using System.Collections.Generic;
using GeometryTD.Procedure;

namespace GeometryTD.UI
{
    public sealed class NodeMapFormUseCase : IUIUseCase
    {
        private RunState _runState;

        public void SetRunState(RunState runState)
        {
            _runState = runState;
        }

        public NodeMapFormRawData CreateInitialModel()
        {
            return BuildRawData(_runState);
        }

        public bool TryRequestEnterNode(int sequenceIndex, out NodeMapNodeRawData selectedNode, out NodeMapFormRawData latestRawData)
        {
            latestRawData = BuildRawData(_runState);
            selectedNode = null;

            if (_runState == null || _runState.IsCompleted)
            {
                return false;
            }

            RunNodeState currentNode = _runState.CurrentNode;
            if (currentNode == null || currentNode.SequenceIndex != sequenceIndex || !_runState.CanEnterCurrentNode)
            {
                return false;
            }

            RunNodeState targetNode = _runState.GetNodeBySequenceIndex(sequenceIndex);
            if (targetNode == null || targetNode.Status != RunNodeStatus.Available)
            {
                return false;
            }

            selectedNode = BuildNodeRawData(_runState.RunId, targetNode, currentNode.SequenceIndex);
            return selectedNode != null && selectedNode.CanEnter;
        }

        private static NodeMapFormRawData BuildRawData(RunState runState)
        {
            if (runState == null)
            {
                return new NodeMapFormRawData
                {
                    Title = "节点地图",
                    ProgressText = "0 / 0",
                    CurrentNodeText = "当前节点: 无",
                    IsRunCompleted = true,
                    Nodes = new List<NodeMapNodeRawData>()
                };
            }

            List<NodeMapNodeRawData> nodes = new List<NodeMapNodeRawData>(runState.NodeCount);
            int currentSequenceIndex = runState.CurrentNode != null ? runState.CurrentNode.SequenceIndex : -1;
            foreach (RunNodeState node in runState.Nodes)
            {
                NodeMapNodeRawData nodeRawData = BuildNodeRawData(runState.RunId, node, currentSequenceIndex);
                if (nodeRawData != null)
                {
                    nodes.Add(nodeRawData);
                }
            }

            string currentNodeText = runState.IsCompleted
                ? "当前节点: 已完成"
                : $"当前节点: {BuildNodeTitle(runState.CurrentNode)}";

            return new NodeMapFormRawData
            {
                RunId = runState.RunId,
                Title = "节点地图",
                ProgressText = $"{runState.CompletedNodeCount} / {runState.NodeCount}",
                CurrentNodeText = currentNodeText,
                IsRunCompleted = runState.IsCompleted,
                Nodes = nodes
            };
        }

        private static NodeMapNodeRawData BuildNodeRawData(string runId, RunNodeState node, int currentSequenceIndex)
        {
            if (node == null)
            {
                return null;
            }

            bool isCurrentNode = node.SequenceIndex == currentSequenceIndex;
            bool canEnter = isCurrentNode && node.Status == RunNodeStatus.Available;

            return new NodeMapNodeRawData
            {
                RunId = runId,
                NodeId = node.NodeId,
                SequenceIndex = node.SequenceIndex,
                NodeType = node.NodeType,
                Status = node.Status,
                IsCurrentNode = isCurrentNode,
                CanEnter = canEnter,
                Title = BuildNodeTitle(node),
                StatusText = BuildStatusText(node.Status, canEnter)
            };
        }

        private static string BuildNodeTitle(RunNodeState node)
        {
            return node == null ? "未知节点" : BuildNodeTitle(node.NodeType);
        }

        private static string BuildNodeTitle(RunNodeType nodeType)
        {
            switch (nodeType)
            {
                case RunNodeType.Combat:
                    return "战斗";
                case RunNodeType.Event:
                    return "事件";
                case RunNodeType.Shop:
                    return "商店";
                case RunNodeType.BossCombat:
                    return "Boss";
                default:
                    return "未知节点";
            }
        }

        private static string BuildStatusText(RunNodeStatus status, bool canEnter)
        {
            if (canEnter)
            {
                return "当前";
            }

            switch (status)
            {
                case RunNodeStatus.Locked:
                    return "未解锁";
                case RunNodeStatus.Available:
                    return "可进入";
                case RunNodeStatus.Completed:
                    return "已完成";
                case RunNodeStatus.Failed:
                    return "失败";
                case RunNodeStatus.Skipped:
                    return "跳过";
                default:
                    return string.Empty;
            }
        }
    }
}