package server

import (
	"bytes"
	"io"

	"github.com/haileyok/cocoon/internal/helpers"
	"github.com/haileyok/cocoon/models"
	"github.com/ipfs/go-cid"
	"github.com/labstack/echo/v4"
	"github.com/multiformats/go-multihash"
)

const (
	blockSize = 0x10000
)

type ComAtprotoRepoUploadBlobResponse struct {
	Blob struct {
		Type string `json:"$type"`
		Ref  struct {
			Link string `json:"$link"`
		} `json:"ref"`
		MimeType string `json:"mimeType"`
		Size     int    `json:"size"`
	} `json:"blob"`
}

func (s *Server) handleRepoUploadBlob(e echo.Context) error {
	urepo := e.Get("repo").(*models.RepoActor)

	mime := e.Request().Header.Get("content-type")
	if mime == "" {
		mime = "application/octet-stream"
	}

	blob := models.Blob{
		Did:       urepo.Repo.Did,
		RefCount:  0,
		CreatedAt: s.repoman.clock.Next().String(),
	}

	if err := s.db.Create(&blob).Error; err != nil {
		s.logger.Error("error creating new blob in db", "error", err)
		return helpers.ServerError(e, nil)
	}

	read := 0
	part := 0

	buf := make([]byte, 0x10000)
	fulldata := new(bytes.Buffer)

	for {
		n, err := io.ReadFull(e.Request().Body, buf)
		if err == io.ErrUnexpectedEOF || err == io.EOF {
			if n == 0 {
				break
			}
		} else if err != nil && err != io.ErrUnexpectedEOF {
			s.logger.Error("error reading blob", "error", err)
			return helpers.ServerError(e, nil)
		}

		data := buf[:n]
		read += n
		fulldata.Write(data)

		blobPart := models.BlobPart{
			BlobID: blob.ID,
			Idx:    part,
			Data:   data,
		}

		if err := s.db.Create(&blobPart).Error; err != nil {
			s.logger.Error("error adding blob part to db", "error", err)
			return helpers.ServerError(e, nil)
		}
		part++

		if n < blockSize {
			break
		}
	}

	c, err := cid.NewPrefixV1(cid.Raw, multihash.SHA2_256).Sum(fulldata.Bytes())
	if err != nil {
		s.logger.Error("error creating cid prefix", "error", err)
		return helpers.ServerError(e, nil)
	}

	if err := s.db.Exec("UPDATE blobs SET cid = ? WHERE id = ?", c.Bytes(), blob.ID).Error; err != nil {
		// there should probably be somme handling here if this fails...
		s.logger.Error("error updating blob", "error", err)
		return helpers.ServerError(e, nil)
	}

	resp := ComAtprotoRepoUploadBlobResponse{}
	resp.Blob.Type = "blob"
	resp.Blob.Ref.Link = c.String()
	resp.Blob.MimeType = mime
	resp.Blob.Size = read

	return e.JSON(200, resp)
}