package attach

import (
	"context"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"gocloud.dev/blob"
	"gocloud.dev/blob/fileblob"
	"gocloud.dev/blob/memblob"
)

func TestStaticHandler(t *testing.T) {
	ctx := t.Context()
	bucket := memblob.OpenBucket(nil)
	t.Cleanup(func() { _ = bucket.Close() })

	diskName := "abc123xyz.jpg"
	key := BlobKey(diskName)
	body := []byte("cover-bytes")
	if err := bucket.WriteAll(ctx, key, body, &blob.WriterOptions{ContentType: "image/jpeg"}); err != nil {
		t.Fatal(err)
	}

	h := StaticHandler(bucket, "/storage/uploads")
	srv := httptest.NewServer(h)
	t.Cleanup(srv.Close)

	res, err := http.Get(srv.URL + "/storage/uploads/abc/123/xyz/abc123xyz.jpg")
	if err != nil {
		t.Fatal(err)
	}
	defer res.Body.Close()
	if res.StatusCode != http.StatusOK {
		t.Fatalf("status = %d", res.StatusCode)
	}
	if ct := res.Header.Get("Content-Type"); ct != "image/jpeg" {
		t.Fatalf("Content-Type = %q, want image/jpeg", ct)
	}
	got, err := io.ReadAll(res.Body)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != string(body) {
		t.Fatalf("body = %q", got)
	}

	missing, err := http.Get(srv.URL + "/storage/uploads/mis/sin/g.j/missing.jpg")
	if err != nil {
		t.Fatal(err)
	}
	defer missing.Body.Close()
	if missing.StatusCode != http.StatusNotFound {
		t.Fatalf("missing status = %d, want 404", missing.StatusCode)
	}

	for _, path := range []string{
		"/storage/uploads/abc/123/xyz/../abc123xyz.jpg",
		"/storage/uploads/abc/123/xyz//abc123xyz.jpg",
		"/storage/uploads/foo/bar/baz/abc123xyz.jpg",
		"/storage/uploads/abc/123/xyz/abc123xyz.jpg/extra",
		"/storage/uploads",
	} {
		rr := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, path, nil)
		h.ServeHTTP(rr, req)
		if rr.Code != http.StatusNotFound {
			t.Fatalf("path %q status = %d, want 404", path, rr.Code)
		}
	}
}

func TestStaticHandlerServesThumbURL(t *testing.T) {
	ctx := t.Context()
	bucket := memblob.OpenBucket(nil)
	t.Cleanup(func() { _ = bucket.Close() })

	f := &File{ID: 42, DiskName: "abc123xyz.jpg"}
	if err := bucket.WriteAll(ctx, BlobKey(f.DiskName), testJPEG(t), &blob.WriterOptions{ContentType: "image/jpeg"}); err != nil {
		t.Fatal(err)
	}
	thumbURL, err := f.Thumb(ctx, bucket, 200, 200, "crop")
	if err != nil {
		t.Fatal(err)
	}
	const wantURL = "/storage/uploads/abc/123/xyz/thumb_42_200_200_0_0_crop.jpg"
	if thumbURL != wantURL {
		t.Fatalf("Thumb URL = %q, want %q", thumbURL, wantURL)
	}

	h := StaticHandler(bucket, "/storage/uploads")
	srv := httptest.NewServer(h)
	t.Cleanup(srv.Close)

	res, err := http.Get(srv.URL + thumbURL)
	if err != nil {
		t.Fatal(err)
	}
	defer res.Body.Close()
	if res.StatusCode != http.StatusOK {
		t.Fatalf("thumb GET status = %d, want 200", res.StatusCode)
	}
	body, err := io.ReadAll(res.Body)
	if err != nil {
		t.Fatal(err)
	}
	if len(body) == 0 {
		t.Fatal("thumb body is empty")
	}

	mismatch := httptest.NewRecorder()
	h.ServeHTTP(mismatch, httptest.NewRequest(http.MethodGet, "/storage/uploads/foo/bar/baz/abc123xyz.jpg", nil))
	if mismatch.Code != http.StatusNotFound {
		t.Fatalf("mismatched original partition status = %d, want 404", mismatch.Code)
	}
}

func TestStaticHandlerPublicGate(t *testing.T) {
	ctx := t.Context()
	bucket := memblob.OpenBucket(nil)
	t.Cleanup(func() { _ = bucket.Close() })

	diskName := "abc123xyz.jpg"
	body := []byte("cover-bytes")
	if err := bucket.WriteAll(ctx, BlobKey(diskName), body, &blob.WriterOptions{ContentType: "image/jpeg"}); err != nil {
		t.Fatal(err)
	}
	thumbName := ThumbFilename(42, 200, 200, 0, 0, "crop", "jpg")
	thumbKey := PartitionDirectory(diskName) + thumbName
	if err := bucket.WriteAll(ctx, thumbKey, []byte("thumb-bytes"), &blob.WriterOptions{ContentType: "image/jpeg"}); err != nil {
		t.Fatal(err)
	}

	var seen []string
	deny := servePublicBlobs(bucket, "/storage/uploads", func(_ context.Context, name string) (bool, error) {
		seen = append(seen, name)
		return false, nil
	})
	for _, path := range []string{
		"/storage/uploads/abc/123/xyz/abc123xyz.jpg",
		"/storage/uploads/abc/123/xyz/" + thumbName,
	} {
		rr := httptest.NewRecorder()
		deny.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, path, nil))
		if rr.Code != http.StatusNotFound {
			t.Fatalf("private %s status = %d, want 404", path, rr.Code)
		}
	}
	if len(seen) != 2 || seen[0] != diskName || seen[1] != thumbName {
		t.Fatalf("allow saw %v, want [%s %s] before NewReader", seen, diskName, thumbName)
	}

	allow := servePublicBlobs(bucket, "/storage/uploads", func(_ context.Context, name string) (bool, error) {
		return name == diskName, nil
	})
	ok := httptest.NewRecorder()
	allow.ServeHTTP(ok, httptest.NewRequest(http.MethodGet, "/storage/uploads/abc/123/xyz/abc123xyz.jpg", nil))
	if ok.Code != http.StatusOK {
		t.Fatalf("public original status = %d, want 200", ok.Code)
	}
	blocked := httptest.NewRecorder()
	allow.ServeHTTP(blocked, httptest.NewRequest(http.MethodGet, "/storage/uploads/abc/123/xyz/"+thumbName, nil))
	if blocked.Code != http.StatusNotFound {
		t.Fatalf("denied thumb status = %d, want 404", blocked.Code)
	}

	nilDB := StaticHandlerPublic(bucket, "/storage/uploads", nil)
	missing := httptest.NewRecorder()
	nilDB.ServeHTTP(missing, httptest.NewRequest(http.MethodGet, "/storage/uploads/abc/123/xyz/abc123xyz.jpg", nil))
	if missing.Code != http.StatusNotFound {
		t.Fatalf("nil db status = %d, want 404", missing.Code)
	}
}

func TestStoredDisposition(t *testing.T) {
	cases := []struct{ in, want string }{
		{"", ""},
		{"   ", ""},
		{"attachment", "attachment"},
		{"inline", "inline"},
		{`attachment; filename="a.png"`, `attachment; filename="a.png"`},
		{" attachment ", "attachment"},
		{"attachment;;", "attachment"},
		{"attachment; filename", "attachment"},
		{"attachment\r\nX-Evil: 1", "attachment"},
	}
	for _, tc := range cases {
		if got := storedDisposition(tc.in); got != tc.want {
			t.Errorf("storedDisposition(%q) = %q, want %q", tc.in, got, tc.want)
		}
	}
}

// TestStaticHandlerSendsStoredDisposition writes through writeBlob, the
// writer attach.Store uses, and reads the headers back through the handlers:
// the stored disposition and nosniff reach the response on GET and HEAD.
func TestStaticHandlerSendsStoredDisposition(t *testing.T) {
	sidecar, err := fileblob.OpenBucket(t.TempDir(), nil)
	if err != nil {
		t.Fatal(err)
	}
	buckets := []struct {
		name   string
		bucket *blob.Bucket
	}{
		{"memblob", memblob.OpenBucket(nil)},
		{"fileblob sidecar", sidecar},
	}
	const (
		prefix   = "/storage/uploads"
		htmlName = "abc123xyz.html"
		pngName  = "def456uvw.png"
		htmlBody = "<html><script>alert(1)</script></html>"
	)
	pngBody := []byte{0x89, 'P', 'N', 'G'}
	url := func(diskName string) string { return prefix + "/" + BlobKey(diskName) }
	serve := func(h http.Handler, method, target string) *httptest.ResponseRecorder {
		rr := httptest.NewRecorder()
		h.ServeHTTP(rr, httptest.NewRequest(method, target, nil))
		return rr
	}
	assertHeaders := func(t *testing.T, label string, rr *httptest.ResponseRecorder, wantCT, wantCD string) {
		t.Helper()
		res := rr.Result()
		if res.StatusCode != http.StatusOK {
			t.Fatalf("%s: status = %d, want 200", label, res.StatusCode)
		}
		if got := res.Header.Get("Content-Type"); got != wantCT {
			t.Errorf("%s: Content-Type = %q, want %q", label, got, wantCT)
		}
		if got := res.Header.Get("X-Content-Type-Options"); got != "nosniff" {
			t.Errorf("%s: X-Content-Type-Options = %q, want nosniff", label, got)
		}
		got := res.Header.Values("Content-Disposition")
		if wantCD == "" {
			if len(got) != 0 {
				t.Errorf("%s: Content-Disposition = %q, want none", label, got)
			}
		} else if len(got) != 1 || got[0] != wantCD {
			t.Errorf("%s: Content-Disposition = %q, want %q", label, got, wantCD)
		}
	}

	for _, b := range buckets {
		bucket := b.bucket
		t.Cleanup(func() { _ = bucket.Close() })
		t.Run(b.name, func(t *testing.T) {
			ctx := t.Context()
			if _, err := writeBlob(ctx, bucket, BlobKey(htmlName), strings.NewReader(htmlBody), "text/html", 0); err != nil {
				t.Fatal(err)
			}
			if _, err := writeBlob(ctx, bucket, BlobKey(pngName), strings.NewReader(string(pngBody)), "image/png", 0); err != nil {
				t.Fatal(err)
			}
			h := StaticHandler(bucket, prefix)

			get := serve(h, http.MethodGet, url(htmlName))
			assertHeaders(t, "html GET", get, "text/html", "attachment")
			if got := get.Body.String(); got != htmlBody {
				t.Errorf("html GET body = %q, want %q", got, htmlBody)
			}
			head := serve(h, http.MethodHead, url(htmlName))
			assertHeaders(t, "html HEAD", head, "text/html", "attachment")
			if head.Body.Len() != 0 {
				t.Errorf("html HEAD body = %q, want empty", head.Body.String())
			}

			png := serve(h, http.MethodGet, url(pngName))
			assertHeaders(t, "png GET", png, "image/png", "")
			if got := png.Body.Bytes(); string(got) != string(pngBody) {
				t.Errorf("png GET body = %q, want %q", got, pngBody)
			}
			assertHeaders(t, "png HEAD", serve(h, http.MethodHead, url(pngName)), "image/png", "")

			gated := servePublicBlobs(bucket, prefix, func(context.Context, string) (bool, error) { return true, nil })
			gatedGet := serve(gated, http.MethodGet, url(htmlName))
			assertHeaders(t, "gated html GET", gatedGet, "text/html", "attachment")
			if got := gatedGet.Body.String(); got != htmlBody {
				t.Errorf("gated html GET body = %q, want %q", got, htmlBody)
			}

			missing := serve(h, http.MethodGet, url("mis123sin.html")).Result()
			if missing.StatusCode != http.StatusNotFound {
				t.Fatalf("missing status = %d, want 404", missing.StatusCode)
			}
			if got := missing.Header.Get("X-Content-Type-Options"); got != "nosniff" {
				t.Errorf("missing X-Content-Type-Options = %q, want nosniff", got)
			}
			if got := missing.Header.Values("Content-Disposition"); len(got) != 0 {
				t.Errorf("missing Content-Disposition = %q, want none", got)
			}
		})
	}

	t.Run("memblob explicit dispositions", func(t *testing.T) {
		ctx := t.Context()
		bucket := memblob.OpenBucket(nil)
		t.Cleanup(func() { _ = bucket.Close() })
		const (
			namedPNG  = "ghi789rst.png"
			brokenTXT = "jkl012mno.txt"
		)
		if err := bucket.WriteAll(ctx, BlobKey(namedPNG), pngBody, &blob.WriterOptions{ContentType: "image/png", ContentDisposition: `attachment; filename="a.png"`}); err != nil {
			t.Fatal(err)
		}
		if err := bucket.WriteAll(ctx, BlobKey(brokenTXT), []byte(htmlBody), &blob.WriterOptions{ContentType: "text/html", ContentDisposition: "attachment;;"}); err != nil {
			t.Fatal(err)
		}
		h := StaticHandler(bucket, prefix)
		assertHeaders(t, "verbatim", serve(h, http.MethodGet, url(namedPNG)), "image/png", `attachment; filename="a.png"`)
		assertHeaders(t, "fail closed", serve(h, http.MethodGet, url(brokenTXT)), "text/html", "attachment")
	})
}