#nullable enable

using System;
using System.Security.Cryptography;
using System.Text;

namespace ReplacedPerson.Core
{
    public static class ReplacedStateHasher
    {
        public static string Compute(ReplacedMatchState state, Pcg32 random)
        {
            var text = new StringBuilder(2048);
            text.Append(state.Round).Append('|').Append(state.LeadPlayer).Append('|').Append(state.InitiativeRoll)
                .Append('|').Append((int)state.Phase).Append('|').Append((int)state.Winner).Append('|')
                .Append(state.IsLastStand ? 1 : 0).Append('|').Append(state.LastStandUsed ? 1 : 0).Append('|')
                .Append(state.ContentHash).Append('|').Append(random.State).Append('|').Append(random.Increment).Append('\n');
            for (var index = 0; index < state.Players.Length; index++)
            {
                var player = state.Players[index];
                text.Append(index).Append('|').Append(player.PlayerId).Append('|').Append(player.Health).Append('|')
                    .Append(player.Cost).Append('|').Append(player.Defense).Append('|').Append(player.BonusNormalDraw)
                    .Append('|').Append(player.GuaranteedDodge ? 1 : 0).Append('|').Append(player.SkipNextEndDraw ? 1 : 0)
                    .Append('|').Append(player.SpentThisRound).Append('|').Append(player.EffectiveEffectsThisRound)
                    .Append('|').Append(player.DamageThisRound).Append('\n');
                AppendList(text, player.NormalDrawPile);
                AppendList(text, player.NormalDiscard);
                AppendList(text, player.NormalHand);
                AppendList(text, player.EndDrawPile);
                AppendList(text, player.EndDiscard);
                AppendList(text, player.EndHand);
            }
            for (var i = 0; i < state.LastAcceptedSequence.Length; i++)
                text.Append("S|").Append(i).Append('|').Append(state.LastAcceptedSequence[i]).Append('\n');
            for (var i = 0; i < state.Submissions.Length; i++)
            {
                var submission = state.Submissions[i];
                text.Append("C|").Append(i).Append('|');
                if (submission == null)
                {
                    text.Append("null\n");
                    continue;
                }
                text.Append(submission.Pass ? 1 : 0).Append('|').Append(submission.DiscardEndOnPass ? 1 : 0)
                    .Append('|').Append(submission.RerollSlot).Append('|');
                AppendList(text, submission.NormalCardIds);
                AppendList(text, submission.EndCardIds);
            }
            foreach (var resolution in state.LastResolution)
            {
                text.Append("R|").Append(resolution.SlotIndex).Append('|').Append((int)resolution.PlayerOneType).Append('|')
                    .Append((int)resolution.PlayerTwoType).Append('|').Append(resolution.PlayerOneRoll).Append('|')
                    .Append(resolution.PlayerTwoRoll).Append('|').Append(resolution.PlayerOneValue).Append('|')
                    .Append(resolution.PlayerTwoValue).Append('|').Append(resolution.PlayerOneRerolled ? 1 : 0).Append('|')
                    .Append(resolution.PlayerTwoRerolled ? 1 : 0).Append('|').Append(resolution.DamageToPlayerOne).Append('|')
                    .Append(resolution.DamageToPlayerTwo).Append('|').Append(resolution.Summary).Append('\n');
            }

            using var sha = SHA256.Create();
            var bytes = sha.ComputeHash(Encoding.UTF8.GetBytes(text.ToString()));
            var result = new StringBuilder(bytes.Length * 2);
            foreach (var value in bytes) result.Append(value.ToString("x2"));
            return result.ToString();
        }

        private static void AppendList(StringBuilder target, System.Collections.Generic.IEnumerable<string> values) =>
            target.Append('[').Append(string.Join(",", values)).Append("]\n");
    }
}