feat: allow to fetch collections

examples/mock_data/PokeApi/Get All Pokemons.bru

@@ -0,0 +1,11 @@
+meta {
+  name: Get All Pokemons
+  type: http
+  seq: 2
+}
+
+get {
+  url: https://pokeapi.co/api/v2/pokemon/
+  body: none
+  auth: none
+}

examples/mock_data/PokeApi/bruno.json

@@ -0,0 +1,9 @@
+{
+  "version": "1",
+  "name": "PokeApi",
+  "type": "collection",
+  "ignore": [
+    "node_modules",
+    ".git"
+  ]
+}

examples/usage.go

@@ -2,24 +2,80 @@ package main
 
 import (
 	"database/sql"
+	"encoding/json"
 	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
 
 	_ "modernc.org/sqlite"
 
 	synchronizator "git.alecodes.page/alecodes/synchronizator/pkg"
 )
 
-type PokeApi struct{}
+type PokeApiResponse[T any] struct {
-
+	Count    int    `json:"count"`
-func (pokeApi *PokeApi) ToNode() (string, []byte, error) {
+	Next     string `json:"next"`
-	return "POKEAPI", nil, nil
+	Previous string `json:"previous"`
+	Results  []T    `json:"results"`
 }
 
-func (pokeApi *PokeApi) FromNode(_class string, name string, metadata []byte) error {
+type Pokedex struct {
-	if _class != "POKEAPI" {
+	Name string `json:"name"`
-		return fmt.Errorf("invalid class %s", _class)
+	Url  string `json:"url"`
 }
-	return nil
+
+type Pokemon struct {
+	Id   int    `json:"id"`
+	Name string `json:"name"`
+}
+
+func getPokemons(
+	sync *synchronizator.DB,
+	pagination synchronizator.Pagination,
+) ([]*synchronizator.Collection, synchronizator.Pagination, error) {
+	var collections []*synchronizator.Collection
+
+	params := url.Values{}
+	params.Add("offset", strconv.Itoa(pagination.Offset))
+	params.Add("limit", strconv.Itoa(pagination.Limit))
+
+	resp, err := http.Get("https://pokeapi.co/api/v2/pokedex?" + params.Encode())
+	if err != nil {
+		return nil, pagination, err
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	resp.Body.Close()
+
+	var data PokeApiResponse[Pokedex]
+	err = json.Unmarshal(body, &data)
+	if err != nil {
+		return nil, pagination, err
+	}
+
+	collections = make([]*synchronizator.Collection, 0, len(data.Results))
+
+	// TODO: this writes to the database in each collection creation
+	// add better strategies, like returning a collection to the platform and the
+	// platform do a final bulk update
+	for _, pokedex := range data.Results {
+		collection_name := "Pokedex_" + pokedex.Name
+		collection, err := sync.NewCollection(collection_name, nil)
+		if err != nil {
+			return nil, pagination, err
+		}
+		collections = append(collections, collection)
+	}
+
+	// fmt.Println(data)
+
+	pagination.Offset += pagination.Limit
+	pagination.HasMore = data.Next != ""
+	pagination.Total = data.Count
+
+	return collections, pagination, nil
 }
 
 func main() {
@@ -43,6 +99,17 @@ func main() {
 		return
 	}
 
-	pokeApi := &PokeApi{}
+	pokeApi, err := sync.NewPlatform("pokeapi", nil)
-	sync.NewPlatform(pokeApi)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(pokeApi)
+
+	err = pokeApi.FetchCollections(getPokemons, synchronizator.StartPagination)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
 }

pkg/collection.go

@@ -54,16 +54,3 @@ func (collection *Collection) AddChild(node *Node) error {
 
 	return nil
 }
-
-// Allows to retreive the saved information back into the user struct. This
-// method will call the [NodeClass.FromNode] of the provided struct.
-//
-// Example:
-//
-//	data := &Library{}
-//	if err := node.Unmarshall(data); err != nil {
-//		println(err)
-//	}
-func (collection *Collection) Unmarshall(dst StandardNode) error {
-	return dst.FromNode("COLLECTION", collection.name, collection.metadata)
-}

pkg/node.go

@@ -1,29 +1,6 @@
 package synchronizator
 
-// A user representation of a node, this interface should be implemented by the user
+type StandardNode interface{}
-// to provide the ability to parse the database node into a user defined
-// struct that fulfills it's requirements.
-//
-// This interface is compatible with the [NodeClass] interface but it doesn't
-// handle the class parameter as it's a static value provided by the
-// StandardNode
-type StandardNode interface {
-	// How to transform the struct into a node. It needs to return the class,
-	// name and a []byte representation of the metadata.
-	//
-	// - name: A user friendly name
-	// - metadata: Arbitrary data. This will be stored as a jsonb in the database
-	//
-	ToNode() (string, []byte, error)
-
-	// How to transform a node into the struct. This method should modify the
-	// struct directly as it receives a pointer.
-	//
-	// - class: The class of the node, should not be modified to avoid inconsistencies.
-	// - name: A user friendly name
-	// - metadata: Arbitrary data. This is stored as a jsonb in the database
-	FromNode(string, string, []byte) error
-}
 
 // A node in the database.
 // It adds some helper methods to easily manage the node.
@@ -112,19 +89,6 @@ func (node *Node) Delete() error {
 	return node._conn.DeleteNode(node.Id)
 }
 
-// Allows to retreive the saved information back into the user struct. This
-// method will call the [NodeClass.FromNode] of the provided struct.
-//
-// Example:
-//
-//	data := &Library{}
-//	if err := node.Unmarshall(data); err != nil {
-//		println(err)
-//	}
-func (node *Node) Unmarshall(dst StandardNode) error {
-	return dst.FromNode(node._class, node.name, node.metadata)
-}
-
 // Returns the class of the node
 func (relationship *Relationship) GetClass() string {
 	return relationship._class

pkg/platform.go

@@ -23,3 +23,32 @@ type Platform struct {
 	Node                      // Underlaying node info
 	collections []*Collection // Child nodes
 }
+
+type Fetcher = func(conn *DB, pagination Pagination) ([]*Collection, Pagination, error)
+
+type Pagination struct {
+	Total   int
+	HasMore bool
+	Limit   int
+	Offset  int
+}
+
+var StartPagination = Pagination{
+	Total:   0,
+	HasMore: false,
+	Limit:   10,
+	Offset:  0,
+}
+
+func (platform *Platform) FetchCollections(fetcher Fetcher, start_pagination Pagination) error {
+	collections, pagination, err := fetcher(platform._conn, start_pagination)
+	if err != nil {
+		return err
+	}
+	platform.collections = collections
+
+	if pagination.HasMore {
+		return platform.FetchCollections(fetcher, pagination)
+	}
+	return nil
+}

pkg/synchronizator.go

@@ -15,6 +15,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"strings"
 	"time"
 )
 
@@ -168,23 +169,24 @@ func (conn *DB) Query(sql string, args ...any) (*sql.Rows, error) {
 // A collection is only a Node wrapper with some extended functionality to
 // manage multiple nodes. For more information see [DB.NewNode] method and the
 // [Platform] struct.
-func (conn *DB) NewPlatform(data StandardNode) (*Platform, error) {
+func (conn *DB) NewPlatform(name string, metadata []byte) (*Platform, error) {
 	var platform *Platform
 	err := conn.withTx(func(tx *sql.Tx) error {
-		node, err := conn.newNodewithTx(tx, "PLATFORM", data)
+		node, err := conn.newNodewithTx(tx, name, "PLATFORM", metadata)
 		if err != nil {
 			return err
 		}
 
 		collection, err := conn.newCollectionwithTx(
 			tx,
-			&default_collection{platform_name: node.name},
+			strings.ToUpper(name)+"_DEFAULT",
+			nil,
 		)
 		if err != nil {
 			return err
 		}
 
-		platform := &Platform{
+		platform = &Platform{
 			Node:        *node,
 			collections: []*Collection{collection},
 		}
@@ -206,12 +208,12 @@ func (conn *DB) NewPlatform(data StandardNode) (*Platform, error) {
 // [Collection] struct.
 //
 // The operation is ran in a database transaction.
-func (conn *DB) NewCollection(data StandardNode) (*Collection, error) {
+func (conn *DB) NewCollection(name string, metadata []byte) (*Collection, error) {
 	var collection *Collection
 
 	err := conn.withTx(func(tx *sql.Tx) error {
 		var err error
-		collection, err = conn.newCollectionwithTx(tx, data)
+		collection, err = conn.newCollectionwithTx(tx, name, metadata)
 		return err
 	})
 
@@ -223,8 +225,8 @@ func (conn *DB) NewCollection(data StandardNode) (*Collection, error) {
 // A collection is only a Node wrapper with some extended functionality to
 // manage multiple nodes. For more information see [DB.NewNode] method and the
 // [Collection] struct.
-func (conn *DB) newCollectionwithTx(tx *sql.Tx, data StandardNode) (*Collection, error) {
+func (conn *DB) newCollectionwithTx(tx *sql.Tx, name string, metadata []byte) (*Collection, error) {
-	node, err := conn.newNodewithTx(tx, "COLLECTION", data)
+	node, err := conn.newNodewithTx(tx, name, "COLLECTION", metadata)
 	if err != nil {
 		return nil, err
 	}
@@ -240,12 +242,12 @@ func (conn *DB) newCollectionwithTx(tx *sql.Tx, data StandardNode) (*Collection,
 // Creates a new node.
 //
 // The operation is ran in a database transaction.
-func (conn *DB) NewNode(class string, data StandardNode) (*Node, error) {
+func (conn *DB) NewNode(name string, class string, metadata []byte) (*Node, error) {
 	var node *Node
 
 	err := conn.withTx(func(tx *sql.Tx) error {
 		var err error
-		node, err = conn.newNodewithTx(tx, class, data)
+		node, err = conn.newNodewithTx(tx, name, class, metadata)
 		return err
 	})
 
@@ -253,12 +255,12 @@ func (conn *DB) NewNode(class string, data StandardNode) (*Node, error) {
 }
 
 // Creates a new node
-func (conn *DB) newNodewithTx(tx *sql.Tx, class string, data StandardNode) (*Node, error) {
+func (conn *DB) newNodewithTx(
-	name, metadata, err := data.ToNode()
+	tx *sql.Tx,
-	if err != nil {
+	name string,
-		return nil, err
+	class string,
-	}
+	metadata []byte,
-
+) (*Node, error) {
 	node := Node{
 		_conn:    conn,
 		_class:   class,
@@ -271,7 +273,7 @@ func (conn *DB) newNodewithTx(tx *sql.Tx, class string, data StandardNode) (*Nod
 
 	sql := "INSERT INTO nodes (_class, name, metadata) VALUES ($1, $2, $3) RETURNING id;"
 
-	err = tx.QueryRow(sql, node._class, node.name, metadata).Scan(&node.Id)
+	err := tx.QueryRow(sql, node._class, node.name, metadata).Scan(&node.Id)
 	if err != nil {
 		return nil, err
 	}
@@ -280,12 +282,7 @@ func (conn *DB) newNodewithTx(tx *sql.Tx, class string, data StandardNode) (*Nod
 }
 
 // Updates a node with the provided id and data
-func (conn *DB) UpdateNode(id int64, data StandardNode) (*Node, error) {
+func (conn *DB) UpdateNode(id int64, name string, metadata []byte) (*Node, error) {
-	name, metadata, err := data.ToNode()
-	if err != nil {
-		return nil, err
-	}
-
 	node := Node{
 		_conn:    conn,
 		name:     name,