// TODO remove types and put them in comments so this can be a .js file

export function initGalaxy({
    acceptedOrigins,
    supportsSaving,
    supportsSaveManager,
    ignoreApiVersion,
    onLoggedInChanged
}: {
    acceptedOrigins?: string[];
    supportsSaving?: boolean;
    supportsSaveManager?: boolean;
    ignoreApiVersion?: boolean;
    onLoggedInChanged?: (loggedIn: boolean) => void;
}) {
    return new Promise((accept, reject) => {
        acceptedOrigins = acceptedOrigins ?? ["https://galaxy.click"];
        if (acceptedOrigins.includes(window.origin)) {
            // Callbacks to resolve promises
            let saveListAccept: (value: SaveListResponse["list"]) => void,
                saveListReject: (reason?: string) => void;

            const galaxy = {
                acceptedOrigins,
                supportsSaving,
                supportsSaveManager,
                ignoreApiVersion,
                onLoggedInChanged,
                origin: window.origin,
                apiVersion: 0,
                loggedIn: false,
                postMessage: function (
                    message: SupportsAction | SaveListAction | SaveAction | LoadAction
                ) {
                    window.top?.postMessage(message, galaxy.origin);
                },
                getSaveList: function () {
                    if (saveListAccept != null || saveListReject != null) {
                        console.warn("save_list action already in progress. Ignoring...");
                        return;
                    }
                    galaxy.postMessage({
                        action: "save_list"
                    });
                    return new Promise<SaveListResponse["list"]>((accept, reject) => {
                        saveListAccept = accept;
                        saveListReject = reject;
                    });
                }
            };

            window.addEventListener("message", e => {
                if (e.origin === galaxy.origin) {
                    console.log("Received message from Galaxy", e.data);
                    const data = e.data as GalaxyResponse;

                    switch (data.type) {
                        case "info": {
                            const { galaxy: isGalaxy, api_version, logged_in } = data;
                            // Ignoring isGalaxy check in case other accepted origins send it as false
                            if (api_version !== 1 && galaxy.ignoreApiVersion !== true) {
                                reject(`API version not recognized: ${api_version}`);
                            } else {
                                // Info responses may be sent again if the information gets updated
                                // Specifically, we care if logged_in gets changed
                                // We can use the api_version to determine if this is the first
                                // info response or a new one.
                                const firstInfoResponse = galaxy.apiVersion === 0;
                                galaxy.apiVersion = api_version;
                                galaxy.loggedIn = logged_in;
                                galaxy.origin = e.origin;
                                if (firstInfoResponse) {
                                    accept(galaxy);
                                } else {
                                    galaxy.onLoggedInChanged?.(logged_in);
                                }
                            }
                            break;
                        }
                        case "save_list": {
                            const { list, error, message } = data;
                            if (error) {
                                saveListReject(message);
                            } else {
                                saveListAccept(list);
                            }
                        }
                    }
                }
            });
        } else {
            reject(`Project is not running on an accepted origin: ${window.origin}`);
        }
    });
}