package journald

import (
	"errors"
	"github.com/coreos/go-systemd/v22/journal"
	"go.uber.org/zap/zapcore"
	"time"
)

var zapToJournaldLevelMap = map[int]int{
	int(zapcore.DebugLevel):  int(journal.PriDebug),
	int(zapcore.InfoLevel):   int(journal.PriInfo),
	int(zapcore.WarnLevel):   int(journal.PriWarning),
	int(zapcore.ErrorLevel):  int(journal.PriErr),
	int(zapcore.DPanicLevel): int(journal.PriCrit),
	int(zapcore.PanicLevel):  int(journal.PriCrit),
	int(zapcore.FatalLevel):  int(journal.PriEmerg),
}

type Core struct {
	zapcore.LevelEnabler
	fields []zapcore.Field
}

func NewLogger(enabler zapcore.LevelEnabler) zapcore.Core {
	core := Core{}
	core.LevelEnabler = enabler
	return &core
}

func (c *Core) With(fields []zapcore.Field) zapcore.Core {
	newFields := make([]zapcore.Field, len(c.fields)+len(fields))
	copy(newFields, c.fields)
	copy(newFields[len(c.fields):], fields)
	c.fields = newFields
	return c
}

func (c *Core) Check(entry zapcore.Entry, checked *zapcore.CheckedEntry) *zapcore.CheckedEntry {
	if c.Enabled(entry.Level) {
		return checked.AddCore(entry, c)
	}
	return checked
}

func (c *Core) Write(entry zapcore.Entry, fields []zapcore.Field) error {
	ok := journal.Enabled()
	if !ok {
		return errors.New("unable to use journal native protocol")
	}

	mappedFields := make(map[string]string)
	mappedFields["SYSLOG_TIMESTAMP"] = entry.Time.Format(time.RFC3339)
	for _, field := range c.fields {
		mappedFields[field.Key] = field.String
	}
	for _, field := range fields {
		mappedFields[field.Key] = field.String
	}

	return journal.Send(entry.Message, journal.Priority(zapToJournaldLevelMap[int(entry.Level)]), mappedFields)
}

func (c *Core) Sync() error {
	return nil
}