RpgRoller/RpgRoller/Services/RollBreakdownFormatter.cs

namespace RpgRoller.Services;

public static class RollBreakdownFormatter
{
    public static string BuildBreakdown(IEnumerable<int> diceValues, int modifier, int total)
    {
        var dicePart = string.Join("+", diceValues);
        if (string.IsNullOrWhiteSpace(dicePart))
            dicePart = "0";

        return BuildModifierBreakdown(dicePart, modifier, total);
    }

    public static string BuildRolemasterOpenEndedBreakdown(int initialRoll, IReadOnlyList<int> followUpRolls, bool subtractFollowUps, int modifier, int total)
    {
        if (subtractFollowUps)
        {
            var segments = new List<string> { $"({FormatRolemasterTriggerRoll(initialRoll)})" };
            segments.AddRange(followUpRolls.Select(roll => $"-{roll}"));
            if (modifier > 0)
                segments.Add($"+{modifier}");
            else if (modifier < 0)
                segments.Add(modifier.ToString());

            return $"{string.Join(" ", segments)} = {total}";
        }

        var core = initialRoll.ToString();
        if (followUpRolls.Count > 0)
        {
            var followUpBreakdown = string.Join("+", followUpRolls);
            core = $"{core}+{followUpBreakdown}";
        }

        return BuildModifierBreakdown(core, modifier, total);
    }

    public static string BuildRolemasterRetryBreakdown(string firstAttemptBreakdown, int retryBonus, string retryAttemptBreakdown, int finalTotal)
    {
        return $"{firstAttemptBreakdown}; retry(+{retryBonus}): {retryAttemptBreakdown}; final={finalTotal}";
    }

    public static string FormatRolemasterTriggerRoll(int roll)
    {
        return roll.ToString("00");
    }

    public static string BuildModifierBreakdown(string core, int modifier, int total)
    {
        return modifier switch
        {
            > 0 => $"{core}+{modifier}={total}",
            < 0 => $"{core}{modifier}={total}",
            _   => $"{core}={total}"
        };
    }
}