feat: user defined currencies (#700)

* basic currency service for loading at runtime

* api endpoint for currencies

* sort slice before return

* remove currency validation

* validate using currency service

* implement selecting dynamic currency options

* bump go version

* fix type definition

* specify explicit type

* change go versions

* proper types for assetId

* log/return currency error

* make case insensative

* use ToUpper instead

* feat: adding new currencies (#715)

* fix: task swag (#710)

Co-authored-by: Quoing <pavel.cadersky@mavenir.com>

* [feat] Adding new currencies

---------

Co-authored-by: quoing <quoing@users.noreply.github.com>
Co-authored-by: Quoing <pavel.cadersky@mavenir.com>
Co-authored-by: Bradley <41597815+userbradley@users.noreply.github.com>

* remove ts file and consoldate new values into json

* move flag to options namespace

* add env config for currencies

* basic documentaion

* remove in sync test

---------

Co-authored-by: quoing <quoing@users.noreply.github.com>
Co-authored-by: Quoing <pavel.cadersky@mavenir.com>
Co-authored-by: Bradley <41597815+userbradley@users.noreply.github.com>
Former-commit-id: c4b923847a1b695dcddd1b346adcccfd3f3ce706

backend/internal/core/currencies/currencies.go

@@ -0,0 +1,99 @@
+// Package currencies provides a shared definition of currencies. This uses a global
+// variable to hold the currencies.
+package currencies
+
+import (
+	"bytes"
+	_ "embed"
+	"encoding/json"
+	"io"
+	"slices"
+	"strings"
+	"sync"
+)
+
+//go:embed currencies.json
+var defaults []byte
+
+type CollectorFunc func() ([]Currency, error)
+
+func CollectJSON(reader io.Reader) CollectorFunc {
+	return func() ([]Currency, error) {
+		var currencies []Currency
+		err := json.NewDecoder(reader).Decode(&currencies)
+		if err != nil {
+			return nil, err
+		}
+
+		return currencies, nil
+	}
+}
+
+func CollectDefaults() CollectorFunc {
+	return CollectJSON(bytes.NewReader(defaults))
+}
+
+func CollectionCurrencies(collectors ...CollectorFunc) ([]Currency, error) {
+	out := make([]Currency, 0, len(collectors))
+	for i := range collectors {
+		c, err := collectors[i]()
+		if err != nil {
+			return nil, err
+		}
+
+		out = append(out, c...)
+	}
+
+	return out, nil
+}
+
+type Currency struct {
+	Name   string `json:"name"`
+	Code   string `json:"code"`
+	Local  string `json:"local"`
+	Symbol string `json:"symbol"`
+}
+
+type CurrencyRegistry struct {
+	mu       sync.RWMutex
+	registry map[string]Currency
+}
+
+func NewCurrencyService(currencies []Currency) *CurrencyRegistry {
+	registry := make(map[string]Currency, len(currencies))
+	for i := range currencies {
+		registry[currencies[i].Code] = currencies[i]
+	}
+
+	return &CurrencyRegistry{
+		registry: registry,
+	}
+}
+
+func (cs *CurrencyRegistry) Slice() []Currency {
+	cs.mu.RLock()
+	defer cs.mu.RUnlock()
+
+	keys := make([]string, 0, len(cs.registry))
+	for key := range cs.registry {
+		keys = append(keys, key)
+	}
+
+	slices.Sort(keys)
+
+	out := make([]Currency, 0, len(cs.registry))
+	for i := range keys {
+		out = append(out, cs.registry[keys[i]])
+	}
+
+	return out
+}
+
+func (cs *CurrencyRegistry) IsSupported(code string) bool {
+	upper := strings.ToUpper(code)
+
+	cs.mu.RLock()
+	defer cs.mu.RUnlock()
+	_, ok := cs.registry[upper]
+	return ok
+}