package handler

import (
	"database/sql"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"
	"time"

	"github.com/git-pkgs/proxy/internal/database"
	"github.com/git-pkgs/proxy/internal/httpclient"
	"github.com/git-pkgs/proxy/internal/metrics"
	"github.com/git-pkgs/proxy/internal/storage"
	"github.com/git-pkgs/purl"
	"github.com/git-pkgs/registries/fetch"
)

// seedPackageWithPURL seeds a package using purl.MakePURLString for PURL generation,
// matching how the handlers construct PURLs internally.
func seedPackageWithPURL(t *testing.T, db *database.DB, store *mockStorage, ecosystem, name, version, filename, content string) {
	t.Helper()

	pkgPURL := purl.MakePURLString(ecosystem, name, "")
	versionPURL := purl.MakePURLString(ecosystem, name, version)

	pkg := &database.Package{
		PURL:      pkgPURL,
		Ecosystem: ecosystem,
		Name:      name,
	}
	if err := db.UpsertPackage(pkg); err != nil {
		t.Fatalf("failed to upsert package: %v", err)
	}

	ver := &database.Version{
		PURL:        versionPURL,
		PackagePURL: pkgPURL,
	}
	if err := db.UpsertVersion(ver); err != nil {
		t.Fatalf("failed to upsert version: %v", err)
	}

	storagePath := storage.ArtifactPath(ecosystem, "", name, version, filename)
	store.files[storagePath] = []byte(content)
	sharedArtifact := testArtifact(content, versionPURL, filename, "application/octet-stream")

	art := &database.Artifact{
		VersionPURL: versionPURL,
		Filename:    filename,
		UpstreamURL: "https://example.com/" + filename,
		StoragePath: sql.NullString{String: storagePath, Valid: true},
		ContentHash: sql.NullString{String: sharedArtifact.Digest.Encoded(), Valid: true},
		Size:        sql.NullInt64{Int64: int64(len(content)), Valid: true},
		ContentType: sql.NullString{String: "application/octet-stream", Valid: true},
		FetchedAt:   sql.NullTime{Time: time.Now(), Valid: true},
	}
	if err := db.UpsertArtifact(art); err != nil {
		t.Fatalf("failed to upsert artifact: %v", err)
	}
}

// assertUpstreamProxied verifies that a handler proxies a request to the upstream
// server and returns the expected response body. The makeHandler function receives
// a configured Proxy and the upstream URL, and returns the handler to test.
func assertUpstreamProxied(t *testing.T, wantBody, path string, makeHandler func(*Proxy, string) http.Handler) {
	t.Helper()

	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprint(w, wantBody)
	}))
	defer upstream.Close()

	proxy, _, _, _ := setupTestProxy(t)
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(makeHandler(proxy, upstream.URL))
	defer srv.Close()

	resp, err := http.Get(srv.URL + path)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != wantBody {
		t.Errorf("body = %q, want %q", body, wantBody)
	}
}

func TestGemHandler_DownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackage(t, db, store, "gem", "rails", "7.1.0", "rails-7.1.0.gem", "gem binary data")

	h := NewGemHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/gems/rails-7.1.0.gem")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "gem binary data" {
		t.Errorf("body = %q, want %q", body, "gem binary data")
	}
}

func TestGemHandler_DownloadCacheHitMultiHyphen(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackage(t, db, store, "gem", "aws-sdk-s3", "1.142.0", "aws-sdk-s3-1.142.0.gem", "aws gem")

	h := NewGemHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/gems/aws-sdk-s3-1.142.0.gem")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "aws gem" {
		t.Errorf("body = %q, want %q", body, "aws gem")
	}
}

func TestGemHandler_InvalidFilename(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	h := NewGemHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	tests := []struct {
		path string
		code int
	}{
		{"/gems/notagem.tar.gz", http.StatusBadRequest},
		{"/gems/noversion.gem", http.StatusBadRequest},
		{"/gems/.gem", http.StatusBadRequest},
	}

	for _, tt := range tests {
		resp, err := http.Get(srv.URL + tt.path)
		if err != nil {
			t.Fatalf("request to %s failed: %v", tt.path, err)
		}
		_ = resp.Body.Close()

		if resp.StatusCode != tt.code {
			t.Errorf("GET %s: status = %d, want %d", tt.path, resp.StatusCode, tt.code)
		}
	}
}

func TestGemHandler_UpstreamProxy(t *testing.T) {
	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("X-Test", "upstream")
		w.WriteHeader(http.StatusOK)
		_, _ = fmt.Fprint(w, "upstream specs data")
	}))
	defer upstream.Close()

	proxy, _, _, _ := setupTestProxy(t)
	h := &GemHandler{
		proxy:       proxy,
		upstreamURL: upstream.URL,
		proxyURL:    "http://localhost",
	}
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/versions")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "upstream specs data" {
		t.Errorf("body = %q, want %q", body, "upstream specs data")
	}
	// Metadata caching reads the response body into storage and serves it back,
	// so arbitrary upstream headers are not forwarded. Content-Type is preserved.
}

func TestGemHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetchesBefore := histogramSampleCount(t, metrics.UpstreamFetchDuration.WithLabelValues("gem"))
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched gem")),
		ContentType: "application/octet-stream",
	}

	upstreamURL := "https://packages.example.com/gem"
	h := NewGemHandlerWithUpstream(proxy, "http://localhost", upstreamURL)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	path := "/gems/sinatra-3.0.0.gem"
	resp, err := http.Get(srv.URL + path)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}
	if want := upstreamURL + path; fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
	if diff := histogramSampleCount(t, metrics.UpstreamFetchDuration.WithLabelValues("gem")) - fetchesBefore; diff != 1 {
		t.Errorf("upstream fetch observations delta = %d, want 1", diff)
	}
}

func TestGoHandler_DownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackage(t, db, store, "golang", "golang.org/x/text", "v0.14.0", "text@v0.14.0.zip", "go module zip")

	h := NewGoHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/golang.org/x/text/@v/v0.14.0.zip")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "go module zip" {
		t.Errorf("body = %q, want %q", body, "go module zip")
	}
}

func TestGoHandler_MethodNotAllowed(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	h := NewGoHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Post(srv.URL+"/golang.org/x/text/@v/v0.14.0.zip", "", nil)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusMethodNotAllowed {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusMethodNotAllowed)
	}
}

func TestGoHandler_NotFound(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	h := NewGoHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/some/unknown/path")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusNotFound {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusNotFound)
	}
}

func TestGoHandler_UnknownAtVSuffix(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	h := NewGoHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/golang.org/x/text/@v/v0.14.0.unknown")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusNotFound {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusNotFound)
	}
}

func TestGoHandler_UpstreamProxy(t *testing.T) {
	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprint(w, "v0.14.0\nv0.13.0\n")
	}))
	defer upstream.Close()

	proxy, _, _, _ := setupTestProxy(t)
	h := &GoHandler{
		proxy:       proxy,
		upstreamURL: upstream.URL,
		proxyURL:    "http://localhost",
	}
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	tests := []string{
		"/golang.org/x/text/@v/list",
		"/golang.org/x/text/@v/v0.14.0.info",
		"/golang.org/x/text/@v/v0.14.0.mod",
		"/golang.org/x/text/@latest",
	}

	for _, path := range tests {
		resp, err := http.Get(srv.URL + path)
		if err != nil {
			t.Fatalf("GET %s failed: %v", path, err)
		}
		_ = resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			t.Errorf("GET %s: status = %d, want %d", path, resp.StatusCode, http.StatusOK)
		}
	}
}

func TestGoHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("module zip data")),
		ContentType: "application/zip",
	}

	upstreamURL := "https://packages.example.com/go"
	h := NewGoHandlerWithUpstream(proxy, "http://localhost", upstreamURL)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	path := "/example.com/mod/@v/v1.0.0.zip"
	resp, err := http.Get(srv.URL + path)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}
	if want := upstreamURL + path; fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestHexHandler_DownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackage(t, db, store, "hex", "phoenix", "1.7.10", "phoenix-1.7.10.tar", "hex tarball")

	h := NewHexHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/tarballs/phoenix-1.7.10.tar")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "hex tarball" {
		t.Errorf("body = %q, want %q", body, "hex tarball")
	}
}

func TestHexHandler_InvalidFilename(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	h := NewHexHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	tests := []struct {
		path string
		code int
	}{
		{"/tarballs/notatar.zip", http.StatusBadRequest},
		{"/tarballs/noversion.tar", http.StatusBadRequest},
	}

	for _, tt := range tests {
		resp, err := http.Get(srv.URL + tt.path)
		if err != nil {
			t.Fatalf("request to %s failed: %v", tt.path, err)
		}
		_ = resp.Body.Close()

		if resp.StatusCode != tt.code {
			t.Errorf("GET %s: status = %d, want %d", tt.path, resp.StatusCode, tt.code)
		}
	}
}

func TestHexHandler_UpstreamProxy(t *testing.T) {
	assertUpstreamProxied(t, "hex registry data", "/packages/phoenix",
		func(proxy *Proxy, upstreamURL string) http.Handler {
			h := &HexHandler{proxy: proxy, upstreamURL: upstreamURL, proxyURL: "http://localhost"}
			return h.Routes()
		},
	)
}

func TestHexHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched hex")),
		ContentType: "application/x-tar",
	}

	upstreamURL := "https://packages.example.com/hex"
	h := NewHexHandlerWithUpstreams(proxy, "http://localhost", upstreamURL, "https://packages.example.com/hex-api")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	path := "/tarballs/plug-1.15.0.tar"
	resp, err := http.Get(srv.URL + path)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}
	if want := upstreamURL + path; fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestPubHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched pub package")),
		ContentType: "application/gzip",
	}

	upstreamURL := "https://packages.example.com/pub"
	h := NewPubHandlerWithUpstream(proxy, "http://localhost", upstreamURL)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	path := "/packages/flutter_bloc/versions/8.1.6.tar.gz"
	resp, err := http.Get(srv.URL + path)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}
	if want := upstreamURL + path; fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestCondaHandler_DownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackageWithPURL(t, db, store, "conda", "main/numpy", "1.24.0", "numpy-1.24.0-py311h64a7726_0.conda", "conda pkg")

	h := NewCondaHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/main/linux-64/numpy-1.24.0-py311h64a7726_0.conda")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "conda pkg" {
		t.Errorf("body = %q, want %q", body, "conda pkg")
	}
}

func TestCondaHandler_DownloadTarBz2CacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackageWithPURL(t, db, store, "conda", "main/scipy", "1.11.0", "scipy-1.11.0-py311hb2e3ea1_0.tar.bz2", "tar bz2 data")

	h := NewCondaHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/main/linux-64/scipy-1.11.0-py311hb2e3ea1_0.tar.bz2")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "tar bz2 data" {
		t.Errorf("body = %q, want %q", body, "tar bz2 data")
	}
}

func TestCondaHandler_NonPackageFileProxied(t *testing.T) {
	assertUpstreamProxied(t, "repodata json", "/main/linux-64/repodata.json",
		func(proxy *Proxy, upstreamURL string) http.Handler {
			h := &CondaHandler{proxy: proxy, upstreamURL: upstreamURL, proxyURL: "http://localhost"}
			return h.Routes()
		},
	)
}

func TestCondaHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched conda")),
		ContentType: "application/octet-stream",
	}

	h := NewCondaHandler(proxy, "http://localhost")

	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		t.Error("should not hit upstream for .conda files when fetcher is set")
	}))
	defer upstream.Close()
	h.upstreamURL = upstream.URL
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/conda-forge/linux-64/pandas-2.0.0-py311h320fe9a_0.conda")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := upstream.URL + "/conda-forge/linux-64/pandas-2.0.0-py311h320fe9a_0.conda"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestCRANHandler_SourceDownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackageWithPURL(t, db, store, "cran", "ggplot2", "3.4.0", "ggplot2_3.4.0.tar.gz", "cran source")

	h := NewCRANHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/src/contrib/ggplot2_3.4.0.tar.gz")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "cran source" {
		t.Errorf("body = %q, want %q", body, "cran source")
	}
}

func TestCRANHandler_BinaryDownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackageWithPURL(t, db, store, "cran", "dplyr", "1.1.0_windows_4.3", "dplyr_1.1.0.zip", "cran binary")

	h := NewCRANHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/bin/windows/contrib/4.3/dplyr_1.1.0.zip")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "cran binary" {
		t.Errorf("body = %q, want %q", body, "cran binary")
	}
}

func TestCRANHandler_NonPackageFileProxied(t *testing.T) {
	assertUpstreamProxied(t, "PACKAGES index", "/src/contrib/PACKAGES",
		func(proxy *Proxy, upstreamURL string) http.Handler {
			h := &CRANHandler{proxy: proxy, upstreamURL: upstreamURL, proxyURL: "http://localhost"}
			return h.Routes()
		},
	)
}

func TestCRANHandler_SourceNonTarGzProxied(t *testing.T) {
	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprint(w, "some other file")
	}))
	defer upstream.Close()

	proxy, _, _, _ := setupTestProxy(t)
	h := &CRANHandler{
		proxy:       proxy,
		upstreamURL: upstream.URL,
		proxyURL:    "http://localhost",
	}
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/src/contrib/somefile.txt")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
}

func TestCRANHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched cran")),
		ContentType: "application/x-gzip",
	}

	h := NewCRANHandler(proxy, "http://localhost")
	h.upstreamURL = "https://cran.r-project.org"

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/src/contrib/tidyr_1.3.0.tar.gz")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://cran.r-project.org/src/contrib/tidyr_1.3.0.tar.gz"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestCRANHandler_BinaryDownloadCacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched binary")),
		ContentType: "application/zip",
	}

	h := NewCRANHandler(proxy, "http://localhost")
	h.upstreamURL = "https://cran.r-project.org"

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/bin/windows/contrib/4.3/dplyr_1.1.0.zip")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://cran.r-project.org/bin/windows/contrib/4.3/dplyr_1.1.0.zip"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestMavenHandler_DownloadCacheHit(t *testing.T) {
	proxy, db, store, _ := setupTestProxy(t)
	seedPackageWithPURL(t, db, store, "maven", "com.google.guava:guava", "32.1.3-jre", "guava-32.1.3-jre.jar", "jar content")

	h := NewMavenHandler(proxy, "http://localhost", "", "")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/com/google/guava/guava/32.1.3-jre/guava-32.1.3-jre.jar")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	body, _ := io.ReadAll(resp.Body)
	if string(body) != "jar content" {
		t.Errorf("body = %q, want %q", body, "jar content")
	}
}

func TestMavenHandler_MetadataProxied(t *testing.T) {
	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprint(w, "<metadata/>")
	}))
	defer upstream.Close()

	proxy, _, _, _ := setupTestProxy(t)
	h := &MavenHandler{
		proxy:       proxy,
		upstreamURL: upstream.URL,
		proxyURL:    "http://localhost",
	}
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	paths := []string{
		"/com/google/guava/guava/maven-metadata.xml",
		"/com/google/guava/guava/maven-metadata.xml.sha1",
		"/com/google/guava/guava/1.0-SNAPSHOT/maven-metadata.xml",
	}

	for _, path := range paths {
		resp, err := http.Get(srv.URL + path)
		if err != nil {
			t.Fatalf("GET %s failed: %v", path, err)
		}
		_ = resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			t.Errorf("GET %s: status = %d, want %d", path, resp.StatusCode, http.StatusOK)
		}
	}
}

func TestMavenHandler_EmptyPathNotFound(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	h := NewMavenHandler(proxy, "http://localhost", "", "")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusNotFound {
		t.Errorf("status = %d, want %d", resp.StatusCode, http.StatusNotFound)
	}
}

func TestMavenHandler_ArtifactExtensions(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)

	extensions := []string{".jar", ".war", ".ear", ".pom", ".aar", ".klib", ".module"}
	for _, ext := range extensions {
		fetcher.artifact = &fetch.Artifact{
			Body:        io.NopCloser(strings.NewReader("artifact")),
			ContentType: "application/java-archive",
		}
		fetcher.fetchCalled = false

		h := NewMavenHandler(proxy, "http://localhost", "", "")

		upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			t.Errorf("should not proxy artifact file %s to upstream", ext)
		}))
		h.upstreamURL = upstream.URL
		proxy.HTTPClient = upstream.Client()

		srv := httptest.NewServer(h.Routes())

		path := fmt.Sprintf("/com/example/lib/1.0/lib-1.0%s", ext)
		resp, err := http.Get(srv.URL + path)
		if err != nil {
			t.Fatalf("GET %s failed: %v", path, err)
		}
		_ = resp.Body.Close()

		if !fetcher.fetchCalled {
			t.Errorf("fetcher not called for %s", ext)
		}

		srv.Close()
		upstream.Close()
	}
}

func TestMavenHandler_ChecksumsCachedAsArtifacts(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)

	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		t.Errorf("checksum %s proxied as metadata", r.URL.Path)
	}))
	defer upstream.Close()

	h := NewMavenHandler(proxy, "http://localhost", "", "")
	h.upstreamURL = upstream.URL
	proxy.HTTPClient = upstream.Client()

	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	for _, name := range []string{"lib-1.0.jar.sha1", "lib-1.0.pom.md5", "lib-1.0.jar.asc", "lib-1.0-bin.tar.gz.sha512"} {
		path := "/com/example/lib/1.0/" + name
		for i := range 2 {
			fetcher.artifact = &fetch.Artifact{
				Body:        io.NopCloser(strings.NewReader("checksum")),
				ContentType: "text/plain",
			}
			fetcher.fetchCalled = false

			resp, err := http.Get(srv.URL + path)
			if err != nil {
				t.Fatalf("GET %s failed: %v", path, err)
			}
			body, _ := io.ReadAll(resp.Body)
			_ = resp.Body.Close()

			if resp.StatusCode != http.StatusOK || string(body) != "checksum" {
				t.Errorf("GET %s: status %d body %q", path, resp.StatusCode, body)
			}
			if fetcher.fetchCalled != (i == 0) {
				t.Errorf("GET %s request %d: fetched = %v, want %v", path, i+1, fetcher.fetchCalled, i == 0)
			}
		}
	}
}

func TestMavenHandler_CacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched jar")),
		ContentType: "application/java-archive",
	}

	h := NewMavenHandler(proxy, "http://localhost", "", "")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/org/apache/commons/commons-lang3/3.14.0/commons-lang3-3.14.0.jar")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://repo1.maven.org/maven2/org/apache/commons/commons-lang3/3.14.0/commons-lang3-3.14.0.jar"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestMavenHandler_GradlePluginMarkerFallbackAndCache(t *testing.T) {
	tests := []struct {
		name       string
		markerPath string
	}{
		{
			name:       "Spotless",
			markerPath: "/com/diffplug/spotless/com.diffplug.spotless.gradle.plugin/8.4.0/com.diffplug.spotless.gradle.plugin-8.4.0.pom",
		},
		{
			name:       "BenManes",
			markerPath: "/com/github/ben-manes/versions/com.github.ben-manes.versions.gradle.plugin/0.54.0/com.github.ben-manes.versions.gradle.plugin-0.54.0.pom",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			proxy, _, _, fetcher := setupTestProxy(t)

			primaryUpstream := "https://repo1.maven.org/maven2"
			pluginPortalUpstream := "https://plugins.gradle.org/m2"
			primaryURL := primaryUpstream + tt.markerPath

			fetcher.fetchErrByURL = map[string]error{
				primaryURL: ErrUpstreamNotFound,
			}
			fetcher.artifact = &fetch.Artifact{
				Body:        io.NopCloser(strings.NewReader("<project/>")),
				ContentType: "application/xml",
			}

			h := NewMavenHandler(proxy, "http://localhost", primaryUpstream, pluginPortalUpstream)
			srv := httptest.NewServer(h.Routes())
			defer srv.Close()

			resp, err := http.Get(srv.URL + tt.markerPath)
			if err != nil {
				t.Fatalf("request failed: %v", err)
			}
			body, _ := io.ReadAll(resp.Body)
			_ = resp.Body.Close()

			if resp.StatusCode != http.StatusOK {
				t.Fatalf("status = %d, want %d", resp.StatusCode, http.StatusOK)
			}
			if string(body) != "<project/>" {
				t.Fatalf("body = %q, want %q", body, "<project/>")
			}

			wantFallbackURL := pluginPortalUpstream + tt.markerPath
			if fetcher.fetchedURL != wantFallbackURL {
				t.Fatalf("fallback URL = %q, want %q", fetcher.fetchedURL, wantFallbackURL)
			}

			fetcher.fetchCalled = false
			resp, err = http.Get(srv.URL + tt.markerPath)
			if err != nil {
				t.Fatalf("second request failed: %v", err)
			}
			_ = resp.Body.Close()

			if resp.StatusCode != http.StatusOK {
				t.Fatalf("second status = %d, want %d", resp.StatusCode, http.StatusOK)
			}
			if fetcher.fetchCalled {
				t.Fatal("expected plugin marker POM to be served from cache on second request")
			}
		})
	}
}

func TestMavenHandler_GradlePluginMarkerMetadataFallback(t *testing.T) {
	paths := map[string]string{
		"/com/diffplug/spotless/com.diffplug.spotless.gradle.plugin/maven-metadata.xml":      "<metadata/>",
		"/com/diffplug/spotless/com.diffplug.spotless.gradle.plugin/maven-metadata.xml.sha1": "sha1",
	}

	primaryHits := map[string]int{}
	pluginHits := map[string]int{}

	primary := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		primaryHits[r.URL.Path]++
		if _, ok := paths[r.URL.Path]; ok {
			http.NotFound(w, r)
			return
		}
		t.Fatalf("unexpected path to primary upstream: %s", r.URL.Path)
	}))
	defer primary.Close()

	pluginPortal := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		pluginHits[r.URL.Path]++
		body, ok := paths[r.URL.Path]
		if !ok {
			http.NotFound(w, r)
			return
		}
		_, _ = io.WriteString(w, body)
	}))
	defer pluginPortal.Close()

	proxy, _, _, _ := setupTestProxy(t)
	proxy.HTTPClient = primary.Client()

	h := NewMavenHandler(proxy, "http://localhost", primary.URL, pluginPortal.URL)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	for reqPath, wantBody := range paths {
		resp, err := http.Get(srv.URL + reqPath)
		if err != nil {
			t.Fatalf("GET %s failed: %v", reqPath, err)
		}
		body, _ := io.ReadAll(resp.Body)
		_ = resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			t.Fatalf("GET %s: status = %d, want %d", reqPath, resp.StatusCode, http.StatusOK)
		}
		if string(body) != wantBody {
			t.Fatalf("GET %s: body = %q, want %q", reqPath, body, wantBody)
		}

		if primaryHits[reqPath] == 0 {
			t.Fatalf("GET %s did not hit primary upstream", reqPath)
		}
		if pluginHits[reqPath] == 0 {
			t.Fatalf("GET %s did not hit plugin portal fallback", reqPath)
		}
	}
}

func TestMavenHandler_GradlePluginChecksumFallbackToPluginPortal(t *testing.T) {
	primaryUpstream := "https://repo1.maven.org/maven2"
	pluginPortalUpstream := "https://plugins.gradle.org/m2"
	paths := []string{
		"/com/diffplug/spotless/com.diffplug.spotless.gradle.plugin/8.4.0/com.diffplug.spotless.gradle.plugin-8.4.0.pom.sha1",
		"/com/diffplug/spotless/com.diffplug.spotless.gradle.plugin/8.4.0/com.diffplug.spotless.gradle.plugin-8.4.0.pom.md5",
		"/com/diffplug/spotless/spotless-plugin-gradle/8.4.0/spotless-plugin-gradle-8.4.0.jar.sha1",
		"/com/diffplug/spotless/spotless-plugin-gradle/8.4.0/spotless-plugin-gradle-8.4.0.jar.sha256",
	}

	for _, reqPath := range paths {
		proxy, _, _, fetcher := setupTestProxy(t)
		fetcher.fetchErrByURL = map[string]error{primaryUpstream + reqPath: ErrUpstreamNotFound}
		fetcher.artifact = &fetch.Artifact{
			Body:        io.NopCloser(strings.NewReader("checksum")),
			ContentType: "text/plain",
		}

		h := NewMavenHandler(proxy, "http://localhost", primaryUpstream, pluginPortalUpstream)
		srv := httptest.NewServer(h.Routes())

		resp, err := http.Get(srv.URL + reqPath)
		if err != nil {
			t.Fatalf("GET %s failed: %v", reqPath, err)
		}
		body, _ := io.ReadAll(resp.Body)
		_ = resp.Body.Close()
		srv.Close()

		if resp.StatusCode != http.StatusOK || string(body) != "checksum" {
			t.Fatalf("GET %s: status %d body %q", reqPath, resp.StatusCode, body)
		}
		if want := pluginPortalUpstream + reqPath; fetcher.fetchedURL != want {
			t.Fatalf("GET %s: fetched URL = %q, want %q", reqPath, fetcher.fetchedURL, want)
		}
	}
}

func TestMavenHandler_GradlePluginImplementation_FallbackToPluginPortal(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)

	primaryUpstream := "https://repo1.maven.org/maven2"
	pluginPortalUpstream := "https://plugins.gradle.org/m2"
	implPath := "/com/diffplug/spotless/spotless-plugin-gradle/8.4.0/spotless-plugin-gradle-8.4.0.jar"
	primaryURL := primaryUpstream + implPath
	pluginPortalURL := pluginPortalUpstream + implPath

	fetcher.fetchErrByURL = map[string]error{
		primaryURL: ErrUpstreamNotFound,
	}
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("plugin impl jar")),
		ContentType: "application/java-archive",
	}

	h := NewMavenHandler(proxy, "http://localhost", primaryUpstream, pluginPortalUpstream)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + implPath)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	body, _ := io.ReadAll(resp.Body)
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status = %d, want %d", resp.StatusCode, http.StatusOK)
	}
	if string(body) != "plugin impl jar" {
		t.Fatalf("body = %q, want %q", body, "plugin impl jar")
	}

	if fetcher.fetchedURL != pluginPortalURL {
		t.Fatalf("implementation artifact should fallback to plugin portal; fetched URL = %q, want %q", fetcher.fetchedURL, pluginPortalURL)
	}
}

func TestMavenHandler_GradlePluginImplementation_NotFoundInBothUpstreams(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)

	primaryUpstream := "https://repo1.maven.org/maven2"
	pluginPortalUpstream := "https://plugins.gradle.org/m2"
	implPath := "/com/diffplug/spotless/spotless-plugin-gradle/8.4.0/spotless-plugin-gradle-8.4.0.jar"
	primaryURL := primaryUpstream + implPath
	pluginPortalURL := pluginPortalUpstream + implPath

	fetcher.fetchErrByURL = map[string]error{
		primaryURL:      ErrUpstreamNotFound,
		pluginPortalURL: ErrUpstreamNotFound,
	}

	h := NewMavenHandler(proxy, "http://localhost", primaryUpstream, pluginPortalUpstream)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + implPath)
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("status = %d, want %d", resp.StatusCode, http.StatusNotFound)
	}

	if fetcher.fetchedURL != pluginPortalURL {
		t.Fatalf("expected fallback attempt to plugin portal; fetched URL = %q, want %q", fetcher.fetchedURL, pluginPortalURL)
	}
}

func TestNuGetHandler_DownloadCacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched nupkg")),
		ContentType: "application/octet-stream",
	}

	h := NewNuGetHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/v3-flatcontainer/newtonsoft.json/13.0.3/newtonsoft.json.13.0.3.nupkg")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://api.nuget.org/v3-flatcontainer/newtonsoft.json/13.0.3/newtonsoft.json.13.0.3.nupkg"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestConanHandler_RecipeFileCacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("conan export")),
		ContentType: "application/octet-stream",
	}

	h := NewConanHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/v2/conans/zlib/1.3/_/_/revisions/abc123/files/conan_export.tgz")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://center.conan.io/v2/conans/zlib/1.3/_/_/revisions/abc123/files/conan_export.tgz"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestConanHandler_PackageFileCacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("conan package")),
		ContentType: "application/octet-stream",
	}

	h := NewConanHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/v2/conans/zlib/1.3/_/_/revisions/abc123/packages/def456/revisions/ghi789/files/conan_package.tgz")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://center.conan.io/v2/conans/zlib/1.3/_/_/revisions/abc123/packages/def456/revisions/ghi789/files/conan_package.tgz"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestDebianHandler_DownloadCacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched deb")),
		ContentType: "application/vnd.debian.binary-package",
	}

	h := NewDebianHandler(proxy, "http://localhost", "", nil)
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/pool/main/n/nginx/nginx_1.18.0-6_amd64.deb")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "http://deb.debian.org/debian/pool/main/n/nginx/nginx_1.18.0-6_amd64.deb"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestRPMHandler_DownloadCacheMiss(t *testing.T) {
	proxy, _, _, fetcher := setupTestProxy(t)
	fetcher.artifact = &fetch.Artifact{
		Body:        io.NopCloser(strings.NewReader("fetched rpm")),
		ContentType: "application/x-rpm",
	}

	h := NewRPMHandler(proxy, "http://localhost")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	resp, err := http.Get(srv.URL + "/releases/39/Everything/x86_64/os/Packages/n/nginx-1.24.0-1.fc39.x86_64.rpm")
	if err != nil {
		t.Fatalf("request failed: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if !fetcher.fetchCalled {
		t.Error("expected fetcher to be called on cache miss")
	}

	want := "https://dl.fedoraproject.org/pub/fedora/linux/releases/39/Everything/x86_64/os/Packages/n/nginx-1.24.0-1.fc39.x86_64.rpm"
	if fetcher.fetchedURL != want {
		t.Errorf("upstream URL = %q, want %q", fetcher.fetchedURL, want)
	}
}

func TestMavenHandler_UpstreamHeldReturns503(t *testing.T) {
	held := &httpclient.HeldError{Host: "repo1.maven.org", Until: time.Now().Add(90 * time.Second), RetryAfter: 90 * time.Second}

	t.Run("artifact", func(t *testing.T) {
		proxy, _, _, fetcher := setupTestProxy(t)
		fetcher.fetchErr = fmt.Errorf("fetching artifact: %w", &url.Error{Op: "Get", URL: "https://repo1.maven.org/x", Err: held})

		h := NewMavenHandler(proxy, "http://localhost", "", "")
		srv := httptest.NewServer(h.Routes())
		defer srv.Close()

		resp, err := http.Get(srv.URL + "/com/example/lib/1.0/lib-1.0.jar")
		if err != nil {
			t.Fatalf("request failed: %v", err)
		}
		_ = resp.Body.Close()
		if resp.StatusCode != http.StatusServiceUnavailable || resp.Header.Get("Retry-After") != "90" {
			t.Errorf("status %d Retry-After %q, want 503 with Retry-After 90", resp.StatusCode, resp.Header.Get("Retry-After"))
		}
	})

	t.Run("metadata", func(t *testing.T) {
		proxy, _, _, _ := setupTestProxy(t)
		proxy.HTTPClient = &http.Client{Transport: roundTripperFunc(func(*http.Request) (*http.Response, error) {
			return nil, held
		})}

		h := NewMavenHandler(proxy, "http://localhost", "", "")
		srv := httptest.NewServer(h.Routes())
		defer srv.Close()

		resp, err := http.Get(srv.URL + "/com/example/lib/maven-metadata.xml")
		if err != nil {
			t.Fatalf("request failed: %v", err)
		}
		_ = resp.Body.Close()
		if resp.StatusCode != http.StatusServiceUnavailable || resp.Header.Get("Retry-After") != "90" {
			t.Errorf("status %d Retry-After %q, want 503 with Retry-After 90", resp.StatusCode, resp.Header.Get("Retry-After"))
		}
	})
}

type roundTripperFunc func(*http.Request) (*http.Response, error)

func (fn roundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) { return fn(req) }

func TestMavenHandler_HeldArtifactMissesSkipCircuitBreaker(t *testing.T) {
	proxy, _, _, _ := setupTestProxy(t)
	upstreamCalls := 0
	gate := httpclient.NewRateLimitGate(roundTripperFunc(func(req *http.Request) (*http.Response, error) {
		upstreamCalls++
		return &http.Response{
			StatusCode: http.StatusTooManyRequests,
			Header:     http.Header{"Retry-After": []string{"600"}},
			Body:       http.NoBody,
			Request:    req,
		}, nil
	}))
	req, _ := http.NewRequest(http.MethodGet, "https://repo1.maven.org/maven2/x", nil)
	if resp, err := gate.RoundTrip(req); err == nil {
		_ = resp.Body.Close()
	}
	breaker := fetch.NewCircuitBreakerFetcher(fetch.NewFetcher(fetch.WithHTTPClient(&http.Client{Transport: gate})))
	proxy.Fetcher = breaker
	proxy.RateLimits = gate

	h := NewMavenHandler(proxy, "http://localhost", "", "")
	srv := httptest.NewServer(h.Routes())
	defer srv.Close()

	for i := range 8 {
		resp, err := http.Get(fmt.Sprintf("%s/com/example/lib/1.%d/lib-1.%d.jar", srv.URL, i, i))
		if err != nil {
			t.Fatalf("request %d failed: %v", i, err)
		}
		_ = resp.Body.Close()
		if resp.StatusCode != http.StatusServiceUnavailable || resp.Header.Get("Retry-After") == "" {
			t.Fatalf("request %d: status %d Retry-After %q, want 503 with Retry-After", i, resp.StatusCode, resp.Header.Get("Retry-After"))
		}
	}
	if upstreamCalls != 1 {
		t.Errorf("upstream calls = %d, want only the one that started the hold", upstreamCalls)
	}
	if state := breaker.GetBreakerState()["repo1.maven.org"]; state == "open" {
		t.Errorf("breaker for repo1.maven.org is open after held misses, want closed")
	}
}

func TestHandlers_UpstreamHeldMetadataReturns503(t *testing.T) {
	held := &httpclient.HeldError{Host: "upstream.example", Until: time.Now().Add(42 * time.Second), RetryAfter: 42 * time.Second}
	tests := []struct {
		name    string
		handler func(*Proxy) http.Handler
		path    string
	}{
		{"npm metadata", func(p *Proxy) http.Handler { return NewNPMHandler(p, "http://localhost", "").Routes() }, "/lodash"},
		{"pypi simple", func(p *Proxy) http.Handler { return NewPyPIHandler(p, "http://localhost").Routes() }, "/simple/requests/"},
		{"pypi json", func(p *Proxy) http.Handler { return NewPyPIHandler(p, "http://localhost").Routes() }, "/pypi/requests/json"},
		{"cargo index", func(p *Proxy) http.Handler {
			return NewCargoHandler(p, "http://localhost", "", "").Routes()
		}, "/se/rd/serde"},
		{"pub metadata", func(p *Proxy) http.Handler { return NewPubHandler(p, "http://localhost").Routes() }, "/api/packages/http"},
		{"nuget service index", func(p *Proxy) http.Handler { return NewNuGetHandler(p, "http://localhost").Routes() }, "/v3/index.json"},
		{"nuget search", func(p *Proxy) http.Handler { return NewNuGetHandler(p, "http://localhost").Routes() }, "/query?q=json"},
		{"conda repodata", func(p *Proxy) http.Handler { return NewCondaHandler(p, "http://localhost").Routes() }, "/conda-forge/noarch/repodata.json"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			proxy, _, _, _ := setupTestProxy(t)
			proxy.HTTPClient = &http.Client{Transport: roundTripperFunc(func(*http.Request) (*http.Response, error) {
				return nil, held
			})}
			srv := httptest.NewServer(tt.handler(proxy))
			defer srv.Close()

			resp, err := http.Get(srv.URL + tt.path)
			if err != nil {
				t.Fatalf("request failed: %v", err)
			}
			_ = resp.Body.Close()
			if resp.StatusCode != http.StatusServiceUnavailable || resp.Header.Get("Retry-After") != "42" {
				t.Errorf("status %d Retry-After %q, want 503 with Retry-After 42", resp.StatusCode, resp.Header.Get("Retry-After"))
			}
		})
	}
}