED_PRICE:
                      return i18n.str`With price`;
                    case Steps.FIXED_SUMMARY:
                      return i18n.str`With summary`;
                    case Steps.BOTH_FIXED:
                      return i18n.str`With price and summary`;
                  }
                }}
              />
              {state.type === Steps.BOTH_FIXED ||
              state.type === Steps.FIXED_SUMMARY ? (
                <Input<Entity>
                  name="summary"
                  inputType="multiline"
                  label={i18n.str`Fixed summary`}
                  tooltip={i18n.str`If specified, this template will create order with the same summary`}
                />
              ) : undefined}
              {state.type === Steps.BOTH_FIXED ||
              state.type === Steps.FIXED_PRICE ? (
                <InputCurrency<Entity>
                  name="amount"
                  label={i18n.str`Fixed price`}
                  tooltip={i18n.str`If specified, this template will create order with the same price`}
                />
              ) : undefined}
              <InputNumber<Entity>
                name="minimum_age"
                label={i18n.str`Minimum age`}
                help=""
                tooltip={i18n.str`Is this contract restricted to some age?`}
              />
              <InputDuration<Entity>
                name="pay_duration"
                label={i18n.str`Payment timeout`}
                help=""
                tooltip={i18n.str`How much time has the customer to complete the payment once the order was created.`}
              />
              <Input<Entity>
                name="otpId"
                label={i18n.str`OTP device`}
                readonly
                side={
                  <button
                    class="button is-danger"
                    data-tooltip={i18n.str`without otp device`}
                    onClick={(): void => {
                      setState((v) => ({ ...v, otpId: undefined }));
                    }}
                  >
                    <span>
                      <i18n.Translate>remove</i18n.Translate>
                    </span>
                  </button>
                }
                tooltip={i18n.str`Use to verify transaction in offline mode.`}
              />
              <InputSearchOnList
                label={i18n.str`Search device`}
                onChange={(p) => setState((v) => ({ ...v, otpId: p?.id }))}
                list={deviceList.map((e) => ({
                  description: e.device_description,
                  id: e.otp_device_id,
                }))}
              />
            </FormProvider>

            <div class="buttons is-right mt-5">
              {onBack && (
                <button class="button" onClick={onBack}>
                  <i18n.Translate>Cancel</i18n.Translate>
                </button>
              )}
              <AsyncButton
                disabled={hasErrors}
                data-tooltip={
                  hasErrors
                    ? i18n.str`Need to complete marked fields`
                    : "confirm operation"
                }
                onClick={submitForm}
              >
                <i18n.Translate>Confirm</i18n.Translate>
              </AsyncButton>
            </div>
          </div>
          <div class="column" />
        </div>
      </section>
    </div>
  );
}