import { Readable } from "stream";
import {
  ResourceService,
  VariableService,
  JobService,
  HelpersService,
  OidcService,
} from "./index";
import { OpenAPI } from "./index";
// import type { DenoS3LightClientSettings } from "./index";
import { DenoS3LightClientSettings, type S3Object } from "./s3Types";

export {
  AdminService,
  AuditService,
  FlowService,
  GranularAclService,
  GroupService,
  JobService,
  ResourceService,
  VariableService,
  ScriptService,
  ScheduleService,
  SettingsService,
  UserService,
  WorkspaceService,
} from "./index";

export type Sql = string;
export type Email = string;
export type Base64 = string;
export type Resource<S extends string> = any;

export const SHARED_FOLDER = "/shared";

let clientSet = false;
export function setClient(token?: string, baseUrl?: string) {
  if (baseUrl === undefined) {
    baseUrl =
      getEnv("BASE_INTERNAL_URL") ??
      getEnv("BASE_URL") ??
      "http://localhost:8000";
  }
  if (token === undefined) {
    token = getEnv("WM_TOKEN") ?? "no_token";
  }
  OpenAPI.WITH_CREDENTIALS = true;
  OpenAPI.TOKEN = token;
  OpenAPI.BASE = baseUrl + "/api";
  clientSet = true;
}

const getEnv = (key: string) => {
  if (typeof window === "undefined") {
    // node
    return process.env[key];
  }
  // browser
  return window.process.env[key];
};

/**
 * Create a client configuration from env variables
 * @returns client configuration
 */
export function getWorkspace(): string {
  return getEnv("WM_WORKSPACE") ?? "no_workspace";
}

/**
 * Get a resource value by path
 * @param path path of the resource,  default to internal state path
 * @param undefinedIfEmpty if the resource does not exist, return undefined instead of throwing an error
 * @returns resource value
 */
export async function getResource(
  path?: string,
  undefinedIfEmpty?: boolean
): Promise<any> {
  !clientSet && setClient();
  const workspace = getWorkspace();
  path = path ?? getStatePath();
  try {
    return await ResourceService.getResourceValueInterpolated({
      workspace,
      path,
    });
  } catch (e: any) {
    if (undefinedIfEmpty && e.status === 404) {
      return undefined;
    } else {
      throw Error(
        `Resource not found at ${path} or not visible to you: ${e.body}`
      );
    }
  }
}

/**
 * Resolve a resource value in case the default value was picked because the input payload was undefined
 * @param obj resource value or path of the resource under the format `$res:path`
 * @returns resource value
 */
export async function resolveDefaultResource(obj: any): Promise<any> {
  if (typeof obj === "string" && obj.startsWith("$res:")) {
    return await getResource(obj.substring(5), true);
  } else {
    return obj;
  }
}

export function getStatePath(): string {
  const state_path = getEnv("WM_STATE_PATH_NEW") ?? getEnv("WM_STATE_PATH");
  if (state_path === undefined) {
    throw Error("State path not set");
  }
  return state_path;
}

/**
 * Set a resource value by path
 * @param path path of the resource to set, default to state path
 * @param value new value of the resource to set
 * @param initializeToTypeIfNotExist if the resource does not exist, initialize it with this type
 */
export async function setResource(
  value: any,
  path?: string,
  initializeToTypeIfNotExist?: string
): Promise<void> {
  !clientSet && setClient();
  path = path ?? getStatePath();
  const workspace = getWorkspace();
  if (await ResourceService.existsResource({ workspace, path })) {
    await ResourceService.updateResourceValue({
      workspace,
      path,
      requestBody: { value },
    });
  } else if (initializeToTypeIfNotExist) {
    await ResourceService.createResource({
      workspace,
      requestBody: { path, value, resource_type: initializeToTypeIfNotExist },
    });
  } else {
    throw Error(
      `Resource at path ${path} does not exist and no type was provided to initialize it`
    );
  }
}

/**
 * Set the state
 * @param state state to set
 * @deprecated use setState instead
 */
export async function setInternalState(state: any): Promise<void> {
  await setResource(state, undefined, "state");
}

/**
 * Set the state
 * @param state state to set
 */
export async function setState(state: any): Promise<void> {
  await setResource(state, undefined, "state");
}

// /**
//  * Set the shared state
//  * @param state state to set
//  */
// export async function setSharedState(
//   state: any,
//   path = "state.json"
// ): Promise<void> {
//   await Deno.writeTextFile(SHARED_FOLDER + "/" + path, JSON.stringify(state));
// }

// /**
//  * Get the shared state
//  * @param state state to set
//  */
// export async function getSharedState(path = "state.json"): Promise<any> {
//   return JSON.parse(await Deno.readTextFile(SHARED_FOLDER + "/" + path));
// }

/**
 * Get the internal state
 * @deprecated use getState instead
 */
export async function getInternalState(): Promise<any> {
  return await getResource(getStatePath(), true);
}

/**
 * Get the state shared across executions
 */
export async function getState(): Promise<any> {
  return await getResource(getStatePath(), true);
}

/**
 * Get a variable by path
 * @param path path of the variable
 * @returns variable value
 */
export async function getVariable(path: string): Promise<string> {
  !clientSet && setClient();
  const workspace = getWorkspace();
  try {
    return await VariableService.getVariableValue({ workspace, path });
  } catch (e: any) {
    throw Error(
      `Variable not found at ${path} or not visible to you: ${e.body}`
    );
  }
}

/**
 * Set a variable by path, create if not exist
 * @param path path of the variable
 * @param value value of the variable
 * @param isSecretIfNotExist if the variable does not exist, create it as secret or not (default: false)
 * @param descriptionIfNotExist if the variable does not exist, create it with this description (default: "")
 */
export async function setVariable(
  path: string,
  value: string,
  isSecretIfNotExist?: boolean,
  descriptionIfNotExist?: string
): Promise<void> {
  !clientSet && setClient();
  const workspace = getWorkspace();
  if (await VariableService.existsVariable({ workspace, path })) {
    await VariableService.updateVariable({
      workspace,
      path,
      requestBody: { value },
    });
  } else {
    await VariableService.createVariable({
      workspace,
      requestBody: {
        path,
        value,
        is_secret: isSecretIfNotExist ?? false,
        description: descriptionIfNotExist ?? "",
      },
    });
  }
}

export async function databaseUrlFromResource(path: string): Promise<string> {
  const resource = await getResource(path);
  return `postgresql://${resource.user}:${resource.password}@${resource.host}:${resource.port}/${resource.dbname}?sslmode=${resource.sslmode}`;
}

// TODO(gb): need to investigate more how Polars and DuckDB work in TS
// export async function polarsConnectionSettings(s3_resource_path: string | undefined): Promise<any> {
//   const workspace = getWorkspace();
//   return await HelpersService.polarsConnectionSettingsV2({
//     workspace: workspace,
// 		requestBody: {
// 			s3_resource_path: s3_resource_path
// 		}
//   });
// }

// export async function duckdbConnectionSettings(s3_resource_path: string | undefined): Promise<any> {
//   const workspace = getWorkspace();
//   return await HelpersService.duckdbConnectionSettingsV2({
//     workspace: workspace,
// 		requestBody: {
// 			s3_resource_path: s3_resource_path
// 		}
//   });
// }

export async function denoS3LightClientSettings(
  s3_resource_path: string | undefined
): Promise<DenoS3LightClientSettings> {
  !clientSet && setClient();
  const workspace = getWorkspace();
  const s3Resource = await HelpersService.s3ResourceInfo({
    workspace: workspace,
    requestBody: {
      s3_resource_path: s3_resource_path,
    },
  });
  let settings: DenoS3LightClientSettings = {
    ...s3Resource,
  };
  return settings;
}

/**
 * Load the content of a file stored in S3. If the s3ResourcePath is undefined, it will default to the workspace S3 resource.
 * 
 * ```typescript
 * let fileContentStream = await wmill.loadS3File(inputFile)
 * // if the file is a raw text file, it can be decoded and printed directly:
 * const text = new TextDecoder().decode(fileContentStream)
 * console.log(text);
 * ```
 */
export async function loadS3File(
  s3object: S3Object,
  s3ResourcePath: string | undefined
): Promise<Uint8Array|undefined> {
  !clientSet && setClient();

  let part_number: number | undefined = 0
  let file_total_size: number|undefined = undefined

  let fetch = async function(controller: any) {
    // console.log("fetching part", part_number)
    if (part_number === undefined || part_number === null) {
      // console.log("finished, closing")
      controller.close()
      return
    }
    let part_response = await HelpersService.multipartFileDownload({
      workspace: getWorkspace(),
      requestBody: {
        file_key: s3object.s3,
        part_number: part_number,
        file_size: file_total_size,
        s3_resource_path: s3ResourcePath,
      }
    })
    
    if (part_response.part_content.length > 0) {
      // console.log("enqueueing part", part_number, part_response.part_content.length)
      let chunk = new Uint8Array(part_response.part_content.length)
      part_response.part_content.forEach((value: number, index: number) => {
        chunk[index] = value
      })
      controller.enqueue(chunk)
    }
    part_number = part_response.next_part_number
    file_total_size = part_response.file_size
  }

  let fileContentStream = new ReadableStream({
    async pull(controller) {
      await fetch(controller)
    }
  })

  // For now we read all the stream in here. In the future return the stream and let the users consume it as they wish
  const reader = fileContentStream.getReader()
  const chunks: Uint8Array[] = [];
  while (true) {
    const {value: chunk, done} = await reader.read();
    if (done) {
      break;
    }
    chunks.push(chunk);
  }
  let fileContentLength = 0;
  chunks.forEach(item => {
    fileContentLength += item.length;
  });
  let fileContent = new Uint8Array(fileContentLength);
  let offset = 0;
  chunks.forEach(chunk => {
    fileContent.set(chunk, offset);
    offset += chunk.length;
  });
  return fileContent
}

/**
 * Persist a file to the S3 bucket. If the s3ResourcePath is undefined, it will default to the workspace S3 resource.
 * 
 * ```typescript
 * const s3object = await writeS3File(s3Object, "Hello Windmill!")
 * const fileContentAsUtf8Str = (await s3object.toArray()).toString('utf-8')
 * console.log(fileContentAsUtf8Str)
 * ```
 */
export async function writeS3File(
  s3object: S3Object | undefined,
  fileContent: string | ReadableStream<Uint8Array>,
  fileExpiration: Date | undefined,
  s3ResourcePath: string | undefined
): Promise<S3Object> {
  !clientSet && setClient();
  let fileContentStream: ReadableStream<Uint8Array>
  if (typeof fileContent === 'string') {
    fileContentStream = new Blob([fileContent as string], {
      type: 'text/plain'
    }).stream();
  } else {
    fileContentStream = fileContent as ReadableStream<Uint8Array>
  }

  let path = s3object?.s3
  let upload_id: string | undefined = undefined
  let parts: any[] = []
  const reader = fileContentStream.getReader()
  let { value: chunk, done: readerDone } = await reader.read()
  if (chunk === undefined || readerDone) {
    throw Error('Error reading stream, no data read');
  }

  while (true) {
    let { value: chunk_2, done: readerDone } = await reader.read()
    if (!readerDone && chunk_2 !== undefined && chunk.length <= 5 * 1024 * 1024) {
      // AWS enforces part to be bigger than 5MB, so we accumulate bytes until we reach that limit before triggering the request to the BE
      chunk = new Uint8Array([...chunk, ...chunk_2])
      continue
    }
    try {
      let response: any = await HelpersService.multipartFileUpload({
        workspace: getWorkspace(),
        requestBody: {
          file_key: path,
          file_extension: undefined,
          part_content: Array.from(chunk),
          upload_id: upload_id,
          parts: parts,
          is_final: readerDone,
          cancel_upload: false,
          s3_resource_path: s3ResourcePath,
          file_expiration: fileExpiration?.toString(),
        }
      })
      path = response.file_key
      upload_id = response.upload_id
      parts = response.parts

      if (response.is_done) {
        break
      }
      if (chunk_2 === undefined) {
        throw Error('File upload is not finished, yet there is no more data to stream. This is unexpected');
      }
      chunk = chunk_2
    } catch (e) {
      throw Error(`Unexpected error uploading data to S3 ${e}`);
    }
  }
  return {
    s3: path as string
  }
}

/**
 * Get URLs needed for resuming a flow after this step
 * @param approver approver name
 * @returns approval page UI URL, resume and cancel API URLs for resuming the flow
 */
export async function getResumeUrls(approver?: string): Promise<{
  approvalPage: string;
  resume: string;
  cancel: string;
}> {
  const nonce = Math.floor(Math.random() * 4294967295);
  !clientSet && setClient();
  const workspace = getWorkspace();
  return await JobService.getResumeUrls({
    workspace,
    resumeId: nonce,
    approver,
    id: getEnv("WM_JOB_ID") ?? "NO_JOB_ID",
  });
}

/**
 * @deprecated use getResumeUrls instead
 */
export function getResumeEndpoints(approver?: string): Promise<{
  approvalPage: string;
  resume: string;
  cancel: string;
}> {
  return getResumeUrls(approver);
}

/**
 * Get an OIDC jwt token for auth to external services (e.g: Vault, AWS) (ee only)
 * @param audience audience of the token
 * @returns jwt token
 */
export async function getIdToken(audience: string): Promise<string> {
  !clientSet && setClient();
  const workspace = getWorkspace();
  return await OidcService.getOidcToken({
    workspace,
    audience,
  });
}

export function base64ToUint8Array(data: string): Uint8Array {
  return Uint8Array.from(atob(data), (c) => c.charCodeAt(0));
}

export function uint8ArrayToBase64(arrayBuffer: Uint8Array): string {
  let base64 = "";
  const encodings =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

  const bytes = new Uint8Array(arrayBuffer);
  const byteLength = bytes.byteLength;
  const byteRemainder = byteLength % 3;
  const mainLength = byteLength - byteRemainder;

  let a, b, c, d;
  let chunk;

  // Main loop deals with bytes in chunks of 3
  for (let i = 0; i < mainLength; i = i + 3) {
    // Combine the three bytes into a single integer
    chunk = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];

    // Use bitmasks to extract 6-bit segments from the triplet
    a = (chunk & 16515072) >> 18; // 16515072 = (2^6 - 1) << 18
    b = (chunk & 258048) >> 12; // 258048   = (2^6 - 1) << 12
    c = (chunk & 4032) >> 6; // 4032     = (2^6 - 1) << 6
    d = chunk & 63; // 63       = 2^6 - 1

    // Convert the raw binary segments to the appropriate ASCII encoding
    base64 += encodings[a] + encodings[b] + encodings[c] + encodings[d];
  }

  // Deal with the remaining bytes and padding
  if (byteRemainder == 1) {
    chunk = bytes[mainLength];

    a = (chunk & 252) >> 2; // 252 = (2^6 - 1) << 2

    // Set the 4 least significant bits to zero
    b = (chunk & 3) << 4; // 3   = 2^2 - 1

    base64 += encodings[a] + encodings[b] + "==";
  } else if (byteRemainder == 2) {
    chunk = (bytes[mainLength] << 8) | bytes[mainLength + 1];

    a = (chunk & 64512) >> 10; // 64512 = (2^6 - 1) << 10
    b = (chunk & 1008) >> 4; // 1008  = (2^6 - 1) << 4

    // Set the 2 least significant bits to zero
    c = (chunk & 15) << 2; // 15    = 2^4 - 1

    base64 += encodings[a] + encodings[b] + encodings[c] + "=";
  }

  return base64;
}