// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you 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 verify

import (
	"fmt"
	"time"

	"github.com/apache/skywalking-infra-e2e/internal/components/verifier"
	"github.com/apache/skywalking-infra-e2e/internal/config"
	"github.com/apache/skywalking-infra-e2e/internal/logger"
	"github.com/apache/skywalking-infra-e2e/internal/util"

	"github.com/spf13/cobra"
)

var (
	query    string
	actual   string
	expected string
)

func init() {
	Verify.Flags().StringVarP(&query, "query", "q", "", "the query to get the actual data, the result of the query should in YAML format")
	Verify.Flags().StringVarP(&actual, "actual", "a", "", "the actual data file, only YAML file format is supported")
	Verify.Flags().StringVarP(&expected, "expected", "e", "", "the expected data file, only YAML file format is supported")
}

var Verify = &cobra.Command{
	Use:   "verify",
	Short: "verify if the actual data match the expected data",
	RunE: func(cmd *cobra.Command, args []string) error {
		if expected != "" {
			return verifySingleCase(expected, actual, query)
		}
		// If there is no given flags.
		return DoVerifyAccordingConfig()
	},
}

func verifySingleCase(expectedFile, actualFile, query string) error {
	expectedData, err := util.ReadFileContent(expectedFile)
	if err != nil {
		return fmt.Errorf("failed to read the expected data file: %v", err)
	}

	var actualData, sourceName string
	if actualFile != "" {
		sourceName = actualFile
		actualData, err = util.ReadFileContent(actualFile)
		if err != nil {
			return fmt.Errorf("failed to read the actual data file: %v", err)
		}
	} else if query != "" {
		sourceName = query
		actualData, err = util.ExecuteCommand(query)
		if err != nil {
			return fmt.Errorf("failed to execute the query: %s, output: %s, error: %v", query, actualData, err)
		}
	}

	if err = verifier.Verify(actualData, expectedData); err != nil {
		if me, ok := err.(*verifier.MismatchError); ok {
			return fmt.Errorf("failed to verify the output: %s, error: %v", sourceName, me.Error())
		}
		return fmt.Errorf("failed to verify the output: %s", sourceName)
	}
	logger.Log.Infof("verified the output: %s\n", sourceName)
	return nil
}

// DoVerifyAccordingConfig reads cases from the config file and verifies them.
func DoVerifyAccordingConfig() error {
	if config.GlobalConfig.Error != nil {
		return config.GlobalConfig.Error
	}

	e2eConfig := config.GlobalConfig.E2EConfig

	retryCount := e2eConfig.Verify.RetryStrategy.Count
	if retryCount <= 0 {
		retryCount = 1
	}
	retryInterval := e2eConfig.Verify.RetryStrategy.Interval
	if retryInterval < 0 {
		retryInterval = 1000
	}

	var err error
	for current := 1; current <= retryCount; current++ {
		for _, v := range e2eConfig.Verify.Cases {
			if v.GetExpected() != "" {
				if err = verifySingleCase(v.GetExpected(), v.GetActual(), v.Query); err != nil {
					break
				}
			} else {
				return fmt.Errorf("the expected data file is not specified")
			}
		}

		if err != nil && current != retryCount {
			logger.Log.Warnf("verify case failure, will continue retry, %v", err)
			time.Sleep(time.Duration(retryInterval) * time.Millisecond)
		} else if err == nil {
			return nil
		}
	}

	return err
}