package internal

import (
	"encoding/json"
	"fmt"
	"log/slog"
	"math/rand"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"time"
)

func ReadConfig(file string, config interface{}) error {
	file, err := filepath.Abs(file)
	if err != nil {
		return err
	}

	jsonFile, err := os.ReadFile(file)
	if err != nil {
		return err
	}

	err = json.Unmarshal(jsonFile, &config)
	if err != nil {
		return err
	}
	return nil
}

func Version(appName, appVersion, gitCommit, goVersion string) string {
	version := appName
	if appVersion != "" {
		version += " " + appVersion
	}
	if gitCommit != "" {
		version += "-" + gitCommit
	}
	if goVersion != "" {
		version += " (compiled with " + goVersion + ")"
	}
	return version
}

func ShowVersion(appName, appVersion, gitCommit, goVersion string) {
	fmt.Print(Version(appName, appVersion, gitCommit, goVersion) + "\n")
}

const randomChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

func GenerateChars(n int) string {
	b := make([]byte, n)
	for i := range b {
		b[i] = randomChars[rand.Intn(len(randomChars))]
	}
	return string(b)
}

// Encryption key must be URL compatible and strong enough
// Requiring only alphanumeric chars with a size between 16 and 256
var encryptionKeyRegexp = regexp.MustCompile("^[a-zA-Z0-9]{16,256}$")

func ValidateEncryptionKey(p string) error {
	if !encryptionKeyRegexp.MatchString(p) {
		return fmt.Errorf("encryption key doesn't match '%s'", encryptionKeyRegexp)
	}
	return nil
}

// HumanDuration converts number of seconds to a human friendly format
// Ex: 3600 -> "1 hour"
// Yes it uses rough approximations ¯\_(ツ)_/¯
func HumanDuration(i int) string {
	var w string
	if i < 0 {
		return ""
	} else if i >= 0 && i < 60 {
		w = "second"
	} else if i >= 60 && i < 60*60 {
		i = i / 60
		w = "minute"
	} else if i >= 60*60 && i < 60*60*24 {
		w = "hour"
		i = i / (60 * 60)
	} else if i >= 60*60*24 && i < 60*60*24*7 {
		w = "day"
		i = i / (60 * 60 * 24)
	} else if i >= 60*60*24*7 && i < 60*60*24*31 {
		w = "week"
		i = i / (60 * 60 * 24 * 7)
	} else if i >= 60*60*24*31 && i < 60*60*24*365 {
		w = "month"
		i = i / (60 * 60 * 24 * 31)
	} else {
		w = "year"
		i = i / (60 * 60 * 24 * 365)
	}
	if i > 1 {
		w = w + "s"
	}
	return fmt.Sprintf("%d %s", i, w)
}

// TimeDiff to return the number of seconds between this time and now
func TimeDiff(ts time.Time) int {
	diff := int(time.Since(ts).Seconds())
	if diff < 0 {
		return diff * -1
	}
	return diff
}

func ReturnError(logger *slog.Logger, message string, err error) int {
	if err != nil {
		logger.Error(message, slog.Any("error", err))
	} else {
		logger.Error(message)
	}
	return RC_ERROR
}

func ToLowerStringSlice(src []string) (dst []string) {
	for _, s := range src {
		dst = append(dst, strings.ToLower(s))
	}
	return
}

func InSlice(s []string, elem string) bool {
	for _, v := range s {
		if v == elem {
			return true
		}
	}
	return false
}