package client

import (
	"context"
	"fmt"
	"sync"

	grpcService "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/services/tree"
	"google.golang.org/grpc"
)

type TreeClient struct {
	mu      sync.RWMutex
	address string
	opts    []grpc.DialOption
	conn    *grpc.ClientConn
	service grpcService.TreeServiceClient
	dialed  bool
}

// NewTreeClient creates new tree client with auto dial.
func NewTreeClient(addr string, opts ...grpc.DialOption) *TreeClient {
	return &TreeClient{
		address: addr,
		opts:    opts,
	}
}

func (c *TreeClient) dial(ctx context.Context) error {
	c.mu.Lock()
	defer c.mu.Unlock()

	if c.dialed {
		return fmt.Errorf("couldn't dial '%s': connection already established", c.address)
	}

	conn, err := grpc.Dial(c.address, c.opts...)
	if err != nil {
		return fmt.Errorf("grpc dial node tree service: %w", err)
	}

	serviceClient := grpcService.NewTreeServiceClient(conn)
	if _, err = serviceClient.Healthcheck(ctx, &grpcService.HealthcheckRequest{}); err != nil {
		return fmt.Errorf("healthcheck tree service: %w", err)
	}

	c.conn = conn
	c.service = serviceClient
	c.dialed = true

	return nil
}

func (c *TreeClient) TreeClient(ctx context.Context) (grpcService.TreeServiceClient, error) {
	c.mu.RLock()
	dialed := c.dialed
	c.mu.RUnlock()

	if !dialed {
		if err := c.dial(ctx); err != nil {
			return nil, err
		}
	}

	return c.service, nil
}

func (c *TreeClient) Address() string {
	return c.address
}