import { describe, expect, it } from "vitest";
import { applyValidatedProposal } from "@/lib/graph/apply-proposal.js";
import { formulateQuestion } from "@/lib/graph/question-formulator.js";
import { selectActiveUnknownCandidate } from "@/lib/graph/utils.js";
import { questionPriorityGeneralisationFixtures } from "@/tests/fixtures/question-priority-generalisation.js";

function clone(value) {
  return JSON.parse(JSON.stringify(value));
}

function buildResolutionProposal(graph) {
  const activeNode = graph.nodes.find(
    (node) => node.id === graph.activeUnknownNodeId,
  );
  const placeholderCandidate = graph.nodes.find(
    (node) => node.kind === "unknown" && node.id !== activeNode.id,
  );

  return {
    addedNodes: [],
    updatedNodes: [
      {
        nodeId: activeNode.id,
        previousStatus: activeNode.status,
        newStatus: "resolved",
        previousValue: activeNode.value ?? null,
        newValue: activeNode.value ?? "Resolved context answer",
        reason:
          "The resolved context unknown is treated as answered for fixture progression.",
      },
    ],
    addedEdges: [],
    removedEdgeIds: [],
    resolvedUnknownNodeIds: [activeNode.id],
    affectedNodeIds: [],
    selectedQuestion: {
      nodeId: placeholderCandidate?.id,
      question: "Placeholder candidate question?",
      reason: "Candidate only; deterministic selector should override it.",
    },
  };
}

function assertQuestionStructure(question) {
  expect(question.match(/\?/g) || []).toHaveLength(1);
  expect(question).not.toMatch(/\?\s*(and|or)\b/i);
  expect(question).not.toMatch(/^What is\s+/i);
  expect(question).toMatch(/^(What|Who|When)\b/);
}

describe("question priority generalisation", () => {
  for (const fixture of questionPriorityGeneralisationFixtures) {
    it(`${fixture.scenario} selects a foundational unknown and singular answerable strategy`, () => {
      const originalGraph = clone(fixture.graph);
      const deterministicSelection = selectActiveUnknownCandidate(
        fixture.graph,
        [fixture.graph.activeUnknownNodeId],
      );

      const result = applyValidatedProposal({
        situationGraph: fixture.graph,
        proposal: buildResolutionProposal(fixture.graph),
      });

      expect(result.success).toBe(true);
      expect(fixture.graph).toEqual(originalGraph);
      expect(result.graphUpdate.selectedQuestion?.question).toBe(
        "Placeholder candidate question?",
      );

      expect(deterministicSelection.nodeId).toBe(
        result.selectedQuestion.nodeId,
      );
      expect(fixture.acceptableFoundationalUnknownNodeIds).toContain(
        result.selectedQuestion.nodeId,
      );
      expect(result.selectedQuestion.nodeId).not.toBe(
        fixture.graph.nodes[fixture.graph.nodes.length - 1].id,
      );

      expect(fixture.acceptableQuestionStrategies).toContain(
        result.selectedQuestion.strategy,
      );
      assertQuestionStructure(result.selectedQuestion.question);

      const lowerQuestion = result.selectedQuestion.question.toLowerCase();
      for (const topic of fixture.prohibitedFirstTopics) {
        expect(lowerQuestion).not.toContain(topic.toLowerCase());
      }

      const selectedNode = result.updatedSituationGraph.nodes.find(
        (node) => node.id === result.selectedQuestion.nodeId,
      );
      const reformulated = formulateQuestion({
        node: selectedNode,
        graph: result.updatedSituationGraph,
        context: {
          resolvedValues: ["Resolved context answer"],
        },
      });

      expect(reformulated.question).toBe(result.selectedQuestion.question);
      expect(clone(result.updatedSituationGraph)).toEqual(
        result.updatedSituationGraph,
      );
    });
  }

  it("reports all five selected unknowns and strategies", () => {
    const summary = questionPriorityGeneralisationFixtures.map((fixture) => {
      const result = applyValidatedProposal({
        situationGraph: fixture.graph,
        proposal: buildResolutionProposal(fixture.graph),
      });

      expect(result.success).toBe(true);

      return {
        scenario: fixture.scenario,
        nodeId: result.selectedQuestion.nodeId,
        strategy: result.selectedQuestion.strategy,
      };
    });

    expect(summary).toMatchInlineSnapshot(`
      [
        {
          "nodeId": "hire-success-criteria",
          "scenario": "Should we hire another engineer?",
          "strategy": "decision_threshold",
        },
        {
          "nodeId": "van-reliability-threshold",
          "scenario": "Should we replace the delivery vans?",
          "strategy": "decision_threshold",
        },
        {
          "nodeId": "country-value-threshold",
          "scenario": "Should we launch in another country?",
          "strategy": "decision_threshold",
        },
        {
          "nodeId": "project-benefit-threshold",
          "scenario": "Should we continue a project that is over budget?",
          "strategy": "decision_threshold",
        },
        {
          "nodeId": "support-value-threshold",
          "scenario": "Should we introduce a paid support tier?",
          "strategy": "baseline_reconstruction",
        },
      ]
    `);
  });
});