package checker

import (
	"strings"
	"testing"
)

func TestSelectedResolvers_DefaultExcludesFiltered(t *testing.T) {
	out := selectedResolvers(false, "all", nil)
	if len(out) == 0 {
		t.Fatalf("default selection is empty")
	}
	for _, r := range out {
		if r.Filtered {
			t.Errorf("filtered resolver %q leaked into default selection", r.ID)
		}
	}
}

func TestSelectedResolvers_IncludeFiltered(t *testing.T) {
	withF := selectedResolvers(true, "all", nil)
	withoutF := selectedResolvers(false, "all", nil)
	if len(withF) <= len(withoutF) {
		t.Errorf("includeFiltered=true should add resolvers, got %d vs %d", len(withF), len(withoutF))
	}
}

func TestSelectedResolvers_RegionFilter(t *testing.T) {
	out := selectedResolvers(false, "eu", nil)
	if len(out) == 0 {
		t.Fatalf("eu selection is empty")
	}
	for _, r := range out {
		if r.Region != "eu" {
			t.Errorf("non-eu resolver %q (%s) leaked in", r.ID, r.Region)
		}
	}
}

func TestSelectedResolvers_AllowlistByID(t *testing.T) {
	out := selectedResolvers(false, "all", []string{"cloudflare", "9.9.9.10"})
	ids := make(map[string]bool)
	for _, r := range out {
		ids[r.ID] = true
	}
	if !ids["cloudflare"] || !ids["quad9-unfiltered"] {
		t.Errorf("allowlist failed: %v", ids)
	}
	if len(out) != 2 {
		t.Errorf("expected exactly 2 resolvers, got %d", len(out))
	}
}

func TestSelectedResolvers_AllowlistOverridesFilteredAndRegion(t *testing.T) {
	// quad9 is Filtered + global; allowlist must still pick it.
	out := selectedResolvers(false, "eu", []string{"quad9"})
	if len(out) != 1 || out[0].ID != "quad9" {
		t.Errorf("allowlist should override filtered/region, got %v", out)
	}
}

func TestRegionLabel(t *testing.T) {
	cases := map[string]string{
		"global":  "Global / Anycast",
		"na":      "North America",
		"eu":      "Europe",
		"asia":    "Asia",
		"ru":      "Russia",
		"me":      "Middle East",
		"oceania": "Oceania",
		"sa":      "South America",
		"africa":  "Africa",
		"unknown": "unknown",
		"":        "",
	}
	for in, want := range cases {
		if got := regionLabel(in); got != want {
			t.Errorf("regionLabel(%q) = %q, want %q", in, got, want)
		}
	}
}

func TestAllResolversCatalogIntegrity(t *testing.T) {
	// Catch typos / duplicates in the static catalog.
	ids := map[string]bool{}
	for _, r := range allResolvers {
		if r.ID == "" {
			t.Errorf("resolver with empty ID: %+v", r)
		}
		if r.IP == "" {
			t.Errorf("resolver %q has empty IP", r.ID)
		}
		if strings.Contains(r.ID, "|") {
			t.Errorf("resolver ID %q contains reserved separator '|'", r.ID)
		}
		if ids[r.ID] {
			t.Errorf("duplicate resolver ID %q", r.ID)
		}
		ids[r.ID] = true
		if r.DoTHost == "" && r.DoHURL != "" {
			// DoH-only is acceptable but log it for visibility.
			t.Logf("resolver %q has DoH but no DoT", r.ID)
		}
	}
}