import { describe, it, expect, beforeEach, afterEach } from "bun:test";
import { mkdir, writeFile, rm } from "node:fs/promises";
import { join } from "node:path";
import { loadConfig, findProjectRoot, getRuneDir, validateConfig } from "../../src/core/config.ts";
import { ConfigError } from "../../src/cli/errors.ts";
import type { RuneConfig } from "../../src/types.ts";

const TMP_DIR = join(import.meta.dir, "__tmp_config_test__");

beforeEach(async () => {
  await mkdir(TMP_DIR, { recursive: true });
});

afterEach(async () => {
  await rm(TMP_DIR, { recursive: true, force: true });
});

describe("findProjectRoot", () => {
  it("当前目录存在 .rune/ 时返回当前目录", async () => {
    await mkdir(join(TMP_DIR, ".rune"));
    expect(findProjectRoot(TMP_DIR)).toBe(TMP_DIR);
  });

  it("子目录中向上查找到 .rune/", async () => {
    await mkdir(join(TMP_DIR, ".rune"));
    const sub = join(TMP_DIR, "src", "commands");
    await mkdir(sub, { recursive: true });
    expect(findProjectRoot(sub)).toBe(TMP_DIR);
  });

  it("找不到 .rune/ 时返回 null", () => {
    expect(findProjectRoot("/tmp/__nonexistent__")).toBeNull();
  });
});

describe("loadConfig", () => {
  it("无配置文件时返回默认配置", async () => {
    await mkdir(join(TMP_DIR, ".rune"));
    const config = await loadConfig(TMP_DIR);
    expect(config.stages.discuss).toBeDefined();
    expect(config.stages.plan).toBeDefined();
    expect(config.stages.build).toBeDefined();
    expect(config.stages.archive).toBeDefined();
  });

  it("用户配置覆盖默认配置（全量替换）", async () => {
    const runeDir = join(TMP_DIR, ".rune");
    await mkdir(runeDir, { recursive: true });
    await writeFile(
      join(runeDir, "config.yaml"),
      `stages:
  discuss:
    prompt: 自定义讨论提示词
`,
    );
    const config = await loadConfig(TMP_DIR);
    expect(config.stages.discuss!.prompt).toBe("自定义讨论提示词");
    expect(config.stages.plan).toBeDefined();
    expect(config.stages.build).toBeDefined();
    expect(config.stages.archive).toBeDefined();
  });

  it("用户配置 plan 时完全替换内置 documents", async () => {
    const runeDir = join(TMP_DIR, ".rune");
    await mkdir(runeDir, { recursive: true });
    await writeFile(
      join(runeDir, "config.yaml"),
      `stages:
  plan:
    documents:
      - name: spec
        prompt: 生成规格文档
`,
    );
    const config = await loadConfig(TMP_DIR);
    expect(config.stages.plan!.documents).toHaveLength(1);
    expect(config.stages.plan!.documents[0].name).toBe("spec");
  });

  it("空配置 stages: {} 时返回完整默认配置", async () => {
    const runeDir = join(TMP_DIR, ".rune");
    await mkdir(runeDir, { recursive: true });
    await writeFile(join(runeDir, "config.yaml"), "stages: {}");
    const config = await loadConfig(TMP_DIR);
    expect(config.stages.discuss).toBeDefined();
    expect(config.stages.plan).toBeDefined();
    expect(config.stages.build).toBeDefined();
    expect(config.stages.archive).toBeDefined();
  });

  it("YAML 解析错误时返回默认配置", async () => {
    const runeDir = join(TMP_DIR, ".rune");
    await mkdir(runeDir, { recursive: true });
    await writeFile(join(runeDir, "config.yaml"), `stages: [invalid yaml {{{`);
    const config = await loadConfig(TMP_DIR);
    expect(config.stages.discuss).toBeDefined();
  });
});

describe("getRuneDir", () => {
  it("返回 .rune 目录路径", () => {
    expect(getRuneDir("/project")).toBe(join("/project", ".rune"));
  });
});

describe("validateConfig", () => {
  it("正常配置不抛错", () => {
    const config: RuneConfig = {
      stages: {
        plan: {
          documents: [
            { name: "design", prompt: "生成设计" },
            { name: "task", prompt: "生成任务", depend: ["design"] },
          ],
        },
      },
    };
    expect(() => validateConfig(config)).not.toThrow();
  });

  it("depend 引用不存在的文档时报错", () => {
    const config: RuneConfig = {
      stages: {
        plan: {
          documents: [{ name: "task", prompt: "生成任务", depend: ["nonexistent"] }],
        },
      },
    };
    expect(() => validateConfig(config)).toThrow(ConfigError);
  });

  it("自依赖报错", () => {
    const config: RuneConfig = {
      stages: {
        plan: {
          documents: [{ name: "design", prompt: "生成设计", depend: ["design"] }],
        },
      },
    };
    expect(() => validateConfig(config)).toThrow(ConfigError);
  });

  it("循环依赖报错", () => {
    const config: RuneConfig = {
      stages: {
        plan: {
          documents: [
            { name: "a", prompt: "a", depend: ["b"] },
            { name: "b", prompt: "b", depend: ["a"] },
          ],
        },
      },
    };
    expect(() => validateConfig(config)).toThrow(ConfigError);
  });

  it("无 plan 阶段时不报错", () => {
    const config: RuneConfig = { stages: {} };
    expect(() => validateConfig(config)).not.toThrow();
  });

  it("depend 为空数组时不报错", () => {
    const config: RuneConfig = {
      stages: {
        plan: {
          documents: [{ name: "design", prompt: "生成设计", depend: [] }],
        },
      },
    };
    expect(() => validateConfig(config)).not.toThrow();
  });
});