package valkey

import (
	"context"
	"fmt"

	vk "github.com/valkey-io/valkey-go"

	"code.nochebuena.dev/go/health"
	"code.nochebuena.dev/go/launcher"
	"code.nochebuena.dev/go/logz"
)

// Provider is the minimal interface for consumers that only need the valkey client.
type Provider interface {
	Client() vk.Client
}

// Component adds lifecycle management and health check to Provider.
type Component interface {
	launcher.Component
	health.Checkable
	Provider
}

// Config holds Valkey connection settings.
type Config struct {
	Addrs             []string `env:"VK_ADDRS,required"  envSeparator:","`
	Password          string   `env:"VK_PASSWORD"`
	SelectDB          int      `env:"VK_DB"              envDefault:"0"`
	CacheSizeEachConn int      `env:"VK_CLIENT_CACHE_MB" envDefault:"0"` // MB; 0 = disable
}

type vkComponent struct {
	cfg    Config
	logger logz.Logger
	client vk.Client
}

// New returns a valkey Component. Call lc.Append(vk) to manage its lifecycle.
func New(logger logz.Logger, cfg Config) Component {
	return &vkComponent{cfg: cfg, logger: logger}
}

func (v *vkComponent) OnInit() error {
	opts := vk.ClientOption{
		InitAddress: v.cfg.Addrs,
		Password:    v.cfg.Password,
		SelectDB:    v.cfg.SelectDB,
	}
	if v.cfg.CacheSizeEachConn > 0 {
		opts.CacheSizeEachConn = v.cfg.CacheSizeEachConn * 1024 * 1024
	}
	client, err := vk.NewClient(opts)
	if err != nil {
		return fmt.Errorf("valkey: failed to create client: %w", err)
	}
	v.client = client
	return nil
}

func (v *vkComponent) OnStart() error {
	v.logger.Info("valkey: verifying connection")
	if v.client == nil {
		return fmt.Errorf("valkey: client not initialized")
	}
	if err := v.client.Do(context.Background(), v.client.B().Ping().Build()).Error(); err != nil {
		return fmt.Errorf("valkey: ping failed: %w", err)
	}
	v.logger.Info("valkey: connected")
	return nil
}

func (v *vkComponent) OnStop() error {
	v.logger.Info("valkey: closing client")
	if v.client != nil {
		v.client.Close()
	}
	return nil
}

func (v *vkComponent) Client() vk.Client { return v.client }

func (v *vkComponent) HealthCheck(ctx context.Context) error {
	if v.client == nil {
		return fmt.Errorf("valkey: client not initialized")
	}
	return v.client.Do(ctx, v.client.B().Ping().Build()).Error()
}

func (v *vkComponent) Name() string          { return "valkey" }
func (v *vkComponent) Priority() health.Level { return health.LevelDegraded }