package repo

import (
	"context"
	"time"

	"github.com/google/uuid"
	"github.com/hay-kot/homebox/backend/internal/data/ent"
	"github.com/hay-kot/homebox/backend/internal/data/ent/attachment"
	"github.com/hay-kot/homebox/backend/internal/data/ent/item"
)

// AttachmentRepo is a repository for Attachments table that links Items to Documents
// While also specifying the type of the attachment. This _ONLY_ provides basic Create Update
// And Delete operations. For accessing the actual documents, use the Items repository since it
// provides the attachments with the documents.
type AttachmentRepo struct {
	db *ent.Client
}

type (
	ItemAttachment struct {
		ID        uuid.UUID   `json:"id"`
		CreatedAt time.Time   `json:"createdAt"`
		UpdatedAt time.Time   `json:"updatedAt"`
		Type      string      `json:"type"`
		Document  DocumentOut `json:"document"`
		Primary   bool        `json:"primary"`
	}

	ItemAttachmentUpdate struct {
		ID      uuid.UUID `json:"-"`
		Type    string    `json:"type"`
		Title   string    `json:"title"`
		Primary bool      `json:"primary"`
	}
)

func ToItemAttachment(attachment *ent.Attachment) ItemAttachment {
	return ItemAttachment{
		ID:        attachment.ID,
		CreatedAt: attachment.CreatedAt,
		UpdatedAt: attachment.UpdatedAt,
		Type:      attachment.Type.String(),
		Primary:   attachment.Primary,
		Document: DocumentOut{
			ID:    attachment.Edges.Document.ID,
			Title: attachment.Edges.Document.Title,
			Path:  attachment.Edges.Document.Path,
		},
	}
}

func (r *AttachmentRepo) Create(ctx context.Context, itemId, docId uuid.UUID, typ attachment.Type) (*ent.Attachment, error) {
	bldr := r.db.Attachment.Create().
		SetType(typ).
		SetDocumentID(docId).
		SetItemID(itemId)

  // Autoset primary to true if this is the first attachment
  // that is of type photo
  if typ == attachment.TypePhoto {
    cnt, err := r.db.Attachment.Query().
      Where(
        attachment.HasItemWith(item.ID(itemId)),
        attachment.TypeEQ(typ),
      ).
      Count(ctx)
    if err != nil {
      return nil, err
    }

    if cnt == 0 {
      bldr = bldr.SetPrimary(true)
    }
  }

  return bldr.Save(ctx)
}

func (r *AttachmentRepo) Get(ctx context.Context, id uuid.UUID) (*ent.Attachment, error) {
	return r.db.Attachment.
		Query().
		Where(attachment.ID(id)).
		WithItem().
		WithDocument().
		Only(ctx)
}

func (r *AttachmentRepo) Update(ctx context.Context, itemId uuid.UUID, data *ItemAttachmentUpdate) (*ent.Attachment, error) {
	// TODO: execute within Tx
	typ := attachment.Type(data.Type)

	bldr := r.db.Attachment.UpdateOneID(itemId).
		SetType(typ)

	// Primary only applies to photos
	if typ == attachment.TypePhoto {
		bldr = bldr.SetPrimary(data.Primary)
	} else {
		bldr = bldr.SetPrimary(false)
	}

	itm, err := bldr.Save(ctx)
	if err != nil {
		return nil, err
	}

	// Ensure all other attachments are not primary
	err = r.db.Attachment.Update().
		Where(
			attachment.HasItemWith(item.ID(itemId)),
			attachment.IDNEQ(itm.ID),
		).
		SetPrimary(false).
		Exec(ctx)
	if err != nil {
		return nil, err
	}

	return r.Get(ctx, itm.ID)
}

func (r *AttachmentRepo) Delete(ctx context.Context, id uuid.UUID) error {
	return r.db.Attachment.DeleteOneID(id).Exec(ctx)
}