package storage

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/credentials"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/tech/sendico/pkg/api/http/response"
	"github.com/tech/sendico/pkg/mlogger"
	"github.com/tech/sendico/pkg/mservice"
	storageconfig "github.com/tech/sendico/server/internal/server/fileserviceimp/storage/config"
	"go.uber.org/zap"
)

type AWSS3Storage struct {
	logger     mlogger.Logger
	s3Client   *s3.Client
	bucketName string
	directory  string
	service    mservice.Type
}

func (storage *AWSS3Storage) Delete(ctx context.Context, objID string) error {
	fullPath := filepath.Join(storage.directory, objID)
	_, err := storage.s3Client.DeleteObject(ctx, &s3.DeleteObjectInput{
		Bucket: aws.String(storage.bucketName),
		Key:    aws.String(fullPath),
	})
	if err != nil {
		storage.logger.Warn("Failed to delete file from AWS S3", zap.Error(err), zap.String("obj_ref", objID))
		return err
	}

	// Wait for object to be deleted
	waiter := s3.NewObjectNotExistsWaiter(storage.s3Client)
	err = waiter.Wait(ctx, &s3.HeadObjectInput{
		Bucket: aws.String(storage.bucketName),
		Key:    aws.String(fullPath),
	}, 30) // 30 second timeout
	if err != nil {
		storage.logger.Warn("Error occurred while waiting for S3 file deletion", zap.Error(err), zap.String("obj_ref", objID))
		return err
	}

	return nil
}

func (storage *AWSS3Storage) s3URL(fullPath string) string {
	return fmt.Sprintf("https://%s.s3.amazonaws.com/%s", storage.bucketName, fullPath)
}

func (storage *AWSS3Storage) Save(ctx context.Context, file io.Reader, objID string) (string, error) {
	fullPath := filepath.Join(storage.directory, objID)
	buf := new(bytes.Buffer)
	_, err := io.Copy(buf, file)
	if err != nil {
		storage.logger.Warn("Failed to read file content", zap.Error(err), zap.String("obj_ref", objID))
		return "", err
	}

	_, err = storage.s3Client.PutObject(ctx, &s3.PutObjectInput{
		Bucket: aws.String(storage.bucketName),
		Key:    aws.String(fullPath),
		Body:   bytes.NewReader(buf.Bytes()),
	})
	if err != nil {
		storage.logger.Warn("Failed to upload file to S3", zap.Error(err), zap.String("obj_ref", objID))
		return "", err
	}

	s3URL := storage.s3URL(fullPath)
	storage.logger.Info("File upload complete", zap.String("obj_ref", objID), zap.String("s3_url", s3URL))
	return s3URL, nil
}

func (storage *AWSS3Storage) Get(ctx context.Context, objID string) http.HandlerFunc {
	storage.logger.Warn("Indirect access to the object should be avoided", zap.String("obj_ref", objID))
	fullPath := filepath.Join(storage.directory, objID)
	_, err := storage.s3Client.GetObject(ctx, &s3.GetObjectInput{
		Bucket: aws.String(storage.bucketName),
		Key:    aws.String(fullPath),
	})
	if err != nil {
		storage.logger.Warn("Failed to get file from S3", zap.Error(err), zap.String("obj_ref", objID))
		return response.NotFound(storage.logger, storage.service, err.Error())
	}

	res := func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, storage.s3URL(fullPath), http.StatusFound)
	}
	return res
}

func CreateAWSS3Storage(logger mlogger.Logger, service mservice.Type, directory string, cfg storageconfig.AWSS3SConfig) (*AWSS3Storage, error) {
	region := os.Getenv(cfg.RegionEnv)
	accessKeyID := os.Getenv(cfg.AccessKeyIDEnv)
	secretAccessKey := os.Getenv(cfg.SecretAccessKeyEnv)
	bucketName := os.Getenv(cfg.BucketNameEnv)

	// Create AWS config with static credentials
	awsConfig, err := config.LoadDefaultConfig(context.Background(),
		config.WithRegion(region),
		config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(
			accessKeyID,
			secretAccessKey,
			"",
		)),
	)
	if err != nil {
		logger.Warn("Failed to create AWS config", zap.Error(err), zap.String("bucket", bucketName),
			zap.String("access_key_id", accessKeyID), zap.String("region", region))
		return nil, err
	}

	// Create S3 client
	s3Client := s3.NewFromConfig(awsConfig)

	res := &AWSS3Storage{
		logger:     logger.Named("aws_s3").Named(directory),
		s3Client:   s3Client,
		bucketName: bucketName,
		directory:  directory,
		service:    service,
	}
	res.logger.Info("Storage installed", zap.String("bucket", bucketName), zap.String("region", region),
		zap.String("access_key_id", accessKeyID))
	return res, nil
}