import { describe, expect, it } from "vitest";
import { submitAnswerForUpdateCase, synthesizeFromFindings } from "@/components/scenario-form.jsx";
import { normalizeFindings } from "@/lib/graph/finding-helpers.js";

/* ───────────── Case A — graph-only update ───────────── */

describe("case/update synthesis — Case A (graph-only update)", () => {
  it("produces exactly 1 synthesis call with updated graph + complete existing Findings", async () => {
    const originalGraph = { centralStatement: "Q3 financial decline", nodes: [{ id: "n1" }], edges: [] };
    const findings = [
      { id: "f-1", proposition: "Revenue dropped 22%", sourceObservation: "Revenue dropped 22%" },
      { id: "f-2", proposition: "Competitor launched pricing campaign", sourceObservation: "Competitor launched pricing campaign" },
    ];

    let synthesisCalls = [];
    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        const body = JSON.parse(init.body);
        return new Response(JSON.stringify({
          success: true,
          updatedSituationGraph: { ...body.situationGraph, centralStatement: "Updated Q3 financial decline" },
          selectedQuestion: "What is the root cause?",
          appendedFindings: [], // graph only — no new findings
        }), { status: 200, headers: { "Content-Type": "application/json" } });
      }
      if (url === "/api/cases/synthesis") {
        synthesisCalls.push(JSON.parse(init.body));
        return new Response(
          JSON.stringify({ currentUnderstanding: "DEDICATED RECONSTRUCTION" }),
          { status: 200, headers: { "Content-Type": "application/json" } },
        );
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: originalGraph,
      previousQuestion: "What's the impact?",
      answer: "Answer text",
      findings,
    });

    expect(submission.ok).toBe(true);
    expect(submission.data.success).toBe(true);

    // Derive next canonical state (explicit — no React reread)
    const nextGraph = submission.data.updatedSituationGraph;
    let nextFindings = [...findings];

    // Trigger synthesis exactly once
    const synResult = await synthesizeFromFindings(mockFetch, { situationGraph: nextGraph, findings: normalizeFindings(nextFindings) });

    expect(synthesisCalls).toHaveLength(1);
    expect(synResult.ok).toBe(true);
    expect(synthesisCalls[0].situationGraph.centralStatement).toBe(nextGraph.centralStatement);
    expect(synthesisCalls[0].findings).toHaveLength(2); // complete existing Findings
  });
});

/* ───────────── Case B — graph + Findings ───────────── */

describe("case/update synthesis — Case B (graph + Findings)", () => {
  it("produces exactly 1 synthesis call with updated graph + all Findings", async () => {
    const originalGraph = { centralStatement: "Q3 decline", nodes: [{ id: "n1" }], edges: [] };
    const findings = [
      { id: "f-1", proposition: "Revenue dropped 22%", sourceObservation: "Revenue dropped 22%" },
    ];

    let synthesisCalls = [];
    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        const body = JSON.parse(init.body);
        return new Response(JSON.stringify({
          success: true,
          updatedSituationGraph: { ...body.situationGraph, centralStatement: "Updated Q3 decline" },
          selectedQuestion: "Root cause?",
          appendedFindings: [
            { id: "f-2-new", proposition: "New Finding from update", sourceObservation: "New Finding from update" },
          ],
        }), { status: 200, headers: { "Content-Type": "application/json" } });
      }
      if (url === "/api/cases/synthesis") {
        synthesisCalls.push(JSON.parse(init.body));
        return new Response(
          JSON.stringify({ currentUnderstanding: "DEDICATED RECONSTRUCTION" }),
          { status: 200, headers: { "Content-Type": "application/json" } },
        );
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: originalGraph,
      previousQuestion: "What's the impact?",
      answer: "Answer text",
      findings,
    });

    expect(submission.ok).toBe(true);

    // Derive next canonical state (explicit)
    const nextGraph = submission.data.updatedSituationGraph;
    let nextFindings = [...findings, ...submission.data.appendedFindings];

    const synResult = await synthesizeFromFindings(mockFetch, { situationGraph: nextGraph, findings: normalizeFindings(nextFindings) });

    expect(synthesisCalls).toHaveLength(1); // exactly one synthesis
    expect(synResult.ok).toBe(true);
    expect(synthesisCalls[0].findings).toHaveLength(2); // original + appended
    expect(synthesisCalls[0].situationGraph.centralStatement).toBe(nextGraph.centralStatement);
  });
});

/* ───────────── Case C — dedicated reconstruction wins ───────────── */

describe("case/update synthesis — Case C (dedicated reconstruction wins)", () => {
  it("final CU is dedicated reconstruction, not outcome.summary", async () => {
    const originalGraph = { centralStatement: "test" };
    let cuState = "previous understanding";

    let synthesisCalls = [];
    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        return new Response(JSON.stringify({
          success: true,
          updatedSituationGraph: { centralStatement: "updated" },
          selectedQuestion: "Q?",
          appendedFindings: [],
          summary: "OLD UPDATE SUMMARY",
        }), { status: 200, headers: { "Content-Type": "application/json" } });
      }
      if (url === "/api/cases/synthesis") {
        synthesisCalls.push(JSON.parse(init.body));
        return new Response(
          JSON.stringify({ currentUnderstanding: "DEDICATED RECONSTRUCTION" }),
          { status: 200, headers: { "Content-Type": "application/json" } },
        );
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: originalGraph,
      previousQuestion: "Q?",
      answer: "A",
      findings: [],
    });

    expect(submission.ok).toBe(true);
    expect(submission.data.summary).toBe("OLD UPDATE SUMMARY");

    // Derive next state and synthesize (the correct path)
    const nextGraph = submission.data.updatedSituationGraph;
    let nextFindings = [];
    const synResult = await synthesizeFromFindings(mockFetch, { situationGraph: nextGraph, findings: normalizeFindings(nextFindings) });

    if (synResult.ok && synResult.data?.currentUnderstanding) {
      cuState = synResult.data.currentUnderstanding;
    }

    expect(cuState).toBe("DEDICATED RECONSTRUCTION");
    expect(cuState).not.toBe("OLD UPDATE SUMMARY");
  });
});

/* ───────────── Case D — synthesis failure ───────────── */

describe("case/update synthesis — Case D (synthesis failure)", () => {
  it("preserves updated graph and Findings, preserves previous CU, one attempt no retry", async () => {
    const originalGraph = { centralStatement: "test" };
    const findings = [{ id: "f-1", proposition: "Fact X" }];
    let cuState = "previous understanding";

    let synthesisCallCount = 0;
    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        return new Response(JSON.stringify({
          success: true,
          updatedSituationGraph: { centralStatement: "updated from update" },
          selectedQuestion: "Q?",
          appendedFindings: [],
          summary: "OLD UPDATE SUMMARY",
        }), { status: 200, headers: { "Content-Type": "application/json" } });
      }
      if (url === "/api/cases/synthesis") {
        synthesisCallCount++;
        return new Response(
          JSON.stringify({ success: false, error: "provider timeout" }),
          { status: 503, headers: { "Content-Type": "application/json" } },
        );
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: originalGraph,
      previousQuestion: "Q?",
      answer: "A",
      findings,
    });

    expect(submission.ok).toBe(true);

    // Derive next state — graph and findings preserved (not lost)
    const nextGraph = submission.data.updatedSituationGraph;
    let nextFindings = [...findings];

    // Synthesis attempt (explicit)
    const synResult = await synthesizeFromFindings(mockFetch, { situationGraph: nextGraph, findings: normalizeFindings(nextFindings) });

    expect(synthesisCallCount).toBe(1); // one attempt only
    expect(synResult.ok).toBe(false); // failed

    // Updated graph and findings are still available (not lost on synthesis failure)
    expect(nextGraph.centralStatement).toBe("updated from update");
    expect(nextFindings).toHaveLength(1);

    // Previous CU preserved — no fallback to outcome.summary
    expect(cuState).toBe("previous understanding");
  });
});

/* ───────────── Case E — update failure ───────────── */

describe("case/update synthesis — Case E (update failure)", () => {
  it("synthesis calls = 0 when update fails", async () => {
    let synthesisCallCount = 0;
    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        return new Response(
          JSON.stringify({ success: false, error: "update failed" }),
          { status: 400, headers: { "Content-Type": "application/json" } },
        );
      }
      if (url === "/api/cases/synthesis") {
        synthesisCallCount++;
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: { centralStatement: "test" },
      previousQuestion: "Q?",
      answer: "A",
      findings: [],
    });

    expect(submission.ok).toBe(false);
    expect(synthesisCallCount).toBe(0); // synthesis NOT called when update fails
  });
});

/* ───────────── Edge: outcome.summary is NOT final CU authority ───────────── */

describe("case/update — outcome.summary retired as final CU authority", () => {
  it("when dedicated reconstruction succeeds, CU = reconstruction not summary", async () => {
    let cuState = "old";
    let synthesisCalls = [];

    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        return new Response(JSON.stringify({
          success: true,
          updatedSituationGraph: { centralStatement: "x" },
          selectedQuestion: "Q?",
          appendedFindings: [],
          summary: "WRONG FINAL CU",
        }), { status: 200 });
      }
      if (url === "/api/cases/synthesis") {
        synthesisCalls.push(JSON.parse(init.body));
        return new Response(
          JSON.stringify({ currentUnderstanding: "DEDICATED RECONSTRUCTION" }),
          { status: 200 },
        );
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: { centralStatement: "x" },
      previousQuestion: "Q?",
      answer: "A",
      findings: [],
    });

    expect(submission.ok).toBe(true);

    // The correct path: synthesize → CU = reconstruction
    const nextGraph = submission.data.updatedSituationGraph;
    let nextFindings = [];
    const synResult = await synthesizeFromFindings(mockFetch, { situationGraph: nextGraph, findings: normalizeFindings(nextFindings) });

    if (synResult.ok && synResult.data?.currentUnderstanding) {
      cuState = synResult.data.currentUnderstanding;
    }

    expect(cuState).toBe("DEDICATED RECONSTRUCTION");
    expect(synthesisCalls).toHaveLength(1);
  });
});

/* ───────────── Edge: previous CU is NOT synthesis input ───────────── */

describe("case/update — previous CU not sent to synthesis", () => {
  it("synthesis payload only contains situationGraph + findings, no currentUnderstanding", async () => {
    let capturedPayload = null;

    const mockFetch = async (url, init) => {
      if (url === "/api/cases/update") {
        return new Response(JSON.stringify({
          success: true,
          updatedSituationGraph: { centralStatement: "x" },
          selectedQuestion: "Q?",
          appendedFindings: [],
        }), { status: 200 });
      }
      if (url === "/api/cases/synthesis") {
        capturedPayload = JSON.parse(init.body);
        return new Response(JSON.stringify({ currentUnderstanding: "RECON" }), { status: 200 });
      }
      return new Response(JSON.stringify({}), { status: 200 });
    };

    const submission = await submitAnswerForUpdateCase(mockFetch, {
      situationGraph: { centralStatement: "x" },
      previousQuestion: "Q?",
      answer: "A",
      findings: [],
    });

    const nextGraph = submission.data.updatedSituationGraph;
    await synthesizeFromFindings(mockFetch, { situationGraph: nextGraph, findings: normalizeFindings([]) });

    expect(capturedPayload).not.toHaveProperty("currentUnderstanding");
    expect(capturedPayload.situationGraph).toBeDefined();
    expect(Array.isArray(capturedPayload.findings)).toBe(true);
  });
});