import LRU from "lru-cache";
import { UpListing, UpObject } from ".";
import type {
  ADDRESS_TYPE,
  Address,
  AttributeListingResult,
  EntityListing,
  IJob,
  IValue,
  ListingResult,
  PutInput,
  PutResult,
  StoreInfo,
  VaultInfo,
} from "./types";
import init_wasm from "upend_wasm";
import {
  AddressComponents,
  AddressTypeConstants,
  addr_to_components,
  components_to_addr,
  InitInput,
} from "upend_wasm";
import debug from "debug";
const dbg = debug("upend:api");

export { AddressComponents };

export class UpEndApi {
  private instanceUrl = "";
  private wasmInit: InitInput | undefined;
  private wasmInitialized = false;
  private addressTypeConstants: AddressTypeConstants | undefined = undefined;

  private queryOnceLRU = new LRU<string, UpListing>({ max: 128 });
  private inFlightRequests: { [key: string]: Promise<UpListing> | null } = {};

  constructor(instanceUrl = "", wasmInit?: InitInput) {
    this.setInstanceUrl(instanceUrl);
    if (wasmInit) {
      this.setWasmInit(wasmInit);
    }
  }

  public setInstanceUrl(apiUrl: string) {
    this.instanceUrl = apiUrl.replace(/\/+$/g, "");
  }

  public setWasmInit(wasmInit: InitInput) {
    this.wasmInit = wasmInit;
  }

  public get apiUrl() {
    return this.instanceUrl + "/api";
  }

  public async fetchEntity(address: string): Promise<UpObject> {
    dbg("Fetching Entity %s", address);
    const entityFetch = await fetch(`${this.apiUrl}/obj/${address}`);
    const entityResult = (await entityFetch.json()) as EntityListing;
    const entityListing = new UpListing(entityResult.entries);
    return entityListing.getObject(address);
  }

  public async fetchEntry(address: string) {
    dbg("Fetching entry %s", address);
    const response = await fetch(`${this.apiUrl}/raw/${address}`);
    const data = await response.json();
    const listing = new UpListing({ address: data });
    return listing.entries[0];
  }

  public async query(query: string): Promise<UpListing> {
    const cacheResult = this.queryOnceLRU.get(query);
    if (!cacheResult) {
      if (!this.inFlightRequests[query]) {
        dbg(`Querying: ${query}`);
        this.inFlightRequests[query] = new Promise((resolve, reject) => {
          fetch(`${this.apiUrl}/query`, {
            method: "POST",
            body: query,
            keepalive: true,
          })
            .then(async (response) => {
              resolve(new UpListing(await response.json()));
              this.inFlightRequests[query] = null;
            })
            .catch((err) => reject(err));
        });
      } else {
        dbg(`Chaining request for ${query}...`);
      }
      return await (this.inFlightRequests[query] as Promise<UpListing>); // TODO?
    } else {
      dbg(`Returning cached: ${query}`);
      return cacheResult;
    }
  }

  public async putEntry(input: PutInput): Promise<PutResult> {
    dbg("Putting %O", input);
    const response = await fetch(`${this.apiUrl}/obj`, {
      method: "PUT",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(input),
    });

    return await response.json();
  }

  public async putEntityAttribute(
    entity: Address,
    attribute: string,
    value: IValue,
    provenance?: string
  ): Promise<Address> {
    dbg("Putting %s = %o for %s (%s)", attribute, value, entity, provenance);
    let url = `${this.apiUrl}/obj/${entity}/${attribute}`;
    if (provenance) {
      url += `?provenance=${provenance}`;
    }
    const response = await fetch(url, {
      method: "PUT",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(value),
    });

    return await response.json();
  }

  public async putBlob(fileOrUrl: File | URL): Promise<PutResult> {
    dbg("Putting Blob: %O", fileOrUrl);
    const formData = new FormData();
    if (fileOrUrl instanceof File) {
      formData.append(fileOrUrl.name, fileOrUrl);
    } else {
      formData.append("@url", fileOrUrl.toString());
    }

    const response = await fetch(`${this.apiUrl}/blob`, {
      method: "PUT",
      body: formData,
    });

    if (!response.ok) {
      throw Error(await response.text());
    }

    return await response.json();
  }

  public async deleteEntry(address: Address): Promise<void> {
    dbg("Deleting entry %s", address);
    await fetch(`${this.apiUrl}/obj/${address}`, { method: "DELETE" });
  }

  public async getRaw(address: Address, preview = false) {
    dbg("Getting %s raw (preview = %s)", address, preview);
    return await fetch(
      `${this.apiUrl}/${preview ? "thumb" : "raw"}/${address}`
    );
  }

  public async refreshVault() {
    dbg("Triggering vault refresh");
    return await fetch(`${this.apiUrl}/refresh`, { method: "POST" });
  }

  public async nativeOpen(address: Address) {
    dbg("Opening %s natively", address);
    return fetch(`${this.apiUrl}/raw/${address}?native=1`);
  }

  public async fetchRoots(): Promise<ListingResult> {
    dbg("Fetching hierarchical roots...");
    const response = await fetch(`${this.apiUrl}/hier_roots`);
    const roots = await response.json();
    dbg("Hierarchical roots: %O", roots);
    return roots;
  }

  public async fetchJobs(): Promise<IJob[]> {
    const response = await fetch(`${this.apiUrl}/jobs`);
    return await response.json();
  }

  public async fetchAllAttributes(): Promise<AttributeListingResult> {
    dbg("Fetching all attributes...");
    const response = await fetch(`${this.apiUrl}/all/attributes`);
    const result = await response.json();
    dbg("All attributes: %O", result);
    return await result;
  }

  public async fetchInfo(): Promise<VaultInfo> {
    const response = await fetch(`${this.apiUrl}/info`);
    const result = await response.json();
    dbg("Vault info: %O", result);
    return result;
  }

  public async fetchStoreInfo(): Promise<{ [key: string]: StoreInfo }> {
    const response = await fetch(`${this.apiUrl}/stats/store`);
    const result = await response.json();
    dbg("Store info: %O");
    return await result;
  }

  public async getAddress(
    input:
      | { attribute: string }
      | { url: string }
      | { urlContent: string }
      | ADDRESS_TYPE
  ): Promise<string> {
    let response: Response;
    if (typeof input === "string") {
      try {
        if (!this.addressTypeConstants) {
          await this.initWasm();
          this.addressTypeConstants = new AddressTypeConstants();
        }
        return this.addressTypeConstants[input];
      } catch (err) {
        console.warn(err);
      }
      response = await fetch(`${this.apiUrl}/address?type=${input}`);
    } else {
      if ("attribute" in input) {
        response = await fetch(
          `${this.apiUrl}/address?attribute=${input.attribute}`
        );
      } else if ("url" in input) {
        response = await fetch(`${this.apiUrl}/address?url=${input.url}`);
      } else if ("urlContent" in input) {
        response = await fetch(
          `${this.apiUrl}/address?url_content=${input.urlContent}`
        );
      } else {
        throw new Error("Input cannot be empty.");
      }
    }
    const result = await response.json();
    dbg("Address for %o = %s", input, result);
    return result;
  }

  public async addressToComponents(
    address: string
  ): Promise<AddressComponents> {
    await this.initWasm();
    return addr_to_components(address);
  }

  public async componentsToAddress(
    components: AddressComponents
  ): Promise<string> {
    await this.initWasm();
    return components_to_addr(components);
  }

  private async initWasm(): Promise<void> {
    if (!this.wasmInitialized) {
      if (!this.wasmInit) {
        throw new Error(
          "WASM init not specified, cannot initialize WASM extensions."
        );
      }
      await init_wasm(this.wasmInit);
      this.wasmInitialized = true;
    }
  }
}