package logging

import (
	native `log`
	`os`
	`path`
	`strings`

	"r00t2.io/goutils/types"

	sysd `github.com/coreos/go-systemd/journal`
	`r00t2.io/sysutils/paths`
)

var (
	_ = sysd.Enabled()
	_ = native.Logger{}
	_ = os.Interrupt
	_ = types.Env{}
)

func GetLogger(enableDebug bool, prefix string) (logger Logger, err error) {

	var logPath string
	var logflags types.MaskBit

	// Configure system-supported logger(s).
	if sysd.Enabled() {
		// Use Journald.
		logflags.AddFlag(LogJournald)
	} else {
		// If we can detect syslog, use that. If not, try to use a file logger (+ stdout).
		// Last ditch, stdout.
		var hasSyslog bool
		var stat os.FileInfo
		var devlogPath string = devlog

		if hasSyslog, stat, err = paths.RealPathExistsStat(&devlogPath); hasSyslog && err != nil {return}

		if hasSyslog && !stat.Mode().IsRegular() {logflags.AddFlag(LogSyslog)} else {
			var exists bool
			var success bool
			logflags.AddFlag(LogStdout)
			for _, p := range defLogPaths {
				if exists, _ = paths.RealPathExists(&p); exists {
					if success, err = testOpen(p); err != nil {
						continue
					} else if !success {
						continue
					}
					logflags.AddFlag(LogFile)
					logPath = p
					break
				} else {
					dirPath := path.Dir(p)
					if err = paths.MakeDirIfNotExist(&dirPath); err != nil {
						continue
					}
					if success, err = testOpen(p); err != nil {
						continue
					} else if !success {
						continue
					}
					logflags.AddFlag(LogFile)
					logPath = p
					break
				}
			}
		}
	}

	if logflags.HasFlag(LogJournald) {
		logger = &SystemDLogger{
			Prefix: logPrefix,
		}
	} else {
		if logflags.HasFlag(LogSyslog) {
			logger = &SyslogLogger{
				Prefix: logPrefix,
			}
		} else {
			if logflags.HasFlag(LogFile) {
				logger = &FileLogger{
					StdLogger: StdLogger{
						Prefix: logPrefix,
					},
					Path:      logPath,
				}
			} else {
				logger = &StdLogger{
					Prefix: logPrefix,
				}
			}
		}
	}

	logger.doDebug(enableDebug)
	if strings.TrimSpace(prefix) != "" {
		logger.setPrefix(prefix)
	}

	return
}

func testOpen(path string) (success bool, err error) {
	var f *os.File

	// Example #2, https://golang.org/pkg/os/#OpenFile
	if f, err = os.OpenFile(path, os.O_RDWR | os.O_CREATE, logPerm); err != nil {
		return
	}
	defer f.Close()

	success = true

	return
}