first commit

provider/gotext/provider.go

@@ -0,0 +1,108 @@
+package gotext
+
+import (
+	"context"
+
+	"gitoa.ru/go-4devs/translation"
+	"gitoa.ru/go-4devs/translation/arg"
+	"golang.org/x/text/currency"
+	"golang.org/x/text/language"
+	"golang.org/x/text/message"
+	"golang.org/x/text/message/catalog"
+	"golang.org/x/text/number"
+)
+
+var _ translation.Provider = (*Provider)(nil)
+
+// Option confires message provider.
+type Option func(*Provider)
+
+// WithCatalog set coatalog bu domain name.
+func WithCatalog(domain string, cat catalog.Catalog) Option {
+	return func(mp *Provider) {
+		mp.catalog[domain] = cat
+	}
+}
+
+// NewProvider creates new messgae provider.
+func NewProvider(opts ...Option) *Provider {
+	mp := &Provider{
+		catalog: map[string]catalog.Catalog{
+			translation.DefaultDomain: message.DefaultCatalog,
+		},
+	}
+
+	for _, o := range opts {
+		o(mp)
+	}
+
+	return mp
+}
+
+// Provider provider messages.
+type Provider struct {
+	catalog map[string]catalog.Catalog
+}
+
+// Translate by key and args.
+func (mp *Provider) Translate(ctx context.Context, key string, opt translation.Translate) string {
+	return message.NewPrinter(opt.Locale, message.Catalog(mp.catalog[opt.Domain])).
+		Sprintf(key, messageArgs(opt.Locale, opt.Args)...)
+}
+
+func currencyMessage(lang language.Tag) func(v arg.Currency) interface{} {
+	return func(v arg.Currency) interface{} {
+		var u currency.Unit
+
+		if v.ISO != "" {
+			u, _ = currency.ParseISO(v.ISO)
+		} else {
+			u, _ = currency.FromTag(lang)
+		}
+
+		switch v.Format {
+		case arg.CurrencyFormatISO:
+			return currency.ISO(u.Amount(v.Val()))
+		case arg.CurrencyFormatSymbol:
+			return currency.Symbol(u.Amount(v.Val()))
+		case arg.CurrencyFormatNarrowSymbol:
+			return currency.NarrowSymbol(u.Amount(v.Val()))
+		}
+
+		return u.Amount(v.Val())
+	}
+}
+
+func numberMessage(v arg.Number) interface{} {
+	switch v.Format {
+	case arg.NumberFormatPercent:
+		return number.Percent(v.Val())
+	case arg.NumberFormatEngineering:
+		return number.Engineering(v.Val())
+	case arg.NumberFormatPerMille:
+		return number.PerMille(v.Val())
+	case arg.NumberFormatDecimal:
+		return number.Decimal(v.Val())
+	case arg.NumberFormatScientific:
+		return number.Scientific(v.Val())
+	}
+
+	return v.Val()
+}
+
+func messageArgs(lang language.Tag, in []translation.Arg) []interface{} {
+	out := make([]interface{}, 0, len(in))
+
+	for _, a := range in {
+		switch v := a.(type) {
+		case arg.Currency:
+			out = append(out, currencyMessage(lang)(v))
+		case arg.Number:
+			out = append(out, numberMessage(v))
+		default:
+			out = append(out, v.Val())
+		}
+	}
+
+	return out
+}