package tools

import (
	"fmt"
	"sync"
	"testing"
)

func TestNewRegistry(t *testing.T) {
	reg := NewRegistry()
	if reg == nil {
		t.Fatal("expected non-nil registry")
	}
	if len(reg.List()) != 0 {
		t.Errorf("expected empty registry, got %d tools", len(reg.List()))
	}
}

func TestRegisterAndGet(t *testing.T) {
	reg := NewRegistry()
	tool := Tool{Name: "test", Description: "test tool"}
	if err := reg.Register(tool); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	got, ok := reg.Get("test")
	if !ok {
		t.Fatal("expected tool to be found")
	}
	if got.Name != "test" {
		t.Errorf("expected name 'test', got %q", got.Name)
	}
}

func TestRegisterDuplicate(t *testing.T) {
	reg := NewRegistry()
	tool := Tool{Name: "test"}
	if err := reg.Register(tool); err != nil {
		t.Fatalf("unexpected error on first register: %v", err)
	}
	if err := reg.Register(tool); err == nil {
		t.Error("expected error for duplicate tool")
	}
}

func TestList(t *testing.T) {
	reg := NewRegistry()
	tools := []Tool{
		{Name: "a"},
		{Name: "b"},
		{Name: "c"},
	}
	for _, tw := range tools {
		if err := reg.Register(tw); err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
	}

	list := reg.List()
	if len(list) != 3 {
		t.Errorf("expected 3 tools, got %d", len(list))
	}
}

func TestFilter(t *testing.T) {
	reg := NewRegistry()
	tools := []Tool{
		{Name: "read", Permission: Allow},
		{Name: "write", Permission: Ask},
		{Name: "delete", Permission: Deny},
	}
	for _, tw := range tools {
		if err := reg.Register(tw); err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
	}

	allowed := reg.Filter(func(t Tool) bool {
		return t.Permission == Allow
	})
	if len(allowed) != 1 {
		t.Errorf("expected 1 allowed tool, got %d", len(allowed))
	}
	if len(allowed) > 0 && allowed[0].Name != "read" {
		t.Errorf("expected 'read' tool, got %q", allowed[0].Name)
	}
}

func TestGetNotFound(t *testing.T) {
	reg := NewRegistry()
	_, ok := reg.Get("nonexistent")
	if ok {
		t.Error("expected false for nonexistent tool")
	}
}

func TestConcurrentRegister(t *testing.T) {
	reg := NewRegistry()
	var wg sync.WaitGroup
	for i := 0; i < 100; i++ {
		wg.Add(1)
		go func(n int) {
			defer wg.Done()
			name := fmt.Sprintf("tool_%d", n)
			_ = reg.Register(Tool{Name: name})
		}(i)
	}
	wg.Wait()

	list := reg.List()
	if len(list) != 100 {
		t.Errorf("expected 100 tools, got %d", len(list))
	}
}