// Package services provides the game service layer for Connect 4,
// handling NATS subscriptions and chat room management.
package services

import (
	"fmt"

	"github.com/nats-io/nats.go"

	"github.com/ryanhamamura/games/chat"
	chatcomponents "github.com/ryanhamamura/games/chat/components"
	"github.com/ryanhamamura/games/connect4"
	"github.com/ryanhamamura/games/db/repository"
)

// c4ChatColors maps player slot (0-indexed) to CSS background colors.
var c4ChatColors = map[int]string{
	0: "#4a2a3a", // Red player
	1: "#2a4545", // Yellow player
}

func c4ChatColor(slot int) string {
	if c, ok := c4ChatColors[slot]; ok {
		return c
	}
	return "#666"
}

// GameService manages NATS subscriptions and chat for Connect 4 games.
type GameService struct {
	nc      *nats.Conn
	queries *repository.Queries
}

// NewGameService creates a new game service.
func NewGameService(nc *nats.Conn, queries *repository.Queries) *GameService {
	return &GameService{
		nc:      nc,
		queries: queries,
	}
}

// SubscribeGameUpdates returns a NATS subscription and channel for game state updates.
func (s *GameService) SubscribeGameUpdates(gameID string) (*nats.Subscription, <-chan *nats.Msg, error) {
	ch := make(chan *nats.Msg, 64)
	sub, err := s.nc.ChanSubscribe(connect4.GameSubject(gameID), ch)
	if err != nil {
		return nil, nil, fmt.Errorf("subscribing to game updates: %w", err)
	}
	return sub, ch, nil
}

// ChatConfig returns the chat configuration for a game.
func (s *GameService) ChatConfig(gameID string) chatcomponents.Config {
	return chatcomponents.Config{
		CSSPrefix: "c4",
		PostURL:   fmt.Sprintf("/games/%s/chat", gameID),
		Color:     c4ChatColor,
	}
}

// ChatRoom returns a persistent chat room for a game.
func (s *GameService) ChatRoom(gameID string) *chat.Room {
	return chat.NewPersistentRoom(s.nc, connect4.ChatSubject(gameID), s.queries, gameID)
}

// PublishGameUpdate sends a notification that the game state has changed.
func (s *GameService) PublishGameUpdate(gameID string) error {
	return s.nc.Publish(connect4.GameSubject(gameID), nil)
}