using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using Cake.Core.Diagnostics;
using Cake.Core.IO;
using Cake.Frosting;
using Cake.Powershell;
using Path = System.IO.Path;

namespace Build.Tasks;

[TaskName("CopyOutput")]
public class CopyOutputTask : FrostingTask<BuildContext>
{
	public override void Run(BuildContext context)
	{
		var powershellModuleName = "PowershellModule";
		// TODO: probably don't create full file locations when I can pass the output dir in and have the script
		//  make the path
		var scriptParams = new
		{
			PowershellModuleFileLocation = $"{context.PowershellModuleOutputDir}/{powershellModuleName}.psd1",
			Guid = Guid.Parse("5cdf4635-edb0-428c-8d9b-92d0bcd47443"),
			Author = "Me",
			NestedModules = new[] { $"{powershellModuleName}.dll" },
			RootModule = $"{powershellModuleName}.psm1",
			CmdletsToExport = GetExportedCmdlets(),
			ManifestFileLocation = $"{context.PowershellModuleOutputDir}/{powershellModuleName}.psm1",
			OutputLocation = context.PowershellModuleOutputDir,
		};

		var psSettings = new PowershellSettings()
		{
			Arguments = new ProcessArgumentBuilder(),
		};

		// This feels a bit ugly/redundant seeing as I've defined the scriptParams above, but I'm leaving it as is
		// until I want to come back and clean this up properly
		psSettings.Arguments.Append("powershellModuleFileLocation", ToPowershellSafeString(scriptParams.PowershellModuleFileLocation));
		psSettings.Arguments.Append("guid", ToPowershellSafeString(scriptParams.Guid.ToString()));
		psSettings.Arguments.Append("author", ToPowershellSafeString(scriptParams.Author));
		psSettings.Arguments.Append("nestedModules", $"@({string.Join(",", scriptParams.NestedModules.Select(ToPowershellSafeString))})");
		psSettings.Arguments.Append("rootModule", ToPowershellSafeString(scriptParams.RootModule));
		psSettings.Arguments.Append("cmdletsToExport", $"@({string.Join(",", scriptParams.CmdletsToExport.Select(ToPowershellSafeString))})");
		psSettings.Arguments.Append("manifestFileLocation", ToPowershellSafeString(scriptParams.ManifestFileLocation));
		psSettings.Arguments.Append("outputDir", ToPowershellSafeString(scriptParams.OutputLocation));

		context.StartPowershellFile(context.CreateModuleManifestScript, psSettings);
		context.Log.Information($"Module output to: {context.PowershellModuleOutputDir.Path.MakeAbsolute(context.Environment)}");

		BundleMinimalFiles(context);

		base.Run(context);
	}

	private static string ToPowershellSafeString(string unescapedString) => $"'{unescapedString}'";

	private static List<string> GetExportedCmdlets()
	{
		return ["Get-Calendar", .. GetGitRepoRegistrationVerbs()];
	}

	private static List<string> GetGitRepoRegistrationVerbs()
	{
		// TODO: I should make some reference file for these verbs and name but that'd pull in powershell dependencies
		//  to the build and I'd like to avoid that.
		//  This isn't great but commands are unlikely to change that frequently
		string[] verbs = ["Get", "New", "Remove", "Show"];
		var commandName = "GitRepoRegistration";
		return [.. verbs.Select(x => $"{x}-{commandName}")];
	}

	private static void BundleMinimalFiles(BuildContext context)
	{
		// We're effectively replicating PostBuild.ps1 with all of this as Remove-Item at the end of it does not remove files the same way.
		// TODO: See if that's something I can fix
		var powershellModuleBuildLocation = context.PowershellModuleOutputDir.Path.MakeAbsolute(context.Environment).FullPath;
		// PowershellModule is here so that the script that adds to the users $Env:PSModulePath correctly resolves when using
		// Import-Module "PowershellModule"
		// TODO: Generate the script to add to the PSModulePath in the bundleOutputLocation directory

		// Top level bundle output location
		var bundleRootLocation = Directory.CreateDirectory(Path.Combine(powershellModuleBuildLocation, "bundle")).FullName;
		// Module folder location that will be zipped up and will contain any setup scripts/readme etc
		var moduleFolderLocation = Directory.CreateDirectory(Path.Combine(bundleRootLocation, "NulahModule")).FullName;
		// Location to put all the module dlls and other files
		var powershelModuleOutputLocation = Directory.CreateDirectory(Path.Combine(moduleFolderLocation, "PowershellModule")).FullName;

		context.Log.Information($"Bundle location: {bundleRootLocation}");
		context.Log.Information($"Built file location: {powershellModuleBuildLocation}");

		// PostBuild.ps1 for PowershellModule should have already been run at this point - it won't remove files, but it will copy the
		// correct e_sqlite3.dll that we need.
		// TODO: Investigate this later as I'm not entirely happy with this now
		// // Get the location for the specific version of e_sqlite3.dll we need - PowerShell binary modules resolve dependent dlls
		// // from the executing assembly directory first, and the built output of the module includes a lot of other dlls that
		// // are already available with the dotnet runtime so there's no need for us to include them.
		// // I mean, we could, but we'd also be terrible software engineers if we couldn't do something as basic as reducing files we need.
		// // TODO: Account for other runtimes such as linux based ones where the dotnet runtime might _not_ provide these files for free.
		// //  It'd require looking into how the module loads for PowerShell on those operating systems, and I might never
		// //  get around to doing that because I use windows (currently).
		// // TODO: Update this later to handle other runtimes, for now we hardcode to win-x64 because it's what I use
		// var nativeSqliteDllLocation = System.IO.Path.Combine(powershellModuleBuildLocation, "runtimes", "win-x64", "native", "e_sqlite3.dll");
		//
		// if (!File.Exists(nativeSqliteDllLocation))
		// {
		// 	context.Log.Error($"BUNDLE FAILED: Unable to locate ${nativeSqliteDllLocation}");
		// 	return;
		// }
		//
		// context.Log.Information($"Copying '${nativeSqliteDllLocation}' to '${bundleOutputLocation}'");
		//
		// File.Copy(nativeSqliteDllLocation, System.IO.Path.Combine(bundleOutputLocation, System.IO.Path.GetFileName(nativeSqliteDllLocation)));

		var moduleCoreFiles = Directory.GetFiles(powershellModuleBuildLocation, "ModuleCore*", searchOption: SearchOption.TopDirectoryOnly);
		var powershellModuleFiles = Directory.GetFiles(powershellModuleBuildLocation, "PowershellModule*", searchOption: SearchOption.TopDirectoryOnly);
		var sqliteFiles = Directory.GetFiles(powershellModuleBuildLocation, "*SQLite*", searchOption: SearchOption.TopDirectoryOnly);

		string[] allFiles = [.. moduleCoreFiles, .. powershellModuleFiles, .. sqliteFiles];

		context.Log.Information($"Copying {allFiles.Length} files to the module folder {powershelModuleOutputLocation}");
		foreach (var file in allFiles)
		{
			context.Log.Information($"Copying {Path.GetFileName(file)}");
			File.Copy(file, Path.Combine(powershelModuleOutputLocation, Path.GetFileName(file)));
		}

		context.Log.Information($"Bundle files copied");

		GenerateModuleImportScript(moduleFolderLocation, context);
		CreateBundleZip(bundleRootLocation, moduleFolderLocation, context);
	}

	private static void GenerateModuleImportScript(string bundleLocation, BuildContext context)
	{
		context.Log.Information($"Generating module import script");

		using var scriptFile = File.Create(Path.Combine(bundleLocation, "NulahPowershell.ps1"));
		using var fileWriter = new StreamWriter(scriptFile);
		// TODO: Document the set up function
		// TODO: Create a ticket for fleshing out the set up function (or just do that work later)
		fileWriter.Write(
			"""
			# To use, first copy all files to the same location as your $profile under ./NulahModule, then open your powershell profile located at $profile and add the following:

			# Script setup style: Using the setup script to import as needed (this method will also set custom prompts and other alias functions)
			# . "$PSScriptRoot/NulahModule/NulahPowershell.ps1"
			# SetupNulahPowershell
			# Just the module: Use the following to just import just the powershell module
			# Import-Module -Name "$PSScriptRoot/NulahModule/PowershellModule"

			function SetupNulahPowershell
			{
			    # only add to our module path once
			    # The intent for this is that a user will have copied this bundle folder alongside their $profile
			    # location, eg, they'll have a folder called NulahModule that will contain everything within the bundle zip
			    $testBundleDirectory = $PSScriptRoot
			    $bundleInPath = ($Env:PSModulePath -split ';').TrimEnd('\') -contains $testBundleDirectory;

			    if ($false -eq $bundleInPath)
			    {
			        $env:PSModulePath = @(
			            $env:PSModulePath
			            $testBundleDirectory
			        ) -Join [System.IO.Path]::PathSeparator
			    }

			    Import-Module "PowershellModule"
			}
			"""
		);
		context.Log.Information($"Module import script created");
	}

	private static void CreateBundleZip(string bundleLocation, string moduleFolderLocation, BuildContext context)
	{
		var bundleZipFileLocaiton = Path.Combine(bundleLocation, "NulahModule.zip");
		ZipFile.CreateFromDirectory(moduleFolderLocation, bundleZipFileLocaiton, CompressionLevel.Fastest, true);
	}
}