package handler

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"

	"github.com/prabhupadasays/spsays-bff/internal/middleware"
	"github.com/prabhupadasays/spsays-bff/pkg/realtime"
	"go.uber.org/zap"
)

const testUser = "user-a"

func testAuthHandler(t *testing.T) *BroadcastingAuthHandler {
	t.Helper()
	rt := realtime.NewSoketiClient("app-1", "test-key", "test-secret", "ws.example.com", 443, true, zap.NewNop())
	if rt == nil {
		t.Fatal("realtime client is nil")
	}
	// A second rule stands in for the chat conversation channels, proving the
	// rule table is what decides access rather than anything hardcoded.
	convRule := ChannelRule{
		Prefix: "presence-conversation.",
		Authorize: func(_ context.Context, userID, suffix string) (bool, error) {
			return suffix == "open-to-user-a" && userID == testUser, nil
		},
	}
	return NewBroadcastingAuthHandler(rt, zap.NewNop(), NotificationsRule(), convRule)
}

// serve posts a form-encoded auth request as userID ("" = unauthenticated).
func serve(t *testing.T, h *BroadcastingAuthHandler, userID, socketID, channel string) *httptest.ResponseRecorder {
	t.Helper()
	form := url.Values{"socket_id": {socketID}, "channel_name": {channel}}
	req := httptest.NewRequest(http.MethodPost, "/api/v1/broadcasting/auth", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	if userID != "" {
		req = req.WithContext(middleware.WithUserID(req.Context(), userID))
	}
	rec := httptest.NewRecorder()
	h.Handle(rec, req)
	return rec
}

func TestBroadcastingAuth_Authorization(t *testing.T) {
	h := testAuthHandler(t)

	tests := []struct {
		name    string
		userID  string
		channel string
		want    int
	}{
		{"own notifications channel", testUser, "private-notifications." + testUser, http.StatusOK},
		{"another user's notifications", testUser, "private-notifications.user-b", http.StatusForbidden},
		{"unauthenticated", "", "private-notifications." + testUser, http.StatusUnauthorized},
		{"unknown channel family", testUser, "private-secrets.42", http.StatusForbidden},
		{"legacy public channel is not signable", testUser, "notifications." + testUser, http.StatusForbidden},
		{"empty suffix", testUser, "private-notifications.", http.StatusForbidden},
		{"presence channel allowed by rule", testUser, "presence-conversation.open-to-user-a", http.StatusOK},
		{"presence channel denied by rule", testUser, "presence-conversation.someone-elses", http.StatusForbidden},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			rec := serve(t, h, tc.userID, "1234.5678", tc.channel)
			if rec.Code != tc.want {
				t.Errorf("status = %d, want %d (body %s)", rec.Code, tc.want, rec.Body.String())
			}
		})
	}
}

// A prefix match must not be mistaken for authorization: "…user-a-evil" starts
// with the victim's id but is a different channel.
func TestBroadcastingAuth_SuffixIsComparedExactly(t *testing.T) {
	rec := serve(t, testAuthHandler(t), testUser, "1234.5678", "private-notifications."+testUser+"-evil")
	if rec.Code != http.StatusForbidden {
		t.Errorf("status = %d, want 403", rec.Code)
	}
}

func TestBroadcastingAuth_SignatureShape(t *testing.T) {
	rec := serve(t, testAuthHandler(t), testUser, "1234.5678", "private-notifications."+testUser)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200", rec.Code)
	}
	var body struct {
		Auth        string `json:"auth"`
		ChannelData string `json:"channel_data"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if !strings.HasPrefix(body.Auth, "test-key:") {
		t.Errorf("auth = %q, want a <key>:<signature> pair", body.Auth)
	}
	// channel_data belongs to presence channels only; sending it for a private
	// channel would make Soketi reject the subscription.
	if body.ChannelData != "" {
		t.Errorf("channel_data = %q, want empty for a private channel", body.ChannelData)
	}
}

func TestBroadcastingAuth_PresenceReturnsChannelData(t *testing.T) {
	rec := serve(t, testAuthHandler(t), testUser, "1234.5678", "presence-conversation.open-to-user-a")
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200", rec.Code)
	}
	var body struct {
		ChannelData string `json:"channel_data"`
	}
	_ = json.Unmarshal(rec.Body.Bytes(), &body)
	if !strings.Contains(body.ChannelData, `"user_id":"`+testUser+`"`) {
		t.Errorf("channel_data = %q, want the caller's user_id", body.ChannelData)
	}
}

func TestBroadcastingAuth_AcceptsJSONBody(t *testing.T) {
	body := `{"socket_id":"1234.5678","channel_name":"private-notifications.` + testUser + `"}`
	req := httptest.NewRequest(http.MethodPost, "/api/v1/broadcasting/auth", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req = req.WithContext(middleware.WithUserID(req.Context(), testUser))
	rec := httptest.NewRecorder()
	testAuthHandler(t).Handle(rec, req)
	if rec.Code != http.StatusOK {
		t.Errorf("status = %d, want 200 (body %s)", rec.Code, rec.Body.String())
	}
}

func TestBroadcastingAuth_MissingParams(t *testing.T) {
	h := testAuthHandler(t)
	if rec := serve(t, h, testUser, "", "private-notifications."+testUser); rec.Code != http.StatusBadRequest {
		t.Errorf("missing socket_id: status = %d, want 400", rec.Code)
	}
	if rec := serve(t, h, testUser, "1234.5678", ""); rec.Code != http.StatusBadRequest {
		t.Errorf("missing channel_name: status = %d, want 400", rec.Code)
	}
}

// With realtime disabled there is no secret to sign with; the endpoint must
// say so rather than hand back an unusable signature.
func TestBroadcastingAuth_UnconfiguredRealtime(t *testing.T) {
	h := NewBroadcastingAuthHandler(nil, zap.NewNop(), NotificationsRule())
	if rec := serve(t, h, testUser, "1234.5678", "private-notifications."+testUser); rec.Code != http.StatusServiceUnavailable {
		t.Errorf("status = %d, want 503", rec.Code)
	}
}