import { Platform } from "react-native";
import * as FileSystem from "expo-file-system";
import { File, Paths } from "expo-file-system/next";
import { getDb } from "./db";
import * as Crypto from "expo-crypto";
import { arrbufToStr, strToArrBuf } from "./util";
import { createReadStream } from "./readstream";

export const WHISPER_MODEL_PATH = Paths.join(
  FileSystem.documentDirectory || "file:///",
  "whisper"
);
export const WHISPER_MODEL_DIR = new File(WHISPER_MODEL_PATH);

// Thanks to https://medium.com/@fabi.mofar/downloading-and-saving-files-in-react-native-expo-5b3499adda84

export async function saveFile(
  uri: string,
  filename: string,
  mimetype: string
) {
  if (Platform.OS === "android") {
    const permissions =
      await FileSystem.StorageAccessFramework.requestDirectoryPermissionsAsync();

    if (permissions.granted) {
      const base64 = await FileSystem.readAsStringAsync(uri, {
        encoding: FileSystem.EncodingType.Base64,
      });

      await FileSystem.StorageAccessFramework.createFileAsync(
        permissions.directoryUri,
        filename,
        mimetype
      )
        .then(async (uri) => {
          await FileSystem.writeAsStringAsync(uri, base64, {
            encoding: FileSystem.EncodingType.Base64,
          });
        })
        .catch((e) => console.log(e));
    } else {
      shareAsync(uri);
    }
  } else {
    shareAsync(uri);
  }
}

function shareAsync(uri: string) {
  throw new Error("Function not implemented.");
}

export const WHISPER_MODEL_TAGS = ["small", "medium", "large"];
export type whisper_model_tag_t = "small" | "medium" | "large";

export const WHISPER_MODELS = {
  small: {
    source:
      "https://huggingface.co/openai/whisper-small/blob/resolve/pytorch_model.bin",
    target: "small.bin",
    label: "Small",
    size: 967092419,
  },
  medium: {
    source:
      "https://huggingface.co/openai/whisper-medium/resolve/main/pytorch_model.bin",
    target: "medium.bin",
    label: "Medium",
    size: 3055735323,
  },
  large: {
    source:
      "https://huggingface.co/openai/whisper-large/resolve/main/pytorch_model.bin",
    target: "large.bin",
    label: "Large",
    size: 6173629930,
  },
} as {
  [key: whisper_model_tag_t]: {
    source: string;
    target: string;
    label: string;
    size: number;
  };
};

export type whisper_tag_t = "small" | "medium" | "large";
export type hf_channel_t = "raw" | "resolve";

export const HF_URL_BASE = "https://huggingface.co/openai/whisper-";
export const HF_URL_RAW = "raw";
export const HF_URL_RESOLVE = "resolve";
export const HF_URL_END = "/main/pytorch_model.bin";

export function create_hf_url(tag: whisper_tag_t, channel: hf_channel_t) {
  return `${HF_URL_BASE}${tag}/${channel}${HF_URL_END}`;
}

export type hf_metadata_t = {
  version: string;
  oid: string;
  size: string;
};

export type download_status_t = {
  doesTargetExist: boolean;
  isDownloadComplete: boolean;
  hasDownloadStarted: boolean;
  progress?: {
    current: number;
    total: number;
    remaining: number;
    percentRemaining: number;
  };
};

export class WhisperFile {
  hf_metadata: hf_metadata_t | undefined;

  target_hash: string | undefined;
  does_target_exist: boolean = false;
  does_part_target_exist: boolean = false;
  download_data: FileSystem.DownloadProgressData | undefined;

  constructor(
    public tag: whisper_model_tag_t,
    private targetFileName?: string,
    public label?: string,
    public size?: number
  ) {
    this.targetFileName = this.targetFileName || `${tag}.bin`;
    this.label =
      this.label || `${tag[0].toUpperCase()}${tag.substring(1).toLowerCase()}`;
  }

  get targetPath() {
    return Paths.join(WHISPER_MODEL_PATH, this.targetFileName as string);
  }

  get targetPartPath() {
    return this.targetPath + ".part";
  }

  get targetFile() {
    return new File(this.targetPath);
  }

  get targetPartFile() {
    return new File(this.targetPartPath);
  }

  async getTargetInfo() {
    return await FileSystem.getInfoAsync(this.targetPath);
  }

  async getTargetPartInfo() {
    return await FileSystem.getInfoAsync(this.targetPartPath);
  }

  async updateTargetExistence() {
    this.does_target_exist = (await this.getTargetInfo()).exists;
    console.log("Determining if %s exists: %s", this.targetPath, this.does_target_exist)
    this.does_part_target_exist = (await this.getTargetPartInfo()).exists;
    console.log("Determining if %s exists: %s", this.targetPartPath, this.does_part_target_exist)
  }

  public async getTargetSha() {
    await this.updateTargetExistence();
    if (!this.does_target_exist) {
      console.debug("%s does not exist", this.targetPath);
      return undefined;
    }

    const strData = await FileSystem.readAsStringAsync(this.targetPath, {
      encoding: FileSystem.EncodingType.Base64,
    });
    const data = strToArrBuf(strData);

    const digest = await Crypto.digest(
      Crypto.CryptoDigestAlgorithm.SHA256,
      data
    );

    return digest;
  }

  public async updateTargetHash() {
    const targetSha = await this.getTargetSha();
    if (!targetSha) return;
    this.target_hash = arrbufToStr(targetSha);
  }

  get isHashValid() {
    return this.target_hash === this.hf_metadata?.oid;
  }

  delete(ignoreErrors = true) {
    try {
      this.does_target_exist && this.targetFile.delete();
      this.does_part_target_exist && this.targetPartFile.delete();
    } catch (err) {
      console.error(err);
      if (!ignoreErrors) {
        throw err;
      }
    }
    console.debug("Successfully deleted %s and %s", this.targetPartPath, this.targetPath);
  }

  get modelUrl() {
    return create_hf_url(this.tag, "resolve");
  }

  get metadataUrl() {
    return create_hf_url(this.tag, "raw");
  }

  get percentDone() {
    if (!this.download_data) return 0;
    return (
      (this.download_data.totalBytesWritten /
        this.download_data.totalBytesExpectedToWrite) *
      100
    );
  }

  get percentLeft() {
    if (!this.download_data) return 0;
    return 100 - this.percentDone;
  }

  public async syncHfMetadata() {
    try {
      const resp = await fetch(this.metadataUrl, {
        credentials: "include",
        headers: {
          "User-Agent":
            "Mozilla/5.0 (X11; Linux x86_64; rv:135.0) Gecko/20100101 Firefox/135.0",
          Accept:
            "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
          "Accept-Language": "en-US,en;q=0.5",
          "Sec-GPC": "1",
          "Upgrade-Insecure-Requests": "1",
          "Sec-Fetch-Dest": "document",
          "Sec-Fetch-Mode": "navigate",
          "Sec-Fetch-Site": "cross-site",
          "If-None-Match": '"8fa71cbce85078986b46fb97caec22039e73351a"',
          Priority: "u=0, i",
        },
        method: "GET",
        mode: "cors",
      });
      const text = await resp.text();
      this.hf_metadata = Object.fromEntries(
        text.split("\n").map((line) => line.split(" "))
      ) as hf_metadata_t;
    } catch (err) {
      console.error("Failed to fetch %s: %s", this.metadataUrl, err);
      throw err;
    }
  }

  async createDownloadResumable(
    options: {
      onData?: DownloadCallback | undefined;
      onComplete?: CompletionCallback | undefined;
    } = {
      onData: undefined,
      onComplete: undefined,
    }
  ) {
    await this.syncHfMetadata();

    // If the whisper model dir doesn't exist, create it.
    if (!WHISPER_MODEL_DIR.exists) {
      FileSystem.makeDirectoryAsync(WHISPER_MODEL_PATH, {
        intermediates: true,
      });
    }

    // Check for the existence of the target file
    // If it exists, load the existing data.
    await this.updateTargetExistence();

    try {
      // const existingData = this.does_target_exist
      //   ? await FileSystem.readAsStringAsync(this.targetPath, {
      //       encoding: FileSystem.EncodingType.Base64,
      //     })
      //   : undefined;

      // Create the resumable.
      return FileSystem.createDownloadResumable(
        this.modelUrl,
        this.targetPartPath,
        {},
        async (data: FileSystem.DownloadProgressData) => {
          console.log(
            "Downloading %s: %d of %d",
            this.targetPartPath,
            data.totalBytesExpectedToWrite,
            data.totalBytesWritten
          );

          // console.debug("yes, I'm still downloading");
          try {
            this.download_data = data;
          } catch (err) {
            console.error("Failed to set downloadData: %s", err);
          }

          try {
            await this.syncHfMetadata();
          } catch (err) {
            console.error("Failed to update HuggingFace metadata: %s", err);
          }

          // try {
          //   await this.updateTargetHash();
          // } catch (er) {
          //   console.error("Failed to update target hash: %s", er);
          // }

          try {
            await this.updateTargetExistence();
          } catch (err) {
            console.error("Failed to update target existence: %s", err);
          }
          if (options.onData) await options.onData(this);

          if (data.totalBytesExpectedToWrite === data.totalBytesWritten) {
            console.debug(
              "Finalizing; copying from %s -> %s",
              this.targetPartPath,
              this.targetPath
            );
            await FileSystem.moveAsync({
              from: this.targetPartPath,
              to: this.targetPath,
            });
            await this.updateTargetExistence();
            options.onComplete && options.onComplete(this);
          }
        },
        // existingData ? existingData : undefined
      );
    } catch (err) {
      console.error("Could not read %s: %s", this.targetPath, err);
    }
  }
}

export type DownloadCallback = (arg0: WhisperFile) => any;
export type CompletionCallback = (arg0: WhisperFile) => any;

export const WHISPER_FILES = {
  small: new WhisperFile("small"),
  medium: new WhisperFile("medium"),
  large: new WhisperFile("large"),
};