types

type Connect func(string) (Datasource, error)

type Datasource interface {

	// Disconnect severs the connection to the data source.
	// After disconnection, the data source cannot be used to correctly
	// fulfil any actions requested.
	Disconnect() error

	// InsertProduct creates a new entry in the product segment of the
	// data source persistant storage. Products have a unique ID, set
	// by the data source, and a unique EAN code. Duplicates are
	// rejected. Product taggings are also saved.
	// InsertProduct also updates the ID of the product to match the
	// unique ID attributed.
	InsertProduct(*Product) error

	// SelectAllProducts returns all products from the product segment
	// of the data source persistant storage. If there are none, returns
	// an empty array of products and a nil error.
	SelectAllProducts() ([]*Product, error)

	// SelectProductById returns the only product with that ID from
	// the product segment of the data source persistant storage.
	// If the ID does not exist, SelectProductById returns an empty
	// product (without any values) and a nil error.
	SelectProductById(uint) (*Product, error)

	// SelectProductLike returns all possible products from the product
	// segment of the data source persistant storage matching the
	// search. If there are none, returns an empty array of products and
	// a nil error.
	SelectProductsLike(*ProductSearch) ([]*Product, error)

	// UpdateProduct updates the product in the product segment of the
	// data source persistant storage to match the passed product.
	// This means that taggings also have to be updated. The updated
	// product is then returned.
	// The ID can never be updated.
	UpdateProduct(*Product) (*Product, error)

	// DeleteProduct completely removes the product from the product
	// segment of the data source persistant storage. This means that
	// taggings are also deleted. It returns the deleted product in
	// full afterwards.
	DeleteProduct(uint) (*Product, error)

	// InsertProuctTag creates a new entry in the product tag segment
	// of the data source persistant storage. Product tags have a
	// unique ID, set by the data source, and name. Duplicates are
	// rejected.
	// InsertProductTag also updates the ID of the tag to match the
	// unique ID attributed.
	InsertProductTag(*Tag) error

	// SelectAllProductTags returns all possible product tags from the
	// product tag segment of the data source persistant storage. If
	// there are none, returns an empty array of produt tags.
	SelectAllProductTags() ([]*Tag, error)

	// SelectProductTagById returns the only product tag with that ID
	// from the product tag segment of the data source persistant
	// storage. If the ID does not exist, returns an emtpy product tag
	// and a nil error.
	SelectProductTagById(uint) (*Tag, error)

	// SelectProductTagByName returns the only product tag with that
	// name from the product tag segment of the data source persistant
	// storage. If none are found, returns an emtpy product tag and a
	// nil error.
	SelectProductTagByName(string) (*Tag, error)

	// SelectProductTagsLikeName returns all possible product tags
	// matching the name. If there are none, returns an empty array
	// of product tags and no error.
	SelectProductTagsLikeName(string) ([]*Tag, error)

	// UpdateProductTag updates the product tag in the product segment
	// of the data source peristant storage to match the passed product
	// tag.
	// The ID can never be updated.
	// Product tags have unique names. Duplicates are expected to be
	// rejected.
	UpdateProductTag(*Tag) (*Tag, error)

	// DeleteProductTag completely removes the product tag from the
	// product tag segment of the data source persistant storage.
	// This means that taggings are also deleted. After that, it
	// returns the deleted tag.
	DeleteProductTag(uint) (*Tag, error)
}

type Location struct {
	Id      uint   `json:"id"`
	Name    string `json:"name"`
	Fridge  bool   `json:"fridge"`
	Freezer bool   `json:"freezer"`
	Tags    []Tag  `json:"tags"`
}

type LogicProvider interface {

	// CreateProduct creates a new product in the data source
	// using the passed product. The product ID is updated to
	// match the one assigned in the data source and the tags
	// are the full tags assigned.
	// TODO: Populate product with OFF data.
	CreateProduct(*Product) error

	// GetAllProducts returns all products saved in the data
	// source.
	GetAllProducts() ([]*Product, error)

	// GetProductByID returns the product saved in the data
	// source matching the ID. If no product matches,
	// GetProductByID returns an empty product and ErrIDNotFound.
	GetProductByID(uint) (*Product, error)

	// GetProductsLike returns all products saved in the data
	// source matching the requested search. If no product
	// matches, GetProductsLike returns an empty array of
	// products and a nil error.
	GetProductsLike(*ProductSearch) ([]*Product, error)

	// UpdateProduct checks if the product ID exists. If
	// it does, it updates the product with the ID to match
	// the data passed. Otherwise, it returns ErrIDNotFound.
	UpdateProduct(*Product) (*Product, error)

	// DeleteProduct checks if the product ID exists. If it
	// does, it requests deletion of the product to the data
	// source and returns the deleted product. Otherwise, it
	// returns an empty produt and ErrIDNotFound.
	DeleteProduct(uint) (*Product, error)

	// CreateProductTag creates a new product tag in the data
	// source using the passed tag. The product tag ID is
	// updated to match the one assigned in the data source.
	CreateProductTag(*Tag) error

	// GetAllProductTags returns all product tags saved in
	// the data source.
	GetAllProductTags() ([]*Tag, error)

	// GetProductTagByID and GetProductTagByName return the
	// product tag matching the ID and name respectively.
	// If no product tag matches, they both return an empty
	// product tag and ErrIDNotFound.
	GetProductTagByID(uint) (*Tag, error)
	GetProductTagByName(string) (*Tag, error)

	// GetProductTagsLikeName returns all product tags
	// matching the requested name. If no product tags match,
	// GetProductTagsLikeName returns an empty array of
	// product tags and a nil error.
	GetProductTagsLikeName(string) ([]*Tag, error)

	// UpdateProductTag checks if the product tag ID exists.
	// If it does, it updates the product tag with the ID to
	// match the data passed. Otherwise, it returns
	// ErrIDNotFound.
	UpdateProductTag(*Tag) (*Tag, error)

	// DeleteProductTag checks if the product tag ID exists.
	// If it does, it requests deletion of the product tag
	// to the data source and returns the deleted product tag.
	// Otherwise, it returns an empty product tag and
	// ErrIDNotFound.
	DeleteProductTag(uint) (*Tag, error)
}

type Product struct {
	Id   uint   `json:"id"`
	EAN  uint   `json:"ean"`
	Name string `json:"name"`
	TTL  TTL    `json:"ttl"`
	Tags []Tag  `json:"tags"`
}

type ProductSearch struct {
	Ean      string
	Names    []string
	TagIds   []uint
	Oprators ProductSearchOperators
}

type ProductSearchOperators struct {
	Master string
	Names  string
	TagIds string
}

type TTL struct {
	Normal  uint `json:"normal"`
	Fridge  uint `json:"fridge"`
	Freezer uint `json:"freezer"`
}

type Tag struct {
	Id    uint   `json:"id"`
	Name  string `json:"name"`
	Color uint   `json:"color"`
}

type UseDatasource func(*Datasource) *LogicProvider