using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using AibisDream.SaveSystem;
using AibisDream.Utility;
using Newtonsoft.Json;

namespace AibisDream
{
    /// <summary>读取并严格校验项目内可提交的开发检查点清单。</summary>
    public static class DevSaveCatalog
    {
        public const int CurrentVersion = 1;
        private const string CatalogFileName = "catalog.json";
        public static string LastError { get; private set; }

        public static List<DevSaveSection> Load(string root)
        {
            LastError = null;
            var result = new List<DevSaveSection>();
            var catalogPath = Path.Combine(root ?? string.Empty, CatalogFileName);
            if (string.IsNullOrWhiteSpace(root) || !File.Exists(catalogPath))
            {
                LastError = $"找不到测试存档清单：{catalogPath}";
                return result;
            }

            DevSaveCatalogDto catalog;
            try
            {
                catalog = JsonConvert.DeserializeObject<DevSaveCatalogDto>(File.ReadAllText(catalogPath));
            }
            catch (Exception ex)
            {
                LastError = $"清单 JSON 损坏：{ex.Message}";
                return result;
            }

            if (catalog == null || catalog.catalogVersion != CurrentVersion)
            {
                LastError = $"不支持的清单版本：{catalog?.catalogVersion.ToString() ?? "none"}";
                return result;
            }

            foreach (var sectionDto in (catalog.sections ?? new List<DevSaveCatalogSectionDto>())
                         .OrderBy(section => section.order))
            {
                if (string.IsNullOrWhiteSpace(sectionDto.id)) continue;
                var entries = (sectionDto.entries ?? new List<DevSaveCatalogEntryDto>())
                    .OrderBy(entry => entry.order)
                    .Select(entry => BuildEntry(root, sectionDto, entry))
                    .ToList();
                result.Add(new DevSaveSection(
                    sectionDto.id,
                    string.IsNullOrWhiteSpace(sectionDto.title) ? sectionDto.id : sectionDto.title,
                    entries));
            }

            return result;
        }

        private static DevSaveEntry BuildEntry(string root, DevSaveCatalogSectionDto section, DevSaveCatalogEntryDto dto)
        {
            var error = ValidateRelativePath(root, dto.path, out var entryDirectory);
            var snapshotPath = error == null
                ? Path.Combine(entryDirectory, ConstRef.SaveSnapshotFileName)
                : string.Empty;
            var entry = new DevSaveEntry(
                dto.order,
                string.IsNullOrWhiteSpace(dto.label) ? dto.anchorNode : dto.label,
                dto.anchorNode,
                snapshotPath,
                section.expectedSceneName,
                section.expectedSceneSoName,
                section.expectedYarnProjectId,
                error);
            entry.Validate();
            return entry;
        }

        private static string ValidateRelativePath(string root, string relativePath, out string fullPath)
        {
            fullPath = null;
            if (string.IsNullOrWhiteSpace(relativePath)) return "清单路径为空";
            if (Path.IsPathRooted(relativePath)) return "清单路径必须是相对路径";

            try
            {
                var rootFull = Path.GetFullPath(root).TrimEnd(Path.DirectorySeparatorChar)
                               + Path.DirectorySeparatorChar;
                fullPath = Path.GetFullPath(Path.Combine(root, relativePath.Replace('/', Path.DirectorySeparatorChar)));
                if (!fullPath.StartsWith(rootFull, StringComparison.OrdinalIgnoreCase))
                    return "清单路径越过 DevSaveFiles 根目录";
                return null;
            }
            catch (Exception ex)
            {
                return $"清单路径无效：{ex.Message}";
            }
        }
    }

    public sealed class DevSaveSection
    {
        public string Id { get; }
        public string Title { get; }
        public List<DevSaveEntry> Entries { get; }

        public DevSaveSection(string id, string title, List<DevSaveEntry> entries)
        {
            Id = id;
            Title = title;
            Entries = entries ?? new List<DevSaveEntry>();
        }
    }

    public sealed class DevSaveEntry
    {
        public int Order { get; }
        public string Label { get; }
        public string AnchorNode { get; }
        public string SnapshotPathWithoutExtension { get; }
        public bool IsValid => string.IsNullOrEmpty(Error);
        public string Error { get; private set; }
        public SaveSnapshot Snapshot { get; private set; }

        private readonly string _expectedSceneName;
        private readonly string _expectedSceneSoName;
        private readonly string _expectedYarnProjectId;

        public DevSaveEntry(
            int order,
            string label,
            string anchorNode,
            string snapshotPathWithoutExtension,
            string expectedSceneName,
            string expectedSceneSoName,
            string expectedYarnProjectId,
            string initialError = null)
        {
            Order = order;
            Label = label ?? string.Empty;
            AnchorNode = anchorNode ?? string.Empty;
            SnapshotPathWithoutExtension = snapshotPathWithoutExtension;
            _expectedSceneName = expectedSceneName;
            _expectedSceneSoName = expectedSceneSoName;
            _expectedYarnProjectId = expectedYarnProjectId;
            Error = initialError;
        }

        public void Validate()
        {
            if (!string.IsNullOrEmpty(Error)) return;
            if (string.IsNullOrEmpty(SnapshotPathWithoutExtension)
                || !File.Exists(SnapshotPathWithoutExtension + ".json"))
            {
                Error = "存档文件缺失";
                return;
            }

            try
            {
                Snapshot = SnapshotPersistence.Load(SnapshotPathWithoutExtension);
            }
            catch (Exception ex)
            {
                Error = $"JSON 无法读取：{ex.Message}";
                return;
            }

            if (Snapshot == null || Snapshot.schemaVersion != SaveSnapshotSchema.CurrentVersion)
                Error = $"存档版本不兼容：{Snapshot?.schemaVersion.ToString() ?? "none"}";
            else if (Snapshot.scene == null || string.IsNullOrWhiteSpace(Snapshot.scene.sceneName))
                Error = "存档缺少场景";
            else if (Snapshot.anchor == null || string.IsNullOrWhiteSpace(Snapshot.anchor.nodeName))
                Error = "存档缺少 Yarn 锚点";
            else if (!Matches(_expectedSceneName, Snapshot.scene.sceneName))
                Error = $"场景不匹配：{Snapshot.scene.sceneName}";
            else if (!Matches(_expectedSceneSoName, Snapshot.anchor.sceneSoName))
                Error = $"TalkSceneSO 不匹配：{Snapshot.anchor.sceneSoName}";
            else if (!Matches(_expectedYarnProjectId, Snapshot.anchor.yarnProjectId))
                Error = $"YarnProject 不匹配：{Snapshot.anchor.yarnProjectId}";
            else if (!string.IsNullOrWhiteSpace(AnchorNode)
                     && !string.Equals(AnchorNode, Snapshot.anchor.nodeName, StringComparison.Ordinal))
                Error = $"节点不匹配：{Snapshot.anchor.nodeName}";
        }

        private static bool Matches(string expected, string actual) =>
            string.IsNullOrWhiteSpace(expected) || string.Equals(expected, actual, StringComparison.Ordinal);
    }

    [Serializable]
    public sealed class DevSaveCatalogDto
    {
        public int catalogVersion = DevSaveCatalog.CurrentVersion;
        public List<DevSaveCatalogSectionDto> sections = new();
    }

    [Serializable]
    public sealed class DevSaveCatalogSectionDto
    {
        public int order;
        public string id;
        public string title;
        public string expectedSceneName;
        public string expectedSceneSoName;
        public string expectedYarnProjectId;
        public List<DevSaveCatalogEntryDto> entries = new();
    }

    [Serializable]
    public sealed class DevSaveCatalogEntryDto
    {
        public int order;
        public string label;
        public string path;
        public string anchorNode;
    }
}