package db

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	_ "image/gif"
	_ "image/png"
	"io"
	"strings"

	"emperror.dev/errors"
	"github.com/davidbyttow/govips/v2/vips"
	"github.com/minio/minio-go/v7"
	"github.com/rs/xid"
)

const ErrInvalidDataURI = errors.Sentinel("invalid data URI")
const ErrInvalidContentType = errors.Sentinel("invalid avatar content type")
const ErrFileTooLarge = errors.Sentinel("file to be converted exceeds maximum size")

// ConvertAvatar parses an avatar from a data URI, converts it to WebP and JPEG, and returns the results.
func (db *DB) ConvertAvatar(data string) (
	webpOut *bytes.Buffer,
	jpgOut *bytes.Buffer,
	err error,
) {
	defer vips.ShutdownThread()

	data = strings.TrimSpace(data)
	if !strings.Contains(data, ",") || !strings.Contains(data, ":") || !strings.Contains(data, ";") {
		return nil, nil, ErrInvalidDataURI
	}
	split := strings.Split(data, ",")

	rawData, err := base64.StdEncoding.DecodeString(split[1])
	if err != nil {
		return nil, nil, errors.Wrap(err, "invalid base64 data")
	}

	image, err := vips.LoadImageFromBuffer(rawData, nil)
	if err != nil {
		return nil, nil, errors.Wrap(err, "decoding image")
	}

	err = image.ThumbnailWithSize(512, 512, vips.InterestingCentre, vips.SizeBoth)
	if err != nil {
		return nil, nil, errors.Wrap(err, "resizing image")
	}

	webpExport := vips.NewWebpExportParams()
	webpExport.Quality = 90
	webpB, _, err := image.ExportWebp(webpExport)
	if err != nil {
		return nil, nil, errors.Wrap(err, "exporting webp image")
	}
	webpOut = bytes.NewBuffer(webpB)

	jpegExport := vips.NewJpegExportParams()
	jpegExport.Quality = 80
	jpegB, _, err := image.ExportJpeg(jpegExport)
	if err != nil {
		return nil, nil, errors.Wrap(err, "exporting jpeg image")
	}
	jpgOut = bytes.NewBuffer(jpegB)

	return webpOut, jpgOut, nil
}

func (db *DB) WriteUserAvatar(ctx context.Context,
	userID xid.ID, webp *bytes.Buffer, jpeg *bytes.Buffer,
) (
	hash string, err error,
) {
	hasher := sha256.New()
	_, err = hasher.Write(webp.Bytes())
	if err != nil {
		return "", errors.Wrap(err, "hashing webp avatar")
	}
	hash = hex.EncodeToString(hasher.Sum(nil))

	_, err = db.minio.PutObject(ctx, db.minioBucket, "users/"+userID.String()+"/"+hash+".webp", webp, -1, minio.PutObjectOptions{
		ContentType:    "image/webp",
		SendContentMd5: true,
	})
	if err != nil {
		return "", errors.Wrap(err, "uploading webp avatar")
	}

	_, err = db.minio.PutObject(ctx, db.minioBucket, "users/"+userID.String()+"/"+hash+".jpg", jpeg, -1, minio.PutObjectOptions{
		ContentType:    "image/jpeg",
		SendContentMd5: true,
	})
	if err != nil {
		return "", errors.Wrap(err, "uploading jpeg avatar")
	}

	return hash, nil
}

func (db *DB) WriteMemberAvatar(ctx context.Context,
	memberID xid.ID, webp *bytes.Buffer, jpeg *bytes.Buffer,
) (
	hash string, err error,
) {
	hasher := sha256.New()
	_, err = hasher.Write(webp.Bytes())
	if err != nil {
		return "", errors.Wrap(err, "hashing webp avatar")
	}
	hash = hex.EncodeToString(hasher.Sum(nil))

	_, err = db.minio.PutObject(ctx, db.minioBucket, "members/"+memberID.String()+"/"+hash+".webp", webp, -1, minio.PutObjectOptions{
		ContentType:    "image/webp",
		SendContentMd5: true,
	})
	if err != nil {
		return "", errors.Wrap(err, "uploading webp avatar")
	}

	_, err = db.minio.PutObject(ctx, db.minioBucket, "members/"+memberID.String()+"/"+hash+".jpg", jpeg, -1, minio.PutObjectOptions{
		ContentType:    "image/jpeg",
		SendContentMd5: true,
	})
	if err != nil {
		return "", errors.Wrap(err, "uploading jpeg avatar")
	}

	return hash, nil
}

func (db *DB) DeleteUserAvatar(ctx context.Context, userID xid.ID, hash string) error {
	err := db.minio.RemoveObject(ctx, db.minioBucket, "users/"+userID.String()+"/"+hash+".webp", minio.RemoveObjectOptions{})
	if err != nil {
		return errors.Wrap(err, "deleting webp avatar")
	}

	err = db.minio.RemoveObject(ctx, db.minioBucket, "users/"+userID.String()+"/"+hash+".jpg", minio.RemoveObjectOptions{})
	if err != nil {
		return errors.Wrap(err, "deleting jpeg avatar")
	}

	return nil
}

func (db *DB) DeleteMemberAvatar(ctx context.Context, memberID xid.ID, hash string) error {
	err := db.minio.RemoveObject(ctx, db.minioBucket, "members/"+memberID.String()+"/"+hash+".webp", minio.RemoveObjectOptions{})
	if err != nil {
		return errors.Wrap(err, "deleting webp avatar")
	}

	err = db.minio.RemoveObject(ctx, db.minioBucket, "members/"+memberID.String()+"/"+hash+".jpg", minio.RemoveObjectOptions{})
	if err != nil {
		return errors.Wrap(err, "deleting jpeg avatar")
	}

	return nil
}

func (db *DB) UserAvatar(ctx context.Context, userID xid.ID, hash string) (io.ReadCloser, error) {
	obj, err := db.minio.GetObject(ctx, db.minioBucket, "users/"+userID.String()+"/"+hash+".webp", minio.GetObjectOptions{})
	if err != nil {
		return nil, errors.Wrap(err, "getting object")
	}
	return obj, nil
}

func (db *DB) MemberAvatar(ctx context.Context, memberID xid.ID, hash string) (io.ReadCloser, error) {
	obj, err := db.minio.GetObject(ctx, db.minioBucket, "members/"+memberID.String()+"/"+hash+".webp", minio.GetObjectOptions{})
	if err != nil {
		return nil, errors.Wrap(err, "getting object")
	}
	return obj, nil
}