settlers/cmd/settlersd/subtract.go

package main

import (
	"encoding/json"
	"net/http"

	"github.com/bvinc/go-sqlite-lite/sqlite3"
	"git.sporestack.com/SporeStack/settlers"
)

func subtract(token string, amount uint64, db *sqlite3.Conn) (userErr, err error) {
	if userErr = settlers.ValidateToken(token); userErr != nil {
		return
	}

	// Check if account is enabled.
	_, userErr, err = balance(token, db)
	if userErr != nil || err != nil {
		return
	}

	// sqlite3 only supports signed integers
	var signedAmount int64
	signedAmount = int64(amount)
	userErr = db.Exec("UPDATE balances SET balance = balance - ? WHERE combined_token = ?", signedAmount, token)
	if userErr != nil {
		userErr = settlers.ErrorInsufficientBalance
	}

	return
}

func httpSubtract(w http.ResponseWriter, r *http.Request, db *sqlite3.Conn) {
	defer r.Body.Close()

	var request settlers.SubtractRequest
	decoder := json.NewDecoder(r.Body)
	decoder.DisallowUnknownFields()
	userErr := decoder.Decode(&request)
	if userErr != nil {
		httpHandle400(w, userErr)
		return
	}

	userErr, err := subtract(request.CombinedToken, request.Amount, db)
	if userErr != nil {
		httpHandle400(w, userErr)
		return
	}
	if err != nil {
		httpHandle500(w, err)
		return
	}
	return
}