package server

import (
	"strings"
	"testing"
)

func TestValidateDNSLabel(t *testing.T) {
	tests := []struct {
		name    string
		label   string
		wantErr string
	}{
		{"valid short", "a", ""},
		{"valid typical", "my-site", ""},
		{"valid numeric", "123", ""},
		{"valid max length", strings.Repeat("a", 63), ""},
		{"too long", strings.Repeat("a", 64), "63-character limit"},
		{"way too long", strings.Repeat("a", 200), "63-character limit"},
		{"uppercase", "MySite", "lowercase letters"},
		{"underscore", "my_site", "lowercase letters"},
		{"starts with hyphen", "-mysite", "lowercase letters"},
		{"ends with hyphen", "mysite-", "lowercase letters"},
		{"empty", "", "lowercase letters"},
		{"spaces", "my site", "lowercase letters"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := validateDNSLabel(tt.label)
			if tt.wantErr == "" {
				if got != "" {
					t.Errorf("validateDNSLabel(%q) = %q, want no error", tt.label, got)
				}
			} else {
				if got == "" {
					t.Errorf("validateDNSLabel(%q) = no error, want error containing %q", tt.label, tt.wantErr)
				} else if !strings.Contains(got, tt.wantErr) {
					t.Errorf("validateDNSLabel(%q) = %q, want error containing %q", tt.label, got, tt.wantErr)
				}
			}
		})
	}
}

func TestValidateFQDN(t *testing.T) {
	tests := []struct {
		name       string
		label      string
		farmDomain string
		wantErr    bool
	}{
		{"typical", "mysite", "wiki.cafe", false},
		{"max label with short domain", strings.Repeat("a", 63), "w.co", false},
		// 63-char label + "." + 189-char domain = 253 chars exactly
		{"exactly 253", strings.Repeat("a", 63), strings.Repeat("b", 189), false},
		// 63-char label + "." + 190-char domain = 254 chars
		{"exceeds 253", strings.Repeat("a", 63), strings.Repeat("b", 190), true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := validateFQDN(tt.label, tt.farmDomain)
			if tt.wantErr && got == "" {
				t.Errorf("validateFQDN(%q, %q) = no error, want error", tt.label, tt.farmDomain)
			}
			if !tt.wantErr && got != "" {
				t.Errorf("validateFQDN(%q, %q) = %q, want no error", tt.label, tt.farmDomain, got)
			}
		})
	}
}