using System;
using System.IO;
using System.Linq;
using System.Diagnostics;
using System.Security.Cryptography;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using Launcher.Next.Application;
using Launcher.Next.Autodesk;
using Launcher.Next.Core;
using Launcher.Next.Infrastructure;

namespace Launcher.Next.App;

/// <summary>
/// Explicit non-production workflow for a legacy-shaped configuration whose source,
/// cache, activation state, starter and evidence all live under one supplied local root.
/// It never accepts UNC roots or uses the legacy compatibility synchronizer.
/// </summary>
internal sealed record LocalParityLaunchProfile(
    int SchemaVersion, string Name, string Root, string SettingsPath, string DownloadListPath,
    string OverlayPath, string CatalogRoot, string PatternName, string EvidenceRoot, string? NetworkSettingsEndpoint = null,
    LegacySettingsSnapshot? SettingsSnapshot = null);

internal sealed record LocalParityPackage(PackageRequirement Requirement, PackageManifest Manifest,
    ImmutableLocalPackage Package, PackageActivationResult Activation);

internal sealed record LocalParityPrepared(LocalParityLaunchProfile Profile, IReadOnlyList<LocalParityPackage> Packages,
    string StarterPath, string StarterSha256);

internal sealed record LocalParityLaunchResult(int ProcessId, bool StartupVerified, bool PackageLoadConfirmed,
    string EvidencePath, string TerminalState);

internal sealed class LocalParityLaunchService
{
    private readonly LegacyConfigurationAdapter adapter = new();

    public static LocalParityLaunchProfile LoadProfile(string path)
    {
        var profile = JsonSerializer.Deserialize<LocalParityLaunchProfile>(File.ReadAllText(path), new JsonSerializerOptions { PropertyNameCaseInsensitive = true })
            ?? throw new InvalidOperationException("LOCAL_PARITY_PROFILE_INVALID");
        if (profile.SchemaVersion != 1 || string.IsNullOrWhiteSpace(profile.Name) || string.IsNullOrWhiteSpace(profile.PatternName))
            throw new InvalidOperationException("LOCAL_PARITY_PROFILE_INVALID");
        ValidateProfile(profile);
        profile = profile with { Root = Path.GetFullPath(profile.Root) };
        if (!string.IsNullOrWhiteSpace(profile.NetworkSettingsEndpoint))
        {
            var snapshot = LegacyNetworkConfiguration.AcquireApprovedSnapshot(profile.NetworkSettingsEndpoint, profile.Root);
            profile = profile with { SettingsPath = snapshot.LocalSnapshotPath, SettingsSnapshot = snapshot };
        }
        return profile;
    }

    public async Task<LocalParityPrepared> PrepareAsync(LocalParityLaunchProfile profile, CancellationToken ct)
    {
        ValidateProfile(profile);
        var settings = adapter.ParseSettings(await File.ReadAllTextAsync(profile.SettingsPath, ct));
        var pattern = settings.Patterns.Where(x => string.Equals(x.Name, profile.PatternName, StringComparison.Ordinal)).ToArray();
        if (pattern.Length != 1) throw new InvalidOperationException(pattern.Length == 0 ? "LOCAL_PARITY_PATTERN_NOT_FOUND" : "LOCAL_PARITY_PATTERN_AMBIGUOUS");
        var selection = adapter.ParseDownloadList(await File.ReadAllTextAsync(profile.DownloadListPath, ct));
        var overlay = LegacyCompatibilityOverlayParser.Parse(await File.ReadAllTextAsync(profile.OverlayPath, ct));
        var requirements = adapter.Join(pattern[0], selection, overlay);
        var store = new LocalPackageStore(profile.Root, new Sha256FileHasher());
        var prepared = new List<LocalParityPackage>();
        foreach (var requirement in requirements)
        {
            var source = Under(profile.CatalogRoot, requirement.PackageId, requirement.RequiredVersion);
            var manifestPath = Under(source, "package.manifest.json");
            var manifest = PackageManifestJson.Parse(await File.ReadAllTextAsync(manifestPath, ct));
            if (!ManifestMatches(manifest, requirement)) throw new InvalidOperationException("LOCAL_PARITY_MANIFEST_REQUIREMENT_MISMATCH");
            var package = await store.MaterializeAsync(manifest, source, ct);
            await store.BindAsync(requirement, package.Version, ct);
            var activation = await store.ActivateImmutableAsync(package, requirement, ct);
            if (activation.Outcome is not ("Activated" or "AlreadyActiveExact")) throw new InvalidOperationException("LOCAL_PARITY_ACTIVATION_" + activation.Outcome);
            if (await store.ResolveAsync(requirement, ct) is null) throw new InvalidOperationException("LOCAL_PARITY_ACTIVE_REVALIDATION_FAILED");
            prepared.Add(new(requirement, manifest, package, activation));
        }
        var starter = await GenerateStarterAsync(profile, prepared, ct);
        return new(profile, prepared, starter.Path, starter.Sha256);
    }

    public async Task<LocalParityLaunchResult> LaunchAsync(LocalParityPrepared prepared, CancellationToken ct)
    {
        var product = new PlantProductDiscovery(new WindowsRegistryReader()).DiscoverPlant3D(2026)
            ?? throw new InvalidOperationException("PLANT3D_2026_NOT_FOUND");
        var operationId = Guid.NewGuid().ToString("N");
        var evidenceDirectory = Under(prepared.Profile.EvidenceRoot, operationId);
        Directory.CreateDirectory(evidenceDirectory);
        var logPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "Promhimproekt", "PRecAnnot2026", "Logs", "runtime.jsonl");
        var beforeLogLength = File.Exists(logPath) ? new FileInfo(logPath).Length : 0L;
        var psi = new ProcessStartInfo { FileName = product.ExecutablePath, WorkingDirectory = Path.GetDirectoryName(product.ExecutablePath)!, UseShellExecute = false };
        psi.ArgumentList.Add("/product"); psi.ArgumentList.Add("PLNT3D"); psi.ArgumentList.Add("/language"); psi.ArgumentList.Add("ru-RU");
        // Controlled-local only: accepted Plant runtime bootstrap. Keep /b and the owned SCR last.
        psi.ArgumentList.Add("/b"); psi.ArgumentList.Add(prepared.StarterPath);
        psi.Environment["P_REC_ANNOT_RUNTIME_MODE"] = "Smoke";
        psi.Environment["P_REC_UPDATE_MARKER_ROOT"] = Path.Combine(Path.GetDirectoryName(prepared.StarterPath)!, "markers");
        using var process = Process.Start(psi) ?? throw new InvalidOperationException("PLANT3D_PROCESS_NOT_CREATED");
        await Task.Delay(TimeSpan.FromSeconds(30), ct);
        var alive = !process.HasExited;
        var marker = Path.Combine(Path.GetDirectoryName(prepared.StarterPath)!, "pxp-oa-netload.marker");
        var markerConfirmed = File.Exists(marker);
        var runtimeConfirmed = false;
        if (File.Exists(logPath))
        {
            await using var stream = new FileStream(logPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            stream.Seek(beforeLogLength, SeekOrigin.Begin);
            using var reader = new StreamReader(stream, Encoding.UTF8);
            var newLog = await reader.ReadToEndAsync(ct);
            runtimeConfirmed = newLog.Contains("AssemblyInitializeCompleted", StringComparison.Ordinal) && newLog.Contains($"\"ProcessId\":{process.Id}", StringComparison.Ordinal);
        }
        var updatePackage = prepared.Packages.SingleOrDefault(x => string.Equals(x.Package.PackageId, "P_Rec_Update", StringComparison.Ordinal));
        var updateInitialized = updatePackage is null || File.Exists(Path.Combine(Path.GetDirectoryName(prepared.StarterPath)!, "markers", "AssemblyInitializeCompleted.marker"));
        var loaded = runtimeConfirmed && updateInitialized;
        var terminal = alive && loaded ? "Succeeded" : "Blocked";
        var settingsSnapshot = prepared.Profile.SettingsSnapshot is null ? null : new { sourceEndpointFingerprint = prepared.Profile.SettingsSnapshot.SourceFingerprint, prepared.Profile.SettingsSnapshot.Sha256, prepared.Profile.SettingsSnapshot.Length, prepared.Profile.SettingsSnapshot.LastWriteUtc, prepared.Profile.SettingsSnapshot.AcquiredUtc, prepared.Profile.SettingsSnapshot.OfflineFallback };
        var evidence = new { schemaVersion = 3, launcherCommit = ThisCommit(), autodeskCommit = "68f5006", operationId, configuration = prepared.Profile.Name, selectedPattern = prepared.Profile.PatternName, settingsSnapshot, orderedPluginIds = prepared.Packages.Select(x => x.Requirement.PackageId), exactPackages = prepared.Packages.Select(x => new { x.Package.PackageId, x.Package.Version, x.Manifest.Product, x.Manifest.ProductYear, x.Manifest.Architecture, x.Manifest.RolloutChannel, manifestSha256 = HashAsync(Path.Combine(x.Package.LocalPackageRoot, "package.manifest.json"), ct).GetAwaiter().GetResult(), payloads = x.Manifest.Files.Select(f => new { path = f.Path, f.Length, f.Sha256 }), activation = x.Activation.Outcome, pointerGeneration = x.Activation.Receipt?.PointerGeneration }), materialization = "MaterializedOrAlreadyPresentExact", bootstrapMechanism="StartupScript", commandLineSwitch="/b", scriptWasLastArgument=true, scriptSha256=prepared.StarterSha256, plant = new { product = "Plant3D", year = 2026, executableFingerprint = Fingerprint(product.ExecutablePath, operationId), interactive = true, batchArgumentUsed = true }, process = new { pid = process.Id, newProcessCreated=true, startupVerified = alive, packageLoadConfirmed = loaded, markerConfirmed, runtimeJournalConfirmed = runtimeConfirmed, updateInitialized, processInteractiveAfterScript=alive }, terminalState = terminal, sideEffects = new { corporateDfsUsed = false, corporateDfsWriteAttempted = false, directDfsExecutionAttempted = false, productionProjectAccessed = false, productionPointerMutationAttempted = false, machineWideSecurityChanged=false, productionDeploymentAttempted = false } };
        var evidencePath = await WriteEvidenceAsync(evidenceDirectory, evidence, ct);
        return new(process.Id, alive, loaded, evidencePath, terminal);
    }

    private static async Task<(string Path, string Sha256)> GenerateStarterAsync(LocalParityLaunchProfile profile, IReadOnlyList<LocalParityPackage> packages, CancellationToken ct)
    {
        var starterRoot = Under(profile.Root, "bootstrap", Guid.NewGuid().ToString("N")); Directory.CreateDirectory(starterRoot);
        var entries = packages.Select(x => Under(x.Package.LocalPackageRoot, x.Manifest.EntryAssembly)).ToArray();
        if (entries.Any(x => !File.Exists(x))) throw new InvalidOperationException("LOCAL_PARITY_ENTRY_MISSING");
        Directory.CreateDirectory(Under(starterRoot, "markers"));
        var content = "_.FILEDIA\r\n0\r\n_.CMDDIA\r\n0\r\n" + string.Concat(entries.Select(entry => "_.NETLOAD\r\n\"" + entry.Replace("\"", "\\\"") + "\"\r\n"));
        var path = Under(starterRoot, "startup.scr");
        await File.WriteAllTextAsync(path, content, new UTF8Encoding(false), ct);
        return (path, await HashAsync(path, ct));
    }

    private static bool ManifestMatches(PackageManifest manifest, PackageRequirement requirement) =>
        manifest.PackageId == requirement.PackageId && manifest.Version == requirement.RequiredVersion && manifest.Product == requirement.Product && manifest.ProductYear == requirement.ProductYear && string.Equals(manifest.Architecture, requirement.Architecture, StringComparison.OrdinalIgnoreCase) && string.Equals(manifest.RolloutChannel, requirement.Channel, StringComparison.OrdinalIgnoreCase);
    private static void ValidateProfile(LocalParityLaunchProfile profile)
    {
        if (profile.SchemaVersion != 1 || string.IsNullOrWhiteSpace(profile.Root)) throw new InvalidOperationException("LOCAL_PARITY_PROFILE_INVALID");
        var root = Path.GetFullPath(profile.Root);
        if (!Path.IsPathFullyQualified(root) || root.StartsWith("\\\\", StringComparison.Ordinal) || root.Contains("?", StringComparison.Ordinal) || new DirectoryInfo(root).Exists && new DirectoryInfo(root).Attributes.HasFlag(FileAttributes.ReparsePoint)) throw new InvalidOperationException("LOCAL_PARITY_ROOT_NOT_LOCAL");
        foreach (var path in new[] { profile.SettingsPath, profile.DownloadListPath, profile.OverlayPath, profile.CatalogRoot, profile.EvidenceRoot }) if (!UnderRoot(root, path)) throw new InvalidOperationException("LOCAL_PARITY_PATH_OUTSIDE_ROOT");
    }
    private static bool UnderRoot(string root, string path) { var r = Path.GetFullPath(root).TrimEnd(Path.DirectorySeparatorChar) + Path.DirectorySeparatorChar; var p = Path.GetFullPath(path); return p.StartsWith(r, StringComparison.OrdinalIgnoreCase); }
    private static string Under(string root, params string[] parts) { var result = Path.GetFullPath(Path.Combine(new[] { root }.Concat(parts).ToArray())); if (!UnderRoot(root, result) && !string.Equals(Path.GetFullPath(root), result, StringComparison.OrdinalIgnoreCase)) throw new InvalidOperationException("LOCAL_PARITY_PATH_ESCAPE"); return result; }
    private static async Task<string> HashAsync(string path, CancellationToken ct) { await using var stream = File.OpenRead(path); return Convert.ToHexString(await SHA256.HashDataAsync(stream, ct)); }
    private static string Fingerprint(string path, string salt) => Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(salt + "|" + path)));
    private static async Task<string> WriteEvidenceAsync(string directory, object value, CancellationToken ct) { var final = Path.Combine(directory, "controlled-local-parity-launch.json"); var temp = final + ".tmp"; await using (var stream = new FileStream(temp, FileMode.CreateNew, FileAccess.Write, FileShare.None)) { await JsonSerializer.SerializeAsync(stream, value, cancellationToken: ct); await stream.FlushAsync(ct); } File.Move(temp, final); using var doc = JsonDocument.Parse(await File.ReadAllTextAsync(final, ct)); if (doc.RootElement.GetProperty("schemaVersion").GetInt32() != 3) throw new InvalidOperationException("LOCAL_PARITY_EVIDENCE_INVALID"); return final; }
    private static string ThisCommit()
    {
        var embedded = Environment.GetEnvironmentVariable("LAUNCHER_COMMIT");
        if (!string.IsNullOrWhiteSpace(embedded)) return embedded;
        try
        {
            var releaseManifest = Path.Combine(AppContext.BaseDirectory, "owner-review-release.json");
            if (File.Exists(releaseManifest))
            {
                using var document = JsonDocument.Parse(File.ReadAllText(releaseManifest));
                if (document.RootElement.TryGetProperty("launcherCommit", out var commit) && !string.IsNullOrWhiteSpace(commit.GetString())) return commit.GetString()!;
            }
            var start = new ProcessStartInfo("git", "rev-parse HEAD") { WorkingDirectory = AppContext.BaseDirectory, UseShellExecute = false, RedirectStandardOutput = true };
            using var process = Process.Start(start);
            var value = process is null ? "" : process.StandardOutput.ReadToEnd().Trim();
            return string.IsNullOrWhiteSpace(value) ? "unknown" : value;
        }
        catch { return "unknown"; }
    }
}