package model

import (
	"sort"
	"strings"

	"git.sendico.io/tech/sxchnge/bff/pkg/merrors"
	"git.sendico.io/tech/sxchnge/bff/pkg/moneybase"
)

type Currency string

const (
	CurrencyEUR  Currency = "EUR"  // Euro
	CurrencyUSD  Currency = "USD"  // US Dollar
	CurrencyRUB  Currency = "RUB"  // Russian Ruble
	CurrencyUAH  Currency = "UAH"  // Ukrainian Hryvnia
	CurrencyPLN  Currency = "PLN"  // Polish Złoty
	CurrencyCZK  Currency = "CZK"  // Czech Koruna
	CurrencyUSDT Currency = "USDT" // Tether USD
)

const MaxCurrencyScale uint32 = moneybase.MaxScale

func NormalizeCurrency(value string) Currency {
	return Currency(strings.ToUpper(strings.TrimSpace(value)))
}

func NormalizeExplicitCurrencyScales(values map[Currency]uint32) (map[Currency]uint32, error) {
	if len(values) == 0 {
		return nil, merrors.InvalidArgument("currency scales are required")
	}
	out := make(map[Currency]uint32, len(values))
	for rawCurrency, scale := range values {
		currency := NormalizeCurrency(string(rawCurrency))
		if currency == "" {
			return nil, merrors.InvalidArgument("currency scale key is required")
		}
		if scale > MaxCurrencyScale {
			return nil, merrors.InvalidArgumentf("currency scale for %s exceeds %d", currency, MaxCurrencyScale)
		}
		out[currency] = scale
	}
	return out, nil
}

func CurrencyScale(scales map[Currency]uint32, currency string) (uint32, error) {
	normalized := NormalizeCurrency(currency)
	if normalized == "" {
		return 0, merrors.InvalidArgument("currency is required")
	}
	if scales == nil {
		return 0, merrors.InvalidArgument("currency scale map is required")
	}
	scale, ok := scales[normalized]
	if !ok {
		return 0, merrors.InvalidArgument("currency scale for " + string(normalized) + " is not configured")
	}
	return scale, nil
}

func CurrencyScaleKeys(scales map[Currency]uint32) []string {
	if scales == nil {
		return nil
	}
	keys := make([]string, 0, len(scales))
	for currency := range scales {
		keys = append(keys, string(currency))
	}
	sort.Strings(keys)
	return keys
}

type Amount struct {
	Total    float64  `bson:"total" json:"total"`       // Total amount billed
	Currency Currency `bson:"currency" json:"currency"` // Currency for the invoice
}