using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using NUnit.Framework;
using NightclubArcadia.Skills;
using UnityEditor;

namespace NightclubArcadia.Skills.Tests
{
    /// <summary>
    /// Source lint over Assets/Dialogue/**/*.yarn. This is a tripwire, not a proof —
    /// it catches the easy-and-wrong wirings, not every possible one.
    /// </summary>
    public class CandidateYarnLintTests
    {
        const string DialogueRoot = "Assets/Dialogue";
        const string DatabasePath = "Assets/Candidates/CandidateDatabase.asset";

        static readonly Regex LeanWrite = new Regex(
            @"\$self_lean_([a-z][a-z0-9_]*)",
            RegexOptions.Compiled);
        static readonly Regex FoundWrite = new Regex(
            @"\$found_([a-z][a-z0-9_]*)",
            RegexOptions.Compiled);
        static readonly Regex LeanVsLean = new Regex(
            @"\$self_lean_[a-z][a-z0-9_]*\s*(>=|<=|==|!=|>|<)\s*\$self_lean_[a-z][a-z0-9_]*",
            RegexOptions.Compiled);
        static readonly Regex NodeSplit = new Regex(
            @"^title:\s*(.+)\s*$",
            RegexOptions.Compiled | RegexOptions.Multiline);

        CandidateDatabase LoadDatabase()
        {
            // Assets are checked in (generated by CandidateSystemSetup). Same pattern as
            // SkillRosterTests — the test assembly cannot reference the Editor setup type.
            var db = AssetDatabase.LoadAssetAtPath<CandidateDatabase>(DatabasePath);
            Assert.IsNotNull(db, $"Expected CandidateDatabase at {DatabasePath}");
            return db;
        }

        static IEnumerable<string> AllYarnFiles()
        {
            return Directory.GetFiles(DialogueRoot, "*.yarn", SearchOption.AllDirectories);
        }

        static string Read(string path) => File.ReadAllText(path);

        [Test]
        public void Lint_LeanAndFoundWrites_MatchRegistryIds()
        {
            var db = LoadDatabase();
            var candidateIds = new HashSet<string>(
                db.All.Select(c => c.Id),
                StringComparer.OrdinalIgnoreCase);
            var clueIds = new HashSet<string>(
                db.All.SelectMany(c => c.Clues).Select(c => c.Id),
                StringComparer.OrdinalIgnoreCase);

            foreach (var path in AllYarnFiles())
            {
                var text = Read(path);
                foreach (Match match in LeanWrite.Matches(text))
                {
                    var id = match.Groups[1].Value;
                    Assert.IsTrue(
                        candidateIds.Contains(id),
                        $"{path}: $self_lean_{id} has no matching candidate id in the registry.");
                }

                foreach (Match match in FoundWrite.Matches(text))
                {
                    var id = match.Groups[1].Value;
                    Assert.IsTrue(
                        clueIds.Contains(id),
                        $"{path}: $found_{id} has no matching clue id in the registry.");
                }
            }
        }

        [Test]
        public void Lint_AuthoredClues_HaveFoundWrites()
        {
            var db = LoadDatabase();
            var allYarn = string.Join("\n", AllYarnFiles().Select(Read));

            foreach (var candidate in db.All)
            {
                foreach (var clue in candidate.Clues)
                {
                    if (clue.Status != CandidateClueStatus.Authored)
                    {
                        continue;
                    }

                    var needle = $"<<set $found_{clue.Id} = true>>";
                    Assert.IsTrue(
                        allYarn.Contains(needle),
                        $"Authored clue '{clue.Id}' has no `{needle}` anywhere under {DialogueRoot}.");
                }
            }
        }

        [Test]
        public void Lint_NoLeanVsLeanComparison()
        {
            foreach (var path in AllYarnFiles())
            {
                var text = Read(path);
                Assert.IsFalse(
                    LeanVsLean.IsMatch(text),
                    $"{path}: comparing two $self_lean_* values against each other is forbidden " +
                    "(no derived winner). Comparing one lean against a constant is fine.");
            }
        }

        [Test]
        public void Lint_ClueAndLeanWrites_NotSkillGated()
        {
            foreach (var path in AllYarnFiles())
            {
                var text = Read(path);
                var matches = NodeSplit.Matches(text);
                for (var i = 0; i < matches.Count; i++)
                {
                    var start = matches[i].Index;
                    var end = i + 1 < matches.Count ? matches[i + 1].Index : text.Length;
                    var nodeBody = text.Substring(start, end - start);
                    var title = matches[i].Groups[1].Value.Trim();

                    var writesLeanOrFound =
                        nodeBody.Contains("$self_lean_") || nodeBody.Contains("$found_");
                    if (!writesLeanOrFound)
                    {
                        continue;
                    }

                    Assert.IsFalse(
                        nodeBody.Contains("skill_rank("),
                        $"{path} node '{title}': a node that writes $self_lean_* / $found_* " +
                        "must not sit behind a skill_rank(...) guard.");
                }
            }
        }

        [Test]
        public void Lint_CommentaryNodes_NeverWriteLeanOrFound()
        {
            foreach (var path in AllYarnFiles())
            {
                var text = Read(path);
                var matches = NodeSplit.Matches(text);
                for (var i = 0; i < matches.Count; i++)
                {
                    var title = matches[i].Groups[1].Value.Trim();
                    if (!title.StartsWith("Commentary_", StringComparison.Ordinal))
                    {
                        continue;
                    }

                    var start = matches[i].Index;
                    var end = i + 1 < matches.Count ? matches[i + 1].Index : text.Length;
                    var nodeBody = text.Substring(start, end - start);

                    Assert.IsFalse(
                        nodeBody.Contains("$self_lean_") || nodeBody.Contains("$found_"),
                        $"{path} node '{title}': Commentary_* nodes must not write lean or found flags " +
                        "(ambient advocacy only; clue lines are scene-authored).");
                }
            }
        }
    }
}