using System;
using System.IO;
using System.Linq;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using PolyTraderSharp.Models;
using Xunit;

namespace PolyTrader.Tests.WebUi
{
    /// <summary>
    /// Server-Einstellungen über das WebUI (#561): eine Freigabeliste ohne Geheimnisse, geprüfte Werte,
    /// alles oder nichts.
    /// </summary>
    public class ServerSettingsEndpointTests
    {
        private static ServerSettings WithSecrets() => new()
        {
            LicenseKey = "enc:v1:LIZENZ",
            WatchdogToken = "enc:v1:WATCHDOG",
            MullvadAccount = "1234567890",
            PolygonRpcUrl = "wss://polygon-mainnet.g.alchemy.com/v2/ALCHEMY",
            WatchdogUrl = "https://dc.example",
            VpnLocation = "cz",
            WatchdogIntervalSeconds = 60
        };

        private static JsonElement Field(JsonElement settings, string key) =>
            settings.GetProperty("sections").EnumerateArray()
                .SelectMany(s => s.GetProperty("fields").EnumerateArray())
                .Single(f => f.GetProperty("key").GetString() == key);

        private static bool HasField(JsonElement settings, string key) =>
            settings.GetProperty("sections").EnumerateArray()
                .SelectMany(s => s.GetProperty("fields").EnumerateArray())
                .Any(f => f.GetProperty("key").GetString() == key);

        [Fact]
        public async Task Anzeige_enthaelt_die_Freigabeliste_aber_keine_Geheimnisfelder()
        {
            await using var web = await WebUiTestHost.StartAsync();
            WithSecrets().Save(web.SettingsPath);

            var settings = await web.GetJsonAsync("/api/settings/server");

            Assert.True(Field(settings, "VpnEnabled").GetProperty("editable").GetBoolean());
            Assert.False(Field(settings, "WatchdogUrl").GetProperty("editable").GetBoolean());
            Assert.False(Field(settings, "MullvadCliPath").GetProperty("editable").GetBoolean());
            Assert.True(Field(settings, "ApplicationTimeZoneId").GetProperty("requiresRestart").GetBoolean());
            Assert.False(Field(settings, "UsePolymarketWebsockets").GetProperty("requiresRestart").GetBoolean());

            foreach (var secret in new[] { "LicenseKey", "WatchdogToken", "MullvadAccount", "PolygonRpcUrl" })
                Assert.False(HasField(settings, secret), secret);

            var secrets = settings.GetProperty("secrets").EnumerateArray()
                .ToDictionary(x => x.GetProperty("label").GetString()!, x => x.GetProperty("status").GetString()!);
            Assert.Equal("gesetzt", secrets["Mullvad-Account"]);
            Assert.Equal("gesetzt (verschlüsselt)", secrets["Lizenzschlüssel"]);
        }

        [Fact]
        public async Task Aendern_schreibt_nur_die_Werte_und_zieht_den_laufenden_Stand_nach()
        {
            var live = WithSecrets();
            await using var web = await WebUiTestHost.StartAsync(s => s.AddSingleton(live));
            WithSecrets().Save(web.SettingsPath);

            var (status, body) = await web.PostJsonAsync("/api/settings/server", new
            {
                values = new { VpnEnabled = true, WatchdogIntervalSeconds = 120, VpnLocation = "cz-prg", Theme = "dunkel" }
            });

            Assert.Equal(200, status);
            Assert.True(body.GetProperty("restartRequired").GetBoolean());   // Theme wirkt erst nach Neustart

            var written = ServerSettings.Load(web.SettingsPath);
            Assert.True(written.VpnEnabled);
            Assert.Equal(120, written.WatchdogIntervalSeconds);
            Assert.Equal("cz-prg", written.VpnLocation);
            Assert.Equal(AppThemeVariant.Dunkel, written.Theme);
            Assert.Equal("enc:v1:LIZENZ", written.LicenseKey);
            Assert.Equal("enc:v1:WATCHDOG", written.WatchdogToken);
            Assert.Equal("1234567890", written.MullvadAccount);
            Assert.Equal("wss://polygon-mainnet.g.alchemy.com/v2/ALCHEMY", written.PolygonRpcUrl);

            Assert.True(live.VpnEnabled);              // laufender Stand
            Assert.Equal(120, live.WatchdogIntervalSeconds);
        }

        [Theory]
        [InlineData("WatchdogUrl", "https://angreifer.example")]
        [InlineData("MullvadCliPath", "/tmp/boese")]
        [InlineData("LicenseKey", "neu")]
        [InlineData("PolygonRpcUrl", "wss://x")]
        public async Task Desktop_Felder_werden_mit_403_abgelehnt_und_nichts_geschrieben(string key, string value)
        {
            await using var web = await WebUiTestHost.StartAsync();
            WithSecrets().Save(web.SettingsPath);
            string before = File.ReadAllText(web.SettingsPath);

            var values = new System.Collections.Generic.Dictionary<string, object> { [key] = value, ["VpnEnabled"] = true };
            var (status, body) = await web.PostJsonAsync("/api/settings/server", new { values });

            Assert.Equal(403, status);
            Assert.Contains("Desktop", body.GetProperty("error").GetString());
            Assert.Equal(before, File.ReadAllText(web.SettingsPath));
        }

        [Theory]
        [InlineData("VpnLocation", "cz account login 999")]   // Argumente fuer das Mullvad-Programm einschleusen
        [InlineData("VpnLocation", "cz;reboot")]
        [InlineData("ApplicationTimeZoneId", "Mars/Olympus")]
        [InlineData("WatchdogSource", "polytrader\\\" , \\\"x")]
        public async Task Ungueltige_Texte_werden_abgelehnt(string key, string value)
        {
            await using var web = await WebUiTestHost.StartAsync();
            WithSecrets().Save(web.SettingsPath);
            string before = File.ReadAllText(web.SettingsPath);

            var values = new System.Collections.Generic.Dictionary<string, object> { [key] = value };
            var (status, _) = await web.PostJsonAsync("/api/settings/server", new { values });

            Assert.Equal(400, status);
            Assert.Equal(before, File.ReadAllText(web.SettingsPath));
        }

        [Fact]
        public async Task Ein_ungueltiger_Wert_verhindert_auch_die_gueltigen()
        {
            await using var web = await WebUiTestHost.StartAsync();
            WithSecrets().Save(web.SettingsPath);

            var (status, body) = await web.PostJsonAsync("/api/settings/server", new
            {
                values = new { VpnEnabled = true, WatchdogIntervalSeconds = 5 }
            });

            Assert.Equal(400, status);
            Assert.Contains("Nichts gespeichert", body.GetProperty("error").GetString());
            Assert.False(ServerSettings.Load(web.SettingsPath).VpnEnabled);
        }

        [Fact]
        public async Task Unbekanntes_Feld_leerer_Rumpf_und_gueltige_Zeitzone()
        {
            await using var web = await WebUiTestHost.StartAsync();

            var (unknown, _) = await web.PostJsonAsync("/api/settings/server", new { values = new { GibtEsNicht = 1 } });
            var (empty, _) = await web.PostJsonAsync("/api/settings/server");
            Assert.Equal(400, unknown);
            Assert.Equal(400, empty);
            Assert.False(File.Exists(web.SettingsPath));

            var (ok, _) = await web.PostJsonAsync("/api/settings/server", new { values = new { ApplicationTimeZoneId = "Europe/Berlin" } });
            Assert.Equal(200, ok);
            Assert.Equal("Europe/Berlin", ServerSettings.Load(web.SettingsPath).ApplicationTimeZoneId);
        }

        [Fact]
        public async Task Unlesbare_Datei_wird_weder_angezeigt_noch_ueberschrieben()
        {
            await using var web = await WebUiTestHost.StartAsync();
            const string kaputt = "<ServerSettings><LicenseKey>enc:v1:LIZENZ</LicenseKey><abgeschn";
            File.WriteAllText(web.SettingsPath, kaputt);

            using var get = await web.Client.GetAsync("/api/settings/server");
            var (post, _) = await web.PostJsonAsync("/api/settings/server", new { values = new { VpnEnabled = true } });

            Assert.Equal(500, (int)get.StatusCode);
            Assert.Equal(500, post);
            Assert.Equal(kaputt, File.ReadAllText(web.SettingsPath));
        }
    }
}