/**
 * Experiment 24A — Tests for assessEvidenceDirection.
 *
 * Validates evidence direction classification (supports, contradicts,
 * informs, cannot_determine) against explicit conditions and the
 * long-investigation scenario fixture.
 */

import { describe, expect, it } from "vitest";
import { assessEvidenceDirection } from "@/lib/graph/evidence-direction.js";
import { buildScenarioFixture } from "@/lib/mocks/scenarios.js";

/* ── Helpers ─────────────────────────────────────────────── */

const DECISION_CONDITIONS = [
  "Credible customer demand exists in Europe",
  "European compliance is achievable",
  "The expected market value justifies the cost of entry",
  "The product offers sufficient competitive differentiation",
];

function makeNode(id, label, opts = {}) {
  return {
    id,
    label,
    description: opts.description || label,
    kind: opts.kind || "observation",
    status: opts.status || "resolved",
  };
}

/* ── supports: evidence confirms the condition ───────────── */

describe("assessEvidenceDirection — supports", () => {
  it("returns supports when observation text contains supporting keywords for demand", () => {
    const evidence = makeNode("obs-2", "European analytics SaaS market valued at approximately €8B and growing 15% annually");

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[0] },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("supports");
    expect(typeof result.reason).toBe("string");
    expect(result.reason.length).toBeGreaterThan(0);
  });

  it("returns supports when observation contains a clear supporting keyword for differentiation", () => {
    const evidence = makeNode("obs-5", "Our real-time collaboration feature has no direct European equivalent");

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[3] },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("supports");
  });
});

/* ── contradicts: evidence directly weakens the condition ─ */

describe("assessEvidenceDirection — contradicts", () => {
  it("returns contradicts when observation contains a contradiction phrase for compliance", () => {
    const evidence = makeNode("obs-3", "Our platform does not support EU data residency requirements");

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[1] },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("contradicts");
  });
});

/* ── informs: evidence provides relevant context only ───── */

describe("assessEvidenceDirection — informs", () => {
  it("returns informs when observation is relevant but contains only neutral keywords", () => {
    const evidence = makeNode("obs-4", "Achieving compliance would require approximately 6 months and $500K engineering investment");

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[2] },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("informs");
  });

  it("returns informs when observation is related but does not strongly support or contradict", () => {
    const evidence = makeNode("obs-1", "Current revenue is $2M ARR in the US market only");

    const result = assessEvidenceDirection({
      condition: { text: "cost" },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("informs");
  });
});

/* ── cannot_determine: insufficient data ─────────────────── */

describe("assessEvidenceDirection — cannot_determine", () => {
  it("returns cannot_determine when condition is missing", () => {
    const evidence = makeNode("obs-2", "European analytics SaaS market valued at €8B");
    const result = assessEvidenceDirection({ evidenceNode: evidence });
    expect(result.direction).toBe("cannot_determine");
  });

  it("returns cannot_determine when condition is null", () => {
    const result = assessEvidenceDirection({ condition: null, evidenceNode: makeNode("t-1", "test") });
    expect(result.direction).toBe("cannot_determine");
  });

  it("returns cannot_determine when evidenceNode is missing", () => {
    const result = assessEvidenceDirection({ condition: { text: "demand" } });
    expect(result.direction).toBe("cannot_determine");
  });

  it("returns cannot_determine when evidenceNode is null", () => {
    const result = assessEvidenceDirection({
      condition: { text: "demand" },
      evidenceNode: null,
    });
    expect(result.direction).toBe("cannot_determine");
  });

  it("returns cannot_determine when condition has empty text", () => {
    const result = assessEvidenceDirection({
      condition: { text: "" },
      evidenceNode: makeNode("t-1", "test"),
    });
    expect(result.direction).toBe("cannot_determine");
  });

  it("returns cannot_determine when evidenceNode has empty description", () => {
    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[0] },
      evidenceNode: makeNode("t-1", ""),
    });
    expect(result.direction).toBe("cannot_determine");
  });

  it("returns cannot_determine when neither input is provided", () => {
    const result = assessEvidenceDirection({});
    expect(result.direction).toBe("cannot_determine");
  });
});

/* ── Deterministic output ───────────────────────────────── */

describe("assessEvidenceDirection — determinism", () => {
  it("returns identical results for identical inputs across multiple calls", () => {
    const evidence = makeNode("det-1", "European analytics market growing 15% annually");
    const input = {
      condition: { text: DECISION_CONDITIONS[0] },
      evidenceNode: evidence,
    };

    const r1 = assessEvidenceDirection(input);
    const r2 = assessEvidenceDirection(input);
    expect(r1).toEqual(r2);
  });

  it("deterministic across 5 calls with long-investigation data", () => {
    const fixture = buildScenarioFixture("long", 2);
    const obs3Node = makeNode("obs-3", "Our platform does not support EU data residency requirements");
    const input = {
      condition: { text: DECISION_CONDITIONS[1] },
      evidenceNode: obs3Node,
    };

    const results = [1, 2, 3, 4, 5].map(() => assessEvidenceDirection(input));
    for (let i = 1; i < results.length; i++) {
      expect(results[i]).toEqual(results[0]);
    }
  });
});

/* ── Input immutability ─────────────────────────────────── */

describe("assessEvidenceDirection — input immutability", () => {
  it("does not mutate the condition object", () => {
    const cond = { text: DECISION_CONDITIONS[0] };
    const originalText = cond.text;
    const evidence = makeNode("imm-1", "European market valued at €8B");

    assessEvidenceDirection({ condition: cond, evidenceNode: evidence });
    expect(cond.text).toBe(originalText);
  });

  it("does not mutate the evidenceNode object", () => {
    const node = makeNode("imm-2", "test description");
    const originalDesc = node.description;
    const condition = { text: DECISION_CONDITIONS[3] };

    assessEvidenceDirection({ condition, evidenceNode: node });
    expect(node.description).toBe(originalDesc);
  });
});

/* ── Four long-investigation examples ───────────────────── */

describe("assessEvidenceDirection — long investigation examples", () => {
  it("demand example: supports (obs-2)", () => {
    const fixture = buildScenarioFixture("long", 1);
    const graphNodes = fixture.situationGraph.nodes;
    const obs2Node = graphNodes.find((n) => n.id === "obs-2");

    expect(obs2Node).toBeDefined();

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[0] },
      evidenceNode: obs2Node,
    });

    expect(result.direction).toBe("supports");
  });

  it("compliance example: contradicts (obs-3)", () => {
    const fixture = buildScenarioFixture("long", 2);
    const graphNodes = fixture.situationGraph.nodes;
    const obs3Node = graphNodes.find((n) => n.id === "obs-3");

    expect(obs3Node).toBeDefined();

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[1] },
      evidenceNode: obs3Node,
    });

    expect(result.direction).toBe("contradicts");
  });

  it("value versus cost example: informs (obs-4)", () => {
    const fixture = buildScenarioFixture("long", 3);
    const graphNodes = fixture.situationGraph.nodes;
    const obs4Node = graphNodes.find((n) => n.id === "obs-4");

    expect(obs4Node).toBeDefined();

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[2] },
      evidenceNode: obs4Node,
    });

    expect(result.direction).toBe("informs");
  });

  it("differentiation example: supports (obs-5)", () => {
    const fixture = buildScenarioFixture("long", 4);
    const graphNodes = fixture.situationGraph.nodes;
    const obs5Node = graphNodes.find((n) => n.id === "obs-5");

    expect(obs5Node).toBeDefined();

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[3] },
      evidenceNode: obs5Node,
    });

    expect(result.direction).toBe("supports");
  });
});

/* ── Unrelated evidence ─────────────────────────────────── */

describe("assessEvidenceDirection — unrelated evidence", () => {
  it("returns informs when evidence is about a different concept area", () => {
    const evidence = makeNode("unrel-1", "Our team has 15 engineers in London");

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[0] },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("informs");
  });

  it("returns informs when observation contains no category-matching keywords", () => {
    const evidence = makeNode("unrel-2", "The office lease expires in December 2026");

    const result = assessEvidenceDirection({
      condition: { text: DECISION_CONDITIONS[1] },
      evidenceNode: evidence,
    });

    expect(result.direction).toBe("informs");
  });
});