package edgeos

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"net/http"
	"sync"
	"testing"
)

type mockTransport struct {
	RoundTripFunc func(req *http.Request) (*http.Response, error)
}

func (m *mockTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	if m.RoundTripFunc != nil {
		return m.RoundTripFunc(req)
	}
	// Default mock response
	return &http.Response{
		StatusCode: 200,
		Body:       io.NopCloser(bytes.NewBufferString("{}")),
		Header:     make(http.Header),
	}, nil
}

func TestClient_ThreadSafety(t *testing.T) {
	ctx := context.Background()
	client := MustNew(ctx, []Config{})

	var wg sync.WaitGroup
	start := make(chan struct{})

	// Writer: Adds and deletes hosts
	wg.Add(1)
	go func() {
		defer wg.Done()
		<-start
		for i := 0; i < 100; i++ {
			host := fmt.Sprintf("host-%d", i)
			cfg := &Config{
				Host:      host,
				Transport: &mockTransport{},
			}
			if err := client.Add(cfg); err != nil {
				// verify we don't error on valid add
				t.Logf("Add error: %v", err)
			}

			// We invoke Del immediately.
			if err := client.Del(host); err != nil {
				t.Logf("Del error: %v", err)
			}
		}
	}()

	// Reader: Iterates hosts
	wg.Add(1)
	go func() {
		defer wg.Done()
		<-start
		for i := 0; i < 10; i++ {
			// GetAllInterfaces iterates keys.
			// With mock transport, this will succeed (returning empty structs)
			// checking for race conditions.
			_, _ = client.GetAllInterfaces(ctx)
		}
	}()

	close(start)
	wg.Wait()
}

func TestClient_AddDel(t *testing.T) {
	ctx := context.Background()
	client := MustNew(ctx, []Config{})

	cfg := &Config{
		Host:      "test-host",
		Transport: &mockTransport{},
	}
	if err := client.Add(cfg); err != nil {
		t.Fatalf("Add failed: %v", err)
	}

	if err := client.Add(cfg); err == nil {
		t.Fatal("Expected error adding duplicate host, got nil")
	}

	// Verify we can retrieve it
	// Mock transport returns 200 OK with empty body, so GetInterfaces should return empty slice (or error decoding if empty body is not valid JSON array? actually "{}" is valid object, but GetInterfaces expects array for /interfaces?)
	// Let's check api.go: GetInterfaces calls /interfaces.
	// We can customize the mock if we want to test success return.
	// For this test, we just care that it doesn't return "device not found".
	_, err := client.GetInterfaces(ctx, "test-host")
	if err != nil && err.Error() == "device not found: test-host" {
		t.Fatal("Device should exist")
	}

	if err := client.Del("test-host"); err != nil {
		t.Fatalf("Del failed: %v", err)
	}

	if err := client.Del("test-host"); err == nil {
		t.Fatal("Expected error deleting non-existent host, got nil")
	}
}