import { describe, expect, test } from "bun:test";
import { collapseHookSummaries } from "../collapseHookSummaries";

function makeHookSummary(overrides: Partial<{
  hookLabel: string;
  hookCount: number;
  hookInfos: any[];
  hookErrors: any[];
  preventedContinuation: boolean;
  hasOutput: boolean;
  totalDurationMs: number;
}> = {}): any {
  return {
    type: "system",
    subtype: "stop_hook_summary",
    hookLabel: overrides.hookLabel ?? "PostToolUse",
    hookCount: overrides.hookCount ?? 1,
    hookInfos: overrides.hookInfos ?? [],
    hookErrors: overrides.hookErrors ?? [],
    preventedContinuation: overrides.preventedContinuation ?? false,
    hasOutput: overrides.hasOutput ?? false,
    totalDurationMs: overrides.totalDurationMs ?? 10,
  };
}

function makeNonHookMessage(): any {
  return { type: "user", message: { content: "hello" } };
}

describe("collapseHookSummaries", () => {
  test("returns same messages when no hook summaries", () => {
    const messages = [makeNonHookMessage(), makeNonHookMessage()];
    expect(collapseHookSummaries(messages)).toEqual(messages);
  });

  test("collapses consecutive messages with same hookLabel", () => {
    const messages = [
      makeHookSummary({ hookLabel: "PostToolUse", hookCount: 1 }),
      makeHookSummary({ hookLabel: "PostToolUse", hookCount: 2 }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result).toHaveLength(1);
    expect(result[0].hookCount).toBe(3);
  });

  test("does not collapse messages with different hookLabels", () => {
    const messages = [
      makeHookSummary({ hookLabel: "PostToolUse" }),
      makeHookSummary({ hookLabel: "PreToolUse" }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result).toHaveLength(2);
  });

  test("aggregates hookCount across collapsed messages", () => {
    const messages = [
      makeHookSummary({ hookLabel: "A", hookCount: 3 }),
      makeHookSummary({ hookLabel: "A", hookCount: 5 }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result[0].hookCount).toBe(8);
  });

  test("merges hookInfos arrays", () => {
    const info1 = { tool: "Read" };
    const info2 = { tool: "Write" };
    const messages = [
      makeHookSummary({ hookLabel: "A", hookInfos: [info1] }),
      makeHookSummary({ hookLabel: "A", hookInfos: [info2] }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result[0].hookInfos).toEqual([info1, info2]);
  });

  test("merges hookErrors arrays", () => {
    const err1 = new Error("e1");
    const err2 = new Error("e2");
    const messages = [
      makeHookSummary({ hookLabel: "A", hookErrors: [err1] }),
      makeHookSummary({ hookLabel: "A", hookErrors: [err2] }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result[0].hookErrors).toHaveLength(2);
  });

  test("takes max totalDurationMs", () => {
    const messages = [
      makeHookSummary({ hookLabel: "A", totalDurationMs: 50 }),
      makeHookSummary({ hookLabel: "A", totalDurationMs: 100 }),
      makeHookSummary({ hookLabel: "A", totalDurationMs: 75 }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result[0].totalDurationMs).toBe(100);
  });

  test("takes any truthy preventContinuation", () => {
    const messages = [
      makeHookSummary({ hookLabel: "A", preventedContinuation: false }),
      makeHookSummary({ hookLabel: "A", preventedContinuation: true }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result[0].preventedContinuation).toBe(true);
  });

  test("leaves single hook summary unchanged", () => {
    const msg = makeHookSummary({ hookLabel: "PostToolUse", hookCount: 5 });
    const result = collapseHookSummaries([msg]);
    expect(result).toHaveLength(1);
    expect(result[0].hookCount).toBe(5);
  });

  test("handles three consecutive same-label summaries", () => {
    const messages = [
      makeHookSummary({ hookLabel: "X", hookCount: 1 }),
      makeHookSummary({ hookLabel: "X", hookCount: 1 }),
      makeHookSummary({ hookLabel: "X", hookCount: 1 }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result).toHaveLength(1);
    expect(result[0].hookCount).toBe(3);
  });

  test("preserves non-hook messages in between", () => {
    const messages = [
      makeHookSummary({ hookLabel: "A" }),
      makeNonHookMessage(),
      makeHookSummary({ hookLabel: "A" }),
    ];
    const result = collapseHookSummaries(messages);
    expect(result).toHaveLength(3);
  });

  test("returns empty array for empty input", () => {
    expect(collapseHookSummaries([])).toEqual([]);
  });
});