|
| 1 | +package coins |
| 2 | + |
| 3 | +import ( |
| 4 | + "fmt" |
| 5 | + "sort" |
| 6 | + "strings" |
| 7 | + |
| 8 | + bankv1beta1 "cosmossdk.io/api/cosmos/bank/v1beta1" |
| 9 | + basev1beta1 "cosmossdk.io/api/cosmos/base/v1beta1" |
| 10 | + "cosmossdk.io/math" |
| 11 | +) |
| 12 | + |
| 13 | +// formatCoin formats a sdk.Coin into a value-rendered string, using the |
| 14 | +// given metadata about the denom. It returns the formatted coin string, the |
| 15 | +// display denom, and an optional error. |
| 16 | +func formatCoin(coin *basev1beta1.Coin, metadata *bankv1beta1.Metadata) (string, error) { |
| 17 | + coinDenom := coin.Denom |
| 18 | + |
| 19 | + // Return early if no display denom or display denom is the current coin denom. |
| 20 | + if metadata == nil || metadata.Display == "" || coinDenom == metadata.Display { |
| 21 | + vr, err := math.FormatDec(coin.Amount) |
| 22 | + return vr + " " + coin.Denom, err |
| 23 | + } |
| 24 | + |
| 25 | + dispDenom := metadata.Display |
| 26 | + |
| 27 | + // Find exponents of both denoms. |
| 28 | + var coinExp, dispExp uint32 |
| 29 | + foundCoinExp, foundDispExp := false, false |
| 30 | + for _, unit := range metadata.DenomUnits { |
| 31 | + if coinDenom == unit.Denom { |
| 32 | + coinExp = unit.Exponent |
| 33 | + foundCoinExp = true |
| 34 | + } |
| 35 | + if dispDenom == unit.Denom { |
| 36 | + dispExp = unit.Exponent |
| 37 | + foundDispExp = true |
| 38 | + } |
| 39 | + } |
| 40 | + |
| 41 | + // If we didn't find either exponent, then we return early. |
| 42 | + if !foundCoinExp || !foundDispExp { |
| 43 | + vr, err := math.FormatInt(coin.Amount) |
| 44 | + return vr + " " + coin.Denom, err |
| 45 | + } |
| 46 | + |
| 47 | + exponentDiff := int64(coinExp) - int64(dispExp) |
| 48 | + |
| 49 | + dispAmount, err := math.LegacyNewDecFromStr(coin.Amount) |
| 50 | + if err != nil { |
| 51 | + return "", err |
| 52 | + } |
| 53 | + |
| 54 | + if exponentDiff > 0 { |
| 55 | + dispAmount = dispAmount.Mul(math.LegacyNewDec(10).Power(uint64(exponentDiff))) |
| 56 | + } else { |
| 57 | + dispAmount = dispAmount.Quo(math.LegacyNewDec(10).Power(uint64(-exponentDiff))) |
| 58 | + } |
| 59 | + |
| 60 | + vr, err := math.FormatDec(dispAmount.String()) |
| 61 | + return vr + " " + dispDenom, err |
| 62 | +} |
| 63 | + |
| 64 | +// formatCoins formats Coins into a value-rendered string, which uses |
| 65 | +// `formatCoin` separated by ", " (a comma and a space), and sorted |
| 66 | +// alphabetically by value-rendered denoms. It expects an array of metadata |
| 67 | +// (optionally nil), where each metadata at index `i` MUST match the coin denom |
| 68 | +// at the same index. |
| 69 | +func FormatCoins(coins []*basev1beta1.Coin, metadata []*bankv1beta1.Metadata) (string, error) { |
| 70 | + if len(coins) != len(metadata) { |
| 71 | + return "", fmt.Errorf("formatCoins expect one metadata for each coin; expected %d, got %d", len(coins), len(metadata)) |
| 72 | + } |
| 73 | + |
| 74 | + formatted := make([]string, len(coins)) |
| 75 | + for i, coin := range coins { |
| 76 | + var err error |
| 77 | + formatted[i], err = formatCoin(coin, metadata[i]) |
| 78 | + if err != nil { |
| 79 | + return "", err |
| 80 | + } |
| 81 | + } |
| 82 | + |
| 83 | + // Sort the formatted coins by display denom. |
| 84 | + sort.SliceStable(formatted, func(i, j int) bool { |
| 85 | + denomI := strings.Split(formatted[i], " ")[1] |
| 86 | + denomJ := strings.Split(formatted[j], " ")[1] |
| 87 | + |
| 88 | + return denomI < denomJ |
| 89 | + }) |
| 90 | + |
| 91 | + return strings.Join(formatted, ", "), nil |
| 92 | +} |
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