// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package scanner

import (
	"strconv"
	"time"

	"github.com/minio/minio/internal/config"
	"github.com/minio/pkg/env"
)

// Compression environment variables
const (
	Delay   = "delay"
	MaxWait = "max_wait"
	Cycle   = "cycle"

	EnvDelay         = "MINIO_SCANNER_DELAY"
	EnvCycle         = "MINIO_SCANNER_CYCLE"
	EnvDelayLegacy   = "MINIO_CRAWLER_DELAY"
	EnvMaxWait       = "MINIO_SCANNER_MAX_WAIT"
	EnvMaxWaitLegacy = "MINIO_CRAWLER_MAX_WAIT"
)

// Config represents the heal settings.
type Config struct {
	// Delay is the sleep multiplier.
	Delay float64 `json:"delay"`
	// MaxWait is maximum wait time between operations
	MaxWait time.Duration
	// Cycle is the time.Duration between each scanner cycles
	Cycle time.Duration
}

var (
	// DefaultKVS - default KV config for heal settings
	DefaultKVS = config.KVS{
		config.KV{
			Key:   Delay,
			Value: "10",
		},
		config.KV{
			Key:   MaxWait,
			Value: "15s",
		},
		config.KV{
			Key:   Cycle,
			Value: "1m",
		},
	}

	// Help provides help for config values
	Help = config.HelpKVS{
		config.HelpKV{
			Key:         Delay,
			Description: `scanner delay multiplier, defaults to '10.0'`,
			Optional:    true,
			Type:        "float",
		},
		config.HelpKV{
			Key:         MaxWait,
			Description: `maximum wait time between operations, defaults to '15s'`,
			Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{
			Key:         Cycle,
			Description: `time duration between scanner cycles, defaults to '1m'`,
			Optional:    true,
			Type:        "duration",
		},
	}
)

// LookupConfig - lookup config and override with valid environment settings if any.
func LookupConfig(kvs config.KVS) (cfg Config, err error) {
	if err = config.CheckValidKeys(config.ScannerSubSys, kvs, DefaultKVS); err != nil {
		return cfg, err
	}
	delay := env.Get(EnvDelayLegacy, "")
	if delay == "" {
		delay = env.Get(EnvDelay, kvs.Get(Delay))
	}
	cfg.Delay, err = strconv.ParseFloat(delay, 64)
	if err != nil {
		return cfg, err
	}
	maxWait := env.Get(EnvMaxWaitLegacy, "")
	if maxWait == "" {
		maxWait = env.Get(EnvMaxWait, kvs.Get(MaxWait))
	}
	cfg.MaxWait, err = time.ParseDuration(maxWait)
	if err != nil {
		return cfg, err
	}

	cfg.Cycle, err = time.ParseDuration(env.Get(EnvCycle, kvs.Get(Cycle)))
	if err != nil {
		return cfg, err
	}
	return cfg, nil
}