/**
 * Tests for episode evidence at the graph application boundary.
 *
 * Scope: applyValidatedProposal accepts structured completed-episode evidence
 * without collapsing it into a synthetic single answer, and preserves existing
 * single-turn behaviour unchanged.
 */

import { describe, expect, it } from "vitest";
import { applyValidatedProposal } from "@/lib/graph/apply-proposal.js";

import { makeEdge, makeGraph, makeNode } from "@/lib/graph/schema.js";

// ── production-style helpers ───────────────────────────────────────

function makeSituationGraph() {
  const parent = makeNode({
    id: "n-parent",
    label: "Commercial justification for continuing development",
    description:
      "Need to know whether this solves a genuine problem and is commercially justified.",
    kind: "unknown",
    status: "unknown",
    confidence: "medium",
  });

  const child1 = makeNode({
    id: "n-child-1",
    label: "Whether the idea solves a genuine problem",
    description: "Need evidence about whether there is real user demand.",
    kind: "unknown",
    status: "unknown",
    confidence: "medium",
    parentId: parent.id,
  });

  const child2 = makeNode({
    id: "n-child-2",
    label: "Whether people would value it enough to pay",
    description: "Need evidence about willingness to pay.",
    kind: "unknown",
    status: "unknown",
    confidence: "medium",
    parentId: parent.id,
  });

  const anchor = makeNode({
    id: "n-anchor",
    label: "Market observation anchor",
    description: "Anchor state introduced by the answer.",
    kind: "state",
    status: "known",
    confidence: "low",
  });

  return makeGraph({
    centralStatement:
      "I have developed a new reasoning method and want to determine whether continuing development is commercially justified.",
    nodes: [parent, child1, child2, anchor],
    edges: [
      makeEdge({
        id: "e-p-c1",
        fromNodeId: child1.id,
        toNodeId: parent.id,
        relationship: "depends_on",
        description: "Genuine problem feeds the parent.",
      }),
      makeEdge({
        id: "e-p-c2",
        fromNodeId: child2.id,
        toNodeId: parent.id,
        relationship: "depends_on",
        description: "Willingness to pay feeds the parent.",
      }),
    ],
    activeUnknownNodeId: "n-child-1",
    resolvedNodeIds: [],
    currentSummary: "Episode evidence boundary fixture",
  });
}

function makeResolvedProposal(resolvedIds = ["n-child-1"]) {
  return {
    addedNodes: [
      makeNode({
        id: "n-anchor2",
        label: "Update anchor 2",
        description: "Anchor state.",
        kind: "state",
        status: "known",
        confidence: "low",
      }),
    ],
    updatedNodes: resolvedIds.map((id) => ({
      nodeId: id,
      previousStatus: "unknown",
      newStatus: "resolved",
      previousValue: null,
      newValue: `answer:${id}`,
      reason: "resolved child",
    })),
    addedEdges: [],
    removedEdgeIds: [],
    resolvedUnknownNodeIds: resolvedIds,
    affectedNodeIds: [],
    selectedQuestion: null,
  };
}

function makeLegacyAnswer() {
  return "Yes, I confirm there is no further material uncertainty.";
}

// ── Legacy single-turn regression ──────────────────────────────────

describe("legacy single-turn path", () => {
  it("continues to work without evidenceContext (backward-compatible signature)", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      answer: makeLegacyAnswer(),
    });

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

  it("legacy raw-answer compatibility check still runs (Regression A)", async () => {
    const graph = makeSituationGraph();

    // Use unstructured answerMeaning (no structured supportCategory/resolutionGuidance)
    // so that validateAnswerMeaningCompatibilityWithRawAnswer actually executes.
    // Raw answer states a hard constraint but the proposal weakens it in newValue.
    const proposalWithWeakening = {
      addedNodes: [
        makeNode({
          id: "n-anchor-lr",
          label: "Update anchor",
          description: "Anchor state.",
          kind: "state",
          status: "known",
          confidence: "low",
        }),
      ],
      updatedNodes: [
        {
          nodeId: "n-child-1",
          previousStatus: "unknown",
          newStatus: "resolved",
          previousValue: null,
          newValue: "It would be good to proceed.", // weaker than raw constraint
          reason: "Evidence supports proceeding.",
        },
      ],
      addedEdges: [],
      removedEdgeIds: [],
      resolvedUnknownNodeIds: ["n-child-1"],
      affectedNodeIds: [],
      selectedQuestion: null,
      answerMeaning: {
        userSupportedMeaning: "It would be good to proceed.",
        supportCategory: null,
        resolutionGuidance: null,
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal: proposalWithWeakening,
      answer: "We MUST proceed — no exceptions.", // explicit hard constraint in raw answer
    });

    // legacy path: raw-answer compatibility check rejects weakening
    expect(result.success).toBe(false);
    expect(result.stage).toBe("proposal_compatibility");
  });
});

// ── Episode evidence path ──────────────────────────────────────────

describe("episode evidence at application boundary", () => {
  it("accepts structured completed-episode evidence without collapsing to synthetic answer", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          {
            contributionId: "c-1",
            sequence: 1,
            question: "Should we proceed with the investment?",
            answer: "Yes, the risk assessment is complete.",
          },
          {
            contributionId: "c-2",
            sequence: 2,
            question: "Any remaining material uncertainties?",
            answer: "No, all findings are aligned.",
          },
        ],
        eligibleCanonicalFindings: [
          {
            findingId: "f-1",
            contributionId: "c-1",
            proposition: "Risk assessment confirms go/no-go criteria met.",
            sourceObservation: "Risk analysis document v3.",
            endorsement: "agree",
          },
          {
            findingId: "f-2",
            contributionId: "c-2",
            proposition: "No remaining material uncertainties identified.",
            sourceObservation: "User confirmation response.",
            endorsement: null,
          },
        ],
        excludedFindingProvenance: [
          {
            findingId: "f-3",
            contributionId: "c-1",
            proposition: "Minor budget variance noted.",
            sourceObservation: "Budget report.",
            disposition: "not_relevant",
          },
        ],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      evidenceContext: episodeEvidence,
    });

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

  it("ordered turns remain distinct (no aggregation)", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          {
            contributionId: "c-10",
            sequence: 1,
            question: "Q1 distinct text?",
            answer: "A1 distinct text.",
          },
          {
            contributionId: "c-11",
            sequence: 2,
            question: "Q2 distinct text?",
            answer: "A2 distinct text.",
          },
          {
            contributionId: "c-12",
            sequence: 3,
            question: "Q3 distinct text?",
            answer: "A3 distinct text.",
          },
        ],
        eligibleCanonicalFindings: [],
        excludedFindingProvenance: [],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      evidenceContext: episodeEvidence,
    });

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

  it("eligible Findings remain structured evidence", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);

    const eligibleFindings = [
      {
        findingId: "f-aggree",
        contributionId: "c-a",
        proposition: "Confirmed proposition A.",
        sourceObservation: "Source A.",
        endorsement: "agree",
      },
      {
        findingId: "f-agenull",
        contributionId: "c-b",
        proposition: "Working premise B.",
        sourceObservation: "Source B.",
        endorsement: null,
      },
    ];

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          { contributionId: "c-a", sequence: 1, question: "Q?", answer: "A." },
          { contributionId: "c-b", sequence: 2, question: "Q?", answer: "A." },
        ],
        eligibleCanonicalFindings: eligibleFindings,
        excludedFindingProvenance: [],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      evidenceContext: episodeEvidence,
    });

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

  it("no synthetic answer is constructed for episode path", async () => {
    // In episode mode, the `answer` parameter is omitted and structured turns
    // are provided via evidenceContext. Since no raw `answer` is passed,
    // validateAnswerMeaningCompatibilityWithRawAnswer returns [] immediately
    // (requires a truthy answer to execute), proving no synthetic/combined
    // answer is constructed from the episode turns.
    const graph = makeSituationGraph();

    // Use structured meaning (bypasses raw-answer compatibility) with valid alignment
    const proposalWithMeaning = {
      addedNodes: [
        makeNode({
          id: "n-anchor-na",
          label: "Update anchor",
          description: "Anchor state.",
          kind: "state",
          status: "known",
          confidence: "low",
        }),
      ],
      updatedNodes: [
        {
          nodeId: "n-child-1",
          previousStatus: "unknown",
          newStatus: "resolved",
          previousValue: null,
          newValue: "Proceed with full commitment.",
          reason: "Evidence supports it.",
        },
      ],
      addedEdges: [],
      removedEdgeIds: [],
      resolvedUnknownNodeIds: ["n-child-1"],
      affectedNodeIds: [],
      selectedQuestion: null,
      structuralActionRequired: true,
      answerMeaning: {
        supportCategory: "explicit_hard_constraint",
        resolutionGuidance: "must_resolve",
        userSupportedMeaning: "Proceed with full commitment.",
      },
    };

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          { contributionId: "c-1", sequence: 1, question: "Go?", answer: "Absolutely yes." },
          { contributionId: "c-2", sequence: 2, question: "Any remaining material uncertainties?", answer: "No." },
        ],
        eligibleCanonicalFindings: [],
        excludedFindingProvenance: [],
      },
    };

    // No `answer` parameter — evidenceContext drives the episode branch.
    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal: proposalWithMeaning,
      evidenceContext: episodeEvidence,
    });

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

  it("proposal-internal validation still runs in episode mode", async () => {
    const graph = makeSituationGraph();

    // Duplicate node ID — structural violation that proposal-internal validation catches.
    const proposalWithDuplicateNodes = {
      addedNodes: [
        {
          id: "n-child-1", // duplicates existing node ID
          kind: "unknown",
          status: "unknown",
          confidence: "medium",
          label: "Duplicate unknown",
          value: null,
          dependsOn: [],
        },
      ],
      updatedNodes: [],
      addedEdges: [],
      removedEdgeIds: [],
      resolvedUnknownNodeIds: [],
      affectedNodeIds: [],
      selectedQuestion: null,
    };

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          { contributionId: "c-1", sequence: 1, question: "Q?", answer: "A." },
        ],
        eligibleCanonicalFindings: [],
        excludedFindingProvenance: [],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal: proposalWithDuplicateNodes,
      evidenceContext: episodeEvidence,
    });

    // Proposal-internal validation (structural) still runs and rejects.
    expect(result.success).toBe(false);
    expect(result.stage).toBe("proposal_compatibility");
  });

  it("structured episode is available for subsequent safeguard adaptation", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);

    const turns = [
      { contributionId: "c-1", sequence: 1, question: "First turn?", answer: "First answer." },
      { contributionId: "c-2", sequence: 2, question: "Second turn?", answer: "Second answer." },
    ];

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns,
        eligibleCanonicalFindings: [],
        excludedFindingProvenance: [],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      evidenceContext: episodeEvidence,
    });

    expect(result.success).toBe(true);
    expect(result.updatedSituationGraph.nodes.find((n) => n.id === "n-child-1")?.status).toBe("resolved");
  });

  it("preserves existing graph mutation behaviour in episode mode", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);
    const originalParentStatus = graph.nodes.find((n) => n.id === "n-parent")?.status;

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          { contributionId: "c-1", sequence: 1, question: "Q?", answer: "A." },
        ],
        eligibleCanonicalFindings: [],
        excludedFindingProvenance: [],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      evidenceContext: episodeEvidence,
    });

    expect(result.success).toBe(true);
    // Graph was mutated (expected)
    expect(result.updatedSituationGraph.nodes.find((n) => n.id === "n-child-1")?.status).toBe("resolved");
    // Original graph not mutated (atomicity test)
    expect(graph.nodes.find((n) => n.id === "n-parent")?.status).toBe(originalParentStatus);
  });
});


// ── Signature compatibility ────────────────────────────────────────

describe("applyValidatedProposal signature", () => {
  it("works with minimal legacy call (situationGraph + proposal only)", async () => {
    const graph = makeSituationGraph();
    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal: makeResolvedProposal(["n-child-1"]),
    });
    expect(result.success).toBe(true);
  });

  it("works with legacy answer parameter still passed", async () => {
    const graph = makeSituationGraph();
    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal: makeResolvedProposal(["n-child-1"]),
      answer: "Yes.",
    });
    expect(result.success).toBe(true);
  });

  it("works with both evidenceContext and legacy parameters (evidenceContext takes precedence)", async () => {
    const graph = makeSituationGraph();
    const proposal = makeResolvedProposal(["n-child-1"]);

    const episodeEvidence = {
      isCompletedEpisode: true,
      episodeEvidence: {
        situationGraph: graph,
        targetNodeId: "n-parent",
        turns: [
          { contributionId: "c-1", sequence: 1, question: "Q?", answer: "A." },
        ],
        eligibleCanonicalFindings: [],
        excludedFindingProvenance: [],
      },
    };

    const result = await applyValidatedProposal({
      situationGraph: graph,
      proposal,
      previousQuestion: "Legacy question?",
      answer: "Legacy answer.", // should be ignored — evidenceContext present
      evidenceContext: episodeEvidence,
    });

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