import { useSignal } from '@preact/signals';

import { Calendar } from '/lib/models/calendar.ts';
import { CALENDAR_COLOR_OPTIONS, getColorAsHex } from '/lib/utils/calendar.ts';
import { RequestBody as AddRequestBody, ResponseBody as AddResponseBody } from '/routes/api/calendar/add.tsx';
import { RequestBody as UpdateRequestBody, ResponseBody as UpdateResponseBody } from '/routes/api/calendar/update.tsx';
import { RequestBody as DeleteRequestBody, ResponseBody as DeleteResponseBody } from '/routes/api/calendar/delete.tsx';

interface CalendarsProps {
  initialCalendars: Calendar[];
}

export default function Calendars({ initialCalendars }: CalendarsProps) {
  const isAdding = useSignal<boolean>(false);
  const isDeleting = useSignal<boolean>(false);
  const isSaving = useSignal<boolean>(false);
  const calendars = useSignal<Calendar[]>(initialCalendars);
  const openCalendar = useSignal<Calendar | null>(null);

  async function onClickAddCalendar() {
    if (isAdding.value) {
      return;
    }

    const name = (prompt(`What's the **name** for the new calendar?`) || '').trim();

    if (!name) {
      alert('A name is required for a new calendar!');
      return;
    }

    isAdding.value = true;

    try {
      const requestBody: AddRequestBody = { name };
      const response = await fetch(`/api/calendar/add`, {
        method: 'POST',
        body: JSON.stringify(requestBody),
      });
      const result = await response.json() as AddResponseBody;

      if (!result.success) {
        throw new Error('Failed to add calendar!');
      }

      calendars.value = [...result.newCalendars];
    } catch (error) {
      console.error(error);
    }

    isAdding.value = false;
  }

  async function onClickDeleteCalendar(calendarId: string) {
    if (confirm('Are you sure you want to delete this calendar and all its events?')) {
      if (isDeleting.value) {
        return;
      }

      isDeleting.value = true;

      try {
        const requestBody: DeleteRequestBody = { calendarId };
        const response = await fetch(`/api/calendar/delete`, {
          method: 'POST',
          body: JSON.stringify(requestBody),
        });
        const result = await response.json() as DeleteResponseBody;

        if (!result.success) {
          throw new Error('Failed to delete calendar!');
        }

        calendars.value = [...result.newCalendars];
      } catch (error) {
        console.error(error);
      }

      isDeleting.value = false;
    }
  }

  async function onClickSaveOpenCalendar() {
    if (isSaving.value) {
      return;
    }

    if (!openCalendar.value?.uid) {
      alert('A calendar is required to update one!');
      return;
    }

    if (!openCalendar.value?.displayName) {
      alert('A name is required to update the calendar!');
      return;
    }

    if (!openCalendar.value?.calendarColor) {
      alert('A color is required to update the calendar!');
      return;
    }

    isSaving.value = true;

    try {
      const requestBody: UpdateRequestBody = {
        id: openCalendar.value.uid!,
        name: openCalendar.value.displayName!,
        color: openCalendar.value.calendarColor!,
        isVisible: openCalendar.value.isVisible!,
      };
      const response = await fetch(`/api/calendar/update`, {
        method: 'POST',
        body: JSON.stringify(requestBody),
      });
      const result = await response.json() as UpdateResponseBody;

      if (!result.success) {
        throw new Error('Failed to update calendar!');
      }

      calendars.value = [...result.newCalendars];
    } catch (error) {
      console.error(error);
    }

    isSaving.value = false;
    openCalendar.value = null;
  }

  return (
    <>
      <section class='flex flex-row items-center justify-between mb-4'>
        <a href='/calendar' class='mr-2'>View calendar</a>
        <section class='flex items-center'>
          <button
            class='inline-block justify-center gap-x-1.5 rounded-md bg-[#51A4FB] px-3 py-2 text-sm font-semibold text-white shadow-sm hover:bg-sky-400 ml-2'
            type='button'
            title='Add new calendar'
            onClick={() => onClickAddCalendar()}
          >
            <img
              src='/images/add.svg'
              alt='Add new calendar'
              class={`white ${isAdding.value ? 'animate-spin' : ''}`}
              width={20}
              height={20}
            />
          </button>
        </section>
      </section>

      <section class='mx-auto max-w-7xl my-8'>
        <table class='w-full border-collapse bg-gray-900 text-left text-sm text-white shadow-sm rounded-md'>
          <thead>
            <tr>
              <th scope='col' class='px-6 py-4 font-medium'>Name</th>
              <th scope='col' class='px-6 py-4 font-medium'>Color</th>
              <th scope='col' class='px-6 py-4 font-medium'>Visible?</th>
              <th scope='col' class='px-6 py-4 font-medium w-20'></th>
            </tr>
          </thead>
          <tbody class='divide-y divide-slate-600 border-t border-slate-600'>
            {calendars.value.map((calendar) => (
              <tr class='bg-slate-700 hover:bg-slate-600 group'>
                <td class='flex gap-3 px-6 py-4 font-medium'>
                  {calendar.displayName}
                </td>
                <td class='px-6 py-4 text-slate-200'>
                  <span
                    class={`w-5 h-5 inline-block rounded-full cursor-pointer`}
                    title={calendar.calendarColor}
                    style={{ backgroundColor: calendar.calendarColor }}
                    onClick={() => openCalendar.value = { ...calendar }}
                  >
                  </span>
                </td>
                <td class='px-6 py-4'>
                  {calendar.isVisible ? 'Yes' : 'No'}
                </td>
                <td class='px-6 py-4'>
                  <span
                    class='invisible cursor-pointer group-hover:visible opacity-50 hover:opacity-100'
                    onClick={() => onClickDeleteCalendar(calendar.uid!)}
                  >
                    <img
                      src='/images/delete.svg'
                      class='red drop-shadow-md'
                      width={24}
                      height={24}
                      alt='Delete calendar'
                      title='Delete calendar'
                    />
                  </span>
                </td>
              </tr>
            ))}
            {calendars.value.length === 0
              ? (
                <tr>
                  <td class='flex gap-3 px-6 py-4 font-normal' colspan={4}>
                    <div class='text-md'>
                      <div class='font-medium text-slate-400'>No calendars to show</div>
                    </div>
                  </td>
                </tr>
              )
              : null}
          </tbody>
        </table>

        <span
          class={`flex justify-end items-center text-sm mt-1 mx-2 text-slate-100`}
        >
          {isDeleting.value
            ? (
              <>
                <img src='/images/loading.svg' class='white mr-2' width={18} height={18} />Deleting...
              </>
            )
            : null}
          {isSaving.value
            ? (
              <>
                <img src='/images/loading.svg' class='white mr-2' width={18} height={18} />Saving...
              </>
            )
            : null}
          {!isDeleting.value && !isSaving.value ? <>&nbsp;</> : null}
        </span>
      </section>

      <section
        class={`fixed ${
          openCalendar.value ? 'block' : 'hidden'
        } z-40 w-screen h-screen inset-0 bg-gray-900 bg-opacity-60`}
      >
      </section>

      <section
        class={`fixed ${
          openCalendar.value ? 'block' : 'hidden'
        } z-50 top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 w-96 bg-slate-600 text-white rounded-md px-8 py-6 drop-shadow-lg`}
      >
        <h1 class='text-2xl font-semibold my-5'>Edit Calendar</h1>
        <section class='py-5 my-2 border-y border-slate-500'>
          <fieldset class='block mb-2'>
            <label class='text-slate-300 block pb-1' for='calendar_name'>Name</label>
            <input
              class='input-field'
              type='text'
              name='calendar_name'
              id='calendar_name'
              value={openCalendar.value?.displayName || ''}
              onInput={(event) =>
                openCalendar.value = { ...openCalendar.value!, displayName: event.currentTarget.value }}
              placeholder='Personal'
            />
          </fieldset>
          <fieldset class='block mb-2'>
            <label class='text-slate-300 block pb-1' for='calendar_color'>Color</label>
            <section class='flex items-center justify-between'>
              <select
                class='input-field mr-2 !w-5/6'
                name='calendar_color'
                id='calendar_color'
                value={openCalendar.value?.calendarColor || ''}
                onChange={(event) =>
                  openCalendar.value = { ...openCalendar.value!, calendarColor: event.currentTarget.value }}
              >
                {CALENDAR_COLOR_OPTIONS.map((color) => <option key={color} value={getColorAsHex(color)}>{color}
                </option>)}
              </select>
              <span
                class={`w-5 h-5 block rounded-full`}
                style={{ backgroundColor: openCalendar.value?.calendarColor }}
                title={openCalendar.value?.calendarColor}
              >
              </span>
            </section>
          </fieldset>
          <fieldset class='block mb-2'>
            <label class='text-slate-300 block pb-1' for='calendar_is_visible'>Visible?</label>
            <input
              type='checkbox'
              name='calendar_is_visible'
              id='calendar_is_visible'
              value='true'
              checked={openCalendar.value?.isVisible}
              onChange={(event) =>
                openCalendar.value = { ...openCalendar.value!, isVisible: event.currentTarget.checked }}
            />
          </fieldset>
        </section>
        <footer class='flex justify-between'>
          <button
            type='button'
            class='px-5 py-2 bg-slate-600 hover:bg-slate-500 text-white cursor-pointer rounded-md'
            onClick={() => onClickSaveOpenCalendar()}
          >
            Save
          </button>
          <button
            type='button'
            class='px-5 py-2 bg-slate-600 hover:bg-slate-500 text-white cursor-pointer rounded-md'
            onClick={() => openCalendar.value = null}
          >
            Close
          </button>
        </footer>
      </section>
    </>
  );
}
