import {
  BadRequestException,
  Injectable,
  Logger,
  NotFoundException,
} from "@nestjs/common";
import {
  resolveFanavaranClientKey,
  resolveFanavaranProductContractId,
} from "src/core/config/fanavaran-client.config";
import {
  FANAVARAN_REMOTE_LOOKUPS,
  type FanavaranRemoteLookupDefinition,
  TEJARAT_STATIC_ACCIDENT_FILES,
} from "src/fanavaran/fanavaran-lookup.config";
import { FanavaranLookupService } from "src/fanavaran/fanavaran-lookup.service";
import { LookupDbService } from "./entities/db-service/lookup.db.service";
import {
  asObjectRecord,
  filterPoliciesByLine,
  insuranceLineIdForProduct,
  parseFanavaranId,
  parseLastCarPolicyInput,
  pickVehicleId,
  selectLastAmongCarMatches,
  sortPoliciesNewestEndDateFirst,
  vehicleMatchesCar,
  type FanavaranCarPolicyProduct,
  type HydratedFanavaranCarPolicy,
} from "./fanavaran-last-car-policy";

type TejaratAccidentReasonRow = {
  id: number;
  persianLabel: string;
  fanavaranID: number;
};

type TejaratAccidentLabelRow = {
  id: number;
  persianLabel: string;
};

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

  constructor(
    private readonly lookupDbService: LookupDbService,
    private readonly fanavaranLookupService: FanavaranLookupService,
  ) {}

  private activeClientKey() {
    return resolveFanavaranClientKey();
  }

  listFanavaranRemoteLookups(): FanavaranRemoteLookupDefinition[] {
    return FANAVARAN_REMOTE_LOOKUPS;
  }

  private findRemoteLookup(name: string) {
    const lookup = FANAVARAN_REMOTE_LOOKUPS.find((item) => item.name === name);
    if (!lookup) {
      throw new NotFoundException(`Unknown Fanavaran remote lookup: ${name}`);
    }
    return lookup;
  }

  /**
   * Returns stored `response` for a lookup document by `name` in the lookups collection.
   * Legacy Tejarat seed data — used as fallback when live fetch is unavailable.
   */
  async getLookup(lookupName: string): Promise<any> {
    const doc = await this.lookupDbService.findOne({ name: lookupName });
    if (!doc) {
      this.logger.warn(`Lookup not found in database: ${lookupName}`);
      throw new NotFoundException(`Lookup "${lookupName}" not found`);
    }
    return doc.response;
  }

  async getClientRemoteLookup(lookupName: string): Promise<unknown> {
    const clientKey = this.activeClientKey();
    const definition = this.findRemoteLookup(lookupName);

    // Parsian: file → lookups collection → Fanavaran (default inside FanavaranLookupService)
    // Tejaratno: file → Fanavaran → DB on API failure
    return this.fanavaranLookupService.getRemoteLookup(
      clientKey,
      definition.url,
      definition.cacheFile,
      clientKey === "tejaratno"
        ? { dbSource: () => this.getLookup(lookupName) }
        : undefined,
    );
  }

  async getAccidentCauses(): Promise<any> {
    return await this.getClientRemoteLookup("accident-causes");
  }

  async getAccidentReportType(): Promise<any> {
    return await this.getClientRemoteLookup("accident-report-type");
  }

  async getVehicleUseTypes(): Promise<any> {
    return await this.getClientRemoteLookup("vehicle-use-types");
  }

  async getDmgPayMethod(): Promise<any> {
    return await this.getClientRemoteLookup("dmg-pay-method");
  }

  async getDrivingLicenceTypes(): Promise<any> {
    return await this.getClientRemoteLookup("driving-licence-types");
  }

  async getAccidentCulpritType(): Promise<any> {
    return await this.getClientRemoteLookup("accident-culprit-type");
  }

  async getInspectionPlace(): Promise<any> {
    return await this.getClientRemoteLookup("inspection-place");
  }

  async getDropAmountStatus(): Promise<any> {
    return await this.getClientRemoteLookup("drop-amount-status");
  }

  async getCarComponents(): Promise<any> {
    return await this.getClientRemoteLookup("car-components");
  }

  async getAccidentLevel(): Promise<any> {
    return await this.getClientRemoteLookup("accident-level");
  }

  async getExpertStatus(): Promise<any> {
    return await this.getClientRemoteLookup("expert-status");
  }

  async getVehicleKinds(): Promise<any> {
    return await this.getClientRemoteLookup("vehicle-kinds");
  }

  async getPersonRole(): Promise<any> {
    return await this.getClientRemoteLookup("person-role");
  }

  async getFileTypes(): Promise<any> {
    return await this.getClientRemoteLookup("file-types");
  }

  async getCities(): Promise<any> {
    return await this.getClientRemoteLookup("cities");
  }

  async getProvinces(): Promise<any> {
    return await this.getClientRemoteLookup("provinces");
  }

  async getDmgCaseType(): Promise<any> {
    return await this.getClientRemoteLookup("dmg-case-type");
  }

  async getDmgHistoryStatus(): Promise<any> {
    return await this.getClientRemoteLookup("dmg-history-status");
  }

  async getUsedPlace(): Promise<any> {
    return await this.getClientRemoteLookup("used-place");
  }

  async getDmgBusinessLine(): Promise<any> {
    return await this.getClientRemoteLookup("dmg-business-line");
  }

  async inquiryByVin(vin: string): Promise<unknown> {
    const clientKey = this.activeClientKey();
    return this.fanavaranLookupService.inquiryByVin(clientKey, vin);
  }

  async myPolicies(
    nationalCode: string,
    insuranceLineId: number = 5,
  ): Promise<unknown> {
    const clientKey = this.activeClientKey();
    return this.fanavaranLookupService.myPolicies(
      clientKey,
      nationalCode,
      insuranceLineId,
    );
  }

  async findLastProcessedCarPolicy(
    product: FanavaranCarPolicyProduct,
    query: {
      nationalCode?: string;
      vin?: string;
      plaqueLeft?: string;
      plaqueLetter?: string;
      plaqueRight?: string;
      plaqueSerial?: string;
    },
  ): Promise<{
    product: FanavaranCarPolicyProduct;
    insuranceLineId: number;
    policyId: number;
    policy: any;
    vehicle: Record<string, unknown> | null;
  }> {
    const parsed = parseLastCarPolicyInput(query);
    if ("error" in parsed) {
      throw new BadRequestException(parsed.error);
    }

    const clientKey = this.activeClientKey();
    const insuranceLineId = insuranceLineIdForProduct(product);
    const contractIdOverride = resolveFanavaranProductContractId(
      clientKey,
      product,
    );
    const requestOptions = { contractIdOverride };

    const listed = await this.fanavaranLookupService.myPolicies(
      clientKey,
      parsed.nationalCode,
      insuranceLineId,
      requestOptions,
    );
    const candidates = sortPoliciesNewestEndDateFirst(
      filterPoliciesByLine(listed, insuranceLineId),
    );

    let vinVehicleId: number | null = null;
    if (parsed.vin) {
      try {
        const inquired = await this.fanavaranLookupService.inquiryByVin(
          clientKey,
          parsed.vin,
          requestOptions,
        );
        vinVehicleId = pickVehicleId(inquired);
      } catch (error) {
        this.logger.warn(
          `VIN vehicle helper failed; continuing with policy hydrate: ${
            error instanceof Error ? error.message : error
          }`,
        );
      }
    }

    const matches: HydratedFanavaranCarPolicy[] = [];
    let hydrationFailures = 0;

    for (const row of candidates) {
      const policyId = parseFanavaranId(row.PolicyId);
      if (policyId === null) continue;

      let policyRaw: unknown;
      try {
        policyRaw =
          product === "car-body"
            ? await this.fanavaranLookupService.bodyPolicyById(
                clientKey,
                policyId,
                requestOptions,
              )
            : await this.fanavaranLookupService.thirdPartyPolicyById(
                clientKey,
                policyId,
                requestOptions,
              );
      } catch (error) {
        hydrationFailures += 1;
        this.logger.warn(
          `Policy GET failed for PolicyId=${policyId}: ${
            error instanceof Error ? error.message : error
          }`,
        );
        continue;
      }

      const policy = asObjectRecord(policyRaw);
      if (!policy) continue;

      const vehicleId = pickVehicleId(policy.VehicleId ?? policy.vehicleId);
      if (
        parsed.vin &&
        vinVehicleId !== null &&
        vehicleId !== null &&
        vehicleId !== vinVehicleId
      ) {
        continue;
      }

      let vehicle: Record<string, unknown> | null = null;
      if (vehicleId !== null) {
        try {
          vehicle = asObjectRecord(
            await this.fanavaranLookupService.vehicleById(
              clientKey,
              vehicleId,
              undefined,
              requestOptions,
            ),
          );
        } catch (error) {
          this.logger.warn(
            `Vehicle GET failed for VehicleId=${vehicleId} (PolicyId=${policyId}): ${
              error instanceof Error ? error.message : error
            }`,
          );
        }
      }

      const matchedByVinVehicleId =
        parsed.vin != null &&
        vinVehicleId != null &&
        vehicleId != null &&
        vinVehicleId === vehicleId;

      if (
        !matchedByVinVehicleId &&
        !vehicleMatchesCar(vehicle, parsed, vinVehicleId)
      ) {
        continue;
      }

      matches.push({
        policyId,
        beginDate: policy.BeginDate ?? row.BeginDate,
        endDate: policy.EndDate ?? row.EndDate,
        vehicleId,
        policy,
        vehicle,
      });
    }

    const selected = selectLastAmongCarMatches(matches);
    if (!selected) {
      if (candidates.length === 0) {
        throw new NotFoundException(
          `No Fanavaran ${product} policy was found for this national code and car.`,
        );
      }
      if (hydrationFailures === candidates.length) {
        throw new NotFoundException(
          `Fanavaran ${product} policy details could not be loaded for this national code.`,
        );
      }
      throw new NotFoundException(
        `No Fanavaran ${product} policy of that line was found for this car.`,
      );
    }

    return {
      product,
      insuranceLineId,
      policyId: selected.policyId,
      policy: await this.mapPolicyDetails(selected.policy),
      vehicle: selected.vehicle,
    };
  }

  async mapPolicyDetails(policy: any): Promise<any> {
    if (!policy || typeof policy !== "object") {
      return policy;
    }

    const mappedPolicy = { ...policy };

    // 1. Map PreviousInsuranceCorpId and TransferorInsuranceCorpId
    try {
      const companies = (await this.getClientRemoteLookup("insurance-corp")) as any[];
      if (Array.isArray(companies)) {
        if (typeof policy.PreviousInsuranceCorpId === "number") {
          const match = companies.find((c) => c.Id === policy.PreviousInsuranceCorpId);
          if (match) {
            mappedPolicy.PreviousInsuranceCorpName = match.Caption;
          }
        }
        if (typeof policy.TransferorInsuranceCorpId === "number") {
          const match = companies.find((c) => c.Id === policy.TransferorInsuranceCorpId);
          if (match) {
            mappedPolicy.TransferorInsuranceCorpName = match.Caption;
          }
        }
      }
    } catch (e) {
      this.logger.warn(`Failed to map insurance-corp lookups: ${e.message}`);
    }

    // 2. Map PolicyUsageTypeId
    try {
      const useTypes = (await this.getClientRemoteLookup("vehicle-use-types")) as any[];
      if (Array.isArray(useTypes) && typeof policy.PolicyUsageTypeId === "number") {
        const match = useTypes.find((t) => t.Id === policy.PolicyUsageTypeId);
        if (match) {
          mappedPolicy.PolicyUsageTypeName = match.Caption;
        }
      }
    } catch (e) {
      this.logger.warn(`Failed to map vehicle-use-types lookups: ${e.message}`);
    }

    return mappedPolicy;
  }

  async thirdPartyPolicyById(policyId: number): Promise<unknown> {
    const clientKey = this.activeClientKey();
    const policy = await this.fanavaranLookupService.thirdPartyPolicyById(clientKey, policyId);
    return this.mapPolicyDetails(policy);
  }

  async bodyPolicyById(policyId: number): Promise<unknown> {
    const clientKey = this.activeClientKey();
    const policy = await this.fanavaranLookupService.bodyPolicyById(
      clientKey,
      policyId,
      {
        contractIdOverride: resolveFanavaranProductContractId(
          clientKey,
          "car-body",
        ),
      },
    );
    return this.mapPolicyDetails(policy);
  }

  async vehicleById(vehicleId: number, versionNo?: number): Promise<unknown> {
    const clientKey = this.activeClientKey();
    return this.fanavaranLookupService.vehicleById(
      clientKey,
      vehicleId,
      versionNo,
    );
  }

  async customerById(customerId: number): Promise<unknown> {
    const clientKey = this.activeClientKey();
    return this.fanavaranLookupService.customerById(clientKey, customerId);
  }

  async getAccidentWay(): Promise<{ id: number; label: string }[]> {
    const clientKey = this.activeClientKey();
    const fileName = TEJARAT_STATIC_ACCIDENT_FILES.accidentWay;

    const cached = await this.fanavaranLookupService.readCacheFile<
      TejaratAccidentLabelRow[]
    >(clientKey, fileName);
    const raw =
      cached ??
      (clientKey === "tejaratno"
        ? await this.fanavaranLookupService.readTejaratStaticAccidentFile<
            TejaratAccidentLabelRow[]
          >(fileName)
        : null);

    if (!raw) {
      this.logger.warn(
        `No accident-way lookup for client ${clientKey}; falling back to tejarat static file`,
      );
      const fallback =
        await this.fanavaranLookupService.readTejaratStaticAccidentFile<
          TejaratAccidentLabelRow[]
        >(fileName);
      return fallback.map((item) => ({
        id: item.id,
        label: item.persianLabel,
      }));
    }

    return raw.map((item) => ({ id: item.id, label: item.persianLabel }));
  }

  async getAccidentReason(): Promise<
    { id: number; label: string; fanavaran: number }[]
  > {
    const clientKey = this.activeClientKey();

    if (clientKey === "parsian") {
      const cacheFile = "accident-reason-options.json";
      const cached = await this.fanavaranLookupService.readCacheFile<
        { id: number; label: string; fanavaran: number }[]
      >(clientKey, cacheFile);
      if (cached) {
        return cached;
      }

      const causes = await this.getAccidentCauses();
      const mapped =
        this.fanavaranLookupService.mapFanavaranAccidentCausesToReasonOptions(
          causes,
        );
      await this.fanavaranLookupService.writeCacheFile(
        clientKey,
        cacheFile,
        mapped,
      );
      return mapped;
    }

    const fileName = TEJARAT_STATIC_ACCIDENT_FILES.accidentReason;
    const cached = await this.fanavaranLookupService.readCacheFile<
      TejaratAccidentReasonRow[]
    >(clientKey, fileName);
    const raw =
      cached ??
      (await this.fanavaranLookupService.readTejaratStaticAccidentFile<
        TejaratAccidentReasonRow[]
      >(fileName));

    return raw.map((item) => ({
      id: item.id,
      label: item.persianLabel,
      fanavaran: item.fanavaranID,
    }));
  }

  async getAccidentType(): Promise<{ id: number; label: string }[]> {
    const clientKey = this.activeClientKey();
    const fileName = TEJARAT_STATIC_ACCIDENT_FILES.accidentType;

    const cached = await this.fanavaranLookupService.readCacheFile<
      TejaratAccidentLabelRow[]
    >(clientKey, fileName);
    const raw =
      cached ??
      (clientKey === "tejaratno"
        ? await this.fanavaranLookupService.readTejaratStaticAccidentFile<
            TejaratAccidentLabelRow[]
          >(fileName)
        : null);

    if (!raw) {
      this.logger.warn(
        `No accident-type lookup for client ${clientKey}; falling back to tejarat static file`,
      );
      const fallback =
        await this.fanavaranLookupService.readTejaratStaticAccidentFile<
          TejaratAccidentLabelRow[]
        >(fileName);
      return fallback.map((item) => ({
        id: item.id,
        label: item.persianLabel,
      }));
    }

    return raw.map((item) => ({ id: item.id, label: item.persianLabel }));
  }

  async getAccidentFields(): Promise<{
    accidentWay: { id: number; label: string }[];
    accidentReason: { id: number; label: string; fanavaran: number }[];
    accidentType: { id: number; label: string }[];
    client: string;
  }> {
    const [accidentWay, accidentReason, accidentType] = await Promise.all([
      this.getAccidentWay(),
      this.getAccidentReason(),
      this.getAccidentType(),
    ]);
    return {
      client: this.activeClientKey(),
      accidentWay,
      accidentReason,
      accidentType,
    };
  }
}