import type { AssistantMessageRequestPayload } from "../types/assistant";
import type { NormalizeRequestPayload, NormalizeResponsePayload } from "../types/normalizer";
import type { InvestigationStateWithProblemUnits } from "../types/stage2ProblemUnits";
import type { AssistantFollowupUsage } from "./assistantFollowupUsage";
import { toRouteHintSummary } from "./routeHintAdapter";

export interface AssistantDeepTurnFollowupBinding {
  normalizedQuestion: string;
  mergedContext: NormalizeRequestPayload["context"] | undefined;
  usage: AssistantFollowupUsage | null;
}

export interface BuildAssistantDeepTurnNormalizationRuntimeInput {
  userMessage: string;
  payload: AssistantMessageRequestPayload;
  featureInvestigationStateV1: boolean;
  featureStateFollowupBindingV1: boolean;
  sessionInvestigationState: InvestigationStateWithProblemUnits | null | undefined;
  buildFollowupStateBinding: (input: {
    userMessage: string;
    payloadContext: NormalizeRequestPayload["context"] | undefined;
    investigationState: InvestigationStateWithProblemUnits;
  }) => AssistantDeepTurnFollowupBinding;
  normalize: (payload: NormalizeRequestPayload) => Promise<NormalizeResponsePayload>;
}

export interface BuildAssistantDeepTurnNormalizationRuntimeOutput {
  followupBinding: AssistantDeepTurnFollowupBinding;
  normalizePayload: NormalizeRequestPayload;
  normalized: NormalizeResponsePayload;
}

function resolveDeepTurnNormalizerPromptVersion(promptVersion: NormalizeRequestPayload["promptVersion"]): string {
  const normalized = String(promptVersion ?? "").trim().toLowerCase();
  if (
    normalized === "normalizer_v2_0_2" ||
    normalized === "normalizer_v2_0_1" ||
    normalized === "normalizer_v2" ||
    normalized === "normalizer_v1"
  ) {
    return String(promptVersion);
  }
  return "normalizer_v2_0_2";
}

function canSynthesizeRouteSummary(normalized: NormalizeResponsePayload["normalized"]): boolean {
  if (!normalized || typeof normalized !== "object") {
    return false;
  }
  const source = normalized as unknown as Record<string, unknown>;
  return Array.isArray(source.fragments);
}

export async function buildAssistantDeepTurnNormalizationRuntime(
  input: BuildAssistantDeepTurnNormalizationRuntimeInput
): Promise<BuildAssistantDeepTurnNormalizationRuntimeOutput> {
  const investigationState = input.sessionInvestigationState;
  const canUseFollowupBinding =
    input.featureInvestigationStateV1 &&
    input.featureStateFollowupBindingV1 &&
    investigationState !== null &&
    investigationState !== undefined;
  const followupBinding =
    canUseFollowupBinding
      ? input.buildFollowupStateBinding({
          userMessage: input.userMessage,
          payloadContext: input.payload.context,
          investigationState
        })
      : {
          normalizedQuestion: input.userMessage,
          mergedContext: input.payload.context,
          usage: null
        };

  const normalizePayload: NormalizeRequestPayload = {
    llmProvider: input.payload.llmProvider,
    apiKey: input.payload.apiKey,
    model: input.payload.model,
    baseUrl: input.payload.baseUrl,
    temperature: input.payload.temperature,
    maxOutputTokens: input.payload.maxOutputTokens,
    promptVersion: resolveDeepTurnNormalizerPromptVersion(input.payload.promptVersion),
    schemaVersion: "v2_0_2",
    systemPrompt: input.payload.systemPrompt,
    developerPrompt: input.payload.developerPrompt,
    domainPrompt: input.payload.domainPrompt,
    fewShotExamples: input.payload.fewShotExamples,
    userQuestion: followupBinding.normalizedQuestion,
    context: followupBinding.mergedContext,
    useMock: Boolean(input.payload.useMock)
  };

  const normalized = await input.normalize(normalizePayload);
  const normalizedPayload = normalized.normalized;
  const synthesizedRouteSummary =
    normalized.route_hint_summary ??
    (normalizedPayload && canSynthesizeRouteSummary(normalizedPayload) ? toRouteHintSummary(normalizedPayload) : null);
  const normalizedWithRouteSummary: NormalizeResponsePayload =
    synthesizedRouteSummary === normalized.route_hint_summary
      ? normalized
      : {
          ...normalized,
          route_hint_summary: synthesizedRouteSummary
        };

  return {
    followupBinding,
    normalizePayload,
    normalized: normalizedWithRouteSummary
  };
}