<template>
  <div class="index-page">
    <div class="index-page__search">
      <UInput
        :model-value="search"
        size="xl"
        class="w-full"
        placeholder="Поиск..."
        :loading="postsIsLoading || usersIsLoading"
        @update:model-value="updateSearch"
      />
    </div>

    <div
      ref="tableContainerRef"
      class="table-wrapper"
    >
      <div :style="{ height: `${totalSize}px` }">
        <!-- Even though we're still using sematic table tags, we must use CSS grid and flexbox for dynamic row heights -->
        <table>
          <thead>
            <tr
              v-for="headerGroup in table?.getHeaderGroups()"
              :key="headerGroup?.id"
            >
              <th
                v-for="header in headerGroup.headers"
                :key="header.id"
                :colspan="header.colSpan"
                :style="[header.column.columnDef.meta?.style, isMobile ? { width: '100%' } : { width: `${header.getSize()}px` }]"
                @click="header?.column?.getToggleSortingHandler()?.($event)"
              >
                <FlexRender
                  v-if="!header?.isPlaceholder"
                  :render="header?.column?.columnDef?.header"
                  :props="header?.getContext()"
                />

                {{ { asc: ' 🔼', desc: ' 🔽' }[header.column.getIsSorted() as string] }}
              </th>
            </tr>
          </thead>

          <tbody :style="{ height: `${totalSize}px` }">
            <tr
              v-for="vRow in virtualRows"
              :ref="measureElement /*measure dynamic row height*/"
              :key="rows[vRow?.index]?.id"
              :data-index=" vRow?.index /* needed for dynamic row height measurement*/ "
              :style="{ transform: `translateY(${vRow?.start}px)` }"
            >
              <td
                v-for="cell in rows[vRow?.index]?.getVisibleCells()"
                :key="cell?.id"
                :style="[cell.column.columnDef.meta?.style, isMobile ? { width: '100%' } : { width: `${cell.column.getSize()}px` }]"
              >
                <FlexRender
                  :render="cell?.column?.columnDef?.cell"
                  :props="cell?.getContext()"
                />
              </td>
            </tr>
          </tbody>
        </table>
      </div>
    </div>

    <UModal v-model:open="open" :title="selectedUser?.email">
      <template #body>
        <div>
          <div>Имя: {{ selectedUser?.name }}</div>
          <div>Логин: {{ selectedUser?.username }}</div>
          <div>Электронная почта: {{ selectedUser?.email }}</div>
          <div>Телефон: {{ selectedUser?.phone }}</div>
          <a :href="`https://${selectedUser?.website}`" target="_blank">Веб-сайт: <span class="title-cell">{{ selectedUser?.website }}</span></a>
          <div>Название компании: {{ selectedUser?.company?.name }}</div>
          <div>Адрес: {{ `${selectedUser?.address?.street} ${selectedUser?.address?.suite} ${selectedUser?.address?.city}` }}</div>
        </div>
      </template>
    </UModal>
  </div>
</template>

<script setup lang="ts">
import { UTooltip } from '#components'
import {
  createColumnHelper,
  FlexRender,
  getCoreRowModel,
  getSortedRowModel,
  useVueTable,
} from '@tanstack/vue-table'
import { useVirtualizer } from '@tanstack/vue-virtual'
import { useDebounceFn, useMediaQuery } from '@vueuse/core'
import { useGetPosts, useGetUsers } from '~/api/queries'

const isMobile = useMediaQuery('(max-width: 1280px)')
const open = ref(false)
const selectedUser = ref<User | null>(null)
const search = ref('')
const updateSearch = useDebounceFn((value: string) => {
  search.value = value
}, 500)
const { data: posts, isLoading: postsIsLoading } = useGetPosts(search)
const { data: users, isLoading: usersIsLoading } = useGetUsers()

const tableData = computed(() =>
  posts?.value?.map(post => ({
    userId: post?.userId,
    userEmail: users?.value?.find(user => user?.id === post?.userId)?.email,
    id: post?.id,
    title: post?.title,
    body: post?.body,
  })))

const columnHelper = createColumnHelper<Posts>()
const columns = [
  columnHelper.accessor('id', {
    header: 'ID',
    footer: props => props?.column?.id,
    meta: {
      style: {
        display: 'flex',
        justifyContent: 'center',
        alignItems: 'center',
      },
    },
    size: 50,
  }),
  columnHelper.accessor('title', {
    header: 'Заголовок',
    cell: info => isMobile.value
      ? info.getValue()
      : h(UTooltip, { text: info.getValue(),
        }, {
          default: () => h('span', { class: 'ellipsis' }, truncate(info.getValue()),
          ),
        }),
    size: 150,
  }),
  columnHelper.accessor('userEmail', {
    header: 'Автор',
    cell: info => isMobile.value
      ? info.getValue()
      : h(UTooltip, { text: info.getValue(),
        }, {
          default: () => h('div', { class: 'title-cell', onClick: () => openPost(info?.row?.original) }, truncate(info.getValue()),
          ),
        }),
    meta: {
      style: {
        display: 'flex',
        justifyContent: 'center',
        alignItems: 'center',
      },
    },
    size: 170,
  }),
  columnHelper.accessor('body', {
    header: 'Контент',
    cell: info => isMobile.value
      ? info.getValue()
      : h(UTooltip, {
          text: info.getValue(),
        }, {
          default: () => h('span', { class: 'ellipsis' }, truncate(info.getValue(), 22)),
        }),
    size: 220,
  }),
]

const table = useVueTable({
  get data() {
    return tableData
  },
  columns,
  getCoreRowModel: getCoreRowModel(),
  getSortedRowModel: getSortedRowModel(),
})

// The virtualizer needs to know the scrollable container element
const rows = computed(() => table?.getRowModel()?.rows)
const tableContainerRef = ref<HTMLDivElement | null>(null)

const rowVirtualizerOptions = computed(() => {
  return {
    count: rows.value.length,
    estimateSize: () => 50, // estimate row height for accurate scrollbar dragging
    getScrollElement: () => tableContainerRef.value,
    overscan: 5,
  }
})

const rowVirtualizer = useVirtualizer(rowVirtualizerOptions)

const virtualRows = computed(() => rowVirtualizer.value.getVirtualItems())
const totalSize = computed(() => rowVirtualizer.value.getTotalSize())

function measureElement(el?: Element) {
  if (!el) {
    return
  }

  rowVirtualizer.value.measureElement(el)

  return undefined
}
// virtualizer end

function openPost(post: Post) {
  selectedUser.value = users?.value?.find(user => user?.id === post?.userId)
  open.value = true
}

function truncate(text: string, max = 15) {
  return text?.length > max ? `${text?.slice(0, max)}…` : text
}
</script>

<style lang="scss">
@use '~/assets/scss/utils' as *;

.index-page {
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 600px;
  margin-inline: auto;
  padding-bottom: 40px;
  position: relative;

  &__search {
    position: fixed;
    top: 48px;
    left: 50%;
    transform: translateX(-50%);
    max-width: 600px;
    width: 100%;

    z-index: 1000;
    background: var(--ui-bg-base);

    @include mobile {
      padding-inline: 10px;
    }
  }
}

/* -------------------- TABLE WRAPPER -------------------- */
.table-wrapper {
  position: relative;
  margin-top: calc(40px + 10px);
  border-radius: 14px;
  overflow-y: auto;
  height: 600px;
  scrollbar-width: thin;

  @include mobile {
    height: 500px;
  }
}

table {
  min-width: 100%;
  border-collapse: separate;
  border-spacing: 0;

  background: var(--ui-bg-elevated);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  white-space: nowrap;
}

/* -------------------- HEADER -------------------- */

thead {
  display: grid;
  position: sticky;
  top: 0;
  z-index: 1;
}

thead tr {
  display: flex;
  width: 100%;
}

thead th {
  background: var(--ui-bg-accented);
  color: var(--ui-text);
  padding: 12px 14px;

  border-bottom: 1px solid var(--ui-border);
  user-select: none;

  transition: background 0.15s ease;
}

thead th:hover {
  cursor: pointer;
}

/* -------------------- BODY -------------------- */

tbody {
  display: grid;
  position: relative;
}

tbody tr {
  display: flex;
  position: absolute;
  width: 100%;
  height: 50px;
  transition: background 0.2s ease;
}

tbody tr:nth-child(odd) {
  background: var(--ui-bg-subtle);
}

tbody tr:hover {
  background: var(--ui-bg-accented);
}

tbody td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--ui-border-subtle);
}

tbody tr:last-child td {
  border-bottom: none;
}

/* -------------------- CLICKABLE USER EMAIL CELL -------------------- */

.title-cell {
  cursor: pointer;
  text-decoration: underline;
  color: var(--ui-primary);
}

.title-cell:hover {
  color: var(--ui-primary-hover);
}
</style>
