using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnityEditor.AddressableAssets.Build.BuildPipelineTasks;
using UnityEditor.AddressableAssets.Build.DataBuilders;
using UnityEditor.AddressableAssets.Settings;
using UnityEditor.AddressableAssets.Settings.GroupSchemas;
using UnityEditor.Build.Content;
using UnityEditor.Build.Pipeline;
using UnityEditor.Build.Pipeline.Interfaces;
using UnityEditor.Build.Pipeline.Tasks;
using UnityEditor.Build.Pipeline.Utilities;
using UnityEditor.Build.Utilities;
using UnityEngine;
using UnityEngine.AddressableAssets.Initialization;
using UnityEngine.AddressableAssets.ResourceLocators;

namespace UnityEditor.AddressableAssets.Build.AnalyzeRules
{
    class MyBundleRuleBase : AnalyzeRule
    {
        [NonSerialized]
        internal List<GUID> m_AddressableAssets = new List<GUID>();
        [NonSerialized]
        internal Dictionary<string, List<GUID>> m_ResourcesToDependencies = new Dictionary<string, List<GUID>>();
        [NonSerialized]
        internal readonly List<ContentCatalogDataEntry> m_Locations = new List<ContentCatalogDataEntry>();
        [NonSerialized]
        internal readonly List<AssetBundleBuild> m_AllBundleInputDefs = new List<AssetBundleBuild>();
        [NonSerialized]
        internal readonly Dictionary<string, string> m_BundleToAssetGroup = new Dictionary<string, string>();
        [NonSerialized]
        internal readonly List<AddressableAssetEntry> m_AssetEntries = new List<AddressableAssetEntry>();
        [NonSerialized]
        internal ExtractDataTask m_ExtractData = new ExtractDataTask();

        internal IList<IBuildTask> RuntimeDataBuildTasks(string builtinShaderBundleName)
        {
            IList<IBuildTask> buildTasks = new List<IBuildTask>();

            // Setup
            buildTasks.Add(new SwitchToBuildPlatform());
            buildTasks.Add(new RebuildSpriteAtlasCache());

            // Player Scripts
            buildTasks.Add(new BuildPlayerScripts());

            // Dependency
            buildTasks.Add(new CalculateSceneDependencyData());
            buildTasks.Add(new CalculateAssetDependencyData());
            buildTasks.Add(new StripUnusedSpriteSources());
            buildTasks.Add(new CreateBuiltInShadersBundle(builtinShaderBundleName));

            // Packing
            buildTasks.Add(new GenerateBundlePacking());
            buildTasks.Add(new UpdateBundleObjectLayout());

            buildTasks.Add(new GenerateBundleCommands());
            buildTasks.Add(new GenerateSubAssetPathMaps());
            buildTasks.Add(new GenerateBundleMaps());

            buildTasks.Add(new GenerateLocationListsTask());

            return buildTasks;
        }

        internal AddressableAssetsBuildContext GetBuildContext(AddressableAssetSettings settings)
        {
            ResourceManagerRuntimeData runtimeData = new ResourceManagerRuntimeData();
            runtimeData.LogResourceManagerExceptions = settings.buildSettings.LogResourceManagerExceptions;

            var aaContext = new AddressableAssetsBuildContext
            {
                Settings = settings,
                runtimeData = runtimeData,
                bundleToAssetGroup = m_BundleToAssetGroup,
                locations = m_Locations,
                providerTypes = new HashSet<Type>(),
                assetEntries = m_AssetEntries,
                assetGroupToBundles = new Dictionary<AddressableAssetGroup, List<string>>()
            };
            return aaContext;
        }

        protected bool IsValidPath(string path)
        {
            return IsPathValidForEntry(path) &&
                !path.ToLower().Contains("/resources/") &&
                !path.ToLower().StartsWith("resources/");
        }

        internal static bool IsPathValidForEntry(string path)
        {
            if (string.IsNullOrEmpty(path))
                return false;
            if (!path.StartsWith("assets", StringComparison.OrdinalIgnoreCase) && !IsPathValidPackageAsset(path))
                return false;
            path = path.ToLower();
            if (path == CommonStrings.UnityEditorResourcePath ||
                path == CommonStrings.UnityDefaultResourcePath ||
                path == CommonStrings.UnityBuiltInExtraPath)
                return false;
            var ext = Path.GetExtension(path);
            if (ext == ".cs" || ext == ".js" || ext == ".boo" || ext == ".exe" || ext == ".dll" || ext == ".meta")
                return false;
            return true;
        }

        internal static bool IsPathValidPackageAsset(string path)
        {
            string convertPath = path.ToLower().Replace("\\", "/");
            string[] splitPath = convertPath.Split('/');

            if (splitPath.Length < 3)
                return false;
            if (splitPath[0] != "packages")
                return false;
            if (splitPath.Length == 3)
            {
                string ext = Path.GetExtension(splitPath[2]);
                if (ext == ".json" || ext == ".asmdef")
                    return false;
            }
            return true;
        }

        internal ReturnCode RefreshBuild(AddressableAssetsBuildContext buildContext)
        {
            var settings = buildContext.Settings;
            var context = new AddressablesDataBuilderInput(settings);

            var buildTarget = context.Target;
            var buildTargetGroup = context.TargetGroup;
            var buildParams = new AddressableAssetsBundleBuildParameters(settings, m_BundleToAssetGroup, buildTarget,
                buildTargetGroup, settings.buildSettings.bundleBuildPath);
            var builtinShaderBundleName =
                settings.DefaultGroup.Name.ToLower().Replace(" ", "").Replace('\\', '/').Replace("//", "/") +
                "_unitybuiltinshaders.bundle";
            var buildTasks = RuntimeDataBuildTasks(builtinShaderBundleName);
            buildTasks.Add(m_ExtractData);

            IBundleBuildResults buildResults;
            var exitCode = ContentPipeline.BuildAssetBundles(buildParams, new BundleBuildContent(m_AllBundleInputDefs),
                out buildResults, buildTasks, buildContext);

            return exitCode;
        }

        internal List<GUID> GetAllBundleDependencies()
        {
            var explicitGuids = m_ExtractData.WriteData.AssetToFiles.Keys;
            var implicitGuids = GetImplicitGuidToFilesMap().Keys;
            var allBundleGuids = explicitGuids.Union(implicitGuids);

            return allBundleGuids.ToList();
        }

        internal void IntersectResourcesDepedenciesWithBundleDependencies(List<GUID> bundleDependencyGuids)
        {
            foreach (var key in m_ResourcesToDependencies.Keys)
            {
                var bundleDependencies = bundleDependencyGuids.Intersect(m_ResourcesToDependencies[key]).ToList();

                m_ResourcesToDependencies[key].Clear();
                m_ResourcesToDependencies[key].AddRange(bundleDependencies);
            }
        }

        internal virtual void BuiltInResourcesToDependenciesMap(string[] resourcePaths)
        {
            foreach (string path in resourcePaths)
            {
                string[] dependencies = AssetDatabase.GetDependencies(path);

                if (!m_ResourcesToDependencies.ContainsKey(path))
                    m_ResourcesToDependencies.Add(path, new List<GUID>());

                m_ResourcesToDependencies[path].AddRange(from dependency in dependencies
                    select new GUID(AssetDatabase.AssetPathToGUID(dependency)));
            }
        }

        internal void ConvertBundleNamesToGroupNames(AddressableAssetsBuildContext buildContext)
        {
            Dictionary<string, string> bundleNamesToUpdate = new Dictionary<string, string>();

            foreach (var assetGroup in buildContext.Settings.groups)
            {
                if (assetGroup == null)
                    continue;

                List<string> bundles;
                if (buildContext.assetGroupToBundles.TryGetValue(assetGroup, out bundles))
                {
                    foreach (string bundle in bundles)
                    {
                        var keys = m_ExtractData.WriteData.FileToBundle.Keys.Where(key => m_ExtractData.WriteData.FileToBundle[key] == bundle);
                        foreach (string key in keys)
                            bundleNamesToUpdate.Add(key, assetGroup.Name);
                    }
                }
            }

            foreach (string key in bundleNamesToUpdate.Keys)
            {
                var bundle = m_ExtractData.WriteData.FileToBundle[key];
                var inputDef = m_AllBundleInputDefs.FirstOrDefault(b => b.assetBundleName == bundle);
                int index = m_AllBundleInputDefs.IndexOf(inputDef);
                if (index >= 0)
                {
                    inputDef.assetBundleName = ConvertBundleName(inputDef.assetBundleName, bundleNamesToUpdate[key]);
                    m_AllBundleInputDefs[index] = inputDef;
                    m_ExtractData.WriteData.FileToBundle[key] = inputDef.assetBundleName;
                }
            }
        }

        internal void CalculateInputDefinitions(AddressableAssetSettings settings)
        {
            foreach (AddressableAssetGroup group in settings.groups)
            {
                if (group == null)
                    continue;

                if (group.HasSchema<BundledAssetGroupSchema>())
                {
                    var schema = group.GetSchema<BundledAssetGroupSchema>();
                    List<AssetBundleBuild> bundleInputDefinitions = new List<AssetBundleBuild>();
                    m_AssetEntries.AddRange(PrepGroupBundlePacking(group, bundleInputDefinitions, schema.BundleMode));

                    for (int i = 0; i < bundleInputDefinitions.Count; i++)
                    {
                        if (m_BundleToAssetGroup.ContainsKey(bundleInputDefinitions[i].assetBundleName))
                            bundleInputDefinitions[i] = CreateUniqueBundle(bundleInputDefinitions[i]);

                        m_BundleToAssetGroup.Add(bundleInputDefinitions[i].assetBundleName, schema.Group.Guid);
                    }

                    m_AllBundleInputDefs.AddRange(bundleInputDefinitions);
                }
            }
        }

        internal static List<AddressableAssetEntry> PrepGroupBundlePacking(AddressableAssetGroup assetGroup, List<AssetBundleBuild> bundleInputDefs, BundledAssetGroupSchema.BundlePackingMode packingMode)
        {
            var combinedEntries = new List<AddressableAssetEntry>();
            switch (packingMode)
            {
                case BundledAssetGroupSchema.BundlePackingMode.PackTogether:
                    {
                        var allEntries = new List<AddressableAssetEntry>();
                        foreach (AddressableAssetEntry a in assetGroup.entries)
                            a.GatherAllAssets(allEntries, true, true, false);
                        combinedEntries.AddRange(allEntries);
                        GenerateBuildInputDefinitions(allEntries, bundleInputDefs, CalculateGroupHash(allEntries), "all");
                    }
                    break;
                case BundledAssetGroupSchema.BundlePackingMode.PackSeparately:
                    {
                        foreach (AddressableAssetEntry a in assetGroup.entries)
                        {
                            var allEntries = new List<AddressableAssetEntry>();
                            a.GatherAllAssets(allEntries, true, true, false);
                            combinedEntries.AddRange(allEntries);
                            GenerateBuildInputDefinitions(allEntries, bundleInputDefs, CalculateGroupHash(allEntries), a.address);
                        }
                    }
                    break;
                case BundledAssetGroupSchema.BundlePackingMode.PackTogetherByLabel:
                    {
                        var labelTable = new Dictionary<string, List<AddressableAssetEntry>>();
                        foreach (AddressableAssetEntry a in assetGroup.entries)
                        {
                            var sb = new StringBuilder();
                            foreach (var l in a.labels)
                                sb.Append(l);
                            var key = sb.ToString();
                            List<AddressableAssetEntry> entries;
                            if (!labelTable.TryGetValue(key, out entries))
                                labelTable.Add(key, entries = new List<AddressableAssetEntry>());
                            entries.Add(a);
                        }

                        foreach (var entryGroup in labelTable)
                        {
                            var allEntries = new List<AddressableAssetEntry>();
                            foreach (var a in entryGroup.Value)
                                a.GatherAllAssets(allEntries, true, true, false);
                            combinedEntries.AddRange(allEntries);
                            GenerateBuildInputDefinitions(allEntries, bundleInputDefs, CalculateGroupHash(allEntries), entryGroup.Key);
                        }
                    }
                    break;
                default:
                    throw new Exception("Unknown Packing Mode");
            }
            return combinedEntries;
        }

        internal static void GenerateBuildInputDefinitions(List<AddressableAssetEntry> allEntries, List<AssetBundleBuild> buildInputDefs, string groupGuid, string address)
        {
            var scenes = new List<AddressableAssetEntry>();
            var assets = new List<AddressableAssetEntry>();
            foreach (var e in allEntries)
            {
                if (string.IsNullOrEmpty(e.AssetPath))
                    continue;
                if (e.IsScene)
                    scenes.Add(e);
                else
                    assets.Add(e);
            }
            if (assets.Count > 0)
                buildInputDefs.Add(GenerateBuildInputDefinition(assets, groupGuid + "_assets_" + address + ".bundle"));
            if (scenes.Count > 0)
                buildInputDefs.Add(GenerateBuildInputDefinition(scenes, groupGuid + "_scenes_" + address + ".bundle"));
        }

        internal static AssetBundleBuild GenerateBuildInputDefinition(List<AddressableAssetEntry> assets, string name)
        {
            var assetInternalIds = new HashSet<string>();
            var assetsInputDef = new AssetBundleBuild();
            assetsInputDef.assetBundleName = name.ToLower().Replace(" ", "").Replace('\\', '/').Replace("//", "/");
            assetsInputDef.assetNames = assets.Select(s => s.AssetPath).ToArray();
            assetsInputDef.addressableNames = new string[0];//assets.Select(s => s.GetAssetLoadPath(true, assetInternalIds)).ToArray();
            return assetsInputDef;
        }

        internal static string CalculateGroupHash(IEnumerable<AddressableAssetEntry> entries)
        {
            return HashingMethods.Calculate(new HashSet<string>(entries.Select(e => e.guid))).ToString();
        }

        internal AssetBundleBuild CreateUniqueBundle(AssetBundleBuild bid)
        {
            int count = 1;
            var newName = bid.assetBundleName;
            while (m_BundleToAssetGroup.ContainsKey(newName) && count < 1000)
                newName = bid.assetBundleName.Replace(".bundle", string.Format("{0}.bundle", count++));
            return new AssetBundleBuild
            {
                assetBundleName = newName,
                addressableNames = bid.addressableNames,
                assetBundleVariant = bid.assetBundleVariant,
                assetNames = bid.assetNames
            };
        }

        internal List<GUID> GetImplicitGuidsForBundle(string fileName)
        {
            List<GUID> guids = (from id in m_ExtractData.WriteData.FileToObjects[fileName]
                where !m_ExtractData.WriteData.AssetToFiles.Keys.Contains(id.guid)
                select id.guid).ToList();
            return guids;
        }

        internal Dictionary<GUID, List<string>> GetImplicitGuidToFilesMap()
        {
            Dictionary<GUID, List<string>> implicitGuids = new Dictionary<GUID, List<string>>();
            IEnumerable<KeyValuePair<ObjectIdentifier, string>> validImplicitGuids =
                from fileToObject in m_ExtractData.WriteData.FileToObjects
                from objectId in fileToObject.Value
                where !m_ExtractData.WriteData.AssetToFiles.Keys.Contains(objectId.guid)
                select new KeyValuePair<ObjectIdentifier, string>(objectId, fileToObject.Key);

            //Build our Dictionary from our list of valid implicit guids (guids not already in explicit guids)
            foreach (var objectIdToFile in validImplicitGuids)
            {
                if (!implicitGuids.ContainsKey(objectIdToFile.Key.guid))
                    implicitGuids.Add(objectIdToFile.Key.guid, new List<string>());
                implicitGuids[objectIdToFile.Key.guid].Add(objectIdToFile.Value);
            }

            return implicitGuids;
        }

        internal List<AnalyzeResult> CalculateBuiltInResourceDependenciesToBundleDependecies(AddressableAssetSettings settings, string[] builtInResourcesPaths)
        {
            List<AnalyzeResult> results = new List<AnalyzeResult>();

            if (!BuildUtility.CheckModifiedScenesAndAskToSave())
            {
                Debug.LogError("Cannot run Analyze with unsaved scenes");
                results.Add(new AnalyzeResult { resultName = ruleName + "Cannot run Analyze with unsaved scenes" });
                return results;
            }

            m_AddressableAssets = (from aaGroup in settings.groups
                where aaGroup != null
                from entry in aaGroup.entries
                select new GUID(entry.guid)).ToList();


            BuiltInResourcesToDependenciesMap(builtInResourcesPaths);
            CalculateInputDefinitions(settings);

            var context = GetBuildContext(settings);
            ReturnCode exitCode = RefreshBuild(context);
            if (exitCode < ReturnCode.Success)
            {
                Debug.LogError("Analyze build failed. " + exitCode);
                results.Add(new AnalyzeResult { resultName = ruleName + "Analyze build failed. " + exitCode });
                return results;
            }

            IntersectResourcesDepedenciesWithBundleDependencies(GetAllBundleDependencies());

            ConvertBundleNamesToGroupNames(context);

            results = (from resource in m_ResourcesToDependencies.Keys
                from dependency in m_ResourcesToDependencies[resource]

                let assetPath = AssetDatabase.GUIDToAssetPath(dependency.ToString())
                    let files = m_ExtractData.WriteData.FileToObjects.Keys

                    from file in files
                    where m_ExtractData.WriteData.FileToObjects[file].Any(oid => oid.guid == dependency)
                    where m_ExtractData.WriteData.FileToBundle.ContainsKey(file)
                    let bundle = m_ExtractData.WriteData.FileToBundle[file]

                    select new AnalyzeResult
                {
                    resultName =
                        resource + kDelimiter +
                        bundle + kDelimiter +
                        assetPath,
                    severity = MessageType.Warning
                }).ToList();

            if (results.Count == 0)
                results.Add(new AnalyzeResult { resultName = ruleName + " - No issues found." });

            return results;
        }

        protected string ConvertBundleName(string bundleName, string groupName)
        {
            string[] bundleNameSegments = bundleName.Split('_');
            bundleNameSegments[0] = groupName.Replace(" ", "").ToLower();
            return string.Join("_", bundleNameSegments);
        }

        public override void ClearAnalysis()
        {
            m_Locations.Clear();
            m_AddressableAssets.Clear();
            m_AssetEntries.Clear(); 
            m_AllBundleInputDefs.Clear();
            m_BundleToAssetGroup.Clear();
            m_ResourcesToDependencies.Clear();
            m_ExtractData = new ExtractDataTask();

            base.ClearAnalysis();
        }
    }
}