import { describe, expect, it } from "vitest";
import {
  formulateQuestion,
  selectInvestigationStrategy,
} from "@/lib/graph/question-formulator.js";
import { makeEdge, makeGraph, makeNode } from "@/lib/graph/schema.js";

function makeGraphFor(node, extra = {}) {
  return makeGraph({
    centralStatement: extra.centralStatement || "Decision context",
    nodes: [node, ...(extra.nodes || [])],
    edges: extra.edges || [],
    activeUnknownNodeId: node.id,
    resolvedNodeIds: extra.resolvedNodeIds || [],
    currentSummary: "Test summary",
  });
}

describe("formulateQuestion", () => {
  it("commercial viability plus build decision produces a decision-threshold question", () => {
    const unknown = makeNode({
      id: "n-commercial",
      label: "Uncertainty regarding the commercial value of the product",
      description:
        "Commercial justification remains unclear because the decision depends on it.",
      kind: "unknown",
      status: "unknown",
      confidence: "high",
      parentId: "n-decision",
    });
    const decision = makeNode({
      id: "n-decision",
      label: "Build decision",
      description: "Decision introduced by the answer.",
      kind: "state",
      status: "known",
      confidence: "medium",
      childIds: [unknown.id],
      value: "Deciding whether to build the product",
    });
    const graph = makeGraphFor(unknown, {
      nodes: [decision],
      resolvedNodeIds: [decision.id],
    });

    const result = formulateQuestion({ node: unknown, graph });

    expect(result.strategy).toBe("decision_threshold");
    expect(result.question).toContain("What outcome");
    expect(result.question.toLowerCase()).toContain("justify");
  });

  it("commercial viability does not produce a pricing-first question", () => {
    const unknown = makeNode({
      id: "n-commercial",
      label: "Commercial viability",
      description:
        "Commercial viability remains unresolved because the decision depends on it.",
      kind: "unknown",
      status: "unknown",
      confidence: "high",
    });
    const graph = makeGraphFor(unknown);

    const result = formulateQuestion({ node: unknown, graph });

    expect(result.question.toLowerCase()).not.toContain("price");
    expect(result.question.toLowerCase()).not.toContain("pricing");
  });

  it("undefined term produces a definition question", () => {
    const unknown = makeNode({
      id: "n-term",
      label: "Success criteria definition",
      description:
        "Need a definition of the term because the team uses it inconsistently.",
      kind: "unknown",
      status: "unknown",
      confidence: "medium",
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown),
    });

    expect(result.strategy).toBe("definition");
    expect(result.question).toMatch(/^What does /);
  });

  it("unsupported claim produces an evidence question", () => {
    const unknown = makeNode({
      id: "n-claim",
      label: "Demand claim",
      description: "Need evidence because the claim has not been validated.",
      kind: "reported_claim",
      status: "provisional",
      confidence: "low",
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown),
    });

    expect(result.strategy).toBe("evidence_gathering");
    expect(result.question).toContain("What evidence");
  });

  it("missing previous state produces a baseline question", () => {
    const unknown = makeNode({
      id: "n-baseline",
      label: "Baseline conversion rate",
      description:
        "Need the previous baseline because the change cannot be assessed without it.",
      kind: "unknown",
      status: "unknown",
      confidence: "medium",
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown),
    });

    expect(result.strategy).toBe("baseline_reconstruction");
    expect(result.question).toContain("What was the comparable state before");
  });

  it("conflicting claim produces a contradiction-resolution question", () => {
    const unknown = makeNode({
      id: "n-conflict",
      label: "Conflicting churn claim",
      description:
        "Need to resolve the inconsistency because the current figures contradict each other.",
      kind: "unknown",
      status: "unknown",
      confidence: "medium",
    });

    const contradiction = makeNode({
      id: "n-contradiction",
      label: "Contradicted report",
      description: "Two sources disagree about churn.",
      kind: "conclusion",
      status: "contradicted",
      confidence: "low",
      childIds: [unknown.id],
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown, { nodes: [contradiction] }),
    });

    expect(result.strategy).toBe("contradiction_resolution");
    expect(result.question).toContain("resolve the contradiction");
  });

  it("constraint unknown uses evidence-gathering within the fixed strategy set", () => {
    const unknown = makeNode({
      id: "n-constraint",
      label: "Budget constraint",
      description:
        "Need the main budget constraint because it limits the available options.",
      kind: "unknown",
      status: "unknown",
      confidence: "medium",
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown),
    });

    expect(result.strategy).toBe("evidence_gathering");
    expect(result.question).toContain("What evidence");
  });

  it("the same unknown can produce different questions when paired with different strategies", () => {
    const unknown = makeNode({
      id: "n-same-unknown",
      label: "Value threshold",
      description: "Need to resolve the value threshold.",
      kind: "unknown",
      status: "unknown",
      confidence: "high",
    });

    const decisionGraph = makeGraphFor(unknown, {
      centralStatement: "We are deciding whether to launch this product.",
      nodes: [
        makeNode({
          id: "n-decision",
          label: "Launch decision",
          description: "Decision depends on the value threshold.",
          kind: "state",
          status: "known",
          confidence: "medium",
          childIds: [unknown.id],
          value: "Deciding whether to launch the product",
        }),
      ],
    });

    const definitionGraph = makeGraphFor(unknown, {
      centralStatement:
        "The team uses the term value threshold inconsistently.",
      nodes: [
        makeNode({
          id: "n-definition",
          label: "Definition disagreement",
          description:
            "Need a definition of value threshold before comparing options.",
          kind: "state",
          status: "known",
          confidence: "medium",
          childIds: [unknown.id],
        }),
      ],
    });

    const decisionResult = formulateQuestion({
      node: unknown,
      graph: decisionGraph,
    });
    const definitionResult = formulateQuestion({
      node: unknown,
      graph: definitionGraph,
    });

    expect(decisionResult.strategy).toBe("decision_threshold");
    expect(definitionResult.strategy).toBe("definition");
    expect(decisionResult.question).not.toBe(definitionResult.question);
  });

  it("strategy selection is deterministic and explainable", () => {
    const unknown = makeNode({
      id: "n-threshold",
      label: "Success threshold",
      description:
        "Need the success threshold because the decision depends on it.",
      kind: "unknown",
      status: "unknown",
      confidence: "high",
    });
    const graph = makeGraphFor(unknown, {
      centralStatement: "We need to decide whether to continue investing.",
    });

    const first = selectInvestigationStrategy({ node: unknown, graph });
    const second = selectInvestigationStrategy({ node: unknown, graph });

    expect(first).toEqual(second);
    expect(first.key).toBe("decision_threshold");
    expect(first.reason).toContain("threshold");
  });

  it("question is singular and answerable", () => {
    const unknown = makeNode({
      id: "n-evidence",
      label: "Evidence of demand",
      description:
        "Need evidence of demand because the decision depends on it.",
      kind: "unknown",
      status: "unknown",
      confidence: "medium",
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown),
    });

    expect(result.question.match(/\?/g) || []).toHaveLength(1);
    expect(result.question.toLowerCase()).not.toContain(" and ");
  });

  it("awkward uncertainty phrasing is rejected via fallback", () => {
    const unknown = makeNode({
      id: "n-weird",
      label: "Uncertainty regarding service reliability",
      description: "Unknown service reliability.",
      kind: "unknown",
      status: "unknown",
      confidence: "medium",
    });

    const result = formulateQuestion({
      node: unknown,
      graph: makeGraphFor(unknown),
    });

    expect(result.question).not.toContain("How should uncertainty regarding");
    expect(result.question).not.toContain(
      "What would resolve uncertainty regarding",
    );
  });
});