memories/src/components/top-matter/OnThisDay.vue

<template>
    <div class="outer" v-show="years.length > 0">
        <div class="inner" ref="inner">
            <div v-for="year of years" class="group" :key="year.year" @click="click(year)">
                <img class="fill-block"
                    :src="year.url" />

                <div class="overlay">
                    {{ year.text }}
                </div>
            </div>
        </div>

        <div class="left-btn dir-btn memories__onthisday__btn" v-if="hasLeft">
            <NcActions>
                <NcActionButton
                    :aria-label="t('memories', 'Move left')"
                    @click="moveLeft">
                    {{ t('memories', 'Move left') }}
                    <template #icon> <LeftMoveIcon :size="28" /> </template>
                </NcActionButton>
            </NcActions>
        </div>
        <div class="right-btn dir-btn memories__onthisday__btn" v-if="hasRight">
            <NcActions>
                <NcActionButton
                    :aria-label="t('memories', 'Move right')"
                    @click="moveRight">
                    {{ t('memories', 'Move right') }}
                    <template #icon> <RightMoveIcon :size="28" /> </template>
                </NcActionButton>
            </NcActions>
        </div>
    </div>
</template>

<script lang="ts">
import { Component, Emit, Mixins, Prop } from 'vue-property-decorator';
import GlobalMixin from '../../mixins/GlobalMixin';
import { NcActions, NcActionButton } from '@nextcloud/vue';

import * as utils from "../../services/Utils";
import * as dav from '../../services/DavRequests';
import { ViewerManager } from "../../services/Viewer";
import { IPhoto } from '../../types';
import { getPreviewUrl } from "../../services/FileUtils";

import LeftMoveIcon from 'vue-material-design-icons/ChevronLeft.vue';
import RightMoveIcon from 'vue-material-design-icons/ChevronRight.vue';

interface IYear {
    year: number;
    url: string;
    preview: IPhoto;
    photos: IPhoto[];
    text: string;
};

@Component({
    name: 'OnThisDay',
    components: {
        NcActions,
        NcActionButton,
        LeftMoveIcon,
        RightMoveIcon,
    }
})
export default class OnThisDay extends Mixins(GlobalMixin) {
    private getPreviewUrl = getPreviewUrl;

    @Emit('load')
    onload() {}

    private years: IYear[] = []

    private hasRight = false;
    private hasLeft = false;
    private scrollStack: number[] = [];

    /**
     * Nextcloud viewer proxy
     * Can't use the timeline instance because these photos
     * might not be in view, so can't delete them
     */
    @Prop()
    private viewerManager!: ViewerManager;

    mounted() {
        const inner = this.$refs.inner as HTMLElement;
        inner.addEventListener('scroll', this.onScroll.bind(this));

        this.refresh();
    }

    async refresh() {
        // Look for cache
        const dayIdToday = utils.dateToDayId(new Date());
        const cacheUrl = `/onthisday/${dayIdToday}`;
        const cache = await utils.getCachedData<IPhoto[]>(cacheUrl);
        if (cache) this.process(cache);

        // Network request
        const photos = await dav.getOnThisDayRaw();
        utils.cacheData(cacheUrl, photos);

        // Check if exactly same as cache
        if (cache?.length === photos.length &&
            cache.every((p, i) => p.fileid === photos[i].fileid)) return;
        this.process(photos);
    }

    async process(photos: IPhoto[]) {
        this.years = [];

        let currentYear = 9999;

        for (const photo of photos) {
            const dateTaken = utils.dayIdToDate(photo.dayid);
            const year = dateTaken.getUTCFullYear();

            if (year !== currentYear) {
                this.years.push({
                    year,
                    url: '',
                    preview: null,
                    photos: [],
                    text: utils.getFromNowStr(dateTaken),
                });
                currentYear = year;
            }

            const yearObj = this.years[this.years.length - 1];
            yearObj.photos.push(photo);
        }

        // For each year, randomly choose 10 photos to display
        for (const year of this.years) {
            year.photos = utils.randomSubarray(year.photos, 10);
        }

        // Choose preview photo
        for (const year of this.years) {
            // Try to prioritize landscape photos on desktop
            if (window.innerWidth <= 600) {
                const landscape = year.photos.filter(p => p.w > p.h);
                year.preview = utils.randomChoice(landscape)
            }

            // Get random photo
            year.preview ||= utils.randomChoice(year.photos);
            year.url = getPreviewUrl(year.preview.fileid, year.preview.etag, false, 512);
        }

        await this.$nextTick();
        this.onScroll();
        this.onload();
    }

    moveLeft() {
        const inner = this.$refs.inner as HTMLElement;
        inner.scrollBy(-(this.scrollStack.pop() || inner.clientWidth), 0);
    }

    moveRight() {
        const inner = this.$refs.inner as HTMLElement;
        const innerRect = inner.getBoundingClientRect();
        const nextChild = Array.from(inner.children).map(c => c.getBoundingClientRect()).find((rect) =>
            rect.right > innerRect.right
        );

        let scroll = nextChild ? (nextChild.left - innerRect.left) : inner.clientWidth;
        scroll = Math.min(inner.scrollWidth - inner.scrollLeft - inner.clientWidth, scroll);
        this.scrollStack.push(scroll);
        inner.scrollBy(scroll, 0);
    }

    onScroll() {
        const inner = this.$refs.inner as HTMLElement;
        if (!inner) return;
        this.hasLeft = inner.scrollLeft > 0;
        this.hasRight = (inner.clientWidth + inner.scrollLeft < inner.scrollWidth - 20);
    }

    click(year: IYear) {
        const allPhotos = this.years.flatMap(y => y.photos);
        this.viewerManager.open(year.preview, allPhotos);
    }
}
</script>

<style lang="scss" scoped>
$height: 200px;
$mobHeight: 150px;

.outer {
    width: calc(100% - 50px);
    height: $height;
    overflow: hidden;
    position: relative;
    padding: 0 calc(28px * 0.6);

    // Sloppy: ideally this should be done in Timeline
    // to put a gap between the title and this
    margin-top: 10px;

    .inner {
        height: calc(100% + 20px);
        white-space: nowrap;
        overflow-x: scroll;
        scroll-behavior: smooth;
        border-radius: 10px;
    }

    .left-btn {
        position: absolute;
        top: 50%; left: 0;
        transform: translate(-10%, -50%);
    }

    .right-btn {
        position: absolute;
        top: 50%; right: 0;
        transform: translate(10%, -50%);
    }

    @media (max-width: 768px) {
        width: 98%;
        padding: 0;
        .inner { padding: 0 8px; }
        .dir-btn { display: none; }
    }
    @media (max-width: 600px) {
        height: $mobHeight;
    }
}

.group {
    height: $height;
    aspect-ratio: 4/3;
    display: inline-block;
    position: relative;
    cursor: pointer;

    &:not(:last-of-type) { margin-right: 8px; }

    img {
        cursor: inherit;
        object-fit: cover;
        border-radius: 10px;
        background-color: var(--color-background-dark);
        background-clip: padding-box, content-box;
    }

    .overlay {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.2);
        border-radius: 10px;
        display: flex;
        align-items: end;
        justify-content: center;
        color: white;
        font-size: 1.2em;
        padding: 5%;
        white-space: normal;
        cursor: inherit;
        transition: background-color 0.2s ease-in-out;
    }

    &:hover .overlay {
        background-color: transparent;
    }

    @media (max-width: 600px) {
        aspect-ratio: 3/4;
        height: $mobHeight;
        .overlay { font-size: 1.1em; }
    }
}
</style>

<style lang="scss">
.memories__onthisday__btn button {
    transform: scale(0.6);
    box-shadow: var(--color-main-text) 0 0 3px 0 !important;
    background-color: var(--color-main-background) !important;
}
</style>