/**
 * Experiment 22 — Tests for assessQuestionAgainstDecisionConditions.
 *
 * Validates the new classifier against explicit decision conditions.
 */

import { describe, expect, it } from "vitest";
import { assessQuestionAgainstDecisionConditions } from "@/lib/graph/question-decision-conditions.js";
import { assessQuestionRelevanceToDecision } from "@/lib/graph/question-decision-relevance.js";
import { buildScenarioFixture } from "@/lib/mocks/scenarios.js";

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

const DECISION_TARGET = "Should we enter the European market with our SaaS analytics platform?";

const 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 makeUnknown(id, label) {
  return {
    id,
    label: label || `Unknown ${id}`,
    description: label || `Unknown ${id}`,
    kind: "unknown",
    status: "unknown",
    confidence: "low",
    value: null,
    unit: null,
    evidenceIds: [],
    dependsOn: [],
    affects: [],
    childIds: [],
  };
}

function makeGraphFor(nodes) {
  return {
    nodes,
    edges: [],
    resolvedNodeIds: [],
    activeUnknownNodeId: null,
    centralStatement: "Test",
    currentSummary: "Test",
    reasoningState: null,
  };
}

/* ── tests_deciding_condition ─────────────────────────────── */

describe("assessQuestionAgainstDecisionConditions — tests_deciding_condition", () => {
  it("classifies a demand question as tests_deciding_condition", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("d1", "Whether there is genuine demand for our category in Europe"),
    });

    expect(result.relevance).toBe("tests_deciding_condition");
    expect(result.matchedCondition).toContain("demand");
  });

  it("classifies a compliance question as tests_deciding_condition", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("d2", "Whether our product is suitable for European compliance requirements"),
    });

    expect(result.relevance).toBe("tests_deciding_condition");
    expect(result.matchedCondition).toContain("compliance");
  });

  it("classifies a competitive differentiation question as tests_deciding_condition", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("d3", "Whether we have competitive differentiation against existing European players"),
    });

    expect(result.relevance).toBe("tests_deciding_condition");
    expect(result.matchedCondition).toContain("differentiation");
  });

  it("classifies a value justification question as tests_deciding_condition", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("d4", "Whether the expected market value justifies the compliance investment"),
    });

    expect(result.relevance).toBe("tests_deciding_condition");
    expect(result.matchedCondition).toContain("value");
  });
});

/* ── adds_supporting_evidence ────────────────────────────── */

describe("assessQuestionAgainstDecisionConditions — adds_supporting_evidence", () => {
  it("classifies a customer segment question as adds_supporting_evidence", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("s1", "Which European countries should we target first"),
    });

    expect(result.relevance).toBe("adds_supporting_evidence");
  });

  it("classifies an investment detail question as adds_supporting_evidence", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("s2", "How should we structure the European subsidiary"),
    });

    expect(result.relevance).toBe("adds_supporting_evidence");
  });
});

/* ── outside_decision_conditions ─────────────────────────── */

describe("assessQuestionAgainstDecisionConditions — outside_decision_conditions", () => {
  it("classifies a background question as outside_decision_conditions", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("o1", "What is the company's current US headquarters location"),
    });

    expect(result.relevance).toBe("outside_decision_conditions");
  });

  it("classifies an unrelated observation as outside_decision_conditions", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("o2", "Our CEO's previous experience in Asian markets"),
    });

    expect(result.relevance).toBe("outside_decision_conditions");
  });
});

/* ── Multiple condition matches ──────────────────────────── */

describe("assessQuestionAgainstDecisionConditions — multiple conditions matched", () => {
  it("returns the first matching condition when a question spans two conditions", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("m1", "What market demand and compliance requirements exist in Europe"),
    });

    expect(result.relevance).toBe("tests_deciding_condition");
    // First condition that matches should be returned
    expect(result.matchedCondition).toContain("demand");
  });

  it("treats tests_deciding_condition as higher priority than adds_supporting_evidence", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("m2", "Does our platform meet European data regulations"),
    });

    expect(result.relevance).toBe("tests_deciding_condition");
  });
});

/* ── cannot_determine — missing input ────────────────────── */

describe("assessQuestionAgainstDecisionConditions — cannot_determine (missing input)", () => {
  it("returns cannot_determine when decisionTarget is missing", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("mi1", "Whether to enter Europe"),
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when decisionTarget is empty string", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: "",
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("mi2", "Whether to enter Europe"),
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when decisionTarget is too short", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: "Europe",
      decisionConditions: CONDITIONS,
      unknown: makeUnknown("mi3", "Whether to enter"),
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when unknown is missing", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when unknown has empty label and description", () => {
    const node = makeUnknown("mi4", "");
    node.label = "";
    node.description = "";

    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: node,
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when no input object is provided", () => {
    const result = assessQuestionAgainstDecisionConditions(null);
    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when unknown node has no kind property", () => {
    const node = makeUnknown("mi5", "test");
    delete node.kind;

    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: CONDITIONS,
      unknown: node,
    });

    expect(result.relevance).toBe("cannot_determine");
  });
});

/* ── cannot_determine — missing / empty conditions ──────── */

describe("assessQuestionAgainstDecisionConditions — cannot_determine (missing conditions)", () => {
  it("returns cannot_determine when decisionConditions is missing", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      unknown: makeUnknown("mc1", "Whether to enter Europe"),
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when decisionConditions is an empty array", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: [],
      unknown: makeUnknown("mc2", "Whether to enter Europe"),
    });

    expect(result.relevance).toBe("cannot_determine");
  });

  it("returns cannot_determine when all conditions are empty strings", () => {
    const result = assessQuestionAgainstDecisionConditions({
      decisionTarget: DECISION_TARGET,
      decisionConditions: ["", "  ", ""],
      unknown: makeUnknown("mc3", "Whether to enter Europe"),
    });

    expect(result.relevance).toBe("cannot_determine");
  });
});

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

describe("assessQuestionAgainstDecisionConditions — deterministic output", () => {
  it("returns identical results for identical inputs", () => {
    const node = makeUnknown("det1", "Whether there is genuine demand in Europe");
    const input = { decisionTarget: DECISION_TARGET, decisionConditions: CONDITIONS, unknown: node };
    const r1 = assessQuestionAgainstDecisionConditions(input);
    const r2 = assessQuestionAgainstDecisionConditions(input);
    expect(r1).toEqual(r2);
  });

  it("returns the same classification across multiple calls", () => {
    const results = [];
    for (let i = 0; i < 5; i++) {
      const result = assessQuestionAgainstDecisionConditions({
        decisionTarget: DECISION_TARGET,
        decisionConditions: CONDITIONS,
        unknown: makeUnknown(`det2-${i}`, "Does our platform comply with GDPR"),
      });
      results.push(result.relevance);
    }
    expect(new Set(results).size).toBe(1);
  });
});

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

describe("assessQuestionAgainstDecisionConditions — input immutability", () => {
  it("does not mutate the unknown node", () => {
    const node = makeUnknown("imm1", "Whether to proceed with European market entry");
    const snapshot = JSON.parse(JSON.stringify(node));
    assessQuestionAgainstDecisionConditions({ decisionTarget: DECISION_TARGET, decisionConditions: CONDITIONS, unknown: node });
    expect(node).toEqual(snapshot);
  });

  it("does not mutate the graph (when provided)", () => {
    const node = makeUnknown("imm2", "test");
    const graph = makeGraphFor([node]);
    const originalNodesJSON = JSON.stringify(graph.nodes);
    assessQuestionAgainstDecisionConditions({ decisionTarget: DECISION_TARGET, decisionConditions: CONDITIONS, unknown: node, graph });
    expect(JSON.stringify(graph.nodes)).toBe(originalNodesJSON);
  });

  it("does not mutate the decisionTarget string", () => {
    const dt = "Should we enter the European market with our SaaS analytics platform?";
    assessQuestionAgainstDecisionConditions({ decisionTarget: dt, decisionConditions: CONDITIONS, unknown: makeUnknown("imm3", "test") });
    expect(dt).toBe("Should we enter the European market with our SaaS analytics platform?");
  });

  it("does not mutate the decisionConditions array", () => {
    const conditions = [...CONDITIONS];
    assessQuestionAgainstDecisionConditions({ decisionTarget: DECISION_TARGET, decisionConditions: conditions, unknown: makeUnknown("imm4", "test") });
    expect(JSON.stringify(conditions)).toBe(JSON.stringify(CONDITIONS));
  });
});

/* ── Complete long-investigation sequence ──────────────────── */

describe("assessQuestionAgainstDecisionConditions — long investigation sequence", () => {
  const scenarioName = "long";
  const turnCount = 5;

  const allResults = [];

  for (let t = 0; t < turnCount; t++) {
    const fixture = buildScenarioFixture(scenarioName, t);
    expect(fixture).not.toBeNull(`Turn ${t} should have a valid fixture`);

    const decisionTarget = fixture.situationGraph.centralStatement;
    const resolvedIds = new Set(fixture.situationGraph.resolvedNodeIds || []);

    for (const node of fixture.situationGraph.nodes) {
      if (node.kind !== "unknown") continue;
      if (resolvedIds.has(node.id)) continue;

      const result = assessQuestionAgainstDecisionConditions({
        decisionTarget,
        decisionConditions: CONDITIONS,
        unknown: node,
        graph: fixture.situationGraph,
      });

      allResults.push({ turn: t, nodeId: node.id, label: node.label, relevance: result.relevance, matchedCondition: result.matchedCondition, reason: result.reason });
    }
  }

  it("every unresolved unknown across all turns receives a valid classification", () => {
    const validCategories = ["tests_deciding_condition", "adds_supporting_evidence", "outside_decision_conditions", "cannot_determine"];
    for (const r of allResults) {
      expect(validCategories).toContain(r.relevance);
    }
  });

  it("every unresolved unknown in the long sequence classifies as tests_deciding_condition", () => {
    for (const r of allResults) {
      expect(r.relevance).toBe("tests_deciding_condition");
    }
  });

  it("each unresolved unknown matches its corresponding decision condition", () => {
    const expectedMatches = [
      { turn: 0, nodeId: "u-1", contains: "demand" },
      { turn: 1, nodeId: "u-2", contains: "compliance" },
      { turn: 2, nodeId: "u-3", contains: "value" },
      { turn: 3, nodeId: "u-4", contains: "differentiation" },
    ];
    for (const expected of expectedMatches) {
      const r = allResults.find((x) => x.turn === expected.turn && x.nodeId === expected.nodeId);
      expect(r).toBeDefined();
      expect(r.relevance).toBe("tests_deciding_condition");
      expect(r.matchedCondition).toContain(expected.contains);
    }
  });

  it("the sequence runs deterministically and does not mutate inputs", () => {
    const node = makeUnknown("det-seq", "Whether there is genuine demand in Europe");
    const r1 = assessQuestionAgainstDecisionConditions({ decisionTarget: DECISION_TARGET, decisionConditions: CONDITIONS, unknown: node });
    const r2 = assessQuestionAgainstDecisionConditions({ decisionTarget: DECISION_TARGET, decisionConditions: CONDITIONS, unknown: node });
    expect(r1).toEqual(r2);
    expect(JSON.stringify(node)).toBe(JSON.stringify(makeUnknown("det-seq", "Whether there is genuine demand in Europe")));
  });

  it("category distribution across the full sequence", () => {
    const categories = {};
    for (const r of allResults) {
      categories[r.relevance] = (categories[r.relevance] || 0) + 1;
    }
    console.log("\n=== Experiment 22 — Classification Results ===");
    console.log(`Total unresolved unknowns classified: ${allResults.length}`);
    console.log("Category distribution:", JSON.stringify(categories, null, 2));
    expect(allResults.length).toBeGreaterThan(0);
  });

  it("detailed per-turn classifications", () => {
    const byTurn = {};
    for (const r of allResults) {
      if (!byTurn[r.turn]) byTurn[r.turn] = [];
      byTurn[r.turn].push(r);
    }
    for (const [turn, results] of Object.entries(byTurn)) {
      console.log(`\n--- Turn ${turn} (${results.length} unresolved unknowns) ---`);
      for (const r of results) {
        const shortLabel = r.label?.length > 60 ? r.label.slice(0, 60) + "..." : r.label;
        console.log(`  [${r.relevance}] ${shortLabel}`);
      }
    }
    expect(allResults.length).toBeGreaterThan(0);
  });

  it("Turn 0 (market demand) is classified as tests_deciding_condition", () => {
    const turn0 = allResults.find((r) => r.turn === 0);
    expect(turn0).toBeDefined();
    expect(turn0.relevance).toBe("tests_deciding_condition");
  });

  it("Turns 1-2 (compliance, cost) are classified as tests_deciding_condition", () => {
    const turns1to2 = allResults.filter((r) => r.turn >= 1 && r.turn <= 2);
    for (const r of turns1to2) {
      expect(r.relevance).toBe("tests_deciding_condition");
    }
  });

  it("Turn 3 (differentiation) is classified as tests_deciding_condition", () => {
    const turn3 = allResults.find((r) => r.turn === 3);
    expect(turn3).toBeDefined();
    expect(turn3.relevance).toBe("tests_deciding_condition");
  });

  it("competitive differentiation becomes a clearly decisive classification", () => {
    const differentiating = allResults.find((r) => r.nodeId === "u-4" && r.turn === 3);
    expect(differentiating).toBeDefined();
    expect(differentiating.relevance).toBe("tests_deciding_condition");
    expect(differentiating.matchedCondition).toContain("differentiation");
  });

  it("all classified questions include a non-empty reason", () => {
    for (const r of allResults) {
      if (r.relevance !== "cannot_determine") {
        expect(typeof r.reason).toBe("string");
        expect(r.reason.length).toBeGreaterThan(0);
      }
    }
  });

  it("every unresolved unknown has a matchedCondition when classified", () => {
    for (const r of allResults) {
      if (r.relevance !== "cannot_determine" && r.relevance !== "outside_decision_conditions") {
        expect(r.matchedCondition).toBeDefined();
        expect(typeof r.matchedCondition).toBe("string");
        expect(r.matchedCondition.length).toBeGreaterThan(0);
      }
    }
  });

  it("the complete long-investigation sequence runs without error and produces results", () => {
    expect(allResults.length).toBeGreaterThan(0);
  });
});

/* ── Comparison with Experiment 21 — clearer distinction ─ */

describe("assessQuestionAgainstDecisionConditions — comparison with Experiment 21", () => {
  it("distinguishes between decisive and supporting questions (Experiment 22 vs 21)", () => {
    const conditions = CONDITIONS;

    const decisions21 = [];
    const decisions22 = [];

    for (let t = 0; t < 4; t++) {
      const fixture = buildScenarioFixture("long", t);
      if (!fixture) continue;
      const decisionTarget = fixture.situationGraph.centralStatement;

      for (const node of fixture.situationGraph.nodes) {
        if (node.kind !== "unknown") continue;
        const resolvedIds = new Set(fixture.situationGraph.resolvedNodeIds || []);
        if (resolvedIds.has(node.id)) continue;

        // Experiment 21 classification
        const r21 = assessQuestionRelevanceToDecision({ decisionTarget, unknown: node });
        decisions21.push({ turn: t, label: node.label, relevance: r21.relevance });

        // Experiment 22 classification
        const r22 = assessQuestionAgainstDecisionConditions({ decisionTarget, decisionConditions: conditions, unknown: node });
        decisions22.push({ turn: t, label: node.label, relevance: r22.relevance });
      }
    }

    const distinct21 = new Set(decisions21.map((r) => r.relevance));
    const distinct22 = new Set(decisions22.map((r) => r.relevance));

    // Experiment 22 should have a clearer distinction than 21
    expect(distinct21.size).toBeGreaterThanOrEqual(1);
    expect(distinct22.size).toBeGreaterThanOrEqual(1);

    // Verify at least some questions moved to tests_deciding_condition in Exp 22
    const decisiveCount = decisions22.filter((r) => r.relevance === "tests_deciding_condition").length;
    expect(decisiveCount).toBeGreaterThan(0);
  });
});