import { promptUpload } from "./prompt_upload.js";
import { downloadFile, slugify } from "./utils.js";
import { HtmlExporter } from "./html_exporter.js";
import { KarlkoderCodec } from "./karlkoder_codec.js";

export class ProjectSaveHandler {
    constructor(editor, assetEditor, assetProvider, projectName) {
        this.editor = editor;
        this.assetEditor = assetEditor;
        this.projectName = projectName;

        this.htmlExporter = new HtmlExporter(assetProvider);

        this.saveName = null;
        this.isSaved = true;

        editor.addEventListener("change", () => {
            this.isSaved = false;
        });

        assetEditor.addChangeListener(() => {
            this.isSaved = false;
        });
    }

    async showLoadFilePrompt() {
        const files = await promptUpload(".karlkode", false);
        if (files.length === 0) {
            return;
        }

        if (files.length > 1) {
            throw new Error(
                `unreachable: something went wrong ! files.length > 1 : files.length = ${files.length}`,
            );
        }

        this.loadFromFile(files[0]);
    }

    async loadFromFile(file) {
        if (
            !this.isSaved &&
            !confirm(
                "Your project has not been saved. Loading a new project will override your current one. Continue?",
            )
        ) {
            return;
        }

        const items = KarlkoderCodec.de(
            await fetch(URL.createObjectURL(file)).then((x) => x.bytes()),
        );

        const assets = items
            .filter((x) => x.tag === "asset")
            .map((x) => {
                delete x.tag;
                return x;
            });

        const code = items.find((x) => x.tag === "code");
        delete code.tag;

        await this.assetEditor.importAssets(
            assets.map(({ name, mime, content }) => {
                const file = new File([content], name, { type: mime });

                return { name, file };
            }),
        );

        this.projectName.value = code.name;
        const dec = new TextDecoder();
        this.editor.setValue(dec.decode(code.content));

        this.isSaved = true;
    }

    async saveFile() {
        const filename = prompt("Filename?", this.getSaveFileName());
        if (!filename) {
            return;
        }

        this.saveName = filename;
        this.isSaved = true;

        downloadFile(
            filename,
            await KarlkoderCodec.en(
                this.projectName.value,
                this.editor.getValue(),
                await this.assetEditor.getAssets(),
            ),
            ".karlkode",
        );
    }

    async exportProject() {
        const filename = prompt("Filename?", this.getSaveFileName());
        if (!filename) {
            return;
        }

        this.saveName = filename;

        const html = await this.htmlExporter.export(this.projectName.value, this.editor.getValue());

        downloadFile(filename, html, ".html", "text/html");
    }

    getSaveFileName() {
        if (this.saveName) {
            return this.saveName;
        }

        return slugify(this.projectName.value) || "project";
    }
}