import { mkdtempSync, readdirSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import {
  EMPTY_NODE_STATE,
  nodeState,
  readServiceState,
  removeNodeState,
  serviceStatePath,
  updateNodeState,
  writeServiceState,
} from "../src/state.js";

let dir: string;

beforeEach(() => {
  dir = mkdtempSync(join(tmpdir(), "mattertimesync-state-"));
});

afterEach(() => {
  rmSync(dir, { recursive: true, force: true });
});

describe("service state", () => {
  it("returns empty state when the file does not exist", () => {
    expect(readServiceState(join(dir, "missing.json"))).toEqual({ nodes: {} });
  });

  it("round-trips per-node state through disk", () => {
    const path = serviceStatePath(dir);
    const state = {
      nodes: {
        "12345678901234567890": {
          lastSuccessfulConnection: "2026-07-26T20:00:00Z",
          lastSuccessfulSync: "2026-07-26T20:00:02Z",
          lastAttemptedSync: "2026-07-26T20:00:01Z",
          lastError: null,
        },
        "2": { ...EMPTY_NODE_STATE, lastError: "unreachable" },
      },
    };
    writeServiceState(path, state);
    expect(readServiceState(path)).toEqual(state);
  });

  it("leaves no temporary file behind after writing", () => {
    const path = serviceStatePath(dir);
    writeServiceState(path, { nodes: {} });
    expect(readdirSync(dir)).toEqual(["service-state.json"]);
  });

  it("returns empty state for a corrupt file instead of throwing", () => {
    const path = join(dir, "corrupt.json");
    writeFileSync(path, "{ this is not json");
    expect(readServiceState(path)).toEqual({ nodes: {} });
  });

  it("drops malformed node keys and wrongly typed fields", () => {
    const path = join(dir, "typed.json");
    writeFileSync(
      path,
      JSON.stringify({
        nodes: {
          "not-a-node-id": { lastError: "x" },
          "7": { lastError: ["array"], lastSuccessfulSync: "2026-07-26T20:00:02Z" },
        },
      }),
    );
    expect(readServiceState(path)).toEqual({
      nodes: { "7": { ...EMPTY_NODE_STATE, lastSuccessfulSync: "2026-07-26T20:00:02Z" } },
    });
  });

  it("merges patches into one node without touching others", () => {
    const path = serviceStatePath(dir);
    updateNodeState(path, 1n, { lastError: "boom" });
    updateNodeState(path, 2n, { lastSuccessfulSync: "2026-07-26T20:00:02Z" });
    updateNodeState(path, 1n, { lastAttemptedSync: "2026-07-26T20:00:01Z" });

    const state = readServiceState(path);
    expect(nodeState(state, 1n)).toEqual({
      ...EMPTY_NODE_STATE,
      lastError: "boom",
      lastAttemptedSync: "2026-07-26T20:00:01Z",
    });
    expect(nodeState(state, 2n)).toEqual({
      ...EMPTY_NODE_STATE,
      lastSuccessfulSync: "2026-07-26T20:00:02Z",
    });
  });

  it("removes a node's entry", () => {
    const path = serviceStatePath(dir);
    updateNodeState(path, 1n, { lastError: "boom" });
    updateNodeState(path, 2n, {});
    removeNodeState(path, 1n);

    const state = readServiceState(path);
    expect(Object.keys(state.nodes)).toEqual(["2"]);
    expect(nodeState(state, 1n)).toEqual(EMPTY_NODE_STATE);
  });
});