package rtpconn

import (
	"regexp"
	"strings"
	"testing"

	"git.stormux.org/storm/skald/hall"
)

func TestParseDiceExpression(t *testing.T) {
	tests := []struct {
		expression string
		count      int64
		sides      int64
		modifier   int64
	}{
		{"2d4", 2, 4, 0},
		{"10d8 + 5", 10, 8, 5},
		{"3 d 2+5", 3, 2, 5},
		{"2 D 20 - 1", 2, 20, -1},
		{" 1d6 ", 1, 6, 0},
	}

	for _, test := range tests {
		t.Run(test.expression, func(t *testing.T) {
			got, err := parseDiceExpression(test.expression)
			if err != nil {
				t.Fatalf("parseDiceExpression(%q): %v", test.expression, err)
			}
			if got.Count != test.count || got.Sides != test.sides || got.Modifier != test.modifier {
				t.Fatalf("parseDiceExpression(%q) = %#v", test.expression, got)
			}
		})
	}
}

func TestParseDiceExpressionRejectsInvalidAndOversizedRolls(t *testing.T) {
	tests := []string{
		"", "d20", "2d", "2d1", "0d6", "101d6", "2d1000001",
		"2d6 + 1000001", "2 0d6", "2d6 trailing",
	}
	for _, expression := range tests {
		t.Run(expression, func(t *testing.T) {
			if _, err := parseDiceExpression(expression); err == nil {
				t.Fatalf("parseDiceExpression(%q) unexpectedly succeeded", expression)
			}
		})
	}
}

func TestFormatDiceAnnouncement(t *testing.T) {
	tests := []struct {
		name     string
		roll     diceRoll
		expected string
	}{
		{
			"two dice",
			diceRoll{Count: 2, Sides: 4, Results: []int64{1, 2}, Total: 3},
			"Storm rolls 2 4-sided dice: 1 and 2, for a total of 3.",
		},
		{
			"many dice with modifier",
			diceRoll{Count: 10, Sides: 10, Modifier: 5, Results: []int64{2, 3, 4, 3, 4, 1, 2, 1, 2, 3}, Total: 30},
			"Storm rolls 10 10-sided dice: 2, 3, 4, 3, 4, and 5 more, plus 5, for a total of 30.",
		},
		{
			"one die with negative modifier",
			diceRoll{Count: 1, Sides: 20, Modifier: -1, Results: []int64{17}, Total: 16},
			"Storm rolls 1 20-sided die: 17, minus 1, for a total of 16.",
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			if got := formatDiceAnnouncement("Storm", test.roll); got != test.expected {
				t.Fatalf("formatDiceAnnouncement() = %q, want %q", got, test.expected)
			}
		})
	}
}

func TestGenerateDiceRollStaysWithinBounds(t *testing.T) {
	roll, err := generateDiceRoll(diceRoll{Count: 100, Sides: 6, Modifier: -50})
	if err != nil {
		t.Fatalf("generateDiceRoll: %v", err)
	}
	if len(roll.Results) != 100 {
		t.Fatalf("generated %d results, want 100", len(roll.Results))
	}
	wantTotal := int64(-50)
	for _, result := range roll.Results {
		if result < 1 || result > 6 {
			t.Fatalf("generated result %d outside 1..6", result)
		}
		wantTotal += result
	}
	if roll.Total != wantTotal {
		t.Fatalf("total = %d, want %d", roll.Total, wantTotal)
	}
}

func TestDiceRollIsServerGeneratedAndStoredInHistory(t *testing.T) {
	hallName := newChalkboardTestHall(t)
	roller := addTestWebClient(t, hallName, "Participant", "message")
	observer := addTestWebClient(t, hallName, "Operator", "op")

	if err := handleClientMessage(roller, clientMessage{
		Type:  "hallaction",
		Kind:  "roll",
		Value: "2d4 + 5",
	}); err != nil {
		t.Fatalf("handleClientMessage(roll): %v", err)
	}

	for name, messages := range map[string][]clientMessage{
		"roller":   drainMessages(roller),
		"observer": drainMessages(observer),
	} {
		if len(messages) != 1 {
			t.Fatalf("%s received %d messages, want 1: %#v", name, len(messages), messages)
		}
		message := messages[0]
		if message.Type != "chat" || message.Kind != "dice" || !message.Privileged {
			t.Fatalf("%s received non-authoritative dice message: %#v", name, message)
		}
		if message.Source != "" || message.Username == nil || *message.Username != "Dice" {
			t.Fatalf("%s received dice message with unexpected identity: %#v", name, message)
		}
		text, ok := message.Value.(string)
		if !ok || !regexp.MustCompile(`^Participant rolls 2 4-sided dice: [1-4] and [1-4], plus 5, for a total of (7|8|9|10|11|12|13)\.$`).MatchString(text) {
			t.Fatalf("%s received malformed dice announcement %q", name, text)
		}
	}

	history := roller.hall.GetChatHistory()
	if len(history) != 1 || history[0].Kind != "dice" {
		t.Fatalf("dice history = %#v", history)
	}

	newcomer := testWebClient("admin-id")
	adminName := "Admin"
	if _, err := hall.AddClient(hallName, newcomer, hall.ClientCredentials{
		Username: &adminName,
		Password: "pw",
	}); err != nil {
		t.Fatalf("AddClient(Admin): %v", err)
	}
	newcomer.hall = hall.Get(hallName)
	drainActions(t, newcomer)
	var historicalDice *clientMessage
	for _, message := range drainMessages(newcomer) {
		if message.Type == "chathistory" && message.Kind == "dice" {
			message := message
			historicalDice = &message
			break
		}
	}
	if historicalDice == nil || !historicalDice.Privileged {
		t.Fatalf("new participant did not receive authoritative dice history: %#v", historicalDice)
	}
}

func TestDiceRollRequiresMessagePermission(t *testing.T) {
	hallName := newChalkboardTestHall(t)
	roller := addTestWebClient(t, hallName, "Participant", "message")
	roller.permissions = remove("message", roller.permissions)

	if err := handleClientMessage(roller, clientMessage{
		Type: "hallaction", Kind: "roll", Value: "1d6",
	}); err != nil {
		t.Fatalf("handleClientMessage(roll): %v", err)
	}
	if got := roller.hall.GetChatHistory(); len(got) != 0 {
		t.Fatalf("unauthorised roll entered history: %#v", got)
	}
	messages := drainMessages(roller)
	if len(messages) != 1 || messages[0].Kind != "error" ||
		!strings.Contains(messages[0].Value.(string), "not authorised") {
		t.Fatalf("unauthorised roll response = %#v", messages)
	}
}

func TestClientsCannotSubmitServerGeneratedMessages(t *testing.T) {
	hallName := newChalkboardTestHall(t)
	roller := addTestWebClient(t, hallName, "Participant", "message")

	for _, messageKind := range []string{"dice", "eightball", "coin"} {
		for _, messageType := range []string{"chat", "usermessage"} {
			drainMessages(roller)
			if err := handleClientMessage(roller, clientMessage{
				Type: messageType, Kind: messageKind, Value: "whatever result I wanted",
			}); err != nil {
				t.Fatalf("handleClientMessage(%s, %s): %v", messageType, messageKind, err)
			}
			messages := drainMessages(roller)
			if len(messages) != 1 || messages[0].Kind != "error" {
				t.Fatalf("reserved %s/%s response = %#v", messageType, messageKind, messages)
			}
		}
	}
	if got := roller.hall.GetChatHistory(); len(got) != 0 {
		t.Fatalf("forged dice message entered history: %#v", got)
	}
}

func TestChatIdentityComesFromConnection(t *testing.T) {
	hallName := newChalkboardTestHall(t)
	sender := addTestWebClient(t, hallName, "Participant", "message")
	observer := addTestWebClient(t, hallName, "Operator", "op")

	if err := handleClientMessage(sender, clientMessage{
		Type: "chat", Value: "hello",
	}); err != nil {
		t.Fatalf("handleClientMessage(chat): %v", err)
	}
	messages := drainMessages(observer)
	if len(messages) != 1 || messages[0].Source != sender.id ||
		messages[0].Username == nil || *messages[0].Username != "Participant" {
		t.Fatalf("chat did not use connection identity: %#v", messages)
	}
}