// Package connector is the backend's gRPC client for the Telegram platform
// connector side-service. The admin console uses it to send operator broadcasts:
// a direct message to one user, or a post to a game channel. Each broadcast
// selects the delivering bot by language (an operator choice, since the connector
// hosts one bot per service language). The connector lives on the trusted internal
// network, so the connection uses insecure (plaintext) transport credentials
// (docs/ARCHITECTURE.md §12). It mirrors gateway/internal/connector, narrowed to
// the two broadcast methods the admin surface needs.
package connector

import (
	"context"
	"fmt"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"

	telegramv1 "scrabble/pkg/proto/telegram/v1"
)

// Client wraps the connector's Telegram gRPC service.
type Client struct {
	conn *grpc.ClientConn
	c    telegramv1.TelegramClient
}

// New dials the connector gRPC endpoint at addr.
func New(addr string) (*Client, error) {
	conn, err := grpc.NewClient(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, fmt.Errorf("connector: dial %s: %w", addr, err)
	}
	return &Client{conn: conn, c: telegramv1.NewTelegramClient(conn)}, nil
}

// Close releases the gRPC connection.
func (c *Client) Close() error { return c.conn.Close() }

// SendToUser sends an operator text message to one user, addressed by their
// platform external_id, through the bot for the given language. delivered reports
// whether the connector actually sent it (false when the user has not started that
// bot).
func (c *Client) SendToUser(ctx context.Context, externalID, text, language string) (bool, error) {
	resp, err := c.c.SendToUser(ctx, &telegramv1.SendToUserRequest{ExternalId: externalID, Text: text, Language: language})
	if err != nil {
		return false, err
	}
	return resp.GetDelivered(), nil
}

// SendToGameChannel posts an operator text message to the game channel of the bot
// for the given language. delivered reports whether the connector sent it (false
// when that bot has no channel configured).
func (c *Client) SendToGameChannel(ctx context.Context, text, language string) (bool, error) {
	resp, err := c.c.SendToGameChannel(ctx, &telegramv1.SendToGameChannelRequest{Text: text, Language: language})
	if err != nil {
		return false, err
	}
	return resp.GetDelivered(), nil
}