using System;
using System.Collections.Generic;

namespace NightclubArcadia.Skills
{
    /// <summary>
    /// Pure rank state. No rolling, DC comparison, modifier math, UI, or Yarn.
    /// </summary>
    public sealed class PlayerSkills
    {
        readonly Dictionary<string, int> _ranks =
            new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);

        public PlayerSkills(SkillDatabase db)
        {
            if (db == null)
            {
                throw new ArgumentNullException(nameof(db));
            }

            foreach (var skill in db.All)
            {
                if (skill == null || string.IsNullOrEmpty(skill.Id))
                {
                    continue;
                }

                _ranks[skill.Id] = skill.StartingRank;
            }
        }

        public IReadOnlyDictionary<string, int> AllRanks => _ranks;

        public int GetRank(string skillId)
        {
            if (string.IsNullOrEmpty(skillId))
            {
                return 0;
            }

            return _ranks.TryGetValue(skillId, out var rank) ? rank : 0;
        }

        public void SetRank(string skillId, int rank)
        {
            if (string.IsNullOrEmpty(skillId))
            {
                throw new ArgumentException("Skill id is required.", nameof(skillId));
            }

            _ranks[skillId] = rank;
        }
    }
}