import { BadRequestException, ForbiddenException } from "@nestjs/common";

/** Insurance company tenant id on the actor JWT (Mongo ObjectId string). */
export function requireActorClientKey(actor: { clientKey?: string }): string {
  const ck = actor?.clientKey;
  if (!ck || typeof ck !== "string") {
    throw new BadRequestException(
      "Client scope is missing for this account. Insurer/expert users must be bound to an insurance company.",
    );
  }
  return ck;
}

export function blameCaseTouchesClient(doc: any, clientKey: string): boolean {
  const id = String(clientKey);

  // CAR_BODY: single party, always the first party's clientId
  if (doc?.type === "CAR_BODY") {
    const firstParty = (doc?.parties ?? []).find(
      (p: any) => p?.role === "FIRST",
    );
    return String(firstParty?.person?.clientId ?? "") === id;
  }

  // THIRD_PARTY: only the guilty party's insurer sees this file
  const guiltyClientId = resolveGuiltyPartyClientId(doc);
  if (guiltyClientId) {
    return guiltyClientId === id;
  }

  // Fallback when guilt cannot be resolved yet — show to any party's insurer
  // This should be rare since guilt is always known upfront in your system
  return (doc?.parties ?? []).some(
    (p: any) => String(p?.person?.clientId ?? "") === id,
  );
}

export function claimCaseTouchesClient(doc: any, clientKey: string): boolean {
  const id = String(clientKey);
  const owner = doc?.owner as
    | { clientId?: unknown; userClientKey?: unknown }
    | undefined;
  const tenantId = owner?.clientId ?? owner?.userClientKey;
  return String(tenantId ?? "") === id;
}

export function blameCaseAccessibleToExpert(
  doc: any,
  actor: { sub: string; clientKey?: string },
): boolean {
  // Expert-initiated cases: only the initiating expert sees them
  if (
    doc.expertInitiated &&
    doc.initiatedByFieldExpertId &&
    String(doc.initiatedByFieldExpertId) === actor.sub
  ) {
    return true;
  }

  const ck = actor?.clientKey;
  if (!ck) return false;

  // Uses the updated blameCaseTouchesClient — guilty party's clientId only
  return blameCaseTouchesClient(doc, ck);
}

export function assertBlameCaseForExpertTenant(
  doc: any,
  actor: { sub: string; clientKey?: string },
): void {
  if (!blameCaseAccessibleToExpert(doc, actor)) {
    throw new ForbiddenException(
      "This blame case does not belong to your organization.",
    );
  }
}

export function assertClaimCaseForTenant(
  doc: any,
  actor: { clientKey?: string },
): void {
  const ck = requireActorClientKey(actor);
  if (!claimCaseTouchesClient(doc, ck)) {
    throw new ForbiddenException(
      "This claim does not belong to your organization.",
    );
  }
}

export function resolveGuiltyPartyClientId(doc: any): string | null {
  const parties: any[] = doc?.parties ?? [];

  // Phase 1: expert decision exists — use it
  const guiltyUserId = doc?.expert?.decision?.guiltyPartyId
    ? String(doc.expert.decision.guiltyPartyId)
    : null;

  if (guiltyUserId) {
    const guiltyParty = parties.find(
      (p) => String(p?.person?.userId ?? "") === guiltyUserId,
    );
    return String(guiltyParty?.person?.clientId ?? "") || null;
  }

  // Phase 2: no expert decision yet — use party self-statements
  // The party who admitsGuilt=true is the guilty one
  const guiltyByStatement = parties.find(
    (p) => p?.statement?.admitsGuilt === true,
  );
  if (guiltyByStatement) {
    return String(guiltyByStatement?.person?.clientId ?? "") || null;
  }

  // Phase 3: fallback — use blameStatus field if set
  // AGREED means first party admitted guilt (convention in your system)
  if (doc?.blameStatus === "AGREED") {
    const firstParty = parties.find((p) => p?.role === "FIRST");
    return String(firstParty?.person?.clientId ?? "") || null;
  }

  return null;
}