import { mkdir, readFile, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { HttpService } from "@nestjs/axios";
import {
  BadGatewayException,
  Injectable,
  Logger,
  NotFoundException,
} from "@nestjs/common";
import { firstValueFrom } from "rxjs";
import { isAxiosError } from "axios";
import {
  getFanavaranClientProfile,
  type FanavaranClientKey,
} from "src/core/config/fanavaran-client.config";
import {
  fanavaranLookupCacheDir,
  tejaratStaticAccidentFilePath,
} from "./fanavaran-lookup.config";

@Injectable()
export class FanavaranLookupService {
  private readonly logger = new Logger(FanavaranLookupService.name);

  private readonly getAppTokenUrl =
    "https://apimanager.iraneit.com/BimeApiManager/api/EITAuthentication/GetAppToken";
  private readonly loginUrl =
    "https://apimanager.iraneit.com/BimeApiManager/api/EITAuthentication/Login";

  constructor(private readonly httpService: HttpService) {}

  private cacheFilePath(clientKey: FanavaranClientKey, fileName: string): string {
    return join(fanavaranLookupCacheDir(clientKey), fileName);
  }

  async readCacheFile<T>(
    clientKey: FanavaranClientKey,
    fileName: string,
  ): Promise<T | null> {
    try {
      const content = await readFile(
        this.cacheFilePath(clientKey, fileName),
        "utf-8",
      );
      return JSON.parse(content) as T;
    } catch {
      return null;
    }
  }

  async writeCacheFile(
    clientKey: FanavaranClientKey,
    fileName: string,
    data: unknown,
  ): Promise<void> {
    const dir = fanavaranLookupCacheDir(clientKey);
    await mkdir(dir, { recursive: true });
    await writeFile(
      join(dir, fileName),
      `${JSON.stringify(data, null, 2)}\n`,
      "utf-8",
    );
    this.logger.log(
      `Cached Fanavaran lookup ${fileName} for client ${clientKey}`,
    );
  }

  async readTejaratStaticAccidentFile<T>(fileName: string): Promise<T> {
    const cached = await readFile(tejaratStaticAccidentFilePath(fileName), "utf-8");
    return JSON.parse(cached) as T;
  }

  private async getAppToken(config: {
    appName: string;
    secret: string;
  }): Promise<string> {
    const response = await firstValueFrom(
      this.httpService.post(this.getAppTokenUrl, "", {
        headers: {
          appname: config.appName,
          secret: config.secret,
          "Content-Length": "0",
        },
        transformRequest: [
          (_data, headers) => {
            if (headers) {
              delete headers["Content-Type"];
              delete headers["content-type"];
            }
            return _data;
          },
        ],
      }),
    );

    const appToken =
      response.headers.apptoken ||
      response.headers.appToken ||
      response.headers["apptoken"] ||
      response.headers["appToken"];

    if (!appToken) {
      throw new BadGatewayException("Failed to get Fanavaran appToken");
    }

    return appToken;
  }

  private async login(
    appToken: string,
    config: { username: string; password: string },
  ): Promise<string> {
    const response = await firstValueFrom(
      this.httpService.post(this.loginUrl, "", {
        headers: {
          appToken,
          userName: config.username,
          password: config.password,
          "Content-Length": "0",
        },
        transformRequest: [
          (_data, headers) => {
            if (headers) {
              delete headers["Content-Type"];
              delete headers["content-type"];
            }
            return _data;
          },
        ],
      }),
    );

    const authenticationToken =
      response.headers.authenticationtoken ||
      response.headers.authenticationToken ||
      response.headers["authenticationtoken"] ||
      response.headers["authenticationToken"] ||
      response.data?.authenticationtoken ||
      response.data?.authenticationToken ||
      response.data?.authentication_token;

    if (!authenticationToken) {
      throw new BadGatewayException("Failed to get Fanavaran authenticationToken");
    }

    return authenticationToken;
  }

  async fetchFromFanavaran(
    clientKey: FanavaranClientKey,
    url: string,
  ): Promise<unknown> {
    const profile = getFanavaranClientProfile(clientKey);

    try {
      const appToken = await this.getAppToken(profile.auth);
      const authenticationToken = await this.login(appToken, profile.auth);

      this.logger.log(
        `[${clientKey}] Calling Fanavaran lookup API: ${url}`,
      );

      const response = await firstValueFrom(
        this.httpService.get(url, {
          headers: {
            authenticationToken,
            CorpId: profile.auth.corpId,
            ContractId: profile.auth.contractId,
            Location: profile.auth.location,
            "Content-Type": "application/json",
          },
          timeout: 20000,
        }),
      );

      const dataCount = Array.isArray(response.data)
        ? response.data.length
        : typeof response.data === "object" && response.data !== null
          ? Object.keys(response.data).length
          : 0;

      this.logger.log(
        `[${clientKey}] Fanavaran lookup response status=${response.status} dataCount=${dataCount}`,
      );
      this.logger.log(
        `[${clientKey}] Fanavaran lookup raw response: ${JSON.stringify(
          response.data,
          null,
          2,
        )}`,
      );

      if (Array.isArray(response.data) && response.data.length > 0) {
        const firstItem = response.data[0];
        if (firstItem && typeof firstItem === "object") {
          this.logger.log(
            `[${clientKey}] Fanavaran lookup first item keys: ${Object.keys(
              firstItem,
            ).join(", ")}`,
          );
        }
      }

      return response.data;
    } catch (error) {
      const message = isAxiosError(error)
        ? error.response?.data?.Message ||
          error.response?.data?.message ||
          error.message
        : error instanceof Error
          ? error.message
          : "Fanavaran lookup request failed";

      this.logger.error(
        `Fanavaran lookup fetch failed for ${clientKey} (${url}): ${message}`,
      );
      throw new BadGatewayException(String(message));
    }
  }

  async getRemoteLookup(
    clientKey: FanavaranClientKey,
    url: string,
    cacheFile: string,
    fallback?: () => Promise<unknown>,
  ): Promise<unknown> {
    const cached = await this.readCacheFile(clientKey, cacheFile);
    if (cached !== null) {
      return cached;
    }

    try {
      const data = await this.fetchFromFanavaran(clientKey, url);
      await this.writeCacheFile(clientKey, cacheFile, data);
      return data;
    } catch (error) {
      if (fallback) {
        this.logger.warn(
          `Fanavaran lookup fetch failed for ${clientKey}/${cacheFile}; using fallback`,
        );
        const data = await fallback();
        await this.writeCacheFile(clientKey, cacheFile, data);
        return data;
      }
      throw error;
    }
  }

  mapFanavaranAccidentCausesToReasonOptions(
    causes: unknown,
  ): { id: number; label: string; fanavaran: number }[] {
    if (!Array.isArray(causes)) {
      throw new NotFoundException("Fanavaran accident-causes response is invalid");
    }

    return causes
      .filter(
        (item) =>
          item &&
          typeof item === "object" &&
          (item as { IsActive?: number }).IsActive === 1 &&
          typeof (item as { Id?: unknown }).Id === "number",
      )
      .map((item) => {
        const row = item as { Id: number; Caption?: string };
        return {
          id: row.Id,
          label: row.Caption ?? String(row.Id),
          fanavaran: row.Id,
        };
      });
  }
}