import { beforeEach, describe, expect, it, vi } from "vitest";

// ── Fixtures ────────────────────────────────────────────────

function makePreparedEpisode(overrides = {}) {
  return {
    situationGraph: {
      centralStatement: "Complaint counts increased.",
      nodes: [
        { id: "n-unknown", label: "Rate denominator", kind: "unknown", status: "unknown" },
      ],
      edges: [],
      activeUnknownNodeId: "n-unknown",
      resolvedNodeIds: [],
    },
    targetNodeId: "n-unknown",
    turns: [
      { contributionId: "contrib-a", sequence: 1, question: "What denominator?", answer: "100 units" },
      { contributionId: "contrib-b", sequence: 2, question: "Is it consistent?", answer: "Yes" },
    ],
    eligibleCanonicalFindings: [
      { findingId: "f-1", contributionId: "contrib-a", proposition: "Denominator is fixed at 100.", endorsement: null },
    ],
    excludedFindingProvenance: [],
    ...overrides,
  };
}

function makeProposalResponse(overrides = {}) {
  return {
    addedNodes: [],
    updatedNodes: [
      {
        nodeId: "n-unknown",
        previousStatus: "unknown",
        newStatus: "resolved",
        previousValue: null,
        newValue: "100 units",
        reason: "Denominator confirmed.",
      },
    ],
    addedEdges: [],
    removedEdgeIds: [],
    resolvedUnknownNodeIds: ["n-unknown"],
    affectedNodeIds: [],
    selectedQuestion: null,
    answerMeaning: null,
    structuralActionRequired: false,
    ...overrides,
  };
}

const MOCK_CONFIG = { OLLAMA_MODEL: "configured" };
const TEST_EPISODE = makePreparedEpisode();

// ── Tests ───────────────────────────────────────────────────

describe("episode reasoning seam (reconsiderCompletedEpisode)", () => {
  beforeEach(() => {
    vi.resetModules();
    vi.clearAllMocks();
  });

  it("uses the episode-aware prompt builder, not legacy buildGraphUpdatePrompt", async () => {
    const buildEpisodeAwareGraphPrompt = vi.fn().mockReturnValue("EPISODE_PROMPT");
    const buildGraphUpdatePrompt = vi.fn();
    const provider = {
      generateReconstruction: vi.fn().mockResolvedValue(makeProposalResponse()),
    };

    // epiParams carries provider via its own key (as in the API contract)
    const result = await (await import("@/lib/graph/orchestrator.js")).reconsiderCompletedEpisode(
      { ...TEST_EPISODE, provider },
      { getModelName: () => "configured", buildEpisodePrompt: buildEpisodeAwareGraphPrompt },
    );

    expect(result.success).toBe(true);
    expect(buildEpisodeAwareGraphPrompt).toHaveBeenCalledWith({ episode: expect.any(Object) });
    expect(provider.generateReconstruction).toHaveBeenCalledWith("EPISODE_PROMPT", "configured");
    expect(buildGraphUpdatePrompt).not.toHaveBeenCalled();
  });

  it("calls provider.generateReconstruction exactly once with the built episode prompt", async () => {
    const buildEpisodeAwareGraphPrompt = vi.fn().mockReturnValue("EPISODE_PROMPT_V2");
    const provider = {
      generateReconstruction: vi.fn().mockResolvedValue(makeProposalResponse()),
    };

    const { reconsiderCompletedEpisode } = await import("@/lib/graph/orchestrator.js");
    const result = await reconsiderCompletedEpisode(
      { ...TEST_EPISODE, provider },
      { getModelName: () => "configured", buildEpisodePrompt: buildEpisodeAwareGraphPrompt },
    );

    expect(result.success).toBe(true);
    expect(provider.generateReconstruction.mock.calls.length).toBe(1);
    expect(provider.generateReconstruction).toHaveBeenCalledWith("EPISODE_PROMPT_V2", "configured");
  });

  it("reuses existing parser — returns parsed GraphUpdateProposal shape for valid JSON", async () => {
    const provider = {
      generateReconstruction: vi.fn().mockResolvedValue(JSON.stringify(makeProposalResponse())),
    };

    const { reconsiderCompletedEpisode } = await import("@/lib/graph/orchestrator.js");
    const result = await reconsiderCompletedEpisode(
      TEST_EPISODE,
      { getModelName: () => "configured", provider },
    );

    expect(result.success).toBe(true);
    expect(result.stage).toBe("proposal_ready");
    expect(result.proposal).toMatchObject({
      updatedNodes: [expect.objectContaining({ nodeId: "n-unknown" })],
      resolvedUnknownNodeIds: ["n-unknown"],
      answerMeaning: null,
      structuralActionRequired: false,
    });
  });

  it("preserves existing parser error behaviour for invalid provider result", async () => {
    const provider = {
      generateReconstruction: vi.fn().mockResolvedValue("{ not valid json }"),
    };

    const { reconsiderCompletedEpisode } = await import("@/lib/graph/orchestrator.js");
    const result = await reconsiderCompletedEpisode(
      TEST_EPISODE,
      { getModelName: () => "configured", provider },
    );

    expect(result.success).toBe(false);
    expect(result.stage).toBe("proposal_validation");
    expect(result.error).toBe("Invalid graph update proposal");
    expect(result.statusCode).toBe(502);
    expect(result.proposalErrors).toBeInstanceOf(Array);
  });

  it("does not perform any graph mutation or application", async () => {
    const applyValidatedProposal = vi.fn();
    const provider = {
      generateReconstruction: vi.fn().mockResolvedValue(makeProposalResponse()),
    };

    const { reconsiderCompletedEpisode } = await import("@/lib/graph/orchestrator.js");
    const result = await reconsiderCompletedEpisode(
      TEST_EPISODE,
      { getModelName: () => "configured", provider, applyValidatedProposal },
    );

    expect(result.success).toBe(true);
    expect(applyValidatedProposal).not.toHaveBeenCalled();

    // No mutation of the input episode's graph
    expect(TEST_EPISODE.situationGraph.nodes.length).toBe(1);
  });

  it("resolves configured model via assertConfig fallback when no deps model is injected", async () => {
    // Set minimal env vars for assertConfig to succeed in this specific test
    const prevBaseUrl = process.env.OLLAMA_BASE_URL;
    const prevModel = process.env.OLLAMA_MODEL;
    process.env.OLLAMA_BASE_URL = "http://localhost:11434";
    process.env.OLLAMA_MODEL = "test-model";

    const modelCaptured = [];
    const provider = {
      generateReconstruction: vi.fn().mockImplementation((prompt, model) => {
        modelCaptured.push(model);
        return makeProposalResponse();
      }),
    };

    // Reset modules so assertConfig reads fresh env vars
    await vi.resetModules();

    const { reconsiderCompletedEpisode } = await import("@/lib/graph/orchestrator.js");
    // Empty deps — matches route.js call: reconsiderCompletedEpisode(prepared)
    // The fix ensures assertConfig() provides a model instead of leaving it null
    const result = await reconsiderCompletedEpisode(
      { ...TEST_EPISODE, provider },
      {},
    );

    expect(result.success).toBe(true);
    expect(modelCaptured.length).toBe(1);
    expect(modelCaptured[0]).not.toBeNull();
    expect(typeof modelCaptured[0]).toBe("string");

    // Restore env
    if (prevBaseUrl == null) delete process.env.OLLAMA_BASE_URL;
    else process.env.OLLAMA_BASE_URL = prevBaseUrl;
    if (prevModel == null) delete process.env.OLLAMA_MODEL;
    else process.env.OLLAMA_MODEL = prevModel;
  });

});