import { getProvider } from "@/lib/llm/provider";
import { buildFocusedDeconstructPrompt, validateFocusedDeconstructSchema } from "@/lib/graph/focused-investigation";

export async function POST(request) {
  try {
    const body = await request.json();

    if (!body.targetNodeId || typeof body.targetNodeId !== "string") {
      return Response.json(
        { error: "Request must include a 'targetNodeId' string field" },
        { status: 400 },
      );
    }
    if (!body.targetLabel || typeof body.targetLabel !== "string") {
      return Response.json(
        { error: "Request must include a 'targetLabel' string field" },
        { status: 400 },
      );
    }
    if (!body.targetDescription || typeof body.targetDescription !== "string") {
      return Response.json(
        { error: "Request must include a 'targetDescription' string field" },
        { status: 400 },
      );
    }
    if (!body.centralStatement || typeof body.centralStatement !== "string") {
      return Response.json(
        { error: "Request must include a 'centralStatement' string field" },
        { status: 400 },
      );
    }
    if (!body.question || typeof body.question !== "string") {
      return Response.json(
        { error: "Request must include a 'question' string field" },
        { status: 400 },
      );
    }
    if (!body.answer || typeof body.answer !== "string") {
      return Response.json(
        { error: "Request must include an 'answer' string field" },
        { status: 400 },
      );
    }

    const prompt = buildFocusedDeconstructPrompt({
      targetLabel: body.targetLabel,
      targetDescription: body.targetDescription,
      centralStatement: body.centralStatement,
      question: body.question,
      answer: body.answer,
    });

    const provider = getProvider();
    const startedAt = Date.now();
    const raw = await provider.generateReconstruction(prompt, process.env.OLLAMA_MODEL);
    const elapsedMs = Date.now() - startedAt;

    // Validate schema (required fields present, no graph-mutation fields)
    const validationErrors = validateFocusedDeconstructSchema(raw);
    if (validationErrors.length > 0) {
      return Response.json(
        {
          success: false,
          error: "Focused deconstruction result did not match expected schema",
          validationErrors,
          targetNodeId: body.targetNodeId,
          elapsedMs,
        },
        { status: 502 },
      );
    }

    return Response.json({
      success: true,
      targetNodeId: body.targetNodeId,
      observations: raw.observations,
      uncertainties: raw.uncertainties,
      assumptions: raw.assumptions,
      relationships: raw.relationships,
      possibleFollowUpQuestions: raw.possibleFollowUpQuestions,
      elapsedMs,
    });
  } catch (e) {
    return Response.json(
      { error: e.message || "Unknown server error" },
      { status: 500 },
    );
  }
}