/**
 * Focused test suite for the second contribution persistence invariant.
 *
 * The flow during a focused deconstruct success is:
 *   1. handleDeconstructSubmit (workspace) calls fetch to /api/focused-investigation/deconstruct
 *   2. Route returns { success: true, observations[], uncertainties[], ... }
 *   3. workspace calls onFocusedContribution({ targetNodeId, question, answer, ... })
 *   4. parent scenario-form calls appendFocusedContribution(contrib) -> [ ...prev, contrib ]
 *   5. useEffect watching focusedContributions triggers saveSession(...)
 *
 * Invariant: a SECOND successful deconstruct appends to the existing collection,
 * not replacing it. Both contributions survive a session reload.
 */

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

// -- helpers that mirror production code exactly --

function simulateAppendContributions(contributions, newContribution) {
  return [
    ...contributions,
    {
      ...newContribution,
      id: `contrib-${String(contributions.length + 1).padStart(4, "0")}`,
      sequence: contributions.length + 1,
    },
  ];
}

function simulateSaveSession(state) {
  return JSON.stringify({
    scenario: state.scenario,
    situationGraph: state.situationGraph,
    selectedQuestion: state.selectedQuestion,
    summary: state.summary,
    updatedAt: new Date().toISOString(),
    focusedContributions: state.focusedContributions,
  });
}

function simulateRestoreSession(raw) {
  if (!raw) return null;
  const parsed = JSON.parse(raw);
  return {
    ...parsed,
    focusedContributions: parsed.focusedContributions || [],
  };
}

/** Simulates a successful deconstruct API response (after the targetNodeId fix). */
function simulateDeconstructResponse(body) {
  return {
    success: true,
    targetNodeId: body.targetNodeId, // fixed: always uses body value
    observations: [`${body.targetNodeId}-observation`],
    uncertainties: [`${body.targetNodeId}-uncertainty`],
    assumptions: [`${body.targetNodeId}-assumption`],
    relationships: [{ from: body.targetNodeId, to: "context", type: "informs" }],
    possibleFollowUpQuestions: [`What about ${body.targetLabel}?`],
  };
}

// -- Second contribution persistence after deconstruct success --

describe("second contribution persistence after deconstruct success", () => {
  it("first deconstruct creates one contribution, session saves it", () => {
    let state = { scenario: "test", situationGraph: {}, focusedContributions: [] };

    const contrib1Data = simulateDeconstructResponse({ targetNodeId: "nk-001", targetLabel: "First thread" });

    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contrib1Data.targetNodeId,
      question: "What is the main risk?",
      answer: "Regulatory compliance in EU.",
      ...contrib1Data,
    });

    expect(state.focusedContributions).toHaveLength(1);
    expect(state.focusedContributions[0].id).toBe("contrib-0001");
    expect(state.focusedContributions[0].targetNodeId).toBe("nk-001");
    expect(state.focusedContributions[0].question).toBe("What is the main risk?");

    const raw = simulateSaveSession(state);
    const restored = simulateRestoreSession(raw);
    expect(restored.focusedContributions).toHaveLength(1);
    expect(restored.focusedContributions[0].targetNodeId).toBe("nk-001");
  });

  it("second deconstruct appends a NEW contribution (not replace)", () => {
    let state = { scenario: "test", situationGraph: {}, focusedContributions: [] };

    // First contribution
    const contrib1Data = simulateDeconstructResponse({ targetNodeId: "nk-001", targetLabel: "First thread" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contrib1Data.targetNodeId,
      question: "What is the main risk?",
      answer: "Regulatory compliance.",
      ...contrib1Data,
    });

    // Second deconstruct -- user reopens SAME thread and submits a different answer
    const contrib2Data = simulateDeconstructResponse({ targetNodeId: "nk-001", targetLabel: "Second follow-up" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contrib2Data.targetNodeId,
      question: "Which EU regulation applies?",
      answer: "GDPR Article 32.",
      ...contrib2Data,
    });

    // CRITICAL INVARIANT: TWO contributions exist (not replaced)
    expect(state.focusedContributions).toHaveLength(2);
    expect(state.focusedContributions[0].id).toBe("contrib-0001");
    expect(state.focusedContributions[0].question).toBe("What is the main risk?");
    expect(state.focusedContributions[1].id).toBe("contrib-0002");
    expect(state.focusedContributions[1].question).toBe("Which EU regulation applies?");

    // Both share the same original targetNodeId (distinct records for same node)
    expect(state.focusedContributions[0].targetNodeId).toBe("nk-001");
    expect(state.focusedContributions[1].targetNodeId).toBe("nk-001");
  });

  it("session save/restore survives two deconstructs on same thread", () => {
    let state = { scenario: "test", situationGraph: {}, focusedContributions: [] };

    // First contribution
    const contrib1Data = simulateDeconstructResponse({ targetNodeId: "nk-002", targetLabel: "Risk" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contrib1Data.targetNodeId, question: "Q1?", answer: "A1", ...contrib1Data,
    });

    // Save
    let raw = simulateSaveSession(state);
    let restored = simulateRestoreSession(raw);
    expect(restored.focusedContributions).toHaveLength(1);

    // Second contribution (simulates reopening the same thread after reload)
    const contrib2Data = simulateDeconstructResponse({ targetNodeId: "nk-002", targetLabel: "Follow-up" });
    restored.focusedContributions = simulateAppendContributions(restored.focusedContributions, {
      targetNodeId: contrib2Data.targetNodeId, question: "Q2?", answer: "A2", ...contrib2Data,
    });

    // Save again
    raw = simulateSaveSession(restored);
    restored = simulateRestoreSession(raw);
    expect(restored.focusedContributions).toHaveLength(2);
    expect(restored.focusedContributions[0].question).toBe("Q1?");
    expect(restored.focusedContributions[1].question).toBe("Q2?");
  });

  it("second deconstruct on DIFFERENT thread also appends correctly", () => {
    let state = { scenario: "test", situationGraph: {}, focusedContributions: [] };

    // First: thread A
    const contribA = simulateDeconstructResponse({ targetNodeId: "nk-A", targetLabel: "Thread A" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contribA.targetNodeId, question: "A?", answer: "A1", ...contribA,
    });

    // Second: thread B (user selects a different open question)
    const contribB = simulateDeconstructResponse({ targetNodeId: "nk-B", targetLabel: "Thread B" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contribB.targetNodeId, question: "B?", answer: "B1", ...contribB,
    });

    expect(state.focusedContributions).toHaveLength(2);
    const threadAContribs = state.focusedContributions.filter((c) => c.targetNodeId === "nk-A");
    const threadBContribs = state.focusedContributions.filter((c) => c.targetNodeId === "nk-B");

    expect(threadAContribs).toHaveLength(1);
    expect(threadAContribs[0].question).toBe("A?");
    expect(threadBContribs).toHaveLength(1);
    expect(threadBContribs[0].question).toBe("B?");
  });

  it("third contribution also appends -- no upper bound limit on count", () => {
    let contributions = [];

    for (let i = 1; i <= 5; i++) {
      const body = { targetNodeId: `nk-${i}`, targetLabel: `Thread ${i}` };
      const data = simulateDeconstructResponse(body);
      contributions = simulateAppendContributions(contributions, {
        targetNodeId: data.targetNodeId,
        question: `Q${i}?`,
        answer: `A${i}`,
        ...data,
      });

      expect(contributions).toHaveLength(i);
      expect(contributions[i - 1].id).toBe(`contrib-${String(i).padStart(4, "0")}`);
      expect(contributions[i - 1].sequence).toBe(i);
    }
  });

  it("deconstruct failure does NOT append (preserves prior contributions)", () => {
    let state = { scenario: "test", situationGraph: {}, focusedContributions: [] };

    // First contribution succeeds
    const contribData = simulateDeconstructResponse({ targetNodeId: "nk-ok", targetLabel: "OK" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contribData.targetNodeId, question: "Q?", answer: "A", ...contribData,
    });

    expect(state.focusedContributions).toHaveLength(1);

    // Second "deconstruct" fails -- no append call occurs
    const beforeCount = state.focusedContributions.length;

    // Simulate failure: the contribution is NOT added
    expect(state.focusedContributions).toHaveLength(beforeCount);
  });

  it("contribution fields survive exact LLM round-trip through append", () => {
    const rawLLMResponse = {
      targetNodeId: "nk-003",
      observations: [
        "The founder has deep tacit knowledge of operational processes.",
        "Documentation exists but is outdated.",
      ],
      uncertainties: ["Whether the founder's knowledge can be transferred without loss."],
      assumptions: ["That the board understands the documentation gap."],
      relationships: [
        { from: "founder", to: "processes", type: "holds" },
        { from: "docs", to: "knowledge", type: "partially_captures" },
      ],
      possibleFollowUpQuestions: [
        "What processes are undocumented?",
        "Who in the board is most aware of this gap?",
      ],
    };

    const contrib = simulateAppendContributions([], {
      ...rawLLMResponse,
      question: "How much operational knowledge is undocumented?",
      answer: "Most of it -- the founder's mind is the repository.",
    });

    expect(contrib[0].id).toBeTruthy();
    expect(contrib[0].targetNodeId).toBe("nk-003");
    expect(contrib[0].observations).toEqual(rawLLMResponse.observations);
    expect(contrib[0].uncertainties).toEqual(rawLLMResponse.uncertainties);
    expect(contrib[0].assumptions).toEqual(rawLLMResponse.assumptions);
    expect(contrib[0].relationships).toEqual(rawLLMResponse.relationships);
    expect(contrib[0].possibleFollowUpQuestions).toEqual(rawLLMResponse.possibleFollowUpQuestions);
  });

  it("full lifecycle: deconstruct -> append -> save -> reload -> second deconstruct -> append again", () => {
    // Phase 1: First deconstruct
    let state = { scenario: "test", situationGraph: {}, focusedContributions: [] };

    const contrib1 = simulateDeconstructResponse({ targetNodeId: "nk-x", targetLabel: "Thread 1" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contrib1.targetNodeId, question: "Initial Q?", answer: "Initial A.", ...contrib1,
    });

    // Save + reload simulates user leaving and returning
    let session = simulateSaveSession(state);
    state = simulateRestoreSession(session) || { scenario: "test", situationGraph: {}, focusedContributions: [] };

    expect(state.focusedContributions).toHaveLength(1);
    expect(state.focusedContributions[0].question).toBe("Initial Q?");

    // Phase 2: Second deconstruct after reload
    const contrib2 = simulateDeconstructResponse({ targetNodeId: "nk-x", targetLabel: "Thread 1 follow-up" });
    state.focusedContributions = simulateAppendContributions(state.focusedContributions, {
      targetNodeId: contrib2.targetNodeId, question: "Follow-up Q?", answer: "Follow-up A.", ...contrib2,
    });

    expect(state.focusedContributions).toHaveLength(2);
    expect(state.focusedContributions[0].question).toBe("Initial Q?");   // First preserved
    expect(state.focusedContributions[1].question).toBe("Follow-up Q?");  // Second appended
    expect(state.focusedContributions[0].targetNodeId).toBe(state.focusedContributions[1].targetNodeId);

    // Final save confirms both survive
    session = simulateSaveSession(state);
    state = simulateRestoreSession(session);
    expect(state.focusedContributions).toHaveLength(2);
  });
});