import { mkdtempSync, rmSync } from "node:fs";
import { Readable } from "node:stream";
import os from "node:os";
import path from "node:path";
import type { IncomingMessage, ServerResponse } from "node:http";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { savePreset } from "../src/preset/store.js";
import { handlePresetLabApi } from "../src/server/preset-lab-handlers.js";
import type { PresetPackage } from "../src/types/preset.js";

function preset(id = "lab"): PresetPackage {
  return {
    id,
    name: "工作台预设",
    source: "native",
    prompts: [
      { id: "sys", name: "规则", enabled: true, role: "system", content: "\u4f60\u662f{{char}}", marker: false, sourceIdentifier: "sys" },
      { id: "chatHistory", name: "历史", enabled: true, role: "system", content: "", marker: true, sourceIdentifier: "chatHistory" },
    ],
    promptOrder: [
      { promptId: "sys", enabled: true, orderIndex: 0 },
      { promptId: "chatHistory", enabled: true, orderIndex: 1 },
    ],
    generation: {},
    unsupported: [],
    importedAt: new Date().toISOString(),
  };
}

type Captured = { status: number; body: any };

async function call(
  pathname: string,
  init: { method?: string; body?: unknown; query?: string } = {},
): Promise<Captured> {
  const raw = init.body === undefined ? "" : JSON.stringify(init.body);
  const req = Readable.from(raw ? [Buffer.from(raw, "utf8")] : []) as unknown as IncomingMessage;
  (req as any).method = init.method ?? "GET";
  let status = 0;
  let payload = "";
  const res = {
    writeHead(code: number) {
      status = code;
    },
    end(chunk: string) {
      payload = chunk ?? "";
    },
  } as unknown as ServerResponse;
  const handled = await handlePresetLabApi(req, res, pathname, new URLSearchParams(init.query ?? ""));
  expect(handled).toBe(true);
  return { status, body: payload ? JSON.parse(payload) : null };
}

let dir = "";
beforeEach(() => {
  dir = mkdtempSync(path.join(os.tmpdir(), "preset-lab-api-"));
  process.env.WRITING_AGENT_DATA_DIR = dir;
  savePreset(preset());
});
afterEach(() => {
  delete process.env.WRITING_AGENT_DATA_DIR;
  rmSync(dir, { recursive: true, force: true });
});

describe("预设工作台 API", () => {
  it("非本模块路径不接管", async () => {
    const req = Readable.from([]) as unknown as IncomingMessage;
    (req as any).method = "GET";
    const res = { writeHead() {}, end() {} } as unknown as ServerResponse;
    expect(await handlePresetLabApi(req, res, "/api/settings/x", new URLSearchParams())).toBe(false);
  });

  it("列出预设", async () => {
    const { status, body } = await call("/api/preset-lab/presets");
    expect(status).toBe(200);
    expect(body.presets.some((p: any) => p.id === "lab")).toBe(true);
  });

  it("读取单个预设与结构检查", async () => {
    const one = await call("/api/preset-lab/preset", { query: "presetId=lab" });
    expect(one.body.preset.id).toBe("lab");
    const checked = await call("/api/preset-lab/check", { method: "POST", body: { preset: one.body.preset } });
    expect(checked.body.issues.filter((i: any) => i.level === "error")).toHaveLength(0);
  });

  it("提交版本后能读回版本树", async () => {
    const committed = await call("/api/preset-lab/versions/commit", {
      method: "POST",
      body: { preset: preset(), note: "第一次" },
    });
    expect(committed.body.nodes).toHaveLength(1);
    const tree = await call("/api/preset-lab/versions", { query: "presetId=lab" });
    expect(tree.body.currentId).toBe(committed.body.nodes[0].id);
  });

  it("保存至当前版本只覆盖节点，不新增", async () => {
    const first = await call("/api/preset-lab/versions/commit", {
      method: "POST",
      body: { preset: preset(), note: "建根" },
    });
    const nodeId = first.body.currentId;
    const edited = { ...preset(), name: "改过的名字" };
    const amended = await call("/api/preset-lab/versions/amend", {
      method: "POST",
      body: { preset: edited, note: "就地改" },
    });
    expect(amended.body.nodes).toHaveLength(1);
    expect(amended.body.currentId).toBe(nodeId);
    const node = amended.body.nodes[0];
    expect(node.id).toBe(nodeId);
    expect(node.parentId).toBe(null);
    expect(node.preset.name).toBe("改过的名字");
    expect(node.note).toBe("就地改");
    expect(typeof node.updatedAt).toBe("string");
  });

  it("预览按用例组装消息，{{char}} 被替换", async () => {
    const { status, body } = await call("/api/preset-lab/preview", {
      method: "POST",
      body: {
        preset: preset(),
        testCase: { id: "c", name: "c", charName: "林", charDescription: "", worldBook: "", userInput: "开门", history: [] },
      },
    });
    expect(status).toBe(200);
    const text = body.messages.map((m: any) => m.content).join("\n");
    expect(text).toContain("你是林");
    expect(text).toContain("开门");
  });

  it("测试组保存与列出", async () => {
    const saved = await call("/api/preset-lab/groups/save", {
      method: "POST",
      body: { presetId: "lab", name: "组一", cases: [{ name: "a", userInput: "hi" }] },
    });
    expect(saved.body.cases[0].id).toBeTruthy();
    const groups = await call("/api/preset-lab/groups", { query: "presetId=lab" });
    expect(groups.body.groups).toHaveLength(1);
  });

  it("缺少 preset 时返回 400 而不是崩溃", async () => {
    const { status, body } = await call("/api/preset-lab/check", { method: "POST", body: {} });
    expect(status).toBe(400);
    expect(body.error).toContain("preset");
  });
});