#if UNITY_EDITOR || DEVELOPMENT_BUILD
using System;
using System.Collections.Generic;
using System.Linq;

namespace AibisDream.SaveSystem
{
    public enum TestSaveCoverageRowKind
    {
        Recorded,
        Missing,
        Invalid
    }

    public sealed class TestSaveCoverageRow
    {
        public TestSaveCoverageRowKind Kind { get; internal set; }
        public string NodeName { get; internal set; }
        public TestSaveEntry Entry { get; internal set; }
        public long SortOrder { get; internal set; }
    }

    public sealed class TestSaveChapterCoverage
    {
        public string ChapterId { get; internal set; }
        public string Title { get; internal set; }
        public int ChapterOrder { get; internal set; }
        public int RecordedCount { get; internal set; }
        public int ExpectedCount { get; internal set; }
        public IReadOnlyList<TestSaveCoverageRow> Rows { get; internal set; } = Array.Empty<TestSaveCoverageRow>();
        public bool IsOrphanGroup { get; internal set; }
    }

    public static class TestSaveCoverage
    {
        public const string OrphanChapterId = "__invalid_or_orphan__";

        public static IReadOnlyList<TestSaveChapterCoverage> Build(
            IReadOnlyList<TalkSceneSO> chapters,
            IReadOnlyList<TestSaveEntry> entries)
        {
            chapters ??= Array.Empty<TalkSceneSO>();
            entries ??= Array.Empty<TestSaveEntry>();
            var result = new List<TestSaveChapterCoverage>();
            var consumed = new HashSet<TestSaveEntry>();

            for (var chapterIndex = 0; chapterIndex < chapters.Count; chapterIndex++)
            {
                var chapter = chapters[chapterIndex];
                if (chapter == null) continue;

                var expectedNodes = GetExpectedNodes(chapter);
                var chapterEntries = entries
                    .Where(item => item.Meta != null
                                   && string.Equals(item.Meta.sceneSoName, chapter.name, StringComparison.Ordinal)
                                   && string.Equals(
                                       item.Meta.yarnProjectId,
                                       chapter.yarnProject?.name,
                                       StringComparison.Ordinal))
                    .ToArray();
                foreach (var entry in chapterEntries) consumed.Add(entry);

                var validByNode = chapterEntries
                    .Where(item => item.IsValid)
                    .GroupBy(item => item.NodeName, StringComparer.Ordinal)
                    .ToDictionary(
                        group => group.Key,
                        group => group.OrderBy(item => item.Meta.firstSeenOrder).First(),
                        StringComparer.Ordinal);
                var rows = new List<TestSaveCoverageRow>();
                foreach (var entry in validByNode.Values.OrderBy(item => item.Meta.firstSeenOrder))
                {
                    rows.Add(new TestSaveCoverageRow
                    {
                        Kind = TestSaveCoverageRowKind.Recorded,
                        NodeName = entry.NodeName,
                        Entry = entry,
                        SortOrder = entry.Meta.firstSeenOrder
                    });
                }

                foreach (var nodeName in expectedNodes
                             .Where(node => !validByNode.ContainsKey(node))
                             .OrderBy(node => node, StringComparer.OrdinalIgnoreCase))
                {
                    rows.Add(new TestSaveCoverageRow
                    {
                        Kind = TestSaveCoverageRowKind.Missing,
                        NodeName = nodeName,
                        SortOrder = long.MaxValue
                    });
                }

                foreach (var entry in chapterEntries.Where(item => !item.IsValid)
                             .OrderBy(item => item.Meta?.firstSeenOrder ?? long.MaxValue))
                {
                    rows.Add(new TestSaveCoverageRow
                    {
                        Kind = TestSaveCoverageRowKind.Invalid,
                        NodeName = entry.NodeName ?? "(未知节点)",
                        Entry = entry,
                        SortOrder = entry.Meta?.firstSeenOrder ?? long.MaxValue
                    });
                }

                result.Add(new TestSaveChapterCoverage
                {
                    ChapterId = chapter.name,
                    Title = string.IsNullOrWhiteSpace(chapter.title) ? chapter.name : chapter.title,
                    ChapterOrder = chapterIndex,
                    RecordedCount = validByNode.Keys.Count(expectedNodes.Contains),
                    ExpectedCount = expectedNodes.Count,
                    Rows = rows
                });
            }

            var orphanEntries = entries.Where(item => !consumed.Contains(item)).ToArray();
            if (orphanEntries.Length > 0)
            {
                result.Add(new TestSaveChapterCoverage
                {
                    ChapterId = OrphanChapterId,
                    Title = "无效 / 已脱离当前流程",
                    ChapterOrder = int.MaxValue,
                    RecordedCount = 0,
                    ExpectedCount = 0,
                    IsOrphanGroup = true,
                    Rows = orphanEntries
                        .OrderBy(item => item.Meta?.firstSeenOrder ?? long.MaxValue)
                        .Select(item => new TestSaveCoverageRow
                        {
                            Kind = TestSaveCoverageRowKind.Invalid,
                            NodeName = item.NodeName ?? "(未知节点)",
                            Entry = item,
                            SortOrder = item.Meta?.firstSeenOrder ?? long.MaxValue
                        })
                        .ToArray()
                });
            }

            return result;
        }

        public static HashSet<string> GetExpectedNodes(TalkSceneSO chapter)
        {
            var result = new HashSet<string>(StringComparer.Ordinal);
            var project = chapter?.yarnProject;
            if (project?.Program?.Nodes == null) return result;

            foreach (var pair in project.Program.Nodes)
            {
                var node = pair.Value;
                if (node == null || node.Name.StartsWith("$", StringComparison.Ordinal)) continue;
                var tagsValue = node.Headers
                    .FirstOrDefault(header => string.Equals(header.Key, "tags", StringComparison.OrdinalIgnoreCase))
                    ?.Value;
                var tags = string.IsNullOrWhiteSpace(tagsValue)
                    ? Array.Empty<string>()
                    : tagsValue.Split(Array.Empty<char>(), StringSplitOptions.RemoveEmptyEntries);
                if (SavePointEvaluator.EvaluateNodeTagsForAutoSaveSilently(node.Name, tags, out _))
                {
                    result.Add(node.Name);
                }
            }

            return result;
        }
    }
}
#endif