waiter.go

// Copyright (c) 2009-present, Alibaba Cloud All rights reserved.
//
// 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 openapi

import (
	"fmt"
	"strconv"
	"time"

	"github.com/aliyun/aliyun-cli/cli"
	"github.com/aliyun/aliyun-cli/i18n"
)

var WaiterFlag = &cli.Flag{Category: "helper",
	Name:         "waiter",
	AssignedMode: cli.AssignedRepeatable,
	Short: i18n.T(
		"use `--waiter expr=<jmesPath> to=<value>` to pull api until result equal to expected value",
		"使用 `--waiter expr=<jmesPath> to=<value>` 来轮询调用OpenAPI，直到返回期望的值"),
	Long: i18n.T(
		"",
		""),
	Fields: []cli.Field{
		{Key: "expr", Required: true, Short: i18n.T("", "")},
		{Key: "to", Required: true, Short: i18n.T("", "")},
		{Key: "timeout", DefaultValue: "180", Short: i18n.T("", "")},
		{Key: "interval", DefaultValue: "5", Short: i18n.T("", "")},
	},
	ExcludeWith: []string{"pager"},
}

type Waiter struct {
	expr string
	to   string
	//	timeout  time.Duration	TODO use Flag.Field to validate
	//	interval time.Duration  TODO use Flag.Field to validate
}

func GetWaiter() *Waiter {
	if !WaiterFlag.IsAssigned() {
		return nil
	}

	waiter := &Waiter{}
	waiter.expr, _ = WaiterFlag.GetFieldValue("expr")
	waiter.to, _ = WaiterFlag.GetFieldValue("to")
	//waiter.timeout = time.Duration(time.Second * 180)
	//waiter.interval = time.Duration(time.Second * 5)

	return waiter
}

func (a *Waiter) CallWith(invoker Invoker) (string, error) {
	//
	// timeout is 1-600 seconds, default is 180
	timeout := time.Duration(time.Second * 180)
	if s, ok := WaiterFlag.GetFieldValue("timeout"); ok {
		if n, err := strconv.Atoi(s); err == nil {
			if n <= 0 && n > 600 {
				return "", fmt.Errorf("--waiter timeout=%s must between 1-600 (seconds)", s)
			}
			timeout = time.Duration(time.Second * time.Duration(n))
		} else {
			return "", fmt.Errorf("--waiter timeout=%s must be integer", s)
		}
	}
	//
	// interval is 2-10 seconds, default is 5
	interval := time.Duration(time.Second * 5)
	if s, ok := WaiterFlag.GetFieldValue("interval"); ok {
		if n, err := strconv.Atoi(s); err == nil {
			if n <= 1 && n > 10 {
				return "", fmt.Errorf("--waiter interval=%s must between 2-10 (seconds)", s)
			}
			interval = time.Duration(time.Second * time.Duration(n))
		} else {
			return "", fmt.Errorf("--waiter interval=%s must be integer", s)
		}
	}

	begin := time.Now()
	for {
		resp, err := invoker.Call()
		if err != nil {
			return "", err
		}

		v, err := evaluateExpr(resp.GetHttpContentBytes(), a.expr)
		if err != nil {
			return "", err
		}

		if v == a.to {
			return resp.GetHttpContentString(), nil
		}
		duration := time.Now().Sub(begin)
		if duration > timeout {
			return "", fmt.Errorf("wait '%s' to '%s' timeout(%dseconds), last='%s'",
				a.expr, a.to, timeout/time.Second, v)
		}
		time.Sleep(interval)
	}
}