// Copyright 2023 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package e2e

import (
	"context"
	"fmt"
	"strings"
	"testing"
	"time"

	"go.uber.org/zap"
	"golang.org/x/sync/errgroup"
	"google.golang.org/grpc"

	"go.etcd.io/etcd/client/pkg/v3/transport"
	clientv3 "go.etcd.io/etcd/client/v3"
	"go.etcd.io/etcd/pkg/v3/stringutil"
	"go.etcd.io/etcd/tests/v3/framework/e2e"
	"go.etcd.io/etcd/tests/v3/framework/integration"
)

func newClient(t *testing.T, entpoints []string, cfg e2e.ClientConfig) *clientv3.Client {
	tlscfg, err := tlsInfo(t, cfg)
	if err != nil {
		t.Fatal(err)
	}
	ccfg := clientv3.Config{
		Endpoints:   entpoints,
		DialTimeout: 5 * time.Second,
		DialOptions: []grpc.DialOption{grpc.WithBlock()},
	}
	if tlscfg != nil {
		tls, err := tlscfg.ClientConfig()
		if err != nil {
			t.Fatal(err)
		}
		ccfg.TLS = tls
	}
	c, err := clientv3.New(ccfg)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		c.Close()
	})
	return c
}

// tlsInfo follows the Client-to-server communication in https://etcd.io/docs/v3.6/op-guide/security/#basic-setup
func tlsInfo(t testing.TB, cfg e2e.ClientConfig) (*transport.TLSInfo, error) {
	switch cfg.ConnectionType {
	case e2e.ClientNonTLS, e2e.ClientTLSAndNonTLS:
		return nil, nil
	case e2e.ClientTLS:
		if cfg.AutoTLS {
			tls, err := transport.SelfCert(zap.NewNop(), t.TempDir(), []string{"localhost"}, 1)
			if err != nil {
				return nil, fmt.Errorf("failed to generate cert: %s", err)
			}
			return &tls, nil
		} else {
			return &integration.TestTLSInfo, nil
		}
	default:
		return nil, fmt.Errorf("config %v not supported", cfg)
	}
}

func fillEtcdWithData(ctx context.Context, c *clientv3.Client, dbSize int) error {
	g := errgroup.Group{}
	concurrency := 10
	keyCount := 100
	keysPerRoutine := keyCount / concurrency
	valueSize := dbSize / keyCount
	for i := 0; i < concurrency; i++ {
		i := i
		g.Go(func() error {
			for j := 0; j < keysPerRoutine; j++ {
				_, err := c.Put(ctx, fmt.Sprintf("%d", i*keysPerRoutine+j), stringutil.RandString(uint(valueSize)))
				if err != nil {
					return err
				}
			}
			return nil
		})
	}
	return g.Wait()
}

func curl(endpoint string, method string, curlReq e2e.CURLReq, connType e2e.ClientConnType) (string, error) {
	args := e2e.CURLPrefixArgs(endpoint, e2e.ClientConfig{ConnectionType: connType}, false, method, curlReq)
	lines, err := e2e.RunUtilCompletion(args, nil)
	if err != nil {
		return "", err
	}
	return strings.Join(lines, "\n"), nil
}