package logging

import (
	"errors"
	"fmt"
	`log`
	"sync"

	"r00t2.io/goutils/multierr"
)

// Setup sets up/configures a MultiLogger (and all its MultiLogger.Loggers) and prepares it for use.
func (m *MultiLogger) Setup() (err error) {

	var wg sync.WaitGroup
	var errs *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logger Logger, lName string) {
			var err2 error
			defer wg.Done()
			if err2 = logger.Setup(); err2 != nil {
				errs.AddError(errors.New(fmt.Sprintf("error on Setup for logger %v; follows (may be out of order):", lName)))
				errs.AddError(err2)
				err2 = nil
			}
		}(l, logName)
	}

	wg.Wait()

	if errs.Count() > 0 {
		err = errs
		return
	}

	return
}

// Shutdown cleanly shuts down a MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Shutdown() (err error) {

	var wg sync.WaitGroup
	var errs *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logger Logger, lName string) {
			var err2 error
			defer wg.Done()
			if err2 = logger.Shutdown(); err2 != nil {
				errs.AddError(errors.New(fmt.Sprintf("error on Shutdown for logger %v; follows (may be out of order):", lName)))
				errs.AddError(err2)
				err2 = nil
			}
		}(l, logName)
	}

	wg.Wait()

	if errs.Count() > 0 {
		err = errs
		return
	}

	return
}

/*
GetPrefix returns the prefix used by this MultiLogger (and all its MultiLogger.Loggers).
err will always be nil; it's there for interface-compat.
*/
func (m *MultiLogger) GetPrefix() (prefix string, err error) {

	prefix = m.Prefix

	return

}

/*
DoDebug sets the debug state of this MultiLogger (and all its MultiLogger.Loggers).
Note that this merely acts as a *safety filter* for debug messages to avoid sensitive information being written to the log.

If you had a logger-specific EnableDebug set, you will need to re-set it to your desired state after running this method.
*/
func (m *MultiLogger) DoDebug(d bool) (err error) {

	var wg sync.WaitGroup
	var errs *multierr.MultiError = multierr.NewMultiError(nil)

	m.EnableDebug = d

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logger Logger, lName string) {
			var err2 error
			defer wg.Done()
			if err2 = l.DoDebug(d); err2 != nil {
				errs.AddError(errors.New(fmt.Sprintf("error on DoDebug for logger %v; follows (may be out of order):", lName)))
				errs.AddError(err2)
				err2 = nil
			}
		}(l, logName)
	}

	wg.Wait()

	if errs.Count() > 0 {
		err = errs
		return
	}

	return
}

// GetDebug returns the debug status of this MultiLogger.
func (m *MultiLogger) GetDebug() (d bool) {

	d = m.EnableDebug

	return
}

/*
SetPrefix sets the prefix for this MultiLogger (and all its MultiLogger.Loggers).

If you had a logger-specific Prefix set, you will need to re-set it to your desired prefix after running this method.
*/
func (m *MultiLogger) SetPrefix(prefix string) (err error) {

	var wg sync.WaitGroup
	var errs *multierr.MultiError = multierr.NewMultiError(nil)

	m.Prefix = prefix

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logger Logger, lName string) {
			var err2 error
			defer wg.Done()
			if err2 = l.SetPrefix(prefix); err != nil {
				errs.AddError(errors.New(fmt.Sprintf("error on SetPrefix for logger %v; follows (may be out of order):", lName)))
				errs.AddError(err2)
				err2 = nil
			}
		}(l, logName)
	}

	wg.Wait()

	if errs.Count() > 0 {
		err = errs
		return
	}

	return
}

// Alert writes an ALERT-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Alert(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Alert(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Alert for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}

	return
}

// Crit writes an CRITICAL-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Crit(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Crit(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Crit for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}

	return
}

// Debug writes a DEBUG-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Debug(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Debug(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Debug for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}
	return
}

// Emerg writes an EMERGENCY-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Emerg(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Emerg(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Emerg for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}
	return
}

// Err writes an ERROR-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Err(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Err(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Err for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}

	return
}

// Info writes an INFO-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Info(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Info(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Info for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}

	return
}

// Notice writes a NOTICE-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Notice(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Notice(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Notice for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}

	return
}

// Warning writes a WARNING/WARN-level message to this MultiLogger (and all its MultiLogger.Loggers).
func (m *MultiLogger) Warning(s string, v ...interface{}) (err error) {

	var wg sync.WaitGroup
	var e *multierr.MultiError = multierr.NewMultiError(nil)

	for logName, l := range m.Loggers {
		wg.Add(1)
		go func(logObj Logger, msg, lName string, rplc ...interface{}) {
			defer wg.Done()
			if err = logObj.Warning(msg, rplc...); err != nil {
				e.AddError(errors.New(fmt.Sprintf("error on Warning for logger %v; follows (may be out of order):", lName)))
				e.AddError(err)
				err = nil
			}
		}(l, s, logName, v...)
	}

	wg.Wait()

	if !e.IsEmpty() {
		err = e
	}

	return
}

// ToLogger returns a stdlib log.Logger.
func (m *MultiLogger) ToLogger(prio logPrio) (stdLibLog *log.Logger) {

	stdLibLog = log.New(&logWriter{backend: m, prio: prio}, "", 0)

	return
}