package ukey

import (
	"crypto/rand"
	"math/big"

	"github.com/cristalhq/base64"
	"github.com/gin-gonic/gin"
	"golang.org/x/crypto/blake2b"
	"stereo.cat/backend/internal/auth"
	"stereo.cat/backend/internal/types"
)

func GenerateUploadKey(cfg *types.StereoConfig, user *auth.User, c *gin.Context) []byte {
	length := 32
	chars := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789@#!&*%~?"

	key := make([]byte, length)
	for i := range length {
		num, err := rand.Int(rand.Reader, big.NewInt(int64(len(chars))))
		if err != nil {
			types.ErrorInvalidParams.Throw(c, err)
			return nil
		}

		key[i] = chars[num.Int64()]
	}

	hasher, err := blake2b.New512(nil)
	if err != nil {
		types.ErrorInvalidParams.Throw(c, err)
		return nil
	}

	_, err = hasher.Write(key)
	if err != nil {
		types.ErrorInvalidParams.Throw(c, err)
		return nil
	}

	hashed := base64.RawStdEncoding.EncodeToString(hasher.Sum(nil))

	user.HashedApiKey = hashed

	err = cfg.Database.Updates(user).Error
	if err != nil {
		types.ErrorDatabase.Throw(c, err)
		return nil
	}

	return key
}