"use strict";

// elements

/** @type {HTMLButtonElement} */
let loadAlbumsBtn

/** @type {HTMLButtonElement} */
let loadPhotosBtn

/** @type {HTMLButtonElement} */
let makeCollageBtn

/** @type {HTMLSelectElement} */
let albumSelect

/** @type {HTMLParagraphElement} */
let noticeSpan

/** @type {HTMLDialogElement} */
let noticeDialog

/** @type {HTMLDivElement} */
let albumPhotosDiv

/** @type {HTMLDivElement} */
let selectedPhotosDiv

/** @type {HTMLImageElement} */
let selectedPhotoImg

function main() {
    loadAlbumsBtn = document.getElementById("load_albums_button")
    loadPhotosBtn = document.getElementById("load_photos_button")
    makeCollageBtn = document.getElementById("make_collage_button")
    albumSelect = document.getElementById("album_selector")
    noticeSpan = document.getElementById("notice_span")
    noticeDialog = document.getElementById("notice_dialog")
    albumPhotosDiv = document.getElementById("album_photos")
    selectedPhotosDiv = document.getElementById("selected_photos")

    loadAlbumsBtn.onclick = () => loadAlbums()
    loadPhotosBtn.onclick = () => loadPhotos()
    makeCollageBtn.onclick = () => gotoCollage()

    /** @type HTMLCollectionOf<HTMLImageElement> */
    const selectedPhotos = selectedPhotosDiv.getElementsByTagName("img")
    for (const img of selectedPhotos) {
        img.onclick = () => {
            selectedPhotoImg?.classList.remove("current")
            selectedPhotoImg = img
            selectedPhotoImg.classList.add("current")
        }
    }
    selectedPhotos[0].click()
}

function moveToNextSlot() {
    /** @type HTMLCollectionOf<HTMLImageElement> */
    const selectedPhotos = selectedPhotosDiv.getElementsByTagName("img")
    for (const img of selectedPhotos) {
        if(img.src.endsWith("stock.svg")) {
            img.click()
            return
        }
    }
}

function loadAlbums() {
    (async () => {
        try {
            closeNotice()
            const resp = await fetch("get-albums")
            const albums = await resp.json()
            if(albums.length == 0) {
                showNotice("No Albums found")
                return
            }
            albumSelect.replaceChildren() // This empties existing options
            for(const album of albums) {
                albumSelect.add(new Option(album.Title, album.UID))
            }
        } catch(e) {
            console.log(e)
        }
    })();
}

function closeNotice() {
    noticeDialog.close()
}

/** @param {string} notice */
function showNotice(notice) {
    noticeSpan.textContent = notice
    noticeDialog.show()
}

function loadPhotos() {
    closeNotice()
    const selected = albumSelect.selectedOptions
    if(selected.length != 1) {
        showNotice("Select an album to load photos")
        return
    }
    const [elem] = selected;

    (async () => {
        try {
            const resp = await fetch(`load-photos/${elem.value}`)
            /** @type String[] */
            const photos = await resp.json()
            if(photos.length == 0) {
                showNotice("No Photos found")
                return
            }
            albumPhotosDiv.replaceChildren()
            for(const url of photos) {
                const img = new Image()
                img.src =  url
                albumPhotosDiv.appendChild(img)
            }

            /** @type HTMLCollectionOf<HTMLImageElement> */
            const photoImgs = albumPhotosDiv.children
            for(const photo of photoImgs) {
                photo.onclick = () => {
                    selectedPhotoImg.src = photo.src
                    moveToNextSlot()
                }
            }
        } catch(e) {
            console.log(e)
        }
    })();
}

function gotoCollage() {
    /** @type HTMLCollectionOf<HTMLImageElement> */
    const selectedPhotos = selectedPhotosDiv.getElementsByTagName("img")
    /** @type String[] */
    const photoUrls = [];

    for (const img of selectedPhotos) {
        if (!img.src.endsWith("stock.svg")) {
            photoUrls.push((new URL(img.src)).pathname)
        }
    }
    const encodedURLS = encodeURIComponent(JSON.stringify(photoUrls))
    window.location.href = `index.html?urls=${encodedURLS}`
}


main()