// TODO: this file is located in the client src folder because
// otherwise, Create React App will refuse to compile it.
// Putting it in the server folder or in its own folder makes more sense.

// This file represents the API interface for Mudbase's back-end.
// Each endpoint is described by its endpoint address,
// a request structure, a response structure and
// a checking function which determines request validity.

export enum ItemType {
    Song = 0,
    Artist,
    Album,
    Tag
}

export interface ArtistDetails {
    artistId: number,
    name: string,
    storeLinks?: string[],
}
export function isArtistDetails(q: any): q is ArtistDetails {
    return 'artistId' in q;
}
export interface AlbumDetails {
    albumId: number,
    name: string,
    storeLinks?: string[],
}
export function isAlbumDetails(q: any): q is ArtistDetails {
    return 'albumId' in q;
}
export interface TagDetails {
    tagId: number,
    name: string,
    parent?: TagDetails,
    storeLinks?: string[],
}
export function isTagDetails(q: any): q is TagDetails {
    return 'tagId' in q;
}
export interface RankingDetails {
    rankingId: number,
    type: ItemType, // The item type being ranked
    rankedId: number, // The item being ranked
    context: ArtistDetails | TagDetails,
    value: number, // The ranking (higher = better)
}
export function isRankingDetails(q: any): q is RankingDetails {
    return 'rankingId' in q;
}
export interface SongDetails {
    songId: number,
    title: string,
    artists?: ArtistDetails[],
    albums?: AlbumDetails[],
    tags?: TagDetails[],
    storeLinks?: string[],
    rankings?: RankingDetails[],
}
export function isSongDetails(q: any): q is SongDetails {
    return 'songId' in q;
}

// Query for items (POST).
export const QueryEndpoint = '/query';
export enum QueryElemOp {
    And = "AND",
    Or = "OR",
}
export enum QueryFilterOp {
    Eq = "EQ",
    Ne = "NE",
    In = "IN",
    NotIn = "NOTIN",
    Like = "LIKE",
}
export enum QueryElemProperty {
    songTitle = "songTitle",
    songId = "songId",
    artistName = "artistName",
    artistId = "artistId",
    albumName = "albumName",
    albumId = "albumId",
    tagId = "tagId",
}
export enum OrderByType {
    Name = 0,
}
export interface QueryElem {
    prop?: QueryElemProperty,
    propOperand?: any,
    propOperator?: QueryFilterOp,
    children?: QueryElem[]
    childrenOperator?: QueryElemOp,
}
export interface Ordering {
    orderBy: {
        type: OrderByType,
    }
    ascending: boolean,
}
export interface Query extends QueryElem { }
export interface QueryRequest {
    query: Query,
    offsetsLimits: OffsetsLimits,
    ordering: Ordering,
}
export interface QueryResponse {
    songs: SongDetails[],
    artists: ArtistDetails[],
    tags: TagDetails[],
    albums: AlbumDetails[],
}
export interface OffsetsLimits {
    songOffset?: number,
    songLimit?: number,
    artistOffset?: number,
    artistLimit?: number,
    tagOffset?: number,
    tagLimit?: number,
    albumOffset?: number,
    albumLimit?: number,
}
export function checkQueryElem(elem: any): boolean {
    if (elem.childrenOperator && elem.children) {
        elem.children.forEach((child: any) => {
            if (!checkQueryElem(child)) {
                return false;
            }
        });
    }
    return (elem.childrenOperator && elem.children) ||
        ("prop" in elem && "propOperand" in elem && "propOperator" in elem) ||
        Object.keys(elem).length === 0;
}
export function checkQueryRequest(req: any): boolean {
    return 'query' in req
        && 'offsetsLimits' in req
        && 'ordering' in req
        && checkQueryElem(req.query);
}

// Get song details (GET).
export const SongDetailsEndpoint = '/song/:id';
export interface SongDetailsRequest { }
export interface SongDetailsResponse {
    title: string,
    storeLinks: string[],
    artistIds: number[],
    albumIds: number[],
    tagIds: number[],
}
export function checkSongDetailsRequest(req: any): boolean {
    return true;
}

// Get artist details (GET).
export const ArtistDetailsEndpoint = '/artist/:id';
export interface ArtistDetailsRequest { }
export interface ArtistDetailsResponse {
    name: string,
    tagIds: number[],
    storeLinks: string[],
}
export function checkArtistDetailsRequest(req: any): boolean {
    return true;
}

// Create a new song (POST).
export const CreateSongEndpoint = '/song';
export interface CreateSongRequest {
    title: string;
    artistIds?: number[];
    albumIds?: number[];
    tagIds?: number[];
    storeLinks?: string[];
}
export interface CreateSongResponse {
    id: number;
}
export function checkCreateSongRequest(req: any): boolean {
    return "body" in req &&
        "title" in req.body;
}

// Modify an existing song (PUT).
export const ModifySongEndpoint = '/song/:id';
export interface ModifySongRequest {
    title?: string;
    artistIds?: number[];
    albumIds?: number[];
    tagIds?: number[];
    storeLinks?: string[];
}
export interface ModifySongResponse { }
export function checkModifySongRequest(req: any): boolean {
    return true;
}

// Create a new album (POST).
export const CreateAlbumEndpoint = '/album';
export interface CreateAlbumRequest {
    name: string;
    tagIds?: number[];
    artistIds?: number[];
    storeLinks?: string[];
}
export interface CreateAlbumResponse {
    id: number;
}
export function checkCreateAlbumRequest(req: any): boolean {
    return "body" in req &&
        "name" in req.body;
}

// Modify an existing album (PUT).
export const ModifyAlbumEndpoint = '/album/:id';
export interface ModifyAlbumRequest {
    name?: string;
    tagIds?: number[];
    artistIds?: number[];
    storeLinks?: string[];
}
export interface ModifyAlbumResponse { }
export function checkModifyAlbumRequest(req: any): boolean {
    return true;
}

// Get album details (GET).
export const AlbumDetailsEndpoint = '/album/:id';
export interface AlbumDetailsRequest { }
export interface AlbumDetailsResponse {
    name: string;
    tagIds: number[];
    artistIds: number[];
    songIds: number[];
    storeLinks: string[];
}
export function checkAlbumDetailsRequest(req: any): boolean {
    return true;
}

// Create a new artist (POST).
export const CreateArtistEndpoint = '/artist';
export interface CreateArtistRequest {
    name: string;
    tagIds?: number[];
    storeLinks?: string[];
}
export interface CreateArtistResponse {
    id: number;
}
export function checkCreateArtistRequest(req: any): boolean {
    return "body" in req &&
        "name" in req.body;
}

// Modify an existing artist (PUT).
export const ModifyArtistEndpoint = '/artist/:id';
export interface ModifyArtistRequest {
    name?: string,
    tagIds?: number[];
    storeLinks?: string[],
}
export interface ModifyArtistResponse { }
export function checkModifyArtistRequest(req: any): boolean {
    return true;
}

// Create a new tag (POST).
export const CreateTagEndpoint = '/tag';
export interface CreateTagRequest {
    name: string;
    parentId?: number;
}
export interface CreateTagResponse {
    id: number;
}
export function checkCreateTagRequest(req: any): boolean {
    return "body" in req &&
        "name" in req.body;
}

// Modify an existing tag (PUT).
export const ModifyTagEndpoint = '/tag/:id';
export interface ModifyTagRequest {
    name?: string,
    parentId?: number;
}
export interface ModifyTagResponse { }
export function checkModifyTagRequest(req: any): boolean {
    return true;
}

// Get tag details (GET).
export const TagDetailsEndpoint = '/tag/:id';
export interface TagDetailsRequest { }
export interface TagDetailsResponse {
    name: string,
    parentId?: number,
}
export function checkTagDetailsRequest(req: any): boolean {
    return true;
}

// Delete tag (DELETE).
export const DeleteTagEndpoint = '/tag/:id';
export interface DeleteTagRequest { }
export interface DeleteTagResponse { }
export function checkDeleteTagRequest(req: any): boolean {
    return true;
}