import { describe, it, expect } from "vitest";
import { parseContentDispositionFilename, sanitizeFilename } from "./auth-fetch";

describe("parseContentDispositionFilename", () => {
  it("returns null for an empty header", () => {
    expect(parseContentDispositionFilename("")).toBeNull();
  });

  it("returns null when no filename directive is present", () => {
    expect(parseContentDispositionFilename("attachment")).toBeNull();
    expect(parseContentDispositionFilename("inline; modification-date=foo")).toBeNull();
  });

  describe("basic form", () => {
    it("extracts a quoted filename", () => {
      expect(parseContentDispositionFilename('attachment; filename="invoice.pdf"')).toBe(
        "invoice.pdf",
      );
    });

    it("extracts an unquoted token filename", () => {
      expect(parseContentDispositionFilename("attachment; filename=invoice.pdf")).toBe(
        "invoice.pdf",
      );
    });

    it("preserves spaces inside a quoted value", () => {
      expect(
        parseContentDispositionFilename('attachment; filename="invoice with spaces.pdf"'),
      ).toBe("invoice with spaces.pdf");
    });

    it("matches case-insensitively", () => {
      expect(parseContentDispositionFilename('attachment; FileName="invoice.pdf"')).toBe(
        "invoice.pdf",
      );
    });

    it("tolerates whitespace around `=`", () => {
      expect(parseContentDispositionFilename('attachment; filename = "invoice.pdf"')).toBe(
        "invoice.pdf",
      );
    });
  });

  describe("RFC 5987 extended form", () => {
    it("decodes a UTF-8 value with no language", () => {
      expect(
        parseContentDispositionFilename("attachment; filename*=UTF-8''invoice%20Jan.pdf"),
      ).toBe("invoice Jan.pdf");
    });

    it("decodes a UTF-8 value with a language tag", () => {
      expect(
        parseContentDispositionFilename("attachment; filename*=UTF-8'en'invoice%20Jan.pdf"),
      ).toBe("invoice Jan.pdf");
    });

    it("decodes non-ASCII characters", () => {
      // %E2%82%AC is the Euro sign.
      expect(
        parseContentDispositionFilename("attachment; filename*=UTF-8''price%20%E2%82%AC.pdf"),
      ).toBe("price €.pdf");
    });

    it("matches the charset case-insensitively", () => {
      expect(
        parseContentDispositionFilename("attachment; filename*=utf-8''invoice%20Jan.pdf"),
      ).toBe("invoice Jan.pdf");
    });

    it("prefers the extended form when both forms are present (RFC 6266)", () => {
      expect(
        parseContentDispositionFilename(
          "attachment; filename=\"fallback.pdf\"; filename*=UTF-8''invoice%20Jan.pdf",
        ),
      ).toBe("invoice Jan.pdf");
    });

    it("falls back to the basic form when the charset is non-UTF-8", () => {
      expect(
        parseContentDispositionFilename(
          "attachment; filename=\"basic.pdf\"; filename*=ISO-8859-1''invoice.pdf",
        ),
      ).toBe("basic.pdf");
    });

    it("returns null when the only filename uses a non-UTF-8 charset", () => {
      expect(
        parseContentDispositionFilename("attachment; filename*=ISO-8859-1''invoice.pdf"),
      ).toBeNull();
    });

    it("falls back to the basic form when extended percent-encoding is malformed", () => {
      // `%E0%` is a truncated escape — decodeURIComponent will throw.
      expect(
        parseContentDispositionFilename(
          "attachment; filename=\"basic.pdf\"; filename*=UTF-8''broken%E0%",
        ),
      ).toBe("basic.pdf");
    });
  });
});

describe("sanitizeFilename", () => {
  it("returns null for nullish input", () => {
    expect(sanitizeFilename(null)).toBeNull();
    expect(sanitizeFilename("")).toBeNull();
  });

  it("returns the input verbatim when already safe", () => {
    expect(sanitizeFilename("invoice.pdf")).toBe("invoice.pdf");
  });

  it("trims surrounding whitespace", () => {
    expect(sanitizeFilename("  invoice.pdf  ")).toBe("invoice.pdf");
  });

  it("strips POSIX path prefixes", () => {
    expect(sanitizeFilename("../etc/passwd")).toBe("passwd");
    expect(sanitizeFilename("/tmp/invoice.pdf")).toBe("invoice.pdf");
    expect(sanitizeFilename("a/b/c/invoice.pdf")).toBe("invoice.pdf");
  });

  it("strips Windows path prefixes", () => {
    expect(sanitizeFilename("C:\\Users\\me\\invoice.pdf")).toBe("invoice.pdf");
    expect(sanitizeFilename("..\\..\\invoice.pdf")).toBe("invoice.pdf");
  });

  it("returns null when the final segment is `.` or `..`", () => {
    expect(sanitizeFilename(".")).toBeNull();
    expect(sanitizeFilename("..")).toBeNull();
    expect(sanitizeFilename("a/b/.")).toBeNull();
    expect(sanitizeFilename("a/b/..")).toBeNull();
  });

  it("returns null when only path separators are supplied", () => {
    expect(sanitizeFilename("/")).toBeNull();
    expect(sanitizeFilename("\\")).toBeNull();
    expect(sanitizeFilename("///")).toBeNull();
  });

  it("preserves dots inside a normal filename", () => {
    expect(sanitizeFilename("invoice.v2.final.pdf")).toBe("invoice.v2.final.pdf");
  });

  it("preserves non-ASCII characters", () => {
    expect(sanitizeFilename("invoice €.pdf")).toBe("invoice €.pdf");
    expect(sanitizeFilename("請求書.pdf")).toBe("請求書.pdf");
  });
});