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

import {
  ReviewFrameBuffer,
  initialReviewState,
  parseReviewBlock,
  reduceReview,
  type ReviewSseEvent,
} from "./sse";

describe("parseReviewBlock", () => {
  it("parses a section frame", () => {
    const evt = parseReviewBlock(
      'event:section\ndata:{"name":"continuity","status":"done"}',
    );
    expect(evt).toEqual({
      event: "section",
      data: { name: "continuity", status: "done" },
    });
  });

  it("parses a conflict frame", () => {
    const evt = parseReviewBlock(
      'event:conflict\ndata:{"type":"设定违例","where":"第4段","refs":["第30章"],"suggestion":"统一血脉设定"}',
    );
    expect(evt).toEqual({
      event: "conflict",
      data: {
        type: "设定违例",
        where: "第4段",
        refs: ["第30章"],
        suggestion: "统一血脉设定",
      },
    });
  });

  it("parses done and error frames", () => {
    expect(parseReviewBlock('event:done\ndata:{"length":1}')).toEqual({
      event: "done",
      data: { length: 1 },
    });
    expect(
      parseReviewBlock(
        'event:error\ndata:{"code":"INTERNAL","message":"boom","request_id":"r1"}',
      ),
    ).toEqual({
      event: "error",
      data: { code: "INTERNAL", message: "boom", request_id: "r1" },
    });
  });

  it("returns null for unknown event or malformed json", () => {
    expect(parseReviewBlock('event:token\ndata:{"text":"x"}')).toBeNull();
    expect(parseReviewBlock("event:conflict\ndata:{not json")).toBeNull();
  });
});

describe("ReviewFrameBuffer", () => {
  it("emits complete blocks and buffers the tail", () => {
    const buf = new ReviewFrameBuffer();
    const first = buf.push(
      'event:section\ndata:{"name":"continuity","status":"started"}\n\nevent:conf',
    );
    expect(first).toEqual([
      { event: "section", data: { name: "continuity", status: "started" } },
    ]);
    const second = buf.push(
      'lict\ndata:{"type":"性格漂移","where":"第2段","refs":[],"suggestion":"x"}\n\n',
    );
    expect(second).toEqual([
      {
        event: "conflict",
        data: { type: "性格漂移", where: "第2段", refs: [], suggestion: "x" },
      },
    ]);
  });
});

describe("reduceReview", () => {
  it("upserts sections by name (last status wins) and marks reviewing", () => {
    const events: ReviewSseEvent[] = [
      { event: "section", data: { name: "continuity", status: "started" } },
      { event: "section", data: { name: "continuity", status: "done" } },
    ];
    const state = events.reduce(reduceReview, initialReviewState);
    expect(state.sections).toEqual([
      { name: "continuity", status: "done" },
    ]);
    expect(state.phase).toBe("reviewing");
  });

  it("accumulates conflicts in order", () => {
    const events: ReviewSseEvent[] = [
      {
        event: "conflict",
        data: { type: "设定违例", where: "a", refs: [], suggestion: "s1" },
      },
      {
        event: "conflict",
        data: { type: "时间线倒错", where: "b", refs: ["第3章"], suggestion: "s2" },
      },
    ];
    const state = events.reduce(reduceReview, initialReviewState);
    expect(state.conflicts.map((c) => c.type)).toEqual([
      "设定违例",
      "时间线倒错",
    ]);
  });

  it("marks done and captures error preserving collected data", () => {
    let s = reduceReview(initialReviewState, {
      event: "section",
      data: { name: "continuity", status: "done" },
    });
    s = reduceReview(s, { event: "done", data: { length: 1 } });
    expect(s.phase).toBe("done");

    let e = reduceReview(initialReviewState, {
      event: "conflict",
      data: { type: "能力不符", where: "x", refs: [], suggestion: "y" },
    });
    e = reduceReview(e, {
      event: "error",
      data: { code: "LLM_UNAVAILABLE", message: "no key" },
    });
    expect(e.phase).toBe("error");
    expect(e.conflicts).toHaveLength(1);
    expect(e.error?.code).toBe("LLM_UNAVAILABLE");
  });
});