// Copyright (C) 2026 SharpEmu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

using System;
using System.Collections.Concurrent;
using System.Threading;
using SharpEmu.HLE;

namespace SharpEmu.Libs.Network;

public static class Http2Exports
{
    private const int Http2ErrorInvalidId = unchecked((int)0x80436004);
    private const int Http2ErrorInvalidArgument = unchecked((int)0x80436016);

    private static readonly ConcurrentDictionary<int, Http2Context> _contexts = new();
    private static int _nextContextId;

    private sealed record Http2Context(int NetId, int SslId, ulong PoolSize, int MaxRequests);

    [SysAbiExport(
        Nid = "3JCe3lCbQ8A",
        ExportName = "sceHttp2Init",
        Target = Generation.Gen4 | Generation.Gen5,
        LibraryName = "libSceHttp2")]
    public static int Http2Init(CpuContext ctx)
    {
        var netId = unchecked((int)ctx[CpuRegister.Rdi]);
        var sslId = unchecked((int)ctx[CpuRegister.Rsi]);
        var poolSize = ctx[CpuRegister.Rdx];
        var maxRequests = unchecked((int)ctx[CpuRegister.Rcx]);

        if (poolSize == 0 || maxRequests <= 0)
        {
            return SetReturn(ctx, Http2ErrorInvalidArgument);
        }

        var id = Interlocked.Increment(ref _nextContextId);
        _contexts[id] = new Http2Context(netId, sslId, poolSize, maxRequests);

        TraceHttp2("init", id, unchecked((ulong)netId), unchecked((ulong)sslId), poolSize, unchecked((ulong)maxRequests));
        ctx[CpuRegister.Rax] = unchecked((ulong)id);
        return (int)OrbisGen2Result.ORBIS_GEN2_OK;
    }

    [SysAbiExport(
        Nid = "YiBUtz-pGkc",
        ExportName = "sceHttp2Term",
        Target = Generation.Gen4 | Generation.Gen5,
        LibraryName = "libSceHttp2")]
    public static int Http2Term(CpuContext ctx)
    {
        var id = unchecked((int)ctx[CpuRegister.Rdi]);
        if (!_contexts.TryRemove(id, out _))
        {
            return SetReturn(ctx, Http2ErrorInvalidId);
        }

        TraceHttp2("term", id, 0, 0, 0, 0);
        return SetReturn(ctx, 0);
    }

    private static int SetReturn(CpuContext ctx, int result)
    {
        ctx[CpuRegister.Rax] = unchecked((ulong)result);
        return result;
    }

    private static void TraceHttp2(string operation, int id, ulong arg0, ulong arg1, ulong arg2, ulong arg3)
    {
        if (!string.Equals(Environment.GetEnvironmentVariable("SHARPEMU_LOG_HTTP2"), "1", StringComparison.Ordinal))
        {
            return;
        }

        Console.Error.WriteLine(
            $"[LOADER][TRACE] http2.{operation} id={id} arg0=0x{arg0:X16} arg1=0x{arg1:X16} arg2=0x{arg2:X16} arg3=0x{arg3:X16}");
    }
}