import { describe, expect, test } from "bun:test";
import { rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";

import { loadServerConfig, parseRuntimeArgs } from "../../src/server/config";

describe("parseRuntimeArgs", () => {
  test("无参数返回空对象", () => {
    const result = parseRuntimeArgs([]);
    expect(result).toEqual({});
  });

  test("有参数返回 configPath", () => {
    const result = parseRuntimeArgs(["config.yaml"]);
    expect(result).toEqual({ configPath: "config.yaml" });
  });

  test("--help 输出用法并退出", () => {
    const logs: string[] = [];
    let exitCode: number | undefined;
    const originalLog = console.log;
    console.log = (...args: unknown[]) => logs.push(args.join(" "));
    Object.defineProperty(process, "exit", {
      configurable: true,
      value: (code: number) => {
        exitCode = code;
      },
      writable: true,
    });
    try {
      parseRuntimeArgs(["--help"]);
    } finally {
      Object.defineProperty(process, "exit", {
        configurable: true,
        value: process.exit.bind(process),
        writable: true,
      });
      console.log = originalLog;
    }
    expect(exitCode).toBe(0);
    expect(logs.some((l) => l.includes("用法"))).toBe(true);
  });

  test("-h 输出用法并退出", () => {
    const logs: string[] = [];
    let exitCode: number | undefined;
    const originalLog = console.log;
    console.log = (...args: unknown[]) => logs.push(args.join(" "));
    Object.defineProperty(process, "exit", {
      configurable: true,
      value: (code: number) => {
        exitCode = code;
      },
      writable: true,
    });
    try {
      parseRuntimeArgs(["-h"]);
    } finally {
      Object.defineProperty(process, "exit", {
        configurable: true,
        value: process.exit.bind(process),
        writable: true,
      });
      console.log = originalLog;
    }
    expect(exitCode).toBe(0);
    expect(logs.some((l) => l.includes("用法"))).toBe(true);
  });
});

describe("loadServerConfig", () => {
  test("无 configPath 使用默认值", async () => {
    const config = await loadServerConfig();
    expect(config.host).toBe("127.0.0.1");
    expect(config.port).toBe(3000);
  });

  test("环境变量 HOST 不影响默认值（无隐式覆盖）", async () => {
    const prev = process.env["HOST"];
    process.env["HOST"] = "0.0.0.0";
    try {
      const config = await loadServerConfig();
      expect(config.host).toBe("127.0.0.1");
    } finally {
      if (prev === undefined) {
        delete process.env["HOST"];
      } else {
        process.env["HOST"] = prev;
      }
    }
  });

  test("环境变量 PORT 不影响默认值（无隐式覆盖）", async () => {
    const prev = process.env["PORT"];
    process.env["PORT"] = "8080";
    try {
      const config = await loadServerConfig();
      expect(config.port).toBe(3000);
    } finally {
      if (prev === undefined) {
        delete process.env["PORT"];
      } else {
        process.env["PORT"] = prev;
      }
    }
  });

  test("YAML 配置文件不存在时报错", async () => {
    try {
      await loadServerConfig("/nonexistent/path/config.yaml");
      expect.unreachable();
    } catch (error) {
      expect((error as Error).message).toContain("配置文件不存在");
    }
  });

  test("新布局 server.listen 加载成功", async () => {
    const temp = tmpdir();
    const yamlPath = join(temp, "test-listen.yaml");
    const yamlContent = 'server:\n  listen:\n    host: "0.0.0.0"\n    port: 9999\n';
    await writeFile(yamlPath, yamlContent);

    try {
      const config = await loadServerConfig(yamlPath);
      expect(config.host).toBe("0.0.0.0");
      expect(config.port).toBe(9999);
    } finally {
      await rm(yamlPath, { force: true });
    }
  });

  test("旧布局 server.host/server.port 被拒绝", async () => {
    const temp = tmpdir();
    const yamlPath = join(temp, "test-old-layout.yaml");
    const yamlContent = 'server:\n  host: "0.0.0.0"\n  port: 9999\n';
    await writeFile(yamlPath, yamlContent);

    try {
      await loadServerConfig(yamlPath);
      expect.unreachable();
    } catch (error) {
      expect((error as Error).message).toContain("未知字段");
    } finally {
      await rm(yamlPath, { force: true });
    }
  });

  test("非法端口被拒绝", async () => {
    const temp = tmpdir();
    const yamlPath = join(temp, "test-bad-port.yaml");
    const yamlContent = "server:\n  listen:\n    port: 99999\n";
    await writeFile(yamlPath, yamlContent);

    try {
      await loadServerConfig(yamlPath);
      expect.unreachable();
    } catch (error) {
      expect((error as Error).message).toBeTruthy();
    } finally {
      await rm(yamlPath, { force: true });
    }
  });

  test("显式变量引用环境变量生效", async () => {
    const prevHost = process.env["HOST"];
    const prevPort = process.env["PORT"];
    process.env["HOST"] = "10.0.0.1";
    process.env["PORT"] = "4000";

    const temp = tmpdir();
    const yamlPath = join(temp, "test-env-var.yaml");
    const yamlContent = 'server:\n  listen:\n    host: "${HOST}"\n    port: ${PORT}\n';
    await writeFile(yamlPath, yamlContent);

    try {
      const config = await loadServerConfig(yamlPath);
      expect(config.host).toBe("10.0.0.1");
      expect(config.port).toBe(4000);
    } finally {
      await rm(yamlPath, { force: true });
      if (prevHost === undefined) delete process.env["HOST"];
      else process.env["HOST"] = prevHost;
      if (prevPort === undefined) delete process.env["PORT"];
      else process.env["PORT"] = prevPort;
    }
  });

  test("变量带默认值生效", async () => {
    delete process.env["MY_HOST"];
    const temp = tmpdir();
    const yamlPath = join(temp, "test-default.yaml");
    const yamlContent = 'server:\n  listen:\n    host: "${MY_HOST|0.0.0.0}"\n    port: ${MY_PORT|5000}\n';
    await writeFile(yamlPath, yamlContent);

    try {
      const config = await loadServerConfig(yamlPath);
      expect(config.host).toBe("0.0.0.0");
      expect(config.port).toBe(5000);
    } finally {
      await rm(yamlPath, { force: true });
    }
  });
});