Add API endpoint for transferring amounts between allowances

backend/api_test.go

@@ -2,10 +2,11 @@ package main
 
 import (
 	"fmt"
-	"github.com/gavv/httpexpect/v2"
 	"strconv"
 	"testing"
 	"time"
+
+	"github.com/gavv/httpexpect/v2"
 )
 
 const (
@@ -914,3 +915,88 @@ func createTestAllowance(e *httpexpect.Expect, name string, target float64, weig
 func createTestTask(e *httpexpect.Expect) int {
 	return createTestTaskWithAmount(e, 100)
 }
+
+// Transfer tests
+func TestTransferSuccessful(t *testing.T) {
+	e := startServer(t)
+
+	// Create two allowances for user 1
+	createTestAllowance(e, "From Allowance", 100, 1)
+	createTestAllowance(e, "To Allowance", 100, 1)
+
+	// Add 30 to allowance 1
+	req := map[string]interface{}{"amount": 30, "description": "funds"}
+	e.POST("/user/1/allowance/1/add").WithJSON(req).Expect().Status(200)
+
+	// Transfer 10 from 1 to 2
+	transfer := map[string]interface{}{"from": 1, "to": 2, "amount": 10}
+	e.POST("/transfer").WithJSON(transfer).Expect().Status(200).JSON().Object().Value("message").IsEqual("Transfer successful")
+
+	// Verify balances
+	allowances := e.GET("/user/1/allowance").Expect().Status(200).JSON().Array()
+	allowances.Value(1).Object().Value("progress").Number().InDelta(20.0, 0.01)
+	allowances.Value(2).Object().Value("progress").Number().InDelta(10.0, 0.01)
+}
+
+func TestTransferCapsAtTarget(t *testing.T) {
+	e := startServer(t)
+
+	// Create two allowances
+	createTestAllowance(e, "From Allowance", 100, 1)
+	createTestAllowance(e, "To Allowance", 5, 1)
+
+	// Add 10 to allowance 1
+	req := map[string]interface{}{"amount": 10, "description": "funds"}
+	e.POST("/user/1/allowance/1/add").WithJSON(req).Expect().Status(200)
+
+	// Transfer 10 from 1 to 2, but to only needs 5
+	transfer := map[string]interface{}{"from": 1, "to": 2, "amount": 10}
+	e.POST("/transfer").WithJSON(transfer).Expect().Status(200)
+
+	// Verify capped transfer
+	allowances := e.GET("/user/1/allowance").Expect().Status(200).JSON().Array()
+	allowances.Value(1).Object().Value("progress").Number().InDelta(5.0, 0.01) // from had 10, transferred 5 -> left 5
+	allowances.Value(2).Object().Value("progress").Number().InDelta(5.0, 0.01) // to reached target
+}
+
+func TestTransferDifferentUsersFails(t *testing.T) {
+	e := startServer(t)
+
+	// Create allowance for user 1 and user 2
+	createTestAllowance(e, "User1 Allowance", 100, 1)
+	// create for user 2
+	e.POST("/user/2/allowance").WithJSON(CreateAllowanceRequest{Name: "User2 Allowance", Target: 100, Weight: 1}).Expect().Status(201)
+
+	// Add to user1 allowance
+	req := map[string]interface{}{"amount": 10, "description": "funds"}
+	e.POST("/user/1/allowance/1/add").WithJSON(req).Expect().Status(200)
+
+	// Attempt transfer between different users
+	transfer := map[string]interface{}{"from": 1, "to": 1 /* wrong id to simulate different user's id? */}
+	// To ensure different user, fetch the allowance id for user2 (it's 1 for user2 in its own context but global id will be 2)
+	// Create above for user2 produced global id 2, so use that
+	transfer = map[string]interface{}{"from": 1, "to": 2, "amount": 5}
+	e.POST("/transfer").WithJSON(transfer).Expect().Status(400)
+}
+
+func TestTransferInsufficientFunds(t *testing.T) {
+	e := startServer(t)
+
+	// Create two allowances
+	createTestAllowance(e, "From Allowance", 100, 1)
+	createTestAllowance(e, "To Allowance", 100, 1)
+
+	// Ensure from has 0 balance
+	transfer := map[string]interface{}{"from": 1, "to": 2, "amount": 10}
+	resp := e.POST("/transfer").WithJSON(transfer).Expect().Status(400).JSON().Object()
+	// Error text should mention insufficient funds
+	resp.Value("error").String().Contains("insufficient")
+}
+
+func TestTransferNotFound(t *testing.T) {
+	e := startServer(t)
+
+	// No allowances exist yet (only user rows). Attempt transfer with non-existent IDs
+	transfer := map[string]interface{}{"from": 999, "to": 1000, "amount": 1}
+	e.POST("/transfer").WithJSON(transfer).Expect().Status(404)
+}

backend/db.go

@@ -7,6 +7,8 @@ import (
 	"math"
 	"time"
 
+	"github.com/adhocore/gronx"
+
 	"gitea.seeseepuff.be/seeseemelk/mysqlite"
 )
 
@@ -631,3 +633,74 @@ func (db *Db) AddAllowanceAmount(userId int, allowanceId int, request AddAllowan
 
 	return tx.Commit()
 }
+
+// TransferAllowance transfers amount from one allowance goal to another.
+// Both allowance ids must exist and belong to the same user. The transfer
+// will not move more than the 'to' goal still needs (target - balance).
+func (db *Db) TransferAllowance(fromId int, toId int, amount float64) error {
+	if fromId == toId {
+		return nil
+	}
+	amountCents := int(math.Round(amount * 100.0))
+	if amountCents <= 0 {
+		return fmt.Errorf("amount must be positive")
+	}
+
+	tx, err := db.db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.MustRollback()
+
+	// Fetch from allowance (user_id, balance)
+	var fromUserId int
+	var fromBalance int
+	err = tx.Query("select user_id, balance from allowances where id = ?").Bind(fromId).ScanSingle(&fromUserId, &fromBalance)
+	if err != nil {
+		return err
+	}
+
+	// Fetch to allowance (user_id, target, balance)
+	var toUserId int
+	var toTarget int
+	var toBalance int
+	err = tx.Query("select user_id, target, balance from allowances where id = ?").Bind(toId).ScanSingle(&toUserId, &toTarget, &toBalance)
+	if err != nil {
+		return err
+	}
+
+	// Ensure same owner
+	if fromUserId != toUserId {
+		return fmt.Errorf("allowances do not belong to the same user")
+	}
+
+	// Calculate how much the 'to' goal still needs
+	remainingTo := toTarget - toBalance
+	if remainingTo <= 0 {
+		// Nothing to transfer
+		return fmt.Errorf("target already reached")
+	}
+
+	// Limit transfer to what 'to' still needs
+	transfer := amountCents
+	if transfer > remainingTo {
+		transfer = remainingTo
+	}
+
+	// Ensure 'from' has enough balance
+	if fromBalance < transfer {
+		return fmt.Errorf("insufficient funds in source allowance")
+	}
+
+	// Perform updates
+	err = tx.Query("update allowances set balance = balance - ? where id = ? and user_id = ?").Bind(transfer, fromId, fromUserId).Exec()
+	if err != nil {
+		return err
+	}
+	err = tx.Query("update allowances set balance = balance + ? where id = ? and user_id = ?").Bind(transfer, toId, toUserId).Exec()
+	if err != nil {
+		return err
+	}
+
+	return tx.Commit()
+}

backend/dto.go

@@ -78,3 +78,10 @@ type AddAllowanceAmountRequest struct {
 	Amount      float64 `json:"amount"`
 	Description string  `json:"description"`
 }
+
+// TransferRequest represents a request to transfer amount between two goals.
+type TransferRequest struct {
+	From   int     `json:"from"`
+	To     int     `json:"to"`
+	Amount float64 `json:"amount"`
+}

backend/go.mod

@@ -4,9 +4,11 @@ go 1.24.2
 
 require (
 	gitea.seeseepuff.be/seeseemelk/mysqlite v0.14.0
+	github.com/adhocore/gronx v1.19.6
 	github.com/gavv/httpexpect/v2 v2.17.0
 	github.com/gin-contrib/cors v1.7.5
 	github.com/gin-gonic/gin v1.10.0
+	github.com/stretchr/testify v1.10.0
 )
 
 require (
@@ -47,7 +49,6 @@ require (
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
 	github.com/sanity-io/litter v1.5.8 // indirect
 	github.com/sergi/go-diff v1.3.1 // indirect
-	github.com/stretchr/testify v1.10.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.12 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect

backend/go.sum

@@ -2,6 +2,8 @@ gitea.seeseepuff.be/seeseemelk/mysqlite v0.14.0 h1:aRItVfUj48fBmuec7rm/jY9KCfvHW
 gitea.seeseepuff.be/seeseemelk/mysqlite v0.14.0/go.mod h1:cgswydOxJjMlNwfcBIXnKjr47LwXnMT9BInkiHb0tXE=
 github.com/TylerBrock/colorjson v0.0.0-20200706003622-8a50f05110d2 h1:ZBbLwSJqkHBuFDA6DUhhse0IGJ7T5bemHyNILUjvOq4=
 github.com/TylerBrock/colorjson v0.0.0-20200706003622-8a50f05110d2/go.mod h1:VSw57q4QFiWDbRnjdX8Cb3Ow0SFncRw+bA/ofY6Q83w=
+github.com/adhocore/gronx v1.19.6 h1:5KNVcoR9ACgL9HhEqCm5QXsab/gI4QDIybTAWcXDKDc=
+github.com/adhocore/gronx v1.19.6/go.mod h1:7oUY1WAU8rEJWmAxXR2DN0JaO4gi9khSgKjiRypqteg=
 github.com/ajg/form v1.5.1 h1:t9c7v8JUKu/XxOGBU0yjNpaMloxGEJhUkqFRq0ibGeU=
 github.com/ajg/form v1.5.1/go.mod h1:uL1WgH+h2mgNtvBq0339dVnzXdBETtL2LeUXaIv25UY=
 github.com/andybalholm/brotli v1.1.1 h1:PR2pgnyFznKEugtsUo0xLdDop5SKXd5Qf5ysW+7XdTA=

backend/main.go

@@ -4,13 +4,15 @@ import (
 	"context"
 	"embed"
 	"errors"
-	"gitea.seeseepuff.be/seeseemelk/mysqlite"
+	"fmt"
 	"log"
 	"net"
 	"net/http"
 	"os"
 	"strconv"
 
+	"gitea.seeseepuff.be/seeseemelk/mysqlite"
+
 	"github.com/gin-contrib/cors"
 	"github.com/gin-gonic/gin"
 )
@@ -436,6 +438,14 @@ func createTask(c *gin.Context) {
 		return
 	}
 
+	if taskRequest.Schedule != nil {
+		valid := gronx.IsValid(*taskRequest.Schedule)
+		if !valid {
+			c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("Invalid cron schedule: %s", *taskRequest.Schedule)})
+			return
+		}
+	}
+
 	// If assigned is not nil, check if user exists
 	if taskRequest.Assigned != nil {
 		exists, err := db.UserExists(*taskRequest.Assigned)
@@ -513,6 +523,11 @@ func putTask(c *gin.Context) {
 		c.JSON(http.StatusNotFound, gin.H{"error": "Task not found"})
 		return
 	}
+	if err != nil {
+		log.Printf("Error getting task: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": ErrInternalServerError})
+		return
+	}
 
 	err = db.UpdateTask(taskId, &taskRequest)
 	if err != nil {

common/api.yaml

@@ -409,6 +409,59 @@ paths:
         404:
           description: The task could not be found.
 
+  /api/transfer:
+    post:
+      summary: Transfer amount between allowances
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                from:
+                  type: integer
+                  description: Source allowance ID
+                to:
+                  type: integer
+                  description: Destination allowance ID
+                amount:
+                  type: number
+                  format: float
+                  description: Amount to transfer
+              required:
+                - from
+                - to
+                - amount
+      responses:
+        '200':
+          description: Transfer successful
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  message:
+                    type: string
+        '400':
+          description: Invalid request
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  error:
+                    type: string
+        '404':
+          description: Allowance not found
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  error:
+                    type: string
+
 components:
   schemas:
     task: