import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import {
  fetchGiteaBranch,
  fetchGiteaText,
  fetchGiteaTreeBlobPaths,
  giteaApiBase,
  giteaHostProbeCache,
  isPrivateOrLoopbackHost,
  parseGiteaSourceUrl,
  probeGiteaHost,
  resolveGiteaPinnedRef,
  resolveRawGiteaUrl,
  resolveRawGiteaUrlLegacy,
  setGiteaHostProbe,
} from "../services/gitea-skills.js";

function jsonResponse(body: unknown, init?: { status?: number; ok?: boolean }) {
  const status = init?.status ?? 200;
  return {
    ok: init?.ok ?? (status >= 200 && status < 300),
    status,
    statusText: status === 200 ? "OK" : "Error",
    text: () => Promise.resolve(JSON.stringify(body)),
    json: () => Promise.resolve(body),
  } as unknown as Response;
}

function textResponse(body: string, init?: { status?: number; ok?: boolean }) {
  const status = init?.status ?? 200;
  return {
    ok: init?.ok ?? (status >= 200 && status < 300),
    status,
    statusText: status === 200 ? "OK" : "Error",
    text: () => Promise.resolve(body),
    json: () => Promise.reject(new Error("not json")),
  } as unknown as Response;
}

describe("giteaApiBase", () => {
  it("returns the Gitea API base", () => {
    expect(giteaApiBase("git.example.com")).toBe("https://git.example.com/api/v1");
  });
});

describe("resolveRawGiteaUrl", () => {
  it("builds the modern /raw/branch/ URL", () => {
    expect(resolveRawGiteaUrl("git.example.com", "acme", "skills", "main", "foo/SKILL.md"))
      .toBe("https://git.example.com/acme/skills/raw/branch/main/foo/SKILL.md");
  });

  it("strips leading slashes from the file path", () => {
    expect(resolveRawGiteaUrl("git.example.com", "acme", "skills", "abc123", "/nested/file.md"))
      .toBe("https://git.example.com/acme/skills/raw/branch/abc123/nested/file.md");
  });
});

describe("resolveRawGiteaUrlLegacy", () => {
  it("builds the legacy /raw/ URL", () => {
    expect(resolveRawGiteaUrlLegacy("git.example.com", "acme", "skills", "main", "SKILL.md"))
      .toBe("https://git.example.com/acme/skills/raw/main/SKILL.md");
  });
});

describe("parseGiteaSourceUrl", () => {
  it("parses a plain repo URL", () => {
    expect(parseGiteaSourceUrl("https://git.example.com/acme/skills")).toEqual({
      hostname: "git.example.com",
      owner: "acme",
      repo: "skills",
      ref: "main",
      basePath: "",
      filePath: null,
      explicitRef: false,
    });
  });

  it("strips .git suffix", () => {
    expect(parseGiteaSourceUrl("https://git.example.com/acme/skills.git").repo).toBe("skills");
  });

  it("parses a /tree/{ref}/{basePath} URL", () => {
    expect(parseGiteaSourceUrl("https://git.example.com/acme/skills/tree/dev/skills/web")).toEqual({
      hostname: "git.example.com",
      owner: "acme",
      repo: "skills",
      ref: "dev",
      basePath: "skills/web",
      filePath: null,
      explicitRef: true,
    });
  });

  it("parses a /blob/{ref}/{filePath} URL", () => {
    expect(parseGiteaSourceUrl("https://git.example.com/acme/skills/blob/main/SKILL.md")).toEqual({
      hostname: "git.example.com",
      owner: "acme",
      repo: "skills",
      ref: "main",
      basePath: ".",
      filePath: "SKILL.md",
      explicitRef: true,
    });
  });

  it("rejects non-HTTPS URLs", () => {
    expect(() => parseGiteaSourceUrl("http://git.example.com/acme/skills")).toThrow(/HTTPS/);
  });

  it("rejects URLs with fewer than 2 path segments", () => {
    expect(() => parseGiteaSourceUrl("https://git.example.com/acme")).toThrow(/Invalid Gitea URL/);
  });

  it("rejects URLs with empty repo after .git strip", () => {
    expect(() => parseGiteaSourceUrl("https://git.example.com/acme/.git")).toThrow(
      /owner and repo are required/,
    );
  });

  it("rejects URLs pointing at private/loopback hosts", () => {
    expect(() => parseGiteaSourceUrl("https://192.168.1.10/acme/skills")).toThrow(
      /private, loopback/,
    );
    expect(() => parseGiteaSourceUrl("https://localhost/acme/skills")).toThrow(
      /private, loopback/,
    );
  });
});

describe("isPrivateOrLoopbackHost", () => {
  it("flags loopback and localhost variants", () => {
    expect(isPrivateOrLoopbackHost("localhost")).toBe(true);
    expect(isPrivateOrLoopbackHost("127.0.0.1")).toBe(true);
    expect(isPrivateOrLoopbackHost("127.99.99.99")).toBe(true);
    expect(isPrivateOrLoopbackHost("::1")).toBe(true);
    expect(isPrivateOrLoopbackHost("foo.localhost")).toBe(true);
  });

  it("flags RFC1918 ranges", () => {
    expect(isPrivateOrLoopbackHost("10.0.0.1")).toBe(true);
    expect(isPrivateOrLoopbackHost("172.16.0.1")).toBe(true);
    expect(isPrivateOrLoopbackHost("172.31.255.254")).toBe(true);
    expect(isPrivateOrLoopbackHost("192.168.1.1")).toBe(true);
  });

  it("flags link-local and 0.0.0.0", () => {
    expect(isPrivateOrLoopbackHost("169.254.169.254")).toBe(true);
    expect(isPrivateOrLoopbackHost("0.0.0.0")).toBe(true);
    expect(isPrivateOrLoopbackHost("fe80::1")).toBe(true);
    expect(isPrivateOrLoopbackHost("fd00::1")).toBe(true);
  });

  it("allows public hosts", () => {
    expect(isPrivateOrLoopbackHost("git.example.com")).toBe(false);
    expect(isPrivateOrLoopbackHost("gitea.com")).toBe(false);
    expect(isPrivateOrLoopbackHost("172.32.0.1")).toBe(false);
    expect(isPrivateOrLoopbackHost("11.0.0.1")).toBe(false);
  });
});

describe("probeGiteaHost", () => {
  beforeEach(() => {
    giteaHostProbeCache.clear();
  });

  it("returns true when /api/v1/version returns Gitea-shaped JSON", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue(jsonResponse({ version: "1.21.0" })),
    );
    const result = await probeGiteaHost("git.example.com");
    expect(result).toBe(true);
  });

  it("returns false on 200 with non-JSON body", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue({
        ok: true,
        status: 200,
        text: () => Promise.resolve("<html>not gitea</html>"),
        json: () => Promise.reject(new Error("not json")),
      } as unknown as Response),
    );
    const result = await probeGiteaHost("git.example.com");
    expect(result).toBe(false);
  });

  it("returns false on 404", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue(jsonResponse({}, { status: 404, ok: false })),
    );
    const result = await probeGiteaHost("git.example.com");
    expect(result).toBe(false);
  });

  it("returns false on network error", async () => {
    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(new Error("ECONNREFUSED")));
    const result = await probeGiteaHost("git.example.com");
    expect(result).toBe(false);
  });

  it("caches positive and negative results", async () => {
    const fetchMock = vi.fn().mockResolvedValue(jsonResponse({ version: "1.21.0" }));
    vi.stubGlobal("fetch", fetchMock);
    await probeGiteaHost("git.example.com");
    await probeGiteaHost("git.example.com");
    expect(fetchMock).toHaveBeenCalledTimes(1);
  });

  it("reuses a manually-set cache entry without hitting fetch", async () => {
    setGiteaHostProbe("git.example.com", true);
    const fetchMock = vi.fn();
    vi.stubGlobal("fetch", fetchMock);
    const result = await probeGiteaHost("git.example.com");
    expect(result).toBe(true);
    expect(fetchMock).not.toHaveBeenCalled();
  });

  it("short-circuits to false for private/loopback hosts without making a request", async () => {
    const fetchMock = vi.fn();
    vi.stubGlobal("fetch", fetchMock);
    expect(await probeGiteaHost("127.0.0.1")).toBe(false);
    expect(await probeGiteaHost("192.168.1.1")).toBe(false);
    expect(await probeGiteaHost("localhost")).toBe(false);
    expect(fetchMock).not.toHaveBeenCalled();
  });
});

describe("resolveGiteaPinnedRef", () => {
  beforeEach(() => {
    giteaHostProbeCache.clear();
  });

  it("returns the 40-hex ref as the pinned ref", async () => {
    const sha = "0123456789abcdef0123456789abcdef01234567";
    vi.stubGlobal("fetch", vi.fn());
    const result = await resolveGiteaPinnedRef(
      parseGiteaSourceUrl(`https://git.example.com/acme/skills/tree/${sha}`),
    );
    expect(result).toEqual({ pinnedRef: sha, trackingRef: sha });
  });

  it("resolves a branch ref to its commit SHA via the branches endpoint", async () => {
    const branchSha = "fedcba9876543210fedcba9876543210fedcba98";
    const fetchMock = vi
      .fn()
      .mockResolvedValueOnce(jsonResponse({ default_branch: "main" }))
      .mockResolvedValueOnce(jsonResponse({ name: "main", commit: { id: branchSha } }));
    vi.stubGlobal("fetch", fetchMock);
    const result = await resolveGiteaPinnedRef(
      parseGiteaSourceUrl("https://git.example.com/acme/skills"),
    );
    expect(result).toEqual({ pinnedRef: branchSha, trackingRef: "main" });
    expect(fetchMock).toHaveBeenCalledTimes(2);
  });
});

describe("fetchGiteaTreeBlobPaths", () => {
  it("returns blob paths from a single-page tree", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue(
        jsonResponse({
          tree: [
            { path: "README.md", type: "blob" },
            { path: "skills", type: "tree" },
            { path: "skills/web/SKILL.md", type: "blob" },
            { path: "skills/cli/SKILL.md", type: "blob" },
          ],
          truncated: false,
        }),
      ),
    );
    const paths = await fetchGiteaTreeBlobPaths(giteaApiBase("git.example.com"), "acme", "skills", "main");
    expect(paths).toEqual(["README.md", "skills/web/SKILL.md", "skills/cli/SKILL.md"]);
  });

  it("paginates when the tree is truncated", async () => {
    const fetchMock = vi
      .fn()
      .mockResolvedValueOnce(
        jsonResponse({
          tree: [{ path: "a.md", type: "blob" }],
          truncated: true,
        }),
      )
      .mockResolvedValueOnce(
        jsonResponse({
          tree: [{ path: "b.md", type: "blob" }],
          truncated: false,
        }),
      );
    vi.stubGlobal("fetch", fetchMock);
    const paths = await fetchGiteaTreeBlobPaths(giteaApiBase("git.example.com"), "acme", "skills", "main");
    expect(paths).toEqual(["a.md", "b.md"]);
    expect(fetchMock).toHaveBeenCalledTimes(2);
    expect(String(fetchMock.mock.calls[1]?.[0])).toContain("page=2");
  });

  it("throws when the page cap is hit while the tree is still truncated", async () => {
    // Return truncated=true on every page so the loop hits MAX_PAGES (50).
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue(
        jsonResponse({
          tree: [{ path: "page.md", type: "blob" }],
          truncated: true,
        }),
      ),
    );
    await expect(
      fetchGiteaTreeBlobPaths(giteaApiBase("git.example.com"), "acme", "skills", "main"),
    ).rejects.toThrow(/exceeds .* entries/);
  });
});

describe("fetchGiteaText", () => {
  it("returns the body from the canonical URL on 200", async () => {
    vi.stubGlobal("fetch", vi.fn().mockResolvedValue(textResponse("---\nname: x\n---\n# body\n")));
    const content = await fetchGiteaText("git.example.com", "acme", "skills", "main", "SKILL.md");
    expect(content).toContain("# body");
  });

  it("falls back to the legacy /raw/ URL on 404", async () => {
    const fetchMock = vi
      .fn()
      .mockResolvedValueOnce(textResponse("", { status: 404, ok: false }))
      .mockResolvedValueOnce(textResponse("legacy body"));
    vi.stubGlobal("fetch", fetchMock);
    const content = await fetchGiteaText("git.example.com", "acme", "skills", "main", "SKILL.md");
    expect(content).toBe("legacy body");
    expect(fetchMock).toHaveBeenCalledTimes(2);
    expect(String(fetchMock.mock.calls[0]?.[0])).toContain("/raw/branch/");
    expect(String(fetchMock.mock.calls[1]?.[0])).toContain("/raw/main/");
  });

  it("throws unprocessable when both URLs fail with non-404", async () => {
    const fetchMock = vi
      .fn()
      .mockResolvedValueOnce(textResponse("", { status: 500, ok: false }));
    vi.stubGlobal("fetch", fetchMock);
    await expect(
      fetchGiteaText("git.example.com", "acme", "skills", "main", "SKILL.md"),
    ).rejects.toThrow(/500/);
  });
});

describe("fetchGiteaBranch", () => {
  it("returns the branch response", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue(
        jsonResponse({ name: "main", commit: { id: "deadbeef".repeat(5) } }),
      ),
    );
    const branch = await fetchGiteaBranch(giteaApiBase("git.example.com"), "acme", "skills", "main");
    expect(branch.commit?.id).toBe("deadbeef".repeat(5));
  });
});

afterEach(() => {
  vi.unstubAllGlobals();
  vi.restoreAllMocks();
});