import { mkdtempSync, readFileSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import { beforeEach, describe, expect, it } from "vitest";
import { importSillyTavernPreset } from "../src/preset/importer.js";
import {
  EMPTY_SHELL_SLOTS,
  assembleDirectChatMessages,
  createShell,
  getDirectChatsDir,
  getShell,
  worldInfoPackFromDirectChat,
} from "../src/direct-chat/index.js";

function samplePreset() {
  return importSillyTavernPreset({
    prompts: [
      { identifier: "main", name: "Main", role: "system", content: "MAIN" },
      { identifier: "chatHistory", name: "History", role: "system", marker: true },
    ],
    prompt_order: [
      {
        character_id: 1,
        order: [
          { identifier: "main", enabled: true },
          { identifier: "chatHistory", enabled: true },
        ],
      },
    ],
  }).preset;
}

const slots = (extra: Record<string, unknown> = {}) => ({
  ...EMPTY_SHELL_SLOTS,
  ...extra,
});

describe("直聊种子历史：结构化真多轮", () => {
  beforeEach(() => {
    process.env.WRITING_AGENT_DATA_DIR = mkdtempSync(
      path.join(tmpdir(), "wa-seed-history-"),
    );
  });

  it("seedMessages 每条一个 message，排在已有轮次之前", () => {
    const messages = assembleDirectChatMessages(samplePreset(), {
      message: "继续",
      slots: slots({
        seedMessages: [
          { role: "user", content: "前情-问" },
          { role: "assistant", content: "前情-答" },
        ],
      }),
      priorMessages: [{ role: "user", content: "真-问" }],
    });
    const contents = messages.map((m) => String(m.content));
    const at = (text: string) => contents.findIndex((c) => c.includes(text));
    expect(at("前情-问")).toBeGreaterThanOrEqual(0);
    expect(at("前情-问")).toBeLessThan(at("前情-答"));
    expect(at("前情-答")).toBeLessThan(at("真-问"));
    expect(at("真-问")).toBeLessThan(at("继续"));
    // 真轮次，不是塞进 system 的 few-shot
    expect(messages.some((m) => m.name)).toBe(false);
  });

  it("seedMessages 优先于旧版 seedHistory 文本", () => {
    const pack = worldInfoPackFromDirectChat({
      message: "继续",
      slots: slots({
        seedHistory: "## 用户\n\n旧文本",
        seedMessages: [{ role: "assistant", content: "新结构" }],
      }),
      priorMessages: [],
    });
    expect(pack.history).toEqual([{ role: "assistant", content: "新结构" }]);
  });

  it("脏条目丢掉，全空时回落旧文本", () => {
    const pack = worldInfoPackFromDirectChat({
      message: "继续",
      slots: slots({
        seedHistory: "## 用户\n\n旧文本",
        seedMessages: [
          { role: "system", content: "不是历史角色" },
          { role: "user", content: "   " },
        ],
      }),
      priorMessages: [],
    });
    expect(pack.history).toEqual([{ role: "user", content: "旧文本" }]);
  });

  it("读旧盘时把种子历史文本迁成结构化条目并落盘", () => {
    const shell = createShell({ name: "旧壳", slots: slots() });
    const file = path.join(getDirectChatsDir(), "shells", `${shell.id}.json`);
    writeFileSync(
      file,
      JSON.stringify({
        ...shell,
        seedHistory: "【用户】\n我推开门\n\n【助手】\n屋里没有人。\n\n【系统】\n旁白一句",
      }),
      "utf8",
    );

    const loaded = getShell(shell.id);
    expect(loaded?.seedHistory).toBe("");
    expect(loaded?.seedMessages).toEqual([
      { role: "user", content: "我推开门" },
      { role: "assistant", content: "屋里没有人。" },
      { role: "assistant", content: "旁白一句" },
    ]);
    // 迁移要写回盘，下次读到的就是新形状
    const onDisk = JSON.parse(readFileSync(file, "utf8")) as { seedMessages?: unknown };
    expect(Array.isArray(onDisk.seedMessages)).toBe(true);
  });

  it("切不出轮次的旧文本挪进前情，避免变成看不见的发送内容", () => {
    const shell = createShell({ name: "读料壳", slots: slots({ loreBefore: "设定" }) });
    const file = path.join(getDirectChatsDir(), "shells", `${shell.id}.json`);
    writeFileSync(file, JSON.stringify({ ...shell, seedHistory: "一段没有块头的读料" }), "utf8");

    const loaded = getShell(shell.id);
    expect(loaded?.seedHistory).toBe("");
    expect(loaded?.seedMessages).toEqual([]);
    expect(loaded?.loreBefore).toBe("设定\n\n一段没有块头的读料");
  });
});