#nullable enable

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using ShrinkSDK.CodeGen;
using Unity.CompilationPipeline.Common.Diagnostics;
using Unity.CompilationPipeline.Common.ILPostProcessing;

namespace ShrinkShared.CodeGen
{
    public static class UnityShrinkCodeGenAdapter
    {
        public static ILPostProcessResult Process(ICompiledAssembly compiledAssembly, string diagnosticPrefix)
        {
            var diagnostics = new List<DiagnosticMessage>();
            var tempRoot = Path.Combine(Path.GetTempPath(), "ShrinkSDK.CodeGen", Guid.NewGuid().ToString("N"));
            Directory.CreateDirectory(tempRoot);
            try
            {
                var inputAssembly = Path.Combine(tempRoot, compiledAssembly.Name + ".dll");
                var inputPdb = Path.Combine(tempRoot, compiledAssembly.Name + ".pdb");
                var outputAssembly = Path.Combine(tempRoot, compiledAssembly.Name + ".woven.dll");
                var outputPdb = Path.Combine(tempRoot, compiledAssembly.Name + ".woven.pdb");
                File.WriteAllBytes(inputAssembly, compiledAssembly.InMemoryAssembly.PeData);
                var hasSymbols = compiledAssembly.InMemoryAssembly.PdbData != null &&
                                 compiledAssembly.InMemoryAssembly.PdbData.Length > 0;
                if (hasSymbols)
                    File.WriteAllBytes(inputPdb, compiledAssembly.InMemoryAssembly.PdbData);

                var result = ShrinkAssemblyWeaver.Weave(inputAssembly, hasSymbols ? inputPdb : null,
                    compiledAssembly.References, outputAssembly, hasSymbols ? outputPdb : null,
                    ShrinkCodeGenPlatform.Unity);
                foreach (var item in result.Diagnostics)
                {
                    diagnostics.Add(new DiagnosticMessage
                    {
                        DiagnosticType = item.Severity == ShrinkCodeGenDiagnosticSeverity.Error
                            ? DiagnosticType.Error
                            : DiagnosticType.Warning,
                        MessageData = $"[{diagnosticPrefix}] {item.Message}"
                    });
                }

                if (!result.Succeeded || !result.Changed)
                    return new ILPostProcessResult(compiledAssembly.InMemoryAssembly, diagnostics);
                var pe = File.ReadAllBytes(outputAssembly);
                var pdb = hasSymbols && File.Exists(outputPdb)
                    ? File.ReadAllBytes(outputPdb)
                    : compiledAssembly.InMemoryAssembly.PdbData ?? Array.Empty<byte>();
                return new ILPostProcessResult(new InMemoryAssembly(pe, pdb), diagnostics);
            }
            catch (Exception exception)
            {
                diagnostics.Add(new DiagnosticMessage
                {
                    DiagnosticType = DiagnosticType.Error,
                    MessageData = $"[{diagnosticPrefix}] {exception.Message}"
                });
                return new ILPostProcessResult(compiledAssembly.InMemoryAssembly, diagnostics);
            }
            finally
            {
                try { Directory.Delete(tempRoot, true); }
                catch { }
            }
        }

        public static bool ReferencesAny(ICompiledAssembly compiledAssembly, params string[] assemblyNames)
        {
            return compiledAssembly.References.Any(reference => assemblyNames.Any(name =>
                string.Equals(Path.GetFileNameWithoutExtension(reference), name, StringComparison.Ordinal)));
        }
    }
}