package ripsawlogger

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"sync"
	"time"
)

type writerLogger struct {
	w  io.Writer
	mu sync.Mutex
}

// Creates a generic logger that writes log entries to any io.Writer as JSON.
func NewWriterLogger(writer io.Writer) Logger {
	return writerLogger{w: writer}
}

func (rl writerLogger) Flush() {
	// if the underlying writer is buffered writer, flush it
	if w, ok := rl.w.(*bufio.Writer); ok {
		w.Flush()
	}
}

func (rl writerLogger) Log(data LogEntry) {

	timestamp := data.Time
	if timestamp.IsZero() {
		timestamp = time.Now()
	}

	rl.mu.Lock()
	defer rl.mu.Unlock()
	fmt.Fprintf(rl.w, "%s [%s] ", timestamp.UTC().Format(time.RFC3339Nano), data.Level)
	json.NewEncoder(rl.w).Encode(data.Contents)
}