using System.Collections.Generic;
using Microsoft.Xna.Framework.Graphics;
using StardewModdingAPI.Events;
using StardewModdingAPI.Framework.ModLoading;
using StardewModdingAPI.Framework.ModLoading.Finders;
using StardewModdingAPI.Framework.ModLoading.RewriteFacades;
using StardewModdingAPI.Framework.ModLoading.Rewriters;
using StardewValley;
using StardewValley.Locations;

namespace StardewModdingAPI.Metadata
{
    /// <summary>Provides CIL instruction handlers which rewrite mods for compatibility and throw exceptions for incompatible code.</summary>
    internal class InstructionMetadata
    {
        /*********
        ** Fields
        *********/
        /// <summary>The assembly names to which to heuristically detect broken references.</summary>
        /// <remarks>The current implementation only works correctly with assemblies that should always be present.</remarks>
        private readonly ISet<string> ValidateReferencesToAssemblies = new HashSet<string> { "StardewModdingAPI", "Stardew Valley", "StardewValley", "Netcode" };


        /*********
        ** Public methods
        *********/
        /// <summary>Get rewriters which detect or fix incompatible CIL instructions in mod assemblies.</summary>
        /// <param name="paranoidMode">Whether to detect paranoid mode issues.</param>
        /// <param name="platformChanged">Whether the assembly was rewritten for crossplatform compatibility.</param>
        /// <param name="rewriteMods">Whether to get handlers which rewrite mods for compatibility.</param>
        public IEnumerable<IInstructionHandler> GetHandlers(bool paranoidMode, bool platformChanged, bool rewriteMods)
        {
            /****
            ** rewrite CIL to fix incompatible code
            ****/
            // rewrite for crossplatform compatibility
            if (rewriteMods)
            {
                // rewrite for Stardew Valley 1.5
                yield return new FieldReplaceRewriter()
                    .AddField(typeof(DecoratableLocation), "furniture", typeof(GameLocation), nameof(GameLocation.furniture))
                    .AddField(typeof(Farm), "resourceClumps", typeof(GameLocation), nameof(GameLocation.resourceClumps))
                    .AddField(typeof(MineShaft), "resourceClumps", typeof(GameLocation), nameof(GameLocation.resourceClumps));

                // heuristic rewrites
                yield return new HeuristicFieldRewriter(this.ValidateReferencesToAssemblies);
                yield return new HeuristicMethodRewriter(this.ValidateReferencesToAssemblies);

                // rewrite for Stardew Valley 1.5.5
                if (platformChanged)
                    yield return new MethodParentRewriter(typeof(SpriteBatch), typeof(SpriteBatchFacade));
                yield return new ArchitectureAssemblyRewriter();

                // detect Harmony & rewrite for SMAPI 3.12 (Harmony 1.x => 2.0 update)
                yield return new HarmonyRewriter();
            }
            else
                yield return new HarmonyRewriter(shouldRewrite: false);

            /****
            ** detect mod issues
            ****/
            // detect broken code
            yield return new ReferenceToMissingMemberFinder(this.ValidateReferencesToAssemblies);
            yield return new ReferenceToMemberWithUnexpectedTypeFinder(this.ValidateReferencesToAssemblies);

            /****
            ** detect code which may impact game stability
            ****/
            yield return new TypeFinder("System.Runtime.CompilerServices.CallSite", InstructionHandleResult.DetectedDynamic);
            yield return new FieldFinder(typeof(SaveGame).FullName!, new[] { nameof(SaveGame.serializer), nameof(SaveGame.farmerSerializer), nameof(SaveGame.locationSerializer) }, InstructionHandleResult.DetectedSaveSerializer);
            yield return new EventFinder(typeof(ISpecializedEvents).FullName!, new[] { nameof(ISpecializedEvents.UnvalidatedUpdateTicked), nameof(ISpecializedEvents.UnvalidatedUpdateTicking) }, InstructionHandleResult.DetectedUnvalidatedUpdateTick);

            /****
            ** detect paranoid issues
            ****/
            if (paranoidMode)
            {
                // filesystem access
                yield return new TypeFinder(typeof(System.Console).FullName!, InstructionHandleResult.DetectedConsoleAccess);
                yield return new TypeFinder(
                    new[]
                    {
                        typeof(System.IO.File).FullName!,
                        typeof(System.IO.FileStream).FullName!,
                        typeof(System.IO.FileInfo).FullName!,
                        typeof(System.IO.Directory).FullName!,
                        typeof(System.IO.DirectoryInfo).FullName!,
                        typeof(System.IO.DriveInfo).FullName!,
                        typeof(System.IO.FileSystemWatcher).FullName!
                    },
                    InstructionHandleResult.DetectedFilesystemAccess
                );

                // shell access
                yield return new TypeFinder(typeof(System.Diagnostics.Process).FullName!, InstructionHandleResult.DetectedShellAccess);
            }
        }
    }
}