/*
Copyright 2021 The Dapr Authors
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.
*/

package logger

import (
	"fmt"
)

const (
	defaultJSONOutput  = false
	defaultOutputLevel = "info"
	undefinedAppID     = ""
)

// Options defines the sets of options for Dapr logging.
type Options struct {
	// appID is the unique id of Dapr Application
	appID string

	// JSONFormatEnabled is the flag to enable JSON formatted log
	JSONFormatEnabled bool

	// OutputLevel is the level of logging
	OutputLevel string
}

// SetOutputLevel sets the log output level.
func (o *Options) SetOutputLevel(outputLevel string) error {
	if toLogLevel(outputLevel) == UndefinedLevel {
		return fmt.Errorf("undefined Log Output Level: %s", outputLevel)
	}
	o.OutputLevel = outputLevel
	return nil
}

// SetAppID sets Application ID.
func (o *Options) SetAppID(id string) {
	o.appID = id
}

// AttachCmdFlags attaches log options to command flags.
func (o *Options) AttachCmdFlags(
	stringVar func(p *string, name string, value string, usage string),
	boolVar func(p *bool, name string, value bool, usage string),
) {
	if stringVar != nil {
		stringVar(
			&o.OutputLevel,
			"log-level",
			defaultOutputLevel,
			"Options are debug, info, warn, error, or fatal (default info)")
	}
	if boolVar != nil {
		boolVar(
			&o.JSONFormatEnabled,
			"log-as-json",
			defaultJSONOutput,
			"print log as JSON (default false)")
	}
}

// DefaultOptions returns default values of Options.
func DefaultOptions() Options {
	return Options{
		JSONFormatEnabled: defaultJSONOutput,
		appID:             undefinedAppID,
		OutputLevel:       defaultOutputLevel,
	}
}

// ApplyOptionsToLoggers applys options to all registered loggers.
func ApplyOptionsToLoggers(options *Options) error {
	internalLoggers := getLoggers()

	// Apply formatting options first
	for _, v := range internalLoggers {
		v.EnableJSONOutput(options.JSONFormatEnabled)

		if options.appID != undefinedAppID {
			v.SetAppID(options.appID)
		}
	}

	daprLogLevel := toLogLevel(options.OutputLevel)
	if daprLogLevel == UndefinedLevel {
		return fmt.Errorf("invalid value for --log-level: %s", options.OutputLevel)
	}

	for _, v := range internalLoggers {
		v.SetOutputLevel(daprLogLevel)
	}
	return nil
}