package asinfo_test

import (
	"cmp"
	"slices"
	"strings"
	"testing"

	"git.eeqj.de/sneak/routewatch/pkg/asinfo"
)

func TestGet(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name     string
		asn      int
		wantOK   bool
		wantDesc string
	}{
		{
			name:     "AS1 Level 3",
			asn:      1,
			wantOK:   true,
			wantDesc: "Level 3 Parent, LLC",
		},
		{
			name:     "AS15169 Google",
			asn:      15169,
			wantOK:   true,
			wantDesc: "Google LLC",
		},
		{
			name:   "Non-existent AS",
			asn:    999999999,
			wantOK: false,
		},
		{
			name:     "AS0 IANA Reserved",
			asn:      0,
			wantOK:   true,
			wantDesc: "Internet Assigned Numbers Authority",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			info, ok := asinfo.Get(tt.asn)
			if ok != tt.wantOK {
				t.Errorf("Get(%d) ok = %v, want %v", tt.asn, ok, tt.wantOK)

				return
			}

			if ok && info.Description != tt.wantDesc {
				t.Errorf("Get(%d) description = %q, want %q",
					tt.asn, info.Description, tt.wantDesc)
			}
		})
	}
}

func TestGetDescription(t *testing.T) {
	t.Parallel()

	tests := []struct {
		asn  int
		want string
	}{
		{1, "Level 3 Parent, LLC"},
		{999999999, ""},
	}

	for _, tt := range tests {
		t.Run("", func(t *testing.T) {
			t.Parallel()

			got := asinfo.GetDescription(tt.asn)
			if got != tt.want {
				t.Errorf("GetDescription(%d) = %q, want %q", tt.asn, got, tt.want)
			}
		})
	}
}

func TestGetHandle(t *testing.T) {
	t.Parallel()

	tests := []struct {
		asn  int
		want string
	}{
		{1, "LVLT"},
		{0, "IANA-RSVD"},
		{999999999, ""},
	}

	for _, tt := range tests {
		t.Run("", func(t *testing.T) {
			t.Parallel()

			got := asinfo.GetHandle(tt.asn)
			if got != tt.want {
				t.Errorf("GetHandle(%d) = %q, want %q", tt.asn, got, tt.want)
			}
		})
	}
}

func TestTotal(t *testing.T) {
	t.Parallel()

	total := asinfo.Total()
	if total < 100000 {
		t.Errorf("Total() = %d, expected > 100000", total)
	}

	// Verify it's consistent
	total2 := asinfo.Total()
	if total2 != total {
		t.Errorf("Total() returned different values: %d vs %d", total, total2)
	}
}

func TestSearch(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name    string
		query   string
		wantMin int
	}{
		{
			name:    "Search for Google",
			query:   "Google",
			wantMin: 1,
		},
		{
			name:    "Search for University",
			query:   "University",
			wantMin: 10,
		},
		{
			name:    "Non-existent org",
			query:   "XYZABC123456",
			wantMin: 0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			results, _ := asinfo.Search(tt.query, asinfo.Total())
			if len(results) < tt.wantMin {
				t.Errorf("Search(%q) returned %d results, want at least %d",
					tt.query, len(results), tt.wantMin)
			}

			// Verify all results contain the query, ignoring case
			query := strings.ToLower(tt.query)
			for _, r := range results {
				if !strings.Contains(strings.ToLower(r.Handle), query) &&
					!strings.Contains(strings.ToLower(r.Description), query) {
					t.Errorf("Search result ASN %d doesn't contain query %q",
						r.ASN, tt.query)
				}
			}
		})
	}
}

// TestSearchEmptyQueryMatchesNothing expects an empty query to match no AS,
// although every handle contains the empty string.
func TestSearchEmptyQueryMatchesNothing(t *testing.T) {
	t.Parallel()

	results, total := asinfo.Search("", asinfo.Total())
	if len(results) != 0 || total != 0 {
		t.Errorf(`Search("") returned %d results and a total of %d, want none`,
			len(results), total)
	}
}

// TestSearchIgnoresCase searches for Cloudflare's handle in lower case and its
// description in upper case, and expects both searches to find AS13335.
func TestSearchIgnoresCase(t *testing.T) {
	t.Parallel()

	const cloudflareASN = 13335 // handle CLOUDFLARENET, "Cloudflare, Inc."

	isCloudflare := func(info asinfo.Info) bool {
		return info.ASN == cloudflareASN
	}

	for _, query := range []string{"cloudflarenet", "CLOUDFLARE, INC."} {
		results, _ := asinfo.Search(query, asinfo.Total())
		if !slices.ContainsFunc(results, isCloudflare) {
			t.Errorf("Search(%q) did not find AS%d", query, cloudflareASN)
		}
	}
}

// TestSearchOrdersByASN expects the matches of a search with many of them to
// come in AS number order.
func TestSearchOrdersByASN(t *testing.T) {
	t.Parallel()

	const query = "University"

	results, _ := asinfo.Search(query, asinfo.Total())

	for i := 1; i < len(results); i++ {
		if results[i-1].ASN >= results[i].ASN {
			t.Fatalf("Search(%q): AS%d comes after AS%d",
				query, results[i].ASN, results[i-1].ASN)
		}
	}
}

// TestSearchStopsAtLimit searches for a word that matches more entries than
// the limit. It expects exactly limit entries, the first matches in AS number
// order, and the number of all matches, counted here from All.
func TestSearchStopsAtLimit(t *testing.T) {
	t.Parallel()

	const (
		query = "university"
		limit = 10
	)

	var matches []asinfo.Info

	for _, info := range asinfo.All() {
		if strings.Contains(strings.ToLower(info.Handle), query) ||
			strings.Contains(strings.ToLower(info.Description), query) {
			matches = append(matches, info)
		}
	}

	if len(matches) <= limit {
		t.Fatalf("%q matches %d entries; the test needs more than %d",
			query, len(matches), limit)
	}

	slices.SortFunc(matches, func(a, b asinfo.Info) int {
		return cmp.Compare(a.ASN, b.ASN)
	})

	results, total := asinfo.Search(query, limit)

	if total != len(matches) {
		t.Errorf("Search(%q, %d): total %d, want %d",
			query, limit, total, len(matches))
	}

	if !slices.Equal(results, matches[:limit]) {
		t.Errorf("Search(%q, %d) = %v, want %v",
			query, limit, results, matches[:limit])
	}
}

func TestDataIntegrity(t *testing.T) {
	t.Parallel()

	// Verify no duplicate ASNs
	all := asinfo.All()
	seen := make(map[int]bool)

	for _, info := range all {
		if seen[info.ASN] {
			t.Errorf("Duplicate ASN found: %d", info.ASN)
		}

		seen[info.ASN] = true
	}

	// Verify all entries have required fields
	for _, info := range all {
		if info.Handle == "" && info.ASN != 0 {
			t.Errorf("ASN %d has empty handle", info.ASN)
		}

		if info.Description == "" {
			t.Errorf("ASN %d has empty description", info.ASN)
		}
	}
}

func BenchmarkGet(b *testing.B) {
	// Common ASNs to lookup
	asns := []int{1, 15169, 13335, 32934, 8075, 16509}

	b.ResetTimer()

	for i := range b.N {
		asinfo.Get(asns[i%len(asns)])
	}
}

func BenchmarkSearch(b *testing.B) {
	const limit = 50

	queries := []string{"Google", "Amazon", "Microsoft", "University"}

	b.ResetTimer()

	for i := range b.N {
		asinfo.Search(queries[i%len(queries)], limit)
	}
}