class Media {
    constructor(data) {
        this.date = new Date(data.date);
        this.md5sum = data.md5sum;
        this.path = data.path;
        this.fileName = data.fileName;
        this.meta = data.meta || {};
        this.meta.height = this.meta.height ? parseInt(this.meta.height) : undefined;
        this.meta.width = this.meta.width ? parseInt(this.meta.width) : undefined;
        this.tags = data.tags || [];
        this.thumbnail = `/api/media/thumbnail/${data.md5sum}.jpg`;
        this.original = `/api/media/original/${data.md5sum}`;
        this.ui = null;
    }

    resize(maxWidth, maxHeight) {
        let ratio = Math.min(1, Math.max(
            maxWidth / (this.meta?.width || maxWidth),
            maxHeight / (this.meta?.height || maxHeight)));
        return {
            width: Math.floor(this.meta.width *ratio),
            height: Math.floor(this.meta.height *ratio),
        };
    }
}

function tryLoadMedia(md5sum) {
    return new Promise((ok, ko) => {
        $.get("/api/media/" +md5sum, data => {
            let item = new Media(data);
            MediaStorage.Instance.pushAll([item], true);
            ok(item);
        }).fail(err => {
            console.error("Trying to get media with md5sum " +md5sum +" failed:", err.responseText);
            ok(null);
        });
    });
}

class MediaStorage extends EventTarget
{
    constructor() {
        super();
        this.medias = [];
        this.oldest = null;
        this.newest = null;
    }

    pushAll(arr, partialLoad) {
        let result = [];
        let reorder = false;
        for (let i of arr) {
            if (this.medias.find(x => x.md5sum === i.md5sum))
                continue;
            if (this.medias.length && this.medias[this.medias.length -1].date.getTime() < i.date.getTime())
                reorder = true;
            this.medias.push(i);
            if (partialLoad !== true) {
                this.oldest = !this.oldest || this.oldest.date.getTime() > i.date.getTime() ? i : this.oldest;
                this.newest = !this.newest || this.newest.date.getTime() < i.date.getTime() ? i : this.newest;
            }
            result.push(i);
        }
        for (let i of result)
            this.dispatchEvent(new CustomEvent("newMedia", { detail: i }));
        if (reorder) {
            this.medias.sort((a, b) => b.date.getTime() - a.date.getTime());
            this.dispatchEvent(new CustomEvent("rebuildMedia"));
        }
    }

    getMediaIndex(media) {
        return this.medias.indexOf(media);
    }

    nextMedia(current) {
        return this.medias[this.getMediaIndex(current) +1];
    }

    previousMedia(current) {
        return this.medias[this.getMediaIndex(current) -1];
    }

    getMediaBetweenIndexes(a, b) {
        if (a > b)
            return this.getMediaBetweenIndexes(b, a);
        return this.medias.slice(a, b +1);
    }

    getMediaBetween(a, b) {
        let aIndex = this.medias.indexOf(a);
        let bIndex = this.medias.indexOf(b);
        if (aIndex < 0 || bIndex < 0 || aIndex === bIndex)
            return [];
        return this.getMediaBetweenIndexes(aIndex, bIndex);
    }

    async getMedia(md5sum) {
        let media = this.medias.find(x => x.md5sum === md5sum);
        if (media)
            return media;
        return await tryLoadMedia(md5sum);
    }
}

MediaStorage.Instance = new MediaStorage();