package dnstrie

import "testing"

func TestTrie(t *testing.T) {
	t.Run("InsertAndContains", func(t *testing.T) {
		trie := New()
		domain := "www.example.com"
		err := trie.Insert(domain)
		if err != nil {
			t.Fatalf("Expected no error on insert, got %v", err)
		}

		if !trie.Contains(domain) {
			t.Errorf("Expected Contains('%s') to be true, but it was false", domain)
		}
	})

	t.Run("ContainsNotFound", func(t *testing.T) {
		trie := New()
		err := trie.Insert("example.com")
		if err != nil {
			t.Fatalf("Insert failed: %v", err)
		}

		if trie.Contains("nonexistent.com") {
			t.Error("Expected not to find domain 'nonexistent.com', but did")
		}

		// Check for a path that exists but is not a terminal node
		if trie.Contains("com") {
			t.Error("Expected not to find non-terminal path 'com', but did")
		}
	})

	t.Run("InsertInvalidDomain", func(t *testing.T) {
		trie := New()
		err := trie.Insert("not-a-valid-domain-")
		if err == nil {
			t.Error("Expected an error when inserting an invalid domain, but got nil")
		}
	})

	t.Run("Canonicalization", func(t *testing.T) {
		trie := New()
		// Insert lowercase with trailing dot
		err := trie.Insert("case.example.org.")
		if err != nil {
			t.Fatalf("Insert failed: %v", err)
		}

		// Check contains with uppercase without trailing dot
		if !trie.Contains("CASE.EXAMPLE.ORG") {
			t.Fatal("Failed to find domain with different case and no trailing dot")
		}
	})

	t.Run("MultipleInsertions", func(t *testing.T) {
		trie := New()
		domains := []string{
			"example.com",
			"www.example.com",
			"api.example.com",
			"google.com",
		}
		for _, domain := range domains {
			if err := trie.Insert(domain); err != nil {
				t.Fatalf("Insert failed for %s: %v", domain, err)
			}
		}

		for _, domain := range domains {
			if !trie.Contains(domain) {
				t.Errorf("Expected to find %s, but did not", domain)
			}
		}

		if trie.Contains("ftp.example.com") {
			t.Error("Found domain 'ftp.example.com' which was not inserted")
		}
	})

	t.Run("MergeTries", func(t *testing.T) {
		trie1 := New()
		trie1.Insert("example.com")
		trie1.Insert("sub.example.com")

		trie2 := New()
		trie2.Insert("google.com")
		trie2.Insert("sub.example.com") // Overlapping domain
		trie2.Insert("another.net")

		trie1.Merge(trie2)

		// Test domains from both tries
		if !trie1.Contains("example.com") {
			t.Error("Merge failed: trie1 should contain 'example.com'")
		}
		if !trie1.Contains("google.com") {
			t.Error("Merge failed: trie1 should contain 'google.com'")
		}
		if !trie1.Contains("sub.example.com") {
			t.Error("Merge failed: trie1 should contain overlapping 'sub.example.com'")
		}
		if !trie1.Contains("another.net") {
			t.Error("Merge failed: trie1 should contain 'another.net'")
		}

		// Ensure trie2 is not modified
		if !trie2.Contains("google.com") {
			t.Error("Source trie (trie2) should not be modified after merge")
		}
		if trie2.Contains("example.com") {
			t.Error("Source trie (trie2) was modified after merge")
		}
	})
}