package logsys

import (
	"bytes"
	"encoding/json"
	"fmt"
	"sort"
	"strings"
	"time"
)

// FormatJSON 把条目编码为一行 JSON（含换行）。
func FormatJSON(e Entry) ([]byte, error) {
	buf := &bytes.Buffer{}
	enc := json.NewEncoder(buf)
	enc.SetEscapeHTML(false)
	if err := enc.Encode(e); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}

// FormatHuman 把条目格式化成单行文本（含换行）。
func FormatHuman(e Entry) string {
	ts := e.Time.UTC().Format(time.RFC3339Nano)
	var b strings.Builder
	fmt.Fprintf(&b, "%s %s", ts, strings.ToUpper(e.Level))
	if e.Service != "" || e.Module != "" {
		b.WriteByte(' ')
		b.WriteString(e.Service)
		if e.Module != "" {
			if e.Service != "" {
				b.WriteByte('/')
			}
			b.WriteString(e.Module)
		}
	}
	b.WriteByte(' ')
	b.WriteString(e.Message)
	if e.Code != "" {
		fmt.Fprintf(&b, " code=%s", e.Code)
	}
	if e.TraceID != "" {
		fmt.Fprintf(&b, " trace=%s", e.TraceID)
	}
	if e.Error != "" {
		fmt.Fprintf(&b, " error=%q", e.Error)
	}
	if len(e.Fields) > 0 {
		keys := make([]string, 0, len(e.Fields))
		for k := range e.Fields {
			keys = append(keys, k)
		}
		sort.Strings(keys)
		for _, k := range keys {
			fmt.Fprintf(&b, " %s=%v", k, e.Fields[k])
		}
	}
	b.WriteByte('\n')
	return b.String()
}