import { BadRequestException } from "@nestjs/common";
import { BlameRequestType } from "src/Types&Enums/blame-request-management/blameRequestType.enum";
import { jalaliToGregorianDate } from "src/helpers/date-jalali";
import { gregorianDateInIran } from "src/helpers/iran-datetime";
import {
  InquiryParticipantFieldsDto,
  InquiryParticipantInputDto,
  InquiryParticipantRole,
  InquiryVehicleInputDto,
  VehicleRegistrationState,
} from "src/common/dto/inquiry-participants.dto";

export interface ResolvedInquiryParticipant {
  participantId: string;
  nationalCode: string;
  birthday: string;
  fullName?: string;
  hasDrivingLicense?: boolean;
  licenseNumber?: string;
  licenseType?: string;
}

export interface InquiryParticipantRoleAssignments {
  driver: string;
  vehicleOwner?: string;
  thirdPartyPolicyholder: string;
  carBodyPolicyholder?: string;
}

export interface ResolvedInquiryParticipants {
  participants: ResolvedInquiryParticipant[];
  roles: InquiryParticipantRoleAssignments;
  legacy: boolean;
}

export interface NormalizedInquirySubmission<T extends Record<string, any>> {
  dto: T & {
    nationalCodeOfDriver: string;
    driverBirthday: string;
    driverLicense?: string;
    licenseType?: string;
    userNoCertificate?: boolean;
    nationalCodeOfInsurer: string;
    insurerBirthday: string;
    driverIsInsurer: boolean;
    insurerLicense?: string;
  };
  participants: ResolvedInquiryParticipants;
  driver: ResolvedInquiryParticipant;
  vehicleOwner?: ResolvedInquiryParticipant;
  thirdPartyPolicyholder: ResolvedInquiryParticipant;
  carBodyPolicyholder?: ResolvedInquiryParticipant;
  vehicle?: ResolvedInquiryVehicle;
}

export interface InquirySubjects {
  thirdPartyPolicyNationalCode: string;
  carBodyPolicyNationalCode?: string;
  shebaNationalCode: string;
  driverNationalCode: string;
}

/**
 * The single routing seam for external inquiries. Policy checks belong to
 * their policyholder, Sheba belongs to the vehicle owner, and licence data
 * belongs to the driver even when those roles resolve to different people.
 */
export function resolveInquirySubjects(
  submission: NormalizedInquirySubmission<Record<string, any>>,
): InquirySubjects {
  if (!submission.vehicleOwner) {
    throw new BadRequestException(
      "Vehicle owner identity is required for Sheba validation.",
    );
  }
  return {
    thirdPartyPolicyNationalCode:
      submission.thirdPartyPolicyholder.nationalCode,
    ...(submission.carBodyPolicyholder
      ? {
          carBodyPolicyNationalCode:
            submission.carBodyPolicyholder.nationalCode,
        }
      : {}),
    shebaNationalCode: submission.vehicleOwner.nationalCode,
    driverNationalCode: submission.driver.nationalCode,
  };
}

export type ResolvedInquiryVehicle = InquiryVehicleInputDto & {
  registrationState: VehicleRegistrationState;
};

function assertCompleteInquiryPlate(
  plate: InquiryVehicleInputDto["currentPlate"],
  path: "vehicle.currentPlate" | "vehicle.previousPlate",
): void {
  for (const field of [
    "leftDigits",
    "centerAlphabet",
    "centerDigits",
    "ir",
  ] as const) {
    if (plate?.[field] == null || String(plate[field]).trim() === "") {
      throw new BadRequestException(`${path}.${field} is required.`);
    }
  }
}

export function participantForRole(
  resolved: ResolvedInquiryParticipants,
  role: InquiryParticipantRole,
): ResolvedInquiryParticipant | undefined {
  const roleField = ROLE_FIELDS[
    role
  ] as keyof InquiryParticipantRoleAssignments;
  const participantId = resolved.roles[roleField];
  return resolved.participants.find(
    (participant) => participant.participantId === participantId,
  );
}

/** Resolve a participant from the role links persisted on a blame party. */
export function participantForStoredPartyRole(
  party: {
    participants?: Array<Record<string, any>>;
    participantRoles?: Partial<InquiryParticipantRoleAssignments>;
  },
  role: InquiryParticipantRole,
): Record<string, any> | undefined {
  const roleField = ROLE_FIELDS[
    role
  ] as keyof InquiryParticipantRoleAssignments;
  const participantId = party.participantRoles?.[roleField];
  if (!participantId || !Array.isArray(party.participants)) return undefined;
  return party.participants.find(
    (participant) => participant?.participantId === participantId,
  );
}

/** Remove fields retired from the participant contract from historical records. */
export function sanitizeStoredInquiryParticipants(
  participants: unknown,
): Array<Record<string, any>> | undefined {
  if (!Array.isArray(participants)) return undefined;
  return participants.map((participant) => {
    const plain =
      participant &&
      typeof participant === "object" &&
      typeof (participant as { toObject?: unknown }).toObject === "function"
        ? (participant as { toObject: () => Record<string, any> }).toObject()
        : { ...(participant as Record<string, any>) };
    delete plain.unknown;
    return plain;
  });
}

const ROLE_FIELDS: Record<
  InquiryParticipantRole,
  keyof InquiryParticipantFieldsDto
> = {
  [InquiryParticipantRole.DRIVER]: "driver",
  [InquiryParticipantRole.VEHICLE_OWNER]: "vehicleOwner",
  [InquiryParticipantRole.THIRD_PARTY_POLICYHOLDER]: "thirdPartyPolicyholder",
  [InquiryParticipantRole.CAR_BODY_POLICYHOLDER]: "carBodyPolicyholder",
};

function requiredIdentity(
  role: InquiryParticipantRole,
  input: InquiryParticipantInputDto,
): ResolvedInquiryParticipant {
  if (Object.prototype.hasOwnProperty.call(input, "phoneNumber")) {
    throw new BadRequestException(
      `${role} does not accept phoneNumber; phone numbers are collected separately from inquiry identity.`,
    );
  }
  const nationalCode = String(input.nationalCode ?? "").trim();
  const birthday = String(input.birthday ?? "").trim();
  if (!nationalCode || !birthday) {
    throw new BadRequestException(
      `${role} requires nationalCode and birthday.`,
    );
  }
  if (
    role === InquiryParticipantRole.DRIVER &&
    typeof input.hasDrivingLicense !== "boolean"
  ) {
    throw new BadRequestException("DRIVER requires hasDrivingLicense.");
  }
  if (
    role === InquiryParticipantRole.DRIVER &&
    input.hasDrivingLicense === true &&
    (!String(input.licenseNumber ?? "").trim() ||
      !String(input.licenseType ?? "").trim())
  ) {
    throw new BadRequestException(
      "DRIVER requires licenseNumber and licenseType when hasDrivingLicense is true.",
    );
  }
  return {
    participantId: role,
    nationalCode,
    birthday,
    ...(input.fullName ? { fullName: input.fullName } : {}),
    ...(input.hasDrivingLicense != null
      ? { hasDrivingLicense: input.hasDrivingLicense }
      : {}),
    ...(input.licenseNumber ? { licenseNumber: input.licenseNumber } : {}),
    ...(input.licenseType ? { licenseType: input.licenseType } : {}),
  };
}

export function resolveInquiryParticipants(
  caseType: BlameRequestType,
  input: Partial<InquiryParticipantFieldsDto> & Record<string, any>,
): ResolvedInquiryParticipants {
  assertStructuredInquiryInput(input);
  const hasRoleCompleteInput = Object.values(ROLE_FIELDS).some(
    (field) => input[field] != null,
  );
  if (!hasRoleCompleteInput) {
    throw new BadRequestException(
      "driver, vehicleOwner, and thirdPartyPolicyholder are required in the structured inquiry format.",
    );
  }
  if (
    caseType === BlameRequestType.THIRD_PARTY &&
    input.carBodyPolicyholder != null
  ) {
    throw new BadRequestException(
      "CAR_BODY_POLICYHOLDER is not allowed for a THIRD_PARTY case.",
    );
  }

  const requiredRoles = [
    InquiryParticipantRole.DRIVER,
    InquiryParticipantRole.VEHICLE_OWNER,
    InquiryParticipantRole.THIRD_PARTY_POLICYHOLDER,
    ...(caseType === BlameRequestType.CAR_BODY
      ? [InquiryParticipantRole.CAR_BODY_POLICYHOLDER]
      : []),
  ];
  const participants = new Map<string, ResolvedInquiryParticipant>();
  const resolvedRoleIds = new Map<InquiryParticipantRole, string>();
  const resolving = new Set<InquiryParticipantRole>();

  const resolveRole = (role: InquiryParticipantRole): string => {
    const existing = resolvedRoleIds.get(role);
    if (existing) return existing;
    if (resolving.has(role)) {
      throw new BadRequestException(
        "Participant sameAs references cannot be circular.",
      );
    }
    const value = input[ROLE_FIELDS[role]] as
      | InquiryParticipantInputDto
      | undefined;
    if (!value) throw new BadRequestException(`${role} is required.`);

    resolving.add(role);
    let participantId: string;
    if (Object.prototype.hasOwnProperty.call(value, "unknown")) {
      throw new BadRequestException(
        `${role} does not support the unknown option.`,
      );
    } else if (value.sameAs) {
      const hasPersonSpecificFields = Object.entries(value).some(
        ([field, fieldValue]) => field !== "sameAs" && fieldValue != null,
      );
      if (hasPersonSpecificFields) {
        throw new BadRequestException(
          `${role} must contain either sameAs or identity fields, not both.`,
        );
      }
      participantId = resolveRole(value.sameAs);
    } else {
      const participant = requiredIdentity(role, value);
      const duplicate = [...participants.values()].find(
        (item) => item.nationalCode === participant.nationalCode,
      );
      if (duplicate) {
        throw new BadRequestException(
          `${role} duplicates an existing nationalCode; use sameAs instead.`,
        );
      }
      participants.set(participant.participantId, participant);
      participantId = participant.participantId;
    }
    resolving.delete(role);
    resolvedRoleIds.set(role, participantId);
    return participantId;
  };

  for (const role of requiredRoles) resolveRole(role);

  return {
    participants: [...participants.values()],
    roles: {
      driver: resolvedRoleIds.get(InquiryParticipantRole.DRIVER)!,
      vehicleOwner: resolvedRoleIds.get(InquiryParticipantRole.VEHICLE_OWNER)!,
      thirdPartyPolicyholder: resolvedRoleIds.get(
        InquiryParticipantRole.THIRD_PARTY_POLICYHOLDER,
      )!,
      ...(caseType === BlameRequestType.CAR_BODY
        ? {
            carBodyPolicyholder: resolvedRoleIds.get(
              InquiryParticipantRole.CAR_BODY_POLICYHOLDER,
            )!,
          }
        : {}),
    },
    legacy: false,
  };
}

export function resolveInquiryVehicle(
  input: InquiryVehicleInputDto,
): ResolvedInquiryVehicle {
  if (!input) {
    throw new BadRequestException("vehicle is required.");
  }
  const registrationState =
    input.registrationState ?? VehicleRegistrationState.CURRENT;
  if (!Object.values(VehicleRegistrationState).includes(registrationState)) {
    throw new BadRequestException(
      "vehicle.registrationState must be CURRENT or RECENTLY_TRANSFERRED.",
    );
  }
  if (input.isNewCar != null && typeof input.isNewCar !== "boolean") {
    throw new BadRequestException("vehicle.isNewCar must be a boolean.");
  }
  const previousPolicyholderNationalCode = String(
    input.previousPolicyholderNationalCode ?? "",
  ).trim();
  if (!input.currentPlate) {
    throw new BadRequestException("vehicle.currentPlate is required.");
  }
  assertCompleteInquiryPlate(input.currentPlate, "vehicle.currentPlate");
  const vin = String(input.vin ?? "").trim();
  if (vin && vin.length !== 17) {
    throw new BadRequestException(
      "vehicle.vin must contain exactly 17 characters.",
    );
  }
  if (
    registrationState === VehicleRegistrationState.RECENTLY_TRANSFERRED &&
    (!input.previousPlate || !vin || !previousPolicyholderNationalCode)
  ) {
    throw new BadRequestException(
      "RECENTLY_TRANSFERRED requires previousPlate, vin, and previousPolicyholderNationalCode.",
    );
  }
  if (
    registrationState !== VehicleRegistrationState.RECENTLY_TRANSFERRED &&
    (input.previousPlate || input.previousPolicyholderNationalCode != null)
  ) {
    throw new BadRequestException(
      "previousPlate and previousPolicyholderNationalCode are only allowed for RECENTLY_TRANSFERRED vehicles.",
    );
  }
  if (input.previousPlate) {
    assertCompleteInquiryPlate(input.previousPlate, "vehicle.previousPlate");
  }
  return {
    ...input,
    registrationState,
    ...(vin ? { vin } : {}),
    ...(previousPolicyholderNationalCode
      ? { previousPolicyholderNationalCode }
      : {}),
  };
}

export function vehiclePlateCandidates(input?: ResolvedInquiryVehicle): Array<{
  kind: "CURRENT" | "PREVIOUS";
  plate: InquiryVehicleInputDto["currentPlate"];
}> {
  if (!input) return [];
  return [
    { kind: "CURRENT" as const, plate: input.currentPlate },
    ...(input.registrationState ===
      VehicleRegistrationState.RECENTLY_TRANSFERRED && input.previousPlate
      ? [{ kind: "PREVIOUS" as const, plate: input.previousPlate }]
      : []),
  ];
}

function normalizeVehicleSerial(value: unknown): string {
  return String(value ?? "")
    .toUpperCase()
    .replace(/[^A-Z0-9]/g, "");
}

/** A dated result is usable only while the returned policy has not expired. */
export function isMappedPolicyCurrent(
  mapped: Record<string, any>,
  todayGregorian: string = gregorianDateInIran(new Date()),
): boolean {
  const rawEndDate =
    mapped?.EndDate ??
    mapped?.HEndDte ??
    mapped?.persianEndDate ??
    mapped?.PolicyEndDate ??
    mapped?.endDate;
  if (rawEndDate == null || String(rawEndDate).trim() === "") return true;
  const endDate = jalaliToGregorianDate(rawEndDate);
  return endDate != null && endDate >= todayGregorian;
}

function normalizePlateForComparison(
  plate: InquiryVehicleInputDto["currentPlate"],
): string {
  return [
    plate?.ir,
    plate?.leftDigits,
    plate?.centerAlphabet,
    plate?.centerDigits,
  ]
    .map((part) => String(part ?? "").trim())
    .join("|");
}

const LEGACY_INQUIRY_FIELDS = [
  "nationalCodeOfDriver",
  "driverBirthday",
  "driverLicense",
  "licenseType",
  "nationalCodeOfInsurer",
  "insurerBirthday",
  "insurerLicense",
  "driverIsInsurer",
  "userNoCertificate",
  "plate",
  "plateId",
  "vin",
  "isNewCar",
] as const;

function assertStructuredInquiryInput(input: Record<string, any>): void {
  const legacyFields = LEGACY_INQUIRY_FIELDS.filter((field) =>
    Object.prototype.hasOwnProperty.call(input, field),
  );
  if (legacyFields.length > 0) {
    throw new BadRequestException(
      `Legacy inquiry fields are not accepted: ${legacyFields.join(", ")}. Use driver, vehicleOwner, thirdPartyPolicyholder, carBodyPolicyholder, and vehicle.`,
    );
  }
}

export function assertPreviousPlateInquiryMatchesVin(
  expectedVin: string,
  mapped: Record<string, any>,
): void {
  const expected = normalizeVehicleSerial(expectedVin);
  const candidates = [
    mapped?.VinNumberField,
    mapped?.vin,
    mapped?.VIN,
    mapped?.ChassisNumberField,
    mapped?.chassisNumber,
    mapped?.ChassisNo,
    mapped?.vehicle?.VIN,
    mapped?.vehicle?.ChassisNo,
  ]
    .map(normalizeVehicleSerial)
    .filter(Boolean);
  if (!expected || !candidates.includes(expected)) {
    throw new BadRequestException(
      "Previous-plate inquiry does not match the submitted VIN/chassis; manual review is required.",
    );
  }
}

export function isPolicyNotFoundError(error: unknown): boolean {
  const candidate = error as Record<string, any> | null;
  const status = candidate?.status ?? candidate?.response?.status;
  if (Number(status) === 404) return true;
  const code = String(
    candidate?.code ?? candidate?.response?.data?.code ?? "",
  ).toUpperCase();
  if (["NOT_FOUND", "POLICY_NOT_FOUND", "NO_POLICY"].includes(code)) {
    return true;
  }
  const message = String(
    candidate?.message ?? candidate?.response?.data?.message ?? error ?? "",
  );
  return /\bnot[ -]?found\b|\bno (?:relevant )?policy\b|یافت نشد|فاقد بیمه(?:نامه)?/i.test(
    message,
  );
}

export async function runPlateInquiryWithFallback<T>(options: {
  vehicle?: ResolvedInquiryVehicle;
  fallbackCurrentPlate: InquiryVehicleInputDto["currentPlate"];
  query: (
    plate: InquiryVehicleInputDto["currentPlate"],
    plateKind: "CURRENT" | "PREVIOUS",
  ) => Promise<T>;
  isUsable: (value: T) => boolean;
  mappedValue: (value: T) => Record<string, any>;
  shouldFallbackOnError?: (error: unknown) => boolean;
}): Promise<{
  value: T;
  plateKind: "CURRENT" | "PREVIOUS";
  attempts: Array<{
    plateKind: "CURRENT" | "PREVIOUS";
    plate: InquiryVehicleInputDto["currentPlate"];
    vin?: string;
    succeeded: boolean;
    usable?: boolean;
    error?: string;
  }>;
}> {
  const candidates = options.vehicle
    ? vehiclePlateCandidates(options.vehicle)
    : [{ kind: "CURRENT" as const, plate: options.fallbackCurrentPlate }];
  let lastError: unknown;
  const attempts: Array<{
    plateKind: "CURRENT" | "PREVIOUS";
    plate: InquiryVehicleInputDto["currentPlate"];
    vin?: string;
    succeeded: boolean;
    usable?: boolean;
    error?: string;
  }> = [];

  for (let index = 0; index < candidates.length; index += 1) {
    const candidate = candidates[index];
    const isLast = index === candidates.length - 1;
    try {
      const value = await options.query(candidate.plate, candidate.kind);
      const usable = options.isUsable(value);
      if (!usable) {
        attempts.push({
          plateKind: candidate.kind,
          plate: candidate.plate,
          ...(options.vehicle?.vin ? { vin: options.vehicle.vin } : {}),
          succeeded: true,
          usable: false,
        });
        if (!isLast) continue;
        const error = new BadRequestException(
          "No current usable policy was found for the submitted vehicle identifiers.",
        ) as BadRequestException & { attempts?: typeof attempts };
        error.attempts = attempts;
        throw error;
      }
      if (candidate.kind === "PREVIOUS" && usable) {
        assertPreviousPlateInquiryMatchesVin(
          options.vehicle!.vin!,
          options.mappedValue(value),
        );
      }
      attempts.push({
        plateKind: candidate.kind,
        plate: candidate.plate,
        ...(options.vehicle?.vin ? { vin: options.vehicle.vin } : {}),
        succeeded: true,
        usable: true,
      });
      return { value, plateKind: candidate.kind, attempts };
    } catch (error) {
      lastError = error;
      const alreadyRecorded =
        typeof error === "object" &&
        error != null &&
        Array.isArray((error as { attempts?: unknown }).attempts);
      if (!alreadyRecorded) {
        attempts.push({
          plateKind: candidate.kind,
          plate: candidate.plate,
          ...(options.vehicle?.vin ? { vin: options.vehicle.vin } : {}),
          succeeded: false,
          error: error instanceof Error ? error.message : String(error),
        });
      }
      if (
        !isLast &&
        !(options.shouldFallbackOnError ?? isPolicyNotFoundError)(error)
      ) {
        if (typeof error === "object" && error != null) {
          (error as { attempts?: typeof attempts }).attempts = attempts;
        }
        throw error;
      }
      if (isLast) {
        if (typeof error === "object" && error != null) {
          (error as { attempts?: typeof attempts }).attempts = attempts;
        }
        throw error;
      }
    }
  }

  throw lastError ?? new BadRequestException("Inquiry failed for all plates.");
}

export function normalizeInquirySubmission<T extends Record<string, any>>(
  caseType: BlameRequestType,
  input: T,
): NormalizedInquirySubmission<T> {
  const participants = resolveInquiryParticipants(caseType, input as any);
  const driver = participantForRole(
    participants,
    InquiryParticipantRole.DRIVER,
  );
  const thirdPartyPolicyholder = participantForRole(
    participants,
    InquiryParticipantRole.THIRD_PARTY_POLICYHOLDER,
  );
  if (!driver || !thirdPartyPolicyholder) {
    throw new BadRequestException(
      "Driver and third-party policyholder identities are required.",
    );
  }
  const vehicleOwner = participantForRole(
    participants,
    InquiryParticipantRole.VEHICLE_OWNER,
  );
  const carBodyPolicyholder = participantForRole(
    participants,
    InquiryParticipantRole.CAR_BODY_POLICYHOLDER,
  );
  const vehicle = resolveInquiryVehicle(
    input.vehicle as InquiryVehicleInputDto,
  );
  const sameDriverAndPolicyholder =
    participants.roles.driver === participants.roles.thirdPartyPolicyholder;

  return {
    dto: {
      ...input,
      plate: vehicle.currentPlate,
      vin: vehicle.vin,
      nationalCodeOfDriver: driver.nationalCode,
      driverBirthday: driver.birthday,
      driverLicense: driver.licenseNumber,
      licenseType: driver.licenseType,
      userNoCertificate:
        driver.hasDrivingLicense == null
          ? undefined
          : !driver.hasDrivingLicense,
      nationalCodeOfInsurer: thirdPartyPolicyholder.nationalCode,
      insurerBirthday: thirdPartyPolicyholder.birthday,
      driverIsInsurer: sameDriverAndPolicyholder,
      insurerLicense: sameDriverAndPolicyholder
        ? driver.licenseNumber
        : undefined,
      isNewCar: vehicle.isNewCar,
    } as NormalizedInquirySubmission<T>["dto"],
    participants,
    driver,
    vehicleOwner,
    thirdPartyPolicyholder,
    carBodyPolicyholder,
    vehicle,
  };
}