package logging

import (
    "encoding/json"
    "fmt"
    "io"
    "log"
    "os"
    "path/filepath"
    "time"
)

func Init(dir string) error {
    if dir == "" {
        dir = "log"
    }
    if err := os.MkdirAll(dir, 0755); err != nil {
        return err
    }
    name := fmt.Sprintf("server-%s.log", time.Now().Format("20060102"))
    p := filepath.Join(dir, name)
    f, err := os.OpenFile(p, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
    if err != nil {
        return err
    }
    mw := io.MultiWriter(os.Stdout, f)
    log.SetOutput(mw)
    log.SetFlags(0)
    return nil
}

func JSON(level string, fields map[string]interface{}) {
    m := map[string]interface{}{"level": level, "ts": time.Now().Format(time.RFC3339)}
    for k, v := range fields {
        m[k] = v
    }
    b, _ := json.Marshal(m)
    log.Println(string(b))
}