package handler

import (
	"bytes"
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"testing"

	"filefast/backend/internal/config"
	"filefast/backend/internal/model"
	"filefast/backend/internal/service"
	"filefast/backend/internal/store"
	"filefast/backend/internal/ws"
)

type registeredDevice struct {
	ID        string `json:"id"`
	AuthToken string `json:"auth_token"`
}

type transferRecord struct {
	ID string `json:"id"`
}

func TestProtectedRoutesRequireDeviceCredentials(t *testing.T) {
	router, _ := newTestRouter()

	device := registerDevice(t, router, map[string]any{
		"device_id": "alpha",
		"name":      "Alpha",
		"type":      "desktop",
	})

	req := httptest.NewRequest(http.MethodGet, "/api/devices/candidates?deviceId="+device.ID, nil)
	resp := httptest.NewRecorder()
	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusUnauthorized {
		t.Fatalf("expected 401 for missing device credentials, got %d", resp.Code)
	}
}

func TestProtectedRoutesRejectMismatchedDeviceIdentity(t *testing.T) {
	router, _ := newTestRouter()

	alpha := registerDevice(t, router, map[string]any{
		"device_id": "alpha",
		"name":      "Alpha",
		"type":      "desktop",
	})
	bravo := registerDevice(t, router, map[string]any{
		"device_id": "bravo",
		"name":      "Bravo",
		"type":      "desktop",
	})

	req := httptest.NewRequest(http.MethodGet, "/api/devices/candidates?deviceId="+bravo.ID, nil)
	req.Header.Set("X-Device-ID", alpha.ID)
	req.Header.Set("X-Device-Token", alpha.AuthToken)
	resp := httptest.NewRecorder()
	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusForbidden {
		t.Fatalf("expected 403 for mismatched device identity, got %d", resp.Code)
	}
}

func TestTransferStatusUpdateRequiresParticipantOwnership(t *testing.T) {
	router, _ := newTestRouter()

	sender := registerDevice(t, router, map[string]any{
		"device_id": "sender",
		"name":      "Sender",
		"type":      "desktop",
	})
	receiver := registerDevice(t, router, map[string]any{
		"device_id": "receiver",
		"name":      "Receiver",
		"type":      "desktop",
	})
	attacker := registerDevice(t, router, map[string]any{
		"device_id": "attacker",
		"name":      "Attacker",
		"type":      "desktop",
	})

	transfer := createTransfer(t, router, sender, map[string]any{
		"kind":               "text",
		"name":               "text-message",
		"content":            "hello",
		"sender_device_id":   sender.ID,
		"receiver_device_id": receiver.ID,
	})

	body, err := json.Marshal(map[string]any{
		"final_status": "completed",
	})
	if err != nil {
		t.Fatalf("marshal update status body: %v", err)
	}

	req := httptest.NewRequest(http.MethodPatch, "/api/transfers/"+transfer.ID+"/status", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Device-ID", attacker.ID)
	req.Header.Set("X-Device-Token", attacker.AuthToken)
	resp := httptest.NewRecorder()
	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusForbidden {
		t.Fatalf("expected 403 for non-participant transfer update, got %d", resp.Code)
	}
}

func newTestRouter() (http.Handler, *store.MemoryStore) {
	memStore := store.NewMemoryStore(model.RuntimeConfig{})
	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
	deviceService := service.NewDeviceService(memStore, nil, nil)
	deps := Dependencies{
		Config:          config.Config{},
		Logger:          logger,
		Store:           memStore,
		DeviceService:   deviceService,
		RoomService:     service.NewRoomService(memStore, 0),
		TransferService: service.NewTransferService(memStore),
		AdminService:    service.NewAdminService(memStore, config.AdminConfig{}, nil, nil),
		Hub:             ws.NewHub(logger, deviceService, nil),
		StorageReady:    true,
		RedisReady:      true,
	}

	return NewHTTPHandler(deps).Router(), memStore
}

func registerDevice(t *testing.T, router http.Handler, payload map[string]any) registeredDevice {
	t.Helper()
	body, err := json.Marshal(payload)
	if err != nil {
		t.Fatalf("marshal register body: %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/devices/register", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	resp := httptest.NewRecorder()
	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusOK {
		t.Fatalf("expected register 200, got %d: %s", resp.Code, resp.Body.String())
	}

	var payloadWrapper struct {
		Data registeredDevice `json:"data"`
	}
	if err := json.Unmarshal(resp.Body.Bytes(), &payloadWrapper); err != nil {
		t.Fatalf("decode register response: %v", err)
	}
	if payloadWrapper.Data.ID == "" || payloadWrapper.Data.AuthToken == "" {
		t.Fatalf("expected device registration to return id and auth token, got %+v", payloadWrapper.Data)
	}

	return payloadWrapper.Data
}

func createTransfer(t *testing.T, router http.Handler, device registeredDevice, payload map[string]any) transferRecord {
	t.Helper()
	body, err := json.Marshal(payload)
	if err != nil {
		t.Fatalf("marshal create transfer body: %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/api/transfers", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Device-ID", device.ID)
	req.Header.Set("X-Device-Token", device.AuthToken)
	resp := httptest.NewRecorder()
	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusOK {
		t.Fatalf("expected create transfer 200, got %d: %s", resp.Code, resp.Body.String())
	}

	var payloadWrapper struct {
		Data transferRecord `json:"data"`
	}
	if err := json.Unmarshal(resp.Body.Bytes(), &payloadWrapper); err != nil {
		t.Fatalf("decode transfer response: %v", err)
	}
	if payloadWrapper.Data.ID == "" {
		t.Fatalf("expected transfer id in response, got %+v", payloadWrapper.Data)
	}

	return payloadWrapper.Data
}