<template>
	<div
		tabindex="-1"
		@focus="focus"
	>
		<Multiselect
			:loading="listUserService.loading"
			:placeholder="$t('task.assignee.placeholder')"
			:multiple="true"
			@search="findUser"
			:search-results="foundUsers"
			@select="addAssignee"
			label="name"
			:select-placeholder="$t('task.assignee.selectPlaceholder')"
			v-model="assignees"
			ref="multiselect"
		>
			<template #tag="{item: user}">
				<span class="assignee">
					<user :avatar-size="32" :show-username="false" :user="user"/>
					<BaseButton @click="removeAssignee(user)" class="remove-assignee" v-if="!disabled">
						<icon icon="times"/>
					</BaseButton>
				</span>
			</template>
		</Multiselect>
	</div>
</template>

<script setup lang="ts">
import {ref, shallowReactive, watch, nextTick, type PropType} from 'vue'
import {useI18n} from 'vue-i18n'

import User from '@/components/misc/user.vue'
import Multiselect from '@/components/input/multiselect.vue'
import BaseButton from '@/components/base/BaseButton.vue'

import {includesById} from '@/helpers/utils'
import ListUserService from '@/services/listUsers'
import {success} from '@/message'
import {useTaskStore} from '@/stores/tasks'

import type {IUser} from '@/modelTypes/IUser'

const props = defineProps({
	taskId: {
		type: Number,
		required: true,
	},
	listId: {
		type: Number,
		required: true,
	},
	disabled: {
		default: false,
	},
	modelValue: {
		type: Array as PropType<IUser[]>,
		default: () => [],
	},
})
const emit = defineEmits(['update:modelValue'])

const taskStore = useTaskStore()
const {t} = useI18n({useScope: 'global'})

const listUserService = shallowReactive(new ListUserService())
const foundUsers = ref([])
const assignees = ref<IUser[]>([])
let isAdding = false

watch(
	() => props.modelValue,
	(value) => {
		assignees.value = value
	},
	{
		immediate: true,
		deep: true,
	},
)

async function addAssignee(user: IUser) {
	if (isAdding) {
		return
	}

	try {
		nextTick(() => isAdding = true)

		await taskStore.addAssignee({user: user, taskId: props.taskId})
		emit('update:modelValue', assignees.value)
		success({message: t('task.assignee.assignSuccess')})
	} finally {
		nextTick(() => isAdding = false)
	}
}

async function removeAssignee(user: IUser) {
	await taskStore.removeAssignee({user: user, taskId: props.taskId})

	// Remove the assignee from the list
	for (const a in assignees.value) {
		if (assignees.value[a].id === user.id) {
			assignees.value.splice(a, 1)
		}
	}
	success({message: t('task.assignee.unassignSuccess')})
}

async function findUser(query: string) {
	if (query === '') {
		clearAllFoundUsers()
		return
	}

	const response = await listUserService.getAll({listId: props.listId}, {s: query})

	// Filter the results to not include users who are already assigned
	foundUsers.value = response.filter(({id}) => !includesById(assignees.value, id))
		.map(u => {
			// Users may not have a display name set, so we fall back on the username in that case
			u.name = u.name === '' ? u.username : u.name
			return u
		})
}

function clearAllFoundUsers() {
	foundUsers.value = []
}

const multiselect = ref()

function focus() {
	multiselect.value.focus()
}
</script>

<style lang="scss" scoped>
.assignee {
	position: relative;

	&:not(:first-child) {
		margin-left: -1.5rem;
	}

	:deep(.user img) {
		border: 2px solid var(--white);
		margin-right: 0;
	}

	.remove-assignee {
		position: absolute;
		top: 4px;
		left: 2px;
		color: var(--danger);
		background: var(--white);
		padding: 0 4px;
		display: block;
		border-radius: 100%;
		font-size: .75rem;
		width: 18px;
		height: 18px;
		z-index: 100;
	}
}
</style>