package lighthouse

import (
	"context"
	"math"
	"reflect"
	"testing"
)

// TestChannelIDMatchesPHP pins ChannelID to PHP's (int) cast of the id
// segment. The expected values were printed by PHP 8.5.10:
//
//	php -r 'foreach ([...] as $s) var_dump((int)$s);'
func TestChannelIDMatchesPHP(t *testing.T) {
	cases := []struct {
		segment string
		want    int64
	}{
		{"5", 5}, {"05", 5}, {" 5", 5}, {"5abc", 5}, {"abc", 0}, {"-3", -3}, {"", 0},
		{"1e3", 1000}, {"0x1A", 0}, {"9999999999999999999", math.MaxInt64},
		{"\t5", 5}, {"\n5", 5}, {"5 ", 5}, {"+5", 5}, {"  -7x", -7}, {"1.9", 1}, {"-0", 0},
		{"1e20", math.MaxInt64}, {"0b11", 0}, {"٥", 0}, {" ", 0},
		{"-9999999999999999999", math.MinInt64}, {"-1e20", math.MinInt64}, {"1e-3", 0},
		{".5", 0}, {"5.", 5}, {"1e", 1}, {"1e+2", 100}, {"\v5", 5}, {"\f5", 5}, {"\r5", 5},
		{"NaN", 0}, {"INF", 0}, {"1E3", 1000}, {"9223372036854775807", math.MaxInt64},
		{"9223372036854775808", math.MaxInt64}, {"1.5e3", 1500}, {"-.5e1", -5}, {"0005", 5},
		{"00", 0}, {"- 5", 0}, {"5e3abc", 5000}, {"12.7e1x", 127}, {"1e400", 0},
	}
	for _, tc := range cases {
		if got := ChannelID("collection:" + tc.segment); got != tc.want {
			t.Errorf("ChannelID(collection:%q) = %d, want %d", tc.segment, got, tc.want)
		}
	}
	if got := ChannelID("collection"); got != 0 {
		t.Errorf("missing segment = %d, want 0", got)
	}
	if got := ChannelID("presence:collection:5"); got != 0 {
		t.Errorf("presence:collection:5 = %d, want 0 (segment 1 is \"collection\")", got)
	}
	if got := ChannelID("wishlist:12:extra"); got != 12 {
		t.Errorf("wishlist:12:extra = %d, want 12", got)
	}
}

func TestParseChannel(t *testing.T) {
	cases := []struct {
		channel   string
		namespace string
		presence  bool
	}{
		{"collection:5", "collection", false},
		{"ns:entity:id", "ns", false},
		{"presence:acme:room:1", "acme", true},
		{"presence:collection:5", "collection", true},
		{"presence:presence:x", "", true},
		{"a:b:c:d", "", false},
		{"presence:a:b:c:d", "", true},
		{"", "", false},
		{":5", "", false},
		{"Collection:5", "Collection", false},
	}
	for _, tc := range cases {
		ns, presence := ParseChannel(tc.channel)
		if ns != tc.namespace || presence != tc.presence {
			t.Errorf("ParseChannel(%q) = (%q, %t), want (%q, %t)", tc.channel, ns, presence, tc.namespace, tc.presence)
		}
	}
}

func TestFormatChannels(t *testing.T) {
	got := FormatChannels("Acme", []string{"Collection:5", "acme:user:1", "ACME:x"})
	want := []string{"acme:collection:5", "acme:user:1", "acme:x"}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("FormatChannels = %v, want %v", got, want)
	}
	if got := FormatChannels("", []string{"Collection:5"}); !reflect.DeepEqual(got, []string{"collection:5"}) {
		t.Fatalf("no namespace = %v", got)
	}
	// PHP treats the namespace "0" as empty; the prefix is applied once.
	if got := FormatChannels("0", []string{"Room:1"}); !reflect.DeepEqual(got, []string{"room:1"}) {
		t.Fatalf("namespace 0 = %v", got)
	}
	if got := FormatChannels("acme", []string{"ACME:room:1", "acme:acme:x"}); !reflect.DeepEqual(got, []string{"acme:room:1", "acme:acme:x"}) {
		t.Fatalf("prefix once = %v", got)
	}
	if got := FormatChannels("acme", nil); len(got) != 0 {
		t.Fatalf("nil channels = %v", got)
	}
}

func TestClientID(t *testing.T) {
	if ClientID(nil) != "" || ClientID(WithClientID(nil, "c-0")) != "c-0" {
		t.Fatal("nil ctx handling")
	}
	if ClientID(context.Background()) != "" {
		t.Fatal("empty ctx has a client id")
	}
	if got := ClientID(WithClientID(context.Background(), "c-1")); got != "c-1" {
		t.Fatalf("ClientID = %q", got)
	}
}