StoreBackEnd/pkg/protocol/rules/readers/RetrieveFileRule.go

package readers

import (
	"StoreBackEnd/pkg/protocol"
	"StoreBackEnd/pkg/protocol/repository"
	"StoreBackEnd/pkg/protocol/rules/writers"
	"StoreBackEnd/pkg/utils"
	"bufio"
	"fmt"
	"os"
)

// RetrieveFileRulePrefix Identifiant de cette règle
const RetrieveFileRulePrefix = "RETRIEVEFILE"

// RetrieveFileRule Demande de suppression d'un fichier
type RetrieveFileRule struct {
	// Cmd Nom de la règle
	Cmd string
	// matcher Permet de vérifier le matching
	matcher *protocol.RegexMatcher
	// protocolRepo Instance de ProtocolRepository
	protocolRepo *repository.ProtocolRepository
	// storagePath Chemin de stockage du fichier
	storagePath string
}

// CreateRetrieveFileRule Création d'une instance de RetrieveFileRule
func CreateRetrieveFileRule(pattern string, protocolRepo *repository.ProtocolRepository, storagePath string) protocol.IProtocolReader {
	return &RetrieveFileRule{
		Cmd:          RetrieveFileRulePrefix,
		matcher:      protocol.CreateRegexMatcher(pattern),
		protocolRepo: protocolRepo,
		storagePath:  storagePath,
	}
}

func (rule RetrieveFileRule) GetCmd() string {
	return rule.Cmd
}

func (rule RetrieveFileRule) Execute(data string) (*protocol.ProtocolWriterResult, func(reader *bufio.Reader) *protocol.ProtocolWriterResult) {
	if rule.Match(data) {
		values := rule.matcher.Parse(data)
		hashFileName := values[1]

		path := fmt.Sprintf("%s/%s", rule.storagePath, hashFileName)
		if fileinfo, err := os.Stat(path); err == nil {
			// Retrieve fingerprint sha256
			fileFingerprint, err := utils.HashFile(path)
			if err == nil {
				return rule.protocolRepo.ExecuteWriter(writers.RetrieveOkRulePrefix, hashFileName, fmt.Sprintf("%d", fileinfo.Size()), fileFingerprint), nil
			}
		}
	}
	return rule.protocolRepo.ExecuteWriter(writers.RetrieveErrorRulePrefix), nil
}

func (rule RetrieveFileRule) Match(data string) bool {
	return rule.matcher.Match(data)
}