package storage

import (
	"fmt"
	"go/weather/pkg/logger"
	"io"
	"os"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/defaults"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
	toml "github.com/pelletier/go-toml"
	"go.uber.org/zap"
)

//AwsDefaultSection toml default section
type AwsDefaultSection struct {
	// attribute should be public ! for go-toml
	EndpointURL string `toml:"endpoint_url" hcl:"endpoint_url"`
}

//CustomAwsConfig custom toml config for aws
type CustomAwsConfig struct {
	Default AwsDefaultSection `toml:"default"`
}

//WeatherS3StorageConfig interface abstracting storageConfig
type WeatherS3StorageConfig struct {
	AwsDefaultSection  `hcl:",nested"`
	Region             string `hcl:"region"`
	AwsAccessKeyID     string `hcl:"aws_access_key_id"`
	AwsSecretAccessKey string `hcl:"aws_secret_access_key"`
}

//s3Storage classe used to store oi.Reader to s3
type s3Storage struct {
	logger  *logger.WeatherLogger
	session *session.Session
	bucket  string
}

//NewS3Storage instanciate storage object
func NewS3Storage(log *logger.WeatherLogger, config *WeatherS3StorageConfig, bucket string) Storage {
	s3 := s3Storage{
		logger: log,
		bucket: bucket,
	}

	var consolidateConfig aws.Config
	// when no config file arer specify overload weather configurable parameter with default one
	if config == nil {
		customConfig := CustomAwsConfig{}
		err := decodeFile(defaults.SharedConfigFilename(), &customConfig)
		s3.handleError(err)

		consolidateConfig = aws.Config{
			Endpoint:         &customConfig.Default.EndpointURL,
			DisableSSL:       aws.Bool(true),
			LogLevel:         aws.LogLevel(aws.LogDebug),
			S3ForcePathStyle: aws.Bool(true),
		}
	} else {
		consolidateConfig = aws.Config{
			Endpoint:         &config.EndpointURL,
			Credentials:      credentials.NewStaticCredentials(config.AwsAccessKeyID, config.AwsSecretAccessKey, ""),
			Region:           &config.Region,
			DisableSSL:       aws.Bool(true),
			LogLevel:         aws.LogLevel(aws.LogDebug),
			S3ForcePathStyle: aws.Bool(true),
		}
	}

	s, err := session.NewSessionWithOptions(session.Options{
		SharedConfigState: session.SharedConfigEnable,
		Config:            consolidateConfig,
	})
	s3.handleError(err)
	s3.session = s

	return &s3
}

//Store send data to s3 bucket
func (ss *s3Storage) Store(content io.Reader) {
	uploader := s3manager.NewUploader(ss.session)

	_, err := uploader.Upload(&s3manager.UploadInput{
		Bucket: aws.String(ss.bucket),
		Key:    aws.String(fmt.Sprintf("%s.json", time.Now().UTC().Format(time.RFC3339))),
		Body:   content,
	})
	ss.handleError(err)
}

//DecodeFile call toml.Decode with file
func decodeFile(fpath string, v interface{}) error {
	bs, err := os.Open(fpath)
	if err != nil {
		return err
	}
	d := toml.NewDecoder(bs)
	err = d.Decode(v)

	return err
}

//handleError generic fatal error
func (ss *s3Storage) handleError(err error) {
	if err != nil {
		ss.logger.Fatal("Storage error", zap.Error(err))
	}
}