import PSPDFKitType, { AnnotationsUnion } from "./index";
import { Instance, WidgetAnnotation, ToolbarItem } from "./index";
import { EnvelopeResponse, Envelope, User, Element, Document } from "./interfaces";

declare const PSPDFKit: typeof PSPDFKitType

const { List } = PSPDFKit.Immutable;
const { Rect } = PSPDFKit.Geometry;
const { SignatureFormField } = PSPDFKit.FormFields;
const { DRAW, TYPE } = PSPDFKit.ElectronicSignatureCreationMode;
const { DISABLED } = PSPDFKit.AutoSaveMode;

const allowedToolbarItems: string[] = [
    "sidebar-thumbnails",
    "sidebar-document-ouline",
    "sidebar-bookmarks",
    "pager",
    "pan",
    "zoom-out",
    "zoom-in",
    "zoom-mode",
    "spacer",
    "search"
]

export class App {
    public static Instance: Instance;
    public static currentDocument

    // This function will be called in the ShowEnvelope.razor page
    // and will trigger loading of the Editor Interface
    public static async loadPDFFromUrl (container: string, envelopeKey: string) {
        console.debug("Loading PSPDFKit..");

        const envelopeObject: EnvelopeResponse = await App.loadData(`/api/get-data/${envelopeKey}`);
        const document: Document = envelopeObject.envelope.documents[0];

        let arrayBuffer
        try {
            arrayBuffer = await App.loadDocument(`/api/download/${envelopeKey}?id=${document.id}`);
        } catch (e) {
            console.error(e)
        }

        App.Instance = await App.loadPSPDFKit(arrayBuffer, container)
        App.configurePSPDFKit(this.Instance)

        console.debug(envelopeObject.envelope);
        console.debug("PSPDFKit configured!");

        const annotations: any[] = [];

        document.elements.forEach(function (element: Element) {
            console.log("Loading element")
            console.debug("Page", element.page)
            console.debug("Width / Height", element.width, element.height)
            console.debug("Top / Left", element.top, element.left)

            const id = PSPDFKit.generateInstantId()
            const annotation: WidgetAnnotation = App.createSignatureAnnotation(id, element.width, element.height, element.top, element.left, element.page)

            const formField = new SignatureFormField({
                name: id,
                annotationIds: List([annotation.id])
            })

            annotations.push(annotation);
            annotations.push(formField);

            console.debug("Annotation created.")
        })    

        const [createdAnnotation] = await App.Instance.create(annotations)

        console.debug(createdAnnotation)
    }

    // Makes a call to the supplied url and fetches the binary response as an array buffer
    private static loadDocument(url: string): Promise<ArrayBuffer> {
        return fetch(url, { credentials: "include" })
            .then(res => res.arrayBuffer());
    }

    // Makes a call to the supplied url and fetches the json response as an object
    private static loadData(url: string): Promise<any> {
        return fetch(url, { credentials: "include" })
            .then(res => res.json());
    }

    // Load the PSPDFKit UI by setting a target element as the container to render in
    // and a arraybuffer which represents the document that should be displayed.
    private static loadPSPDFKit(arrayBuffer: ArrayBuffer, container: string): Promise<Instance> {
        const annotationPresets = PSPDFKit.defaultAnnotationPresets;
        console.log(annotationPresets)
        annotationPresets.ink = {
            lineWidth: 10
        };

        return PSPDFKit.load({
            container: container,
            document: arrayBuffer,
            autoSaveMode: DISABLED,
            annotationPresets,
            electronicSignatures: {            
                creationModes: [DRAW]
            }
        })
    }

    private static configurePSPDFKit(instance: Instance) {
        instance.addEventListener("annotations.load", (loadedAnnotations) => {
            console.log("annotations loaded", loadedAnnotations.toJS());
        })

        instance.addEventListener("annotations.change", () => {
            console.log("annotations changed")
        })

        instance.addEventListener("annotations.create", (createdAnnotations) => {
            const annotation: AnnotationsUnion = createdAnnotations[0];
            console.log("annotations created", createdAnnotations.toJS());
        })   

        const filteredItems: Array<ToolbarItem> = instance.toolbarItems
            .filter((item) => allowedToolbarItems.includes(item.type))


        const customItems: ToolbarItem[] = [
            {
                type: "custom",
                id: "button-finish",
                title: "Abschließen",
                icon: `<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" fill="currentColor" class="bi bi-check2-circle" viewBox="0 0 16 16">
                        <path d="M2.5 8a5.5 5.5 0 0 1 8.25-4.764.5.5 0 0 0 .5-.866A6.5 6.5 0 1 0 14.5 8a.5.5 0 0 0-1 0 5.5 5.5 0 1 1-11 0z"/>
                        <path d="M15.354 3.354a.5.5 0 0 0-.708-.708L8 9.293 5.354 6.646a.5.5 0 1 0-.708.708l3 3a.5.5 0 0 0 .708 0l7-7z" />
                      </svg>`,
                onPress: this.handleFinish
            }
        ]

        instance.setToolbarItems(filteredItems.concat(customItems))
    }

    private static async handleFinish(event: any) {
        await App.Instance.applyOperations([{ type: "flattenAnnotations" }])

        //await downloadDocument();
    }

    private static async downloadDocument() {
        const buffer = await App.Instance.exportPDF({ flatten: true });
        const supportsDownloadAttribute = HTMLAnchorElement.prototype.hasOwnProperty("download");
        const blob = new Blob([buffer], { type: "application/pdf" });

        if (!supportsDownloadAttribute) {
            const reader = new FileReader();
            reader.onloadend = function () {
                const dataUrl = reader.result;
                downloadPdf(dataUrl);
            };
            reader.readAsDataURL(blob);
        } else {
            const objectUrl = window.URL.createObjectURL(blob);
            downloadPdf(objectUrl);
            window.URL.revokeObjectURL(objectUrl);
        }
        function downloadPdf(blob) {
            const a = document.createElement("a");
            a.href = blob;
            a.style.display = "none";
            a.download = "download.pdf";
            a.setAttribute("download", "download.pdf");
            document.body.appendChild(a);
            a.click();
            document.body.removeChild(a);
        }
    }


    private static createSignatureAnnotation(id: string, width: number, height: number, top: number, left: number, pageIndex: number): WidgetAnnotation {     
        const annotation = new PSPDFKit.Annotations.WidgetAnnotation({
            id: id,
            pageIndex: pageIndex,
            formFieldName: id,
            boundingBox: new Rect({ width, height, top, left })
        })

        return annotation
    }

}