using Microsoft.AspNetCore.Mvc;
using System.Text.Json;
using System.Text.Json.Nodes;

namespace RadicadeServer.API.Launcher
{
	[Route("api/launcher")]
	public class LauncherBuildAPI : Controller
	{
		private static readonly string LauncherDirectory = Path.GetFullPath("./Launcher");
		private static readonly string LauncherManifestPath = Path.Join(LauncherDirectory, "manifest.json");

		private static async Task<JsonObject?> LoadLauncherManifest()
		{
			if (!System.IO.File.Exists(LauncherManifestPath))
				return null;

			var raw = await System.IO.File.ReadAllTextAsync(LauncherManifestPath);
			return JsonNode.Parse(raw)?.AsObject();
		}

		private static string? GetString(JsonObject manifest, string key)
		{
			return manifest[key]?.GetValue<string>();
		}

		private static string? GetNestedString(JsonObject manifest, string parentKey, string childKey)
		{
			return manifest[parentKey]?[childKey]?.GetValue<string>();
		}

		private static bool GetBool(JsonObject manifest, string key, bool fallback = false)
		{
			return manifest[key]?.GetValue<bool>() ?? fallback;
		}

		private static IActionResult MissingManifestFile()
		{
			return new JsonResult(new
			{
				error = "Launcher manifest file was not found.",
				path = LauncherManifestPath
			})
			{
				StatusCode = StatusCodes.Status404NotFound
			};
		}

		private static IActionResult InvalidManifestFile(string message, object? extra = null)
		{
			return new JsonResult(new
			{
				error = message,
				path = LauncherManifestPath,
				extra
			})
			{
				StatusCode = StatusCodes.Status503ServiceUnavailable
			};
		}

		[HttpGet("approved-build")]
		public async Task<IActionResult> GetApprovedBuild()
		{
			if (!System.IO.File.Exists(LauncherManifestPath))
				return MissingManifestFile();

			try
			{
				var raw = await System.IO.File.ReadAllTextAsync(LauncherManifestPath);
				var manifest = JsonNode.Parse(raw)?.AsObject();
				if (manifest == null)
					return InvalidManifestFile("Launcher manifest file is not a JSON object.");

				var gameVersion = GetString(manifest, "version");
				var manifestVersion = GetString(manifest, "manifestVersion");
				var gameDownloadUrl = GetNestedString(manifest, "package", "url");
				var packageSha256 = GetNestedString(manifest, "package", "sha256");

				if (string.IsNullOrWhiteSpace(gameVersion) ||
					string.IsNullOrWhiteSpace(manifestVersion) ||
					string.IsNullOrWhiteSpace(gameDownloadUrl) ||
					string.IsNullOrWhiteSpace(packageSha256))
				{
					return InvalidManifestFile(
						"Approved build metadata is incomplete.",
						new
						{
							missing = new[]
							{
								string.IsNullOrWhiteSpace(gameVersion) ? "version" : null,
								string.IsNullOrWhiteSpace(manifestVersion) ? "manifestVersion" : null,
								string.IsNullOrWhiteSpace(gameDownloadUrl) ? "package.url" : null,
								string.IsNullOrWhiteSpace(packageSha256) ? "package.sha256" : null
							}.Where(x => x != null).ToArray()
						});
				}

				return Ok(new
				{
					gameVersion,
					manifestVersion,
					gameDownloadUrl,
					packageSha256,
					required = GetBool(manifest, "required", true),
					launchTicket = GetString(manifest, "launchTicket"),
					launchTicketRequired = GetBool(manifest, "launchTicketRequired"),
					launchTicketUrl = GetString(manifest, "launchTicketUrl"),
					launchTicketAudience = GetString(manifest, "launchTicketAudience"),
					launchTicketNonce = GetString(manifest, "launchTicketNonce")
				});
			}
			catch (JsonException ex)
			{
				return InvalidManifestFile("Launcher manifest file contains invalid JSON.", new { details = ex.Message });
			}
		}

		[HttpGet("manifest.json")]
		public async Task<IActionResult> GetManifest()
		{
			if (!System.IO.File.Exists(LauncherManifestPath))
				return MissingManifestFile();

			try
			{
				var raw = await System.IO.File.ReadAllTextAsync(LauncherManifestPath);
				var manifest = JsonNode.Parse(raw)?.AsObject();
				if (manifest == null)
					return InvalidManifestFile("Launcher manifest file is not a JSON object.");

				var version = GetString(manifest, "version");
				var packageUrl = GetNestedString(manifest, "package", "url");

				if (string.IsNullOrWhiteSpace(version) || string.IsNullOrWhiteSpace(packageUrl))
				{
					return InvalidManifestFile(
						"Launcher manifest file is missing required fields.",
						new
						{
							missing = new[]
							{
								string.IsNullOrWhiteSpace(version) ? "version" : null,
								string.IsNullOrWhiteSpace(packageUrl) ? "package.url" : null
							}.Where(x => x != null).ToArray()
						});
				}

				return Content(raw, "application/json");
			}
			catch (JsonException ex)
			{
				return InvalidManifestFile("Launcher manifest file contains invalid JSON.", new { details = ex.Message });
			}
		}
	}
}