using System.Collections.Generic;
using System.Text;

using UnityEngine;

using Colosseum.Skills;
using Colosseum.Stats;

namespace Colosseum.Passives
{
    /// <summary>
    /// 패시브 노드와 효과를 UI 친화적인 문자열로 변환합니다.
    /// </summary>
    public static class PassivePresentationUtility
    {
        public static string GetBranchLabel(PassiveNodeBranch branch)
        {
            return branch switch
            {
                PassiveNodeBranch.Common => "공통",
                PassiveNodeBranch.Attack => "공격",
                PassiveNodeBranch.Defense => "방어",
                PassiveNodeBranch.Support => "지원",
                PassiveNodeBranch.Bridge => "연결",
                _ => "미분류",
            };
        }

        public static string GetNodeKindLabel(PassiveNodeKind nodeKind)
        {
            return nodeKind switch
            {
                PassiveNodeKind.Hub => "허브",
                PassiveNodeKind.Axis => "축 노드",
                PassiveNodeKind.Bridge => "브릿지",
                PassiveNodeKind.Capstone => "완성 노드",
                _ => "노드",
            };
        }

        public static string GetAxisSummary(PassiveAxisMask axisMask)
        {
            if (axisMask == PassiveAxisMask.None)
                return "중립";

            if (axisMask == PassiveAxisMask.All)
                return "공격 / 방어 / 지원";

            List<string> labels = new();
            if ((axisMask & PassiveAxisMask.Attack) != 0)
                labels.Add("공격");
            if ((axisMask & PassiveAxisMask.Defense) != 0)
                labels.Add("방어");
            if ((axisMask & PassiveAxisMask.Support) != 0)
                labels.Add("지원");

            return labels.Count > 0 ? string.Join(" / ", labels) : "중립";
        }

        public static string GetStatLabel(StatType statType)
        {
            return statType switch
            {
                StatType.Strength => "근력 (STR)",
                StatType.Dexterity => "민첩 (DEX)",
                StatType.Intelligence => "지능 (INT)",
                StatType.Vitality => "활력 (VIT)",
                StatType.Wisdom => "지혜 (WIS)",
                StatType.Spirit => "정신 (SPI)",
                _ => "알 수 없는 스탯",
            };
        }

        public static string BuildNodeSummary(PassiveNodeData node)
        {
            if (node == null)
                return string.Empty;

            StringBuilder builder = new StringBuilder();
            builder.Append(node.DisplayName);
            builder.Append('\n');
            builder.Append(GetAxisSummary(node.AxisMask));
            builder.Append(" | 비용 ");
            builder.Append(node.Cost);

            string effectSummary = BuildEffectSummary(node);
            if (!string.IsNullOrWhiteSpace(effectSummary))
            {
                builder.Append('\n');
                builder.Append(effectSummary);
            }

            return builder.ToString();
        }

        public static string BuildNodeDetail(PassiveNodeData node)
        {
            if (node == null)
                return "노드를 선택하면 설명을 표시합니다.";

            StringBuilder builder = new StringBuilder();
            builder.AppendLine($"{node.DisplayName} [{GetBranchLabel(node.Branch)}]");
            builder.AppendLine($"{GetNodeKindLabel(node.NodeKind)} | 축: {GetAxisSummary(node.AxisMask)}");
            builder.AppendLine($"티어 {node.Tier} | 비용 {node.Cost}");

            if (!string.IsNullOrWhiteSpace(node.Description))
            {
                builder.AppendLine();
                builder.AppendLine(node.Description.Trim());
            }

            if (node.Effects != null && node.Effects.Count > 0)
            {
                builder.AppendLine();
                builder.AppendLine("효과");
                for (int i = 0; i < node.Effects.Count; i++)
                {
                    PassiveEffectEntry effect = node.Effects[i];
                    if (effect == null)
                        continue;

                    builder.Append("• ");
                    builder.AppendLine(GetEffectLabel(effect));
                }
            }

            if (node.PrerequisiteNodes != null && node.PrerequisiteNodes.Count > 0)
            {
                builder.AppendLine();
                builder.AppendLine("선행 노드");
                for (int i = 0; i < node.PrerequisiteNodes.Count; i++)
                {
                    PassiveNodeData prerequisiteNode = node.PrerequisiteNodes[i];
                    if (prerequisiteNode == null)
                        continue;

                    builder.Append("• ");
                    builder.AppendLine(prerequisiteNode.DisplayName);
                }
            }

            return builder.ToString().TrimEnd();
        }

        public static string BuildEffectSummary(PassiveNodeData node)
        {
            if (node?.Effects == null || node.Effects.Count <= 0)
                return "효과 없음";

            StringBuilder builder = new StringBuilder();
            int writtenCount = 0;

            for (int i = 0; i < node.Effects.Count; i++)
            {
                PassiveEffectEntry effect = node.Effects[i];
                if (effect == null)
                    continue;

                if (writtenCount > 0)
                    builder.Append(" / ");

                builder.Append(GetEffectLabel(effect));
                writtenCount++;
            }

            return writtenCount > 0 ? builder.ToString() : "효과 없음";
        }

        public static string GetEffectLabel(PassiveEffectEntry effect)
        {
            if (effect == null)
                return string.Empty;

            string label = effect.EffectType switch
            {
                PassiveEffectType.StatModifier => BuildStatModifierLabel(effect),
                PassiveEffectType.DamageMultiplier => $"공격 피해 {FormatMultiplierDelta(effect.Value)}",
                PassiveEffectType.HealMultiplier => $"회복량 {FormatMultiplierDelta(effect.Value)}",
                PassiveEffectType.ShieldDoneMultiplier => $"보호막 부여량 {FormatMultiplierDelta(effect.Value)}",
                PassiveEffectType.ShieldReceivedMultiplier => $"보호막 수혜량 {FormatMultiplierDelta(effect.Value)}",
                PassiveEffectType.ThreatGeneratedMultiplier => $"위협 생성 {FormatMultiplierDelta(effect.Value)}",
                PassiveEffectType.IncomingDamageMultiplier => $"받는 피해 {FormatMultiplierDelta(effect.Value)}",
                PassiveEffectType.ManaCostMultiplier => $"마나 비용 {FormatMultiplierDelta(effect.Value)}",
                _ => $"알 수 없는 효과 ({effect.EffectType})",
            };

            if (effect.SkillRoleMask != SkillRoleType.None && effect.SkillRoleMask != SkillRoleType.All)
            {
                label += $" ({SkillClassificationUtility.GetAllowedRoleSummary(effect.SkillRoleMask)} 스킬 한정)";
            }

            return label;
        }

        private static string BuildStatModifierLabel(PassiveEffectEntry effect)
        {
            string statLabel = GetStatLabel(effect.StatType);

            return effect.ModType switch
            {
                StatModType.Flat => $"{statLabel} {FormatFlatValue(effect.Value)}",
                StatModType.PercentAdd => $"{statLabel} {FormatSignedPercent(effect.Value * 100f)}",
                StatModType.PercentMult => $"{statLabel} {FormatSignedPercent((effect.Value - 1f) * 100f)}",
                _ => $"{statLabel} {effect.Value:0.##}",
            };
        }

        private static string FormatMultiplierDelta(float multiplier)
        {
            return FormatSignedPercent((multiplier - 1f) * 100f);
        }

        private static string FormatSignedPercent(float percentValue)
        {
            string sign = percentValue >= 0f ? "+" : string.Empty;
            return $"{sign}{percentValue:0.##}%";
        }

        private static string FormatFlatValue(float value)
        {
            string sign = value >= 0f ? "+" : string.Empty;
            return $"{sign}{value:0.##}";
        }
    }
}