// Copyright 2013, Cong Ding. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// author: Cong Ding <dinggnu@gmail.com>
//
package logging

import (
	"errors"
	"fmt"
	"strings"
)

// pre-defined formats
const (
	BasicFormat = "%s [%6s] %30s - %s\n name,levelname,time,message"
	RichFormat  = "%s [%6s] %d %30s - %d - %s:%s:%d - %s\n name, levelname, seqid, time, thread, filename, funcname, lineno, message"
)

// genLog generates log string from the format setting.
func (logger *Logger) genLog(level Level, message string) string {
	fs := make([]interface{}, len(logger.recordArgs))
	r := new(record)
	r.message = message
	r.level = level
	for k, v := range logger.recordArgs {
		fs[k] = fields[v](logger, r)
	}
	return fmt.Sprintf(logger.recordFormat, fs...)
}

// parseFormat checks the legality of format and parses it to recordFormat and recordArgs
func (logger *Logger) parseFormat(format string) error {
	logger.runtime = false
	fts := strings.Split(format, "\n")
	if len(fts) != 2 {
		return errors.New("logging format error")
	}
	logger.recordFormat = fts[0]
	logger.recordArgs = strings.Split(fts[1], ",")
	for k, v := range logger.recordArgs {
		tv := strings.TrimSpace(v)
		_, ok := fields[tv]
		if ok == false {
			return errors.New("logging format error")
		}
		logger.recordArgs[k] = tv
		logger.runtime = logger.runtime || runtimeFields[tv]
	}
	return nil
}