import { CloseVectorHNSWWeb } from './hnswlibWasm';
import { download } from './loader';
import { CloseVectorEmbeddings, CloseVectorDocument } from 'closevector-common';
import { createPublicGetFileOperationUrl } from './lib';
import { CloseVectorFreeEmbeddings } from './embeddings';

type TypeOfOnProgress = Parameters<typeof download>[0]["onProgress"];
type TypeOfFileUrlCreator = (...args: any[]) => Promise<string>;
type TypeOfCreateLib = ConstructorParameters<typeof CloseVectorHNSWWeb>[1];

export class CloseVectorManager {

    accessKey: string | undefined;
    uuid: string | undefined;
    customEmbeddings: CloseVectorEmbeddings | undefined;

    lib: CloseVectorHNSWWeb | null = null;
    urlCreator: TypeOfFileUrlCreator | null = null;
    onProgress: TypeOfOnProgress | null = null;

    constructor(options: {
        // To download CloseVector database from server, you need to provide accessKey and uuid
        accessKey?: string,
        uuid?: string,

        // If you want to use your own embeddings, you can provide it here. Otherwise, we will use free embeddings
        customEmbeddings?: CloseVectorEmbeddings,

        // If you want to use your own urlCreator, you can provide it here. Otherwise, we will use default urlCreator
        fileUrlCreator?: TypeOfFileUrlCreator,

        // Progress callback for downloading from cloud. If you want to use your own onProgress, you can provide it here. Otherwise, we will use default onProgress
        onProgress?: TypeOfOnProgress,

    }) {
        const { accessKey, uuid, customEmbeddings } = options;
        this.accessKey = accessKey;
        this.uuid = uuid;
        this.customEmbeddings = customEmbeddings;

        this.onProgress = options.onProgress || null;
        this.urlCreator = options.fileUrlCreator || null;

        if (!this.urlCreator) {
            this.urlCreator = async () => {
                if (!this.uuid || !this.accessKey) {
                    throw new Error("uuid and accessKey are required");
                }

                let resp = await createPublicGetFileOperationUrl({
                    uuid: this.uuid,
                    accessKey: this.accessKey
                });
                return resp.url;
            }
        }

        if (!this.customEmbeddings) {
            if (!this.accessKey) {
                throw new Error("accessKey is required when customEmbeddings is not provided");
            }
            this.customEmbeddings = new CloseVectorFreeEmbeddings({ key: this.accessKey });
        }
    }

    async loadFromCloud() {
        if (!this.accessKey || !this.uuid) {
            throw new Error("uuid and accessKey are required");
        }

        if (!this.customEmbeddings) {
            throw new Error("customEmbeddings is required");
        }

        if (!this.urlCreator) {
            throw new Error("urlCreator is required");
        }

        const url = await this.urlCreator();
        await download({
            url,
            onProgress: this.onProgress || undefined,
        });

        const lib = await CloseVectorHNSWWeb.load(`${this.uuid}.hnsw`, this.customEmbeddings);
        return lib;
    }

    async createNewCloseVector(args: Partial<TypeOfCreateLib>) {
        if (!this.customEmbeddings) {
            throw new Error("customEmbeddings is required");
        }

        if (!args.space) {
            args.space = 'cosine';
        }

        const lib = new CloseVectorHNSWWeb(this.customEmbeddings, args as TypeOfCreateLib);
        return lib;
    }

    async fromDocuments(documents: CloseVectorDocument[]) {
        if (!this.customEmbeddings) {
            throw new Error("customEmbeddings is required");
        }

        let lib = await CloseVectorHNSWWeb.fromDocuments(documents, this.customEmbeddings);
        this.lib = lib;
    }

    async fromTexts(texts: string[], metadatas: object[] | object) {
        if (!this.customEmbeddings) {
            throw new Error("customEmbeddings is required");
        }

        let lib = await CloseVectorHNSWWeb.fromTexts(texts, metadatas, this.customEmbeddings);
        this.lib = lib;
    } 
}