package coverart

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

// newMBCAAProviderForTest registers a fresh mbcaaProvider pointing at
// a test server.
func newMBCAAProviderForTest(t *testing.T, mockURL string) *mbcaaProvider {
	t.Helper()
	resetRegistryForTests()
	t.Cleanup(resetRegistryForTests)

	p := newMBCAAProvider(FetcherConfig{
		BaseURL:    mockURL,
		UserAgent:  "Minstrel/test (https://example.com)",
		MinPeriod:  0,
		HTTPClient: &http.Client{Timeout: 5 * time.Second},
	})
	Register(p)
	p.enabled.Store(true)
	return p
}

func TestMBCAAProvider_ID(t *testing.T) {
	resetRegistryForTests()
	defer resetRegistryForTests()
	p := newMBCAAProvider(FetcherConfig{})
	if p.ID() != "mbcaa" {
		t.Errorf("ID = %q, want mbcaa", p.ID())
	}
	if p.DisplayName() != "Cover Art Archive" {
		t.Errorf("DisplayName = %q, want Cover Art Archive", p.DisplayName())
	}
	if p.RequiresAPIKey() {
		t.Error("RequiresAPIKey = true, want false")
	}
	if !p.DefaultEnabled() {
		t.Error("DefaultEnabled = false, want true")
	}
}

func TestMBCAAProvider_FetchAlbumCover_Success(t *testing.T) {
	imageBody := []byte("FAKE_JPEG")
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if !strings.Contains(r.URL.Path, "/release/abc-123/front-500") {
			http.Error(w, "wrong path: "+r.URL.Path, http.StatusBadRequest)
			return
		}
		w.Header().Set("Content-Type", "image/jpeg")
		_, _ = w.Write(imageBody)
	}))
	defer srv.Close()

	p := newMBCAAProviderForTest(t, srv.URL)
	body, err := p.FetchAlbumCover(context.Background(), AlbumRef{MBID: "abc-123"})
	if err != nil {
		t.Fatalf("FetchAlbumCover err = %v, want nil", err)
	}
	if string(body) != string(imageBody) {
		t.Errorf("body = %q, want %q", body, imageBody)
	}
}

func TestMBCAAProvider_FetchAlbumCover_NotFound(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		http.Error(w, "not found", http.StatusNotFound)
	}))
	defer srv.Close()

	p := newMBCAAProviderForTest(t, srv.URL)
	_, err := p.FetchAlbumCover(context.Background(), AlbumRef{MBID: "missing"})
	if !errors.Is(err, ErrNotFound) {
		t.Errorf("err = %v, want ErrNotFound", err)
	}
}

func TestMBCAAProvider_FetchAlbumCover_DisabledReturnsNotFound(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {
		t.Error("server should not be hit when provider is disabled")
	}))
	defer srv.Close()

	p := newMBCAAProviderForTest(t, srv.URL)
	p.enabled.Store(false)

	_, err := p.FetchAlbumCover(context.Background(), AlbumRef{MBID: "any"})
	if !errors.Is(err, ErrNotFound) {
		t.Errorf("err = %v, want ErrNotFound (disabled)", err)
	}
}

func TestMBCAAProvider_Configure_TogglesEnabled(t *testing.T) {
	resetRegistryForTests()
	defer resetRegistryForTests()
	p := newMBCAAProvider(FetcherConfig{})

	if err := p.Configure(ProviderSettings{Enabled: true}); err != nil {
		t.Fatalf("Configure: %v", err)
	}
	if !p.enabled.Load() {
		t.Error("after Configure(Enabled: true), enabled = false")
	}

	if err := p.Configure(ProviderSettings{Enabled: false}); err != nil {
		t.Fatalf("Configure: %v", err)
	}
	if p.enabled.Load() {
		t.Error("after Configure(Enabled: false), enabled = true")
	}
}

func TestMBCAAProvider_TestConnection_TreatsNotFoundAsSuccess(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		http.Error(w, "not found", http.StatusNotFound)
	}))
	defer srv.Close()

	p := newMBCAAProviderForTest(t, srv.URL)
	if err := p.TestConnection(context.Background()); err != nil {
		t.Errorf("TestConnection err = %v, want nil (404 should be treated as connection ok)", err)
	}
}

func TestMBCAAProvider_TestConnection_PropagatesTransient(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		http.Error(w, "boom", http.StatusInternalServerError)
	}))
	defer srv.Close()

	p := newMBCAAProviderForTest(t, srv.URL)
	if err := p.TestConnection(context.Background()); err == nil {
		t.Error("TestConnection err = nil, want non-nil for 500")
	}
}

func TestNewMBCAAProviderFromConfig_ReplacesRegisteredConfig(t *testing.T) {
	resetRegistryForTests()
	defer resetRegistryForTests()

	// Pre-register with default config (mimics init() behaviour).
	Register(newMBCAAProvider(FetcherConfig{}))

	cfg := FetcherConfig{
		UserAgent: "Minstrel/test-replaced (x)",
		MinPeriod: 100 * time.Millisecond,
	}
	NewMBCAAProviderFromConfig(cfg)

	p, err := ProviderByID("mbcaa")
	if err != nil {
		t.Fatalf("ProviderByID: %v", err)
	}
	mp := p.(*mbcaaProvider)
	// Verify the cfg was replaced on the registered instance.
	mp.mu.Lock()
	gotUA := mp.cfg.UserAgent
	mp.mu.Unlock()
	if gotUA != "Minstrel/test-replaced (x)" {
		t.Errorf("cfg.UserAgent = %q, want %q", gotUA, "Minstrel/test-replaced (x)")
	}
}