package avatar

import (
	"bytes"
	"mime/multipart"
	"net/textproto"
	"os"
	"path/filepath"
	"testing"

	"github.com/google/uuid"
)

func TestResolveAbsRejectsTraversal(t *testing.T) {
	dir := t.TempDir()
	id := uuid.New()
	name := id.String() + ".jpg"
	if err := os.WriteFile(filepath.Join(dir, name), []byte("x"), 0o644); err != nil {
		t.Fatal(err)
	}
	if _, err := ResolveAbs(dir, "../"+name); err == nil {
		t.Fatal("expected reject ..")
	}
	if _, err := ResolveAbs(dir, "not-a-uuid.jpg"); err == nil {
		t.Fatal("expected reject bad id")
	}
	if _, err := ResolveAbs(dir, id.String()+".gif"); err == nil {
		t.Fatal("expected reject gif")
	}
	full, err := ResolveAbs(dir, name)
	if err != nil {
		t.Fatal(err)
	}
	if filepath.Base(full) != name {
		t.Fatalf("full=%s", full)
	}
}

func TestStoreRejectsBadTypeAndSize(t *testing.T) {
	dir := t.TempDir()
	uid := uuid.New()

	fhExe := mustFormFile(t, "x.exe", "application/octet-stream", []byte("MZ"))
	if _, err := Store(dir, uid, fhExe); err == nil {
		t.Fatal("expected bad type")
	}

	big := bytes.Repeat([]byte("a"), MaxBytes+10)
	fhBig := mustFormFile(t, "big.jpg", "image/jpeg", big)
	if _, err := Store(dir, uid, fhBig); err == nil {
		t.Fatal("expected too large")
	}
}

func TestStoreOKAndOverwrite(t *testing.T) {
	dir := t.TempDir()
	uid := uuid.New()
	fh := mustFormFile(t, "a.png", "image/png", []byte{0x89, 0x50, 0x4e, 0x47})
	path, err := Store(dir, uid, fh)
	if err != nil {
		t.Fatal(err)
	}
	want := "/api/v1/media/avatars/" + uid.String() + ".png"
	if path != want {
		t.Fatalf("path=%s want=%s", path, want)
	}
	if _, err := os.Stat(filepath.Join(dir, uid.String()+".png")); err != nil {
		t.Fatal(err)
	}

	fh2 := mustFormFile(t, "b.jpg", "image/jpeg", []byte{0xff, 0xd8, 0xff})
	path2, err := Store(dir, uid, fh2)
	if err != nil {
		t.Fatal(err)
	}
	if path2 != "/api/v1/media/avatars/"+uid.String()+".jpg" {
		t.Fatalf("path2=%s", path2)
	}
	if _, err := os.Stat(filepath.Join(dir, uid.String()+".png")); !os.IsNotExist(err) {
		t.Fatal("old png should be removed")
	}
}

func mustFormFile(t *testing.T, filename, contentType string, data []byte) *multipart.FileHeader {
	t.Helper()
	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	h := make(textproto.MIMEHeader)
	h.Set("Content-Disposition", `form-data; name="file"; filename="`+filename+`"`)
	h.Set("Content-Type", contentType)
	part, err := w.CreatePart(h)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := part.Write(data); err != nil {
		t.Fatal(err)
	}
	if err := w.Close(); err != nil {
		t.Fatal(err)
	}
	r := multipart.NewReader(&buf, w.Boundary())
	form, err := r.ReadForm(int64(len(data)) + 1024)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = form.RemoveAll() })
	files := form.File["file"]
	if len(files) == 0 {
		t.Fatal("no file part")
	}
	return files[0]
}