gocustomurls/conf.go

package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
)

type ParsedConf struct {
	RulesFp      string `json:"rulesPath"`
	LogFp        string `json:"logPath"`
	Compression  bool   `json:"compress"`
	SizeToRotate string `json:"sizeToRotate"`
	Port         string `json:"port"`
}

type Config struct {
	MappingFilePath string
	MappingRules    ImportRulesMappings
	sync.Mutex
}

type ImportRulesMappings struct {
	Mappings []struct {
		Protocol  string `json:"protocol"`
		VanityUrl string `json:"vanity_url"`
		RealUrl   string `json:"real_url"`
	} `json:"mappings"`
}

type ImportRuleStruct struct {
	VanityUrl string
	Proto     string
	RepoUrl   string
}

// isFile - check if fp is a valid file
func isFile(fp string) bool {
	info, err := os.Stat(fp)
	if os.IsNotExist(err) || !info.Mode().IsRegular() {
		return false
	}
	return true
}

// load mapping file
func (c *Config) LoadMappingFile(fp string) error {
	var mapping ImportRulesMappings
	mappingFilePath := fp
	if len(c.MappingFilePath) == 0 {
		ok := isFile(mappingFilePath)
		if !ok {
			return fmt.Errorf("mappingfile %s is not found", mappingFilePath)
		}
	} else {
		mappingFilePath = c.MappingFilePath
	}
	mappingFile, err := os.Open(mappingFilePath)
	if err != nil {
		return err
	}
	defer mappingFile.Close()

	err = json.NewDecoder(mappingFile).Decode(&mapping)
	if err != nil {
		return err
	}
	c.MappingRules = mapping
	if len(c.MappingFilePath) == 0 {
		c.MappingFilePath = mappingFilePath
	}
	return nil
}

// generate default locations for all the config files
func getDefaults() (map[string]string, error) {
	m := make(map[string]string)
	confDir, err := os.UserConfigDir()
	if err != nil {
		return m, err
	}
	homeDir, err := os.UserHomeDir()
	if err != nil {
		return m, err
	}
	m["rulesFp"] = filepath.Join(confDir, "gocustomcurls", "rules.json")
	m["confFp"] = filepath.Join(confDir, "gocustomcurls", "config.json")
	m["logFp"] = filepath.Join(homeDir, ".gocustomurls", "logs", "app.log")
	return m, nil
}

// generate and write to a location, the default values for the config.json file
func generateDefaultConfigFile(defaultObj map[string]string) (ParsedConf, error) {
	var p ParsedConf
	var err error
	var defaults map[string]string
	if len(defaultObj) == 0 {
		defaults, err = getDefaults()
	} else {
		defaults = defaultObj
	}

	if err != nil {
		return p, err
	}
	parentDir := filepath.Dir(defaults["confFp"])
	err = os.MkdirAll(parentDir, 0755)
	if err != nil {
		return p, err
	}
	f, err := os.OpenFile(defaults["confFp"], os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
	if err != nil {
		return p, err
	}
	defer f.Close()
	p.RulesFp = defaults["rulesFp"]
	p.LogFp = defaults["logFp"]
	p.Port = "7070"
	p.Compression = true
	p.SizeToRotate = "5MiB"
	jsonString, _ := json.Marshal(p)
	err = os.WriteFile(defaults["confFp"], jsonString, 0666)
	if err != nil {
		return p, err
	}
	return p, nil
}

func checkIfSizeIsConfigured(fsize string) (bool, error) {
	suffixes := []string{"KB", "MB", "GB"}
	var found string
	for _, suffix := range suffixes {
		if strings.HasSuffix(fsize, suffix) {
			found = suffix
		}
	}
	if len(found) == 0 {
		return false, fmt.Errorf("%s has the incorrect suffix, Please use one of this suffixes {\"KB\", \"MB\", \"GB\"}", fsize)
	}

	return true, nil
}

// load the main config file
func (c *Config) LoadMainConfigFile(fp string) (ParsedConf, error) {
	var conf ParsedConf
	var err error
	c.Lock()
	defer c.Unlock()
	ok := isFile(fp)
	if !ok {
		// generate config file
		errorLog.Println("Warning, generating default config file")
		conf, err = generateDefaultConfigFile(map[string]string{})
		if err != nil {
			return conf, err
		}
		c.MappingFilePath = conf.RulesFp
		return conf, nil
	}
	f, err := os.Open(fp)
	if err != nil {
		return conf, err
	}
	defer f.Close()

	err = json.NewDecoder(f).Decode(&conf)
	if err != nil {
		return conf, err
	}

	_, err = checkIfSizeIsConfigured(conf.SizeToRotate)
	if err != nil {
		return conf, err
	}

	c.MappingFilePath = conf.RulesFp
	return conf, nil
}