package client

import (
	"context"
	"net/url"
	"strconv"
	"sync"

	"github.com/jackc/puddle/v2"
	"github.com/keegancsmith/rpc"
	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/logger"
)

func NewClientPool(serverURL *url.URL, poolSize int) (*puddle.Pool[*rpc.Client], error) {
	constructor := func(context.Context) (*rpc.Client, error) {
		client, err := rpc.DialHTTPPath("tcp", serverURL.Host, serverURL.Path+"?"+serverURL.RawQuery)
		if err != nil {
			return nil, errors.WithStack(err)
		}

		return client, nil
	}

	destructor := func(client *rpc.Client) {
		if err := client.Close(); err != nil {
			logger.Error(context.Background(), "could not close client", logger.CapturedE(errors.WithStack(err)))
		}
	}

	maxPoolSize := int32(poolSize)

	pool, err := puddle.NewPool(&puddle.Config[*rpc.Client]{Constructor: constructor, Destructor: destructor, MaxSize: maxPoolSize})
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return pool, nil
}

type WithClientFunc func(ctx context.Context, fn func(ctx context.Context, client *rpc.Client) error) error

func WithPooledClient(serverURL *url.URL) WithClientFunc {
	var (
		pool       *puddle.Pool[*rpc.Client]
		createPool sync.Once
	)

	return func(ctx context.Context, fn func(context.Context, *rpc.Client) error) error {
		var err error
		createPool.Do(func() {
			rawPoolSize := serverURL.Query().Get("clientPoolSize")
			if rawPoolSize == "" {
				rawPoolSize = "5"
			}

			var poolSize int64

			poolSize, err = strconv.ParseInt(rawPoolSize, 10, 32)
			if err != nil {
				err = errors.Wrap(err, "could not parse clientPoolSize url query parameter")

				return
			}

			pool, err = NewClientPool(serverURL, int(poolSize))
			if err != nil {
				err = errors.WithStack(err)

				return
			}
		})
		if err != nil {
			return errors.WithStack(err)
		}

		clientResource, err := pool.Acquire(ctx)
		if err != nil {
			return errors.WithStack(err)
		}

		if err := fn(ctx, clientResource.Value()); err != nil {
			if errors.Is(err, rpc.ErrShutdown) {
				clientResource.Destroy()
			}

			return errors.WithStack(err)
		}

		clientResource.Release()

		return nil
	}
}