using AssetRipper.Text.SourceGeneration;
using Microsoft.CodeAnalysis.CSharp;
using System.CodeDom.Compiler;
using System.Net.Http.Headers;
using System.Security.Cryptography;
using System.Text;

namespace AssetRipper.GUI.Web.Dependencies.SourceGenerator;

public static class Program
{
	private readonly record struct Dependency(string Name, string Website, string ProductionDownloadUrl, string? ProductionIntegrity, string? DevelopmentDownloadUrl, string? DevelopmentIntegrity, string Path, string MimeType);
	private static readonly Dependency[] dependencies =
	[
		new(
			"BabylonMain",
			"https://www.babylonjs.com/",
			"https://cdn.babylonjs.com/babylon.js",
			null,
			null,
			null,
			"/js/babylon.js",
			"application/javascript"),
		new(
			"BabylonLoader",
			"https://www.babylonjs.com/",
			"https://cdn.babylonjs.com/loaders/babylonjs.loaders.min.js",
			null,
			null,
			null,
			"/js/babylonjs.loaders.min.js",
			"application/javascript"),
		new(
			"BootstrapStyleSheet",
			"https://getbootstrap.com/",
			"https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css",
			"sha384-sRIl4kxILFvY47J16cr9ZwB07vP4J8+LH7qKQnuqkuIAvNWLzeN8tE5YBujZqJLB",
			null,
			null,
			"/css/bootstrap.min.css",
			"text/css"),
		new(
			"BootstrapScript",
			"https://getbootstrap.com/",
			"https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/js/bootstrap.bundle.min.js",
			"sha384-FKyoEForCGlyvwx9Hj09JcYn3nv7wiPVlz7YYwJrWVcXK/BmnVDxM+D2scQbITxI",
			null,
			null,
			"/js/bootstrap.bundle.min.js",
			"application/javascript"),
		new(
			"Popper",
			"https://jquery.com/",
			"https://cdn.jsdelivr.net/npm/@popperjs/core@2.11.8/dist/umd/popper.min.js",
			"sha384-I7E8VVD/ismYTF4hNIPjVp/Zjvgyol6VFvRkX/vR+Vc4jQkC+hVqc2pM8ODewa9r",
			null,
			null,
			"/js/popper.min.js",
			"application/javascript"),
		new(
			"Vue",
			"https://vuejs.org/",
			"https://unpkg.com/vue@3.5.27/dist/vue.global.prod.js",
			null,
			"https://unpkg.com/vue@3.5.27/dist/vue.global.js",
			null,
			"/js/vue.js",
			"application/javascript"),
	];
	public static void Main(string[] args)
	{
		string outputDirectory = args[0];
		using HttpClient client = CreateClient();

		string outputPath = Path.Combine(outputDirectory, "Dependencies");
		IndentedTextWriter writer = IndentedTextWriterFactory.Create(outputDirectory, "EmbeddedDependency");
		writer.WriteGeneratedCodeWarning();
		writer.WriteLineNoTabs();
		writer.WriteUsing("System.Text");
		writer.WriteLineNoTabs();
		writer.WriteFileScopedNamespace("AssetRipper.GUI.Web.Dependencies");
		writer.WriteLineNoTabs();
		writer.WriteLine("public readonly record struct EmbeddedDependency(string Content, string Path, string MimeType, bool IsDevelopment)");
		using (new CurlyBrackets(writer))
		{
			writer.WriteLine("public bool IsScript => MimeType == \"application/javascript\";");
			writer.WriteLine("public bool IsStyleSheet => MimeType == \"text/css\";");
			writer.WriteLine("public bool IsProduction => !IsDevelopment;");
			foreach (Dependency dependency in dependencies)
			{
				writer.WriteSummaryDocumentation($"<see href={GetLiteral(dependency.Website)} />");
				WriteProperty(client, writer, dependency.Name, dependency.ProductionDownloadUrl, dependency.ProductionIntegrity, dependency.Path, dependency.MimeType, false);
				if (dependency.DevelopmentDownloadUrl is null)
				{
					writer.WriteLine($"internal static EmbeddedDependency {dependency.Name}Development => {dependency.Name};");
				}
				else
				{
					writer.WriteSummaryDocumentation($"<see href={GetLiteral(dependency.Website)} />");
					WriteProperty(client, writer, dependency.Name + "Development", dependency.DevelopmentDownloadUrl, dependency.DevelopmentIntegrity, dependency.Path, dependency.MimeType, true);
				}
			}
			writer.WriteLine("public static IReadOnlyList<EmbeddedDependency> GetAllProduction() =>");
			writer.WriteLine('[');
			using (new Indented(writer))
			{
				foreach (Dependency dependency in dependencies)
				{
					writer.WriteLine($"{dependency.Name},");
				}
			}
			writer.WriteLine("];");
			writer.WriteLine("public static IReadOnlyList<EmbeddedDependency> GetAllDevelopment() =>");
			writer.WriteLine('[');
			using (new Indented(writer))
			{
				foreach (Dependency dependency in dependencies)
				{
					writer.WriteLine($"{dependency.Name}Development,");
				}
			}
			writer.WriteLine("];");
		}
	}

	private static void WriteProperty(HttpClient client, IndentedTextWriter writer, string name, string url, string? integrity, string path, string mimeType, bool isDevelopment)
	{
		writer.WriteLine($"public static EmbeddedDependency {name}");
		using (new CurlyBrackets(writer))
		{
			writer.WriteLine("get");
			using (new CurlyBrackets(writer))
			{
				using (new If(writer, "field == default"))
				{
					byte[] data = DownloadAsync(client, url, integrity).GetAwaiter().GetResult();
					string content = GetLiteral(Encoding.UTF8.GetString(data));
					string isDevelopmentString = isDevelopment ? "true" : "false";
					writer.WriteLine($"ReadOnlySpan<byte> data = {content}u8;");
					writer.WriteLine($"field = new(Encoding.UTF8.GetString(data), {GetLiteral(path)}, {GetLiteral(mimeType)}, {isDevelopmentString});");
				}
				writer.WriteLine("return field;");
			}
		}
	}

	private static HttpClient CreateClient()
	{
		HttpClient client = new();
		client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("AssetRipper.GUI.Web.Dependencies.SourceGenerator", "1.0"));
		return client;
	}

	private static async Task<byte[]> DownloadAsync(HttpClient client, string url, string? integrity)
	{
		using HttpResponseMessage response = await client.GetAsync(url);
		response.EnsureSuccessStatusCode();
		byte[] result = await response.Content.ReadAsByteArrayAsync();
		if (!ValidateIntegrity(result, integrity))
		{
			throw new InvalidOperationException($"Integrity check failed for {url}");
		}
		return result;
	}

	private static bool ValidateIntegrity(byte[] data, string? integrity)
	{
		if (string.IsNullOrEmpty(integrity))
		{
			return true;
		}

		const string Sha384Prefix = "sha384-";
		if (integrity.StartsWith(Sha384Prefix, StringComparison.Ordinal))
		{
			byte[] hash = SHA384.HashData(data);
			byte[] integrityHash = Convert.FromBase64String(integrity[Sha384Prefix.Length..]);
			return hash.SequenceEqual(integrityHash);
		}
		else
		{
			return false;
		}
	}

	private static string GetLiteral(string content) => SymbolDisplay.FormatLiteral(content, true);
}