/*
 * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
 *
 * 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 (
	"strings"

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

// Console logger target
type Console struct {
	Enabled bool `json:"enabled"`
}

// HTTP logger target
type HTTP struct {
	Enabled   bool   `json:"enabled"`
	Endpoint  string `json:"endpoint"`
	AuthToken string `json:"authToken"`
}

// Config console and http logger targets
type Config struct {
	Console Console         `json:"console"`
	HTTP    map[string]HTTP `json:"http"`
	Audit   map[string]HTTP `json:"audit"`
}

// HTTP endpoint logger
const (
	Endpoint  = "endpoint"
	AuthToken = "auth_token"

	EnvLoggerHTTPEndpoint  = "MINIO_LOGGER_HTTP_ENDPOINT"
	EnvLoggerHTTPAuthToken = "MINIO_LOGGER_HTTP_AUTH_TOKEN"

	EnvLoggerHTTPAuditEndpoint  = "MINIO_LOGGER_HTTP_AUDIT_ENDPOINT"
	EnvLoggerHTTPAuditAuthToken = "MINIO_LOGGER_HTTP_AUDIT_AUTH_TOKEN"
)

// Default KVS for loggerHTTP and loggerAuditHTTP
var (
	DefaultKVS = config.KVS{
		config.State:   config.StateOff,
		config.Comment: "This is a default HTTP logging configuration",
		Endpoint:       "",
		AuthToken:      "",
	}
	DefaultAuditKVS = config.KVS{
		config.State:   config.StateOff,
		config.Comment: "This is a default HTTP Audit logging configuration",
		Endpoint:       "",
		AuthToken:      "",
	}
)

// NewConfig - initialize new logger config.
func NewConfig() Config {
	cfg := Config{
		// Console logging is on by default
		Console: Console{
			Enabled: true,
		},
		HTTP:  make(map[string]HTTP),
		Audit: make(map[string]HTTP),
	}

	// Create an example HTTP logger
	cfg.HTTP[config.Default] = HTTP{
		Endpoint: "https://username:password@example.com/api",
	}

	// Create an example Audit logger
	cfg.Audit[config.Default] = HTTP{
		Endpoint: "https://username:password@example.com/api/audit",
	}

	return cfg
}

// LookupConfig - lookup logger config, override with ENVs if set.
func LookupConfig(scfg config.Config) (Config, error) {
	cfg := NewConfig()

	envs := env.List(EnvLoggerHTTPEndpoint)
	var loggerTargets []string
	for _, k := range envs {
		target := strings.TrimPrefix(k, EnvLoggerHTTPEndpoint+config.Default)
		if target == EnvLoggerHTTPEndpoint {
			target = config.Default
		}
		loggerTargets = append(loggerTargets, target)
	}

	var loggerAuditTargets []string
	envs = env.List(EnvLoggerHTTPAuditEndpoint)
	for _, k := range envs {
		target := strings.TrimPrefix(k, EnvLoggerHTTPAuditEndpoint+config.Default)
		if target == EnvLoggerHTTPAuditEndpoint {
			target = config.Default
		}
		loggerAuditTargets = append(loggerAuditTargets, target)
	}

	// List legacy ENVs if any.
	envs = env.List(EnvAuditLoggerHTTPEndpoint)
	for _, k := range envs {
		target := strings.TrimPrefix(k, EnvAuditLoggerHTTPEndpoint+config.Default)
		if target == EnvAuditLoggerHTTPEndpoint {
			target = config.Default
		}
		loggerAuditTargets = append(loggerAuditTargets, target)
	}

	for starget, kv := range scfg[config.LoggerHTTPSubSys] {
		subSysTarget := config.LoggerHTTPSubSys
		if starget != config.Default {
			subSysTarget = config.LoggerHTTPSubSys + ":" + starget
		}
		if err := config.CheckValidKeys(subSysTarget, kv, DefaultKVS); err != nil {
			return cfg, err
		}

		enabled, err := config.ParseBool(kv.Get(config.State))
		if err != nil {
			return cfg, err
		}
		if !enabled {
			continue
		}

		endpointEnv := EnvLoggerHTTPEndpoint
		if starget != config.Default {
			endpointEnv = EnvLoggerHTTPEndpoint + config.Default + starget
		}
		authTokenEnv := EnvLoggerHTTPAuthToken
		if starget != config.Default {
			authTokenEnv = EnvLoggerHTTPAuthToken + config.Default + starget
		}
		cfg.HTTP[starget] = HTTP{
			Enabled:   true,
			Endpoint:  env.Get(endpointEnv, kv.Get(Endpoint)),
			AuthToken: env.Get(authTokenEnv, kv.Get(AuthToken)),
		}
	}

	for starget, kv := range scfg[config.LoggerHTTPAuditSubSys] {
		subSysTarget := config.LoggerHTTPAuditSubSys
		if starget != config.Default {
			subSysTarget = config.LoggerHTTPAuditSubSys + config.SubSystemSeparator + starget
		}
		if err := config.CheckValidKeys(subSysTarget, kv, DefaultAuditKVS); err != nil {
			return cfg, err
		}

		enabled, err := config.ParseBool(kv.Get(config.State))
		if err != nil {
			return cfg, err
		}
		if !enabled {
			continue
		}

		endpointEnv := EnvLoggerHTTPAuditEndpoint
		if starget != config.Default {
			endpointEnv = EnvLoggerHTTPAuditEndpoint + config.Default + starget
		}
		legacyEndpointEnv := EnvAuditLoggerHTTPEndpoint
		if starget != config.Default {
			legacyEndpointEnv = EnvAuditLoggerHTTPEndpoint + config.Default + starget
		}
		endpoint := env.Get(legacyEndpointEnv, "")
		if endpoint == "" {
			endpoint = env.Get(endpointEnv, kv.Get(Endpoint))
		}
		authTokenEnv := EnvLoggerHTTPAuditAuthToken
		if starget != config.Default {
			authTokenEnv = EnvLoggerHTTPAuditAuthToken + config.Default + starget
		}
		cfg.HTTP[starget] = HTTP{
			Enabled:   true,
			Endpoint:  endpoint,
			AuthToken: env.Get(authTokenEnv, kv.Get(AuthToken)),
		}
	}

	for _, target := range loggerTargets {
		endpointEnv := EnvLoggerHTTPEndpoint
		if target != config.Default {
			endpointEnv = EnvLoggerHTTPEndpoint + config.Default + target
		}
		authTokenEnv := EnvLoggerHTTPAuthToken
		if target != config.Default {
			authTokenEnv = EnvLoggerHTTPAuthToken + config.Default + target
		}
		cfg.HTTP[target] = HTTP{
			Enabled:   true,
			Endpoint:  env.Get(endpointEnv, ""),
			AuthToken: env.Get(authTokenEnv, ""),
		}
	}

	for _, target := range loggerAuditTargets {
		endpointEnv := EnvLoggerHTTPAuditEndpoint
		if target != config.Default {
			endpointEnv = EnvLoggerHTTPAuditEndpoint + config.Default + target
		}
		legacyEndpointEnv := EnvAuditLoggerHTTPEndpoint
		if target != config.Default {
			legacyEndpointEnv = EnvAuditLoggerHTTPEndpoint + config.Default + target
		}
		endpoint := env.Get(legacyEndpointEnv, "")
		if endpoint == "" {
			endpoint = env.Get(endpointEnv, "")
		}
		authTokenEnv := EnvLoggerHTTPAuditAuthToken
		if target != config.Default {
			authTokenEnv = EnvLoggerHTTPAuditAuthToken + config.Default + target
		}
		cfg.HTTP[target] = HTTP{
			Enabled:   true,
			Endpoint:  endpoint,
			AuthToken: env.Get(authTokenEnv, ""),
		}
	}

	return cfg, nil
}