package s3

import (
	"context"
	"io"

	"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"
)

// Client wraps the AWS S3 client for vaultik operations
type Client struct {
	s3Client *s3.Client
	bucket   string
	prefix   string
}

// Config contains S3 client configuration
type Config struct {
	Endpoint        string
	Bucket          string
	Prefix          string
	AccessKeyID     string
	SecretAccessKey string
	Region          string
}

// NewClient creates a new S3 client
func NewClient(ctx context.Context, cfg Config) (*Client, error) {
	// Create AWS config
	awsCfg, err := config.LoadDefaultConfig(ctx,
		config.WithRegion(cfg.Region),
		config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(
			cfg.AccessKeyID,
			cfg.SecretAccessKey,
			"",
		)),
	)
	if err != nil {
		return nil, err
	}

	// Configure custom endpoint if provided
	s3Opts := func(o *s3.Options) {
		if cfg.Endpoint != "" {
			o.BaseEndpoint = aws.String(cfg.Endpoint)
			o.UsePathStyle = true
		}
	}

	s3Client := s3.NewFromConfig(awsCfg, s3Opts)

	return &Client{
		s3Client: s3Client,
		bucket:   cfg.Bucket,
		prefix:   cfg.Prefix,
	}, nil
}

// PutObject uploads an object to S3
func (c *Client) PutObject(ctx context.Context, key string, data io.Reader) error {
	fullKey := c.prefix + key
	_, err := c.s3Client.PutObject(ctx, &s3.PutObjectInput{
		Bucket: aws.String(c.bucket),
		Key:    aws.String(fullKey),
		Body:   data,
	})
	return err
}

// GetObject downloads an object from S3
func (c *Client) GetObject(ctx context.Context, key string) (io.ReadCloser, error) {
	fullKey := c.prefix + key
	result, err := c.s3Client.GetObject(ctx, &s3.GetObjectInput{
		Bucket: aws.String(c.bucket),
		Key:    aws.String(fullKey),
	})
	if err != nil {
		return nil, err
	}
	return result.Body, nil
}

// DeleteObject removes an object from S3
func (c *Client) DeleteObject(ctx context.Context, key string) error {
	fullKey := c.prefix + key
	_, err := c.s3Client.DeleteObject(ctx, &s3.DeleteObjectInput{
		Bucket: aws.String(c.bucket),
		Key:    aws.String(fullKey),
	})
	return err
}

// ListObjects lists objects with the given prefix
func (c *Client) ListObjects(ctx context.Context, prefix string) ([]string, error) {
	fullPrefix := c.prefix + prefix

	var keys []string
	paginator := s3.NewListObjectsV2Paginator(c.s3Client, &s3.ListObjectsV2Input{
		Bucket: aws.String(c.bucket),
		Prefix: aws.String(fullPrefix),
	})

	for paginator.HasMorePages() {
		page, err := paginator.NextPage(ctx)
		if err != nil {
			return nil, err
		}

		for _, obj := range page.Contents {
			if obj.Key != nil {
				// Remove the base prefix from the key
				key := *obj.Key
				if len(key) > len(c.prefix) {
					key = key[len(c.prefix):]
				}
				keys = append(keys, key)
			}
		}
	}

	return keys, nil
}

// HeadObject checks if an object exists
func (c *Client) HeadObject(ctx context.Context, key string) (bool, error) {
	fullKey := c.prefix + key
	_, err := c.s3Client.HeadObject(ctx, &s3.HeadObjectInput{
		Bucket: aws.String(c.bucket),
		Key:    aws.String(fullKey),
	})
	if err != nil {
		// Check if it's a not found error
		// TODO: Add proper error type checking
		return false, nil
	}
	return true, nil
}