// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2021 Zig Contributors
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
// The MIT license requires this copyright notice to be included in all copies
// and substantial portions of the software.
const std = @import("../std.zig");
const builtin = std.builtin;
const net = std.net;
const mem = std.mem;
const testing = std.testing;

test "parse and render IPv6 addresses" {
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    var buffer: [100]u8 = undefined;
    const ips = [_][]const u8{
        "FF01:0:0:0:0:0:0:FB",
        "FF01::Fb",
        "::1",
        "::",
        "2001:db8::",
        "::1234:5678",
        "2001:db8::1234:5678",
        "FF01::FB%1234",
        "::ffff:123.5.123.5",
    };
    const printed = [_][]const u8{
        "ff01::fb",
        "ff01::fb",
        "::1",
        "::",
        "2001:db8::",
        "::1234:5678",
        "2001:db8::1234:5678",
        "ff01::fb",
        "::ffff:123.5.123.5",
    };
    for (ips) |ip, i| {
        var addr = net.Address.parseIp6(ip, 0) catch unreachable;
        var newIp = std.fmt.bufPrint(buffer[0..], "{}", .{addr}) catch unreachable;
        std.testing.expect(std.mem.eql(u8, printed[i], newIp[1 .. newIp.len - 3]));

        if (std.builtin.os.tag == .linux) {
            var addr_via_resolve = net.Address.resolveIp6(ip, 0) catch unreachable;
            var newResolvedIp = std.fmt.bufPrint(buffer[0..], "{}", .{addr_via_resolve}) catch unreachable;
            std.testing.expect(std.mem.eql(u8, printed[i], newResolvedIp[1 .. newResolvedIp.len - 3]));
        }
    }

    testing.expectError(error.InvalidCharacter, net.Address.parseIp6(":::", 0));
    testing.expectError(error.Overflow, net.Address.parseIp6("FF001::FB", 0));
    testing.expectError(error.InvalidCharacter, net.Address.parseIp6("FF01::Fb:zig", 0));
    testing.expectError(error.InvalidEnd, net.Address.parseIp6("FF01:0:0:0:0:0:0:FB:", 0));
    testing.expectError(error.Incomplete, net.Address.parseIp6("FF01:", 0));
    testing.expectError(error.InvalidIpv4Mapping, net.Address.parseIp6("::123.123.123.123", 0));
    // TODO Make this test pass on other operating systems.
    if (std.builtin.os.tag == .linux) {
        testing.expectError(error.Incomplete, net.Address.resolveIp6("ff01::fb%", 0));
        testing.expectError(error.Overflow, net.Address.resolveIp6("ff01::fb%wlp3s0s0s0s0s0s0s0s0", 0));
        testing.expectError(error.Overflow, net.Address.resolveIp6("ff01::fb%12345678901234", 0));
    }
}

test "invalid but parseable IPv6 scope ids" {
    if (std.builtin.os.tag != .linux) {
        // Currently, resolveIp6 with alphanumerical scope IDs only works on Linux.
        // TODO Make this test pass on other operating systems.
        return error.SkipZigTest;
    }

    testing.expectError(error.InterfaceNotFound, net.Address.resolveIp6("ff01::fb%123s45678901234", 0));
}

test "parse and render IPv4 addresses" {
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    var buffer: [18]u8 = undefined;
    for ([_][]const u8{
        "0.0.0.0",
        "255.255.255.255",
        "1.2.3.4",
        "123.255.0.91",
        "127.0.0.1",
    }) |ip| {
        var addr = net.Address.parseIp4(ip, 0) catch unreachable;
        var newIp = std.fmt.bufPrint(buffer[0..], "{}", .{addr}) catch unreachable;
        std.testing.expect(std.mem.eql(u8, ip, newIp[0 .. newIp.len - 2]));
    }

    testing.expectError(error.Overflow, net.Address.parseIp4("256.0.0.1", 0));
    testing.expectError(error.InvalidCharacter, net.Address.parseIp4("x.0.0.1", 0));
    testing.expectError(error.InvalidEnd, net.Address.parseIp4("127.0.0.1.1", 0));
    testing.expectError(error.Incomplete, net.Address.parseIp4("127.0.0.", 0));
    testing.expectError(error.InvalidCharacter, net.Address.parseIp4("100..0.1", 0));
}

test "resolve DNS" {
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    if (std.builtin.os.tag == .windows) {
        _ = try std.os.windows.WSAStartup(2, 2);
    }
    defer {
        if (std.builtin.os.tag == .windows) {
            std.os.windows.WSACleanup() catch unreachable;
        }
    }

    // Resolve localhost, this should not fail.
    {
        const localhost_v4 = try net.Address.parseIp("127.0.0.1", 80);
        const localhost_v6 = try net.Address.parseIp("::2", 80);

        const result = try net.getAddressList(testing.allocator, "localhost", 80);
        defer result.deinit();
        for (result.addrs) |addr| {
            if (addr.eql(localhost_v4) or addr.eql(localhost_v6)) break;
        } else @panic("unexpected address for localhost");
    }

    {
        // The tests are required to work even when there is no Internet connection,
        // so some of these errors we must accept and skip the test.
        const result = net.getAddressList(testing.allocator, "example.com", 80) catch |err| switch (err) {
            error.UnknownHostName => return error.SkipZigTest,
            error.TemporaryNameServerFailure => return error.SkipZigTest,
            else => return err,
        };
        result.deinit();
    }
}

test "listen on a port, send bytes, receive bytes" {
    if (builtin.single_threaded) return error.SkipZigTest;
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    if (std.builtin.os.tag == .windows) {
        _ = try std.os.windows.WSAStartup(2, 2);
    }
    defer {
        if (std.builtin.os.tag == .windows) {
            std.os.windows.WSACleanup() catch unreachable;
        }
    }

    // Try only the IPv4 variant as some CI builders have no IPv6 localhost
    // configured.
    const localhost = try net.Address.parseIp("127.0.0.1", 8080);

    var server = net.StreamServer.init(.{});
    defer server.deinit();

    try server.listen(localhost);

    const S = struct {
        fn clientFn(server_address: net.Address) !void {
            const socket = try net.tcpConnectToAddress(server_address);
            defer socket.close();

            _ = try socket.writer().writeAll("Hello world!");
        }
    };

    const t = try std.Thread.spawn(server.listen_address, S.clientFn);
    defer t.wait();

    var client = try server.accept();
    var buf: [16]u8 = undefined;
    const n = try client.file.reader().read(&buf);

    testing.expectEqual(@as(usize, 12), n);
    testing.expectEqualSlices(u8, "Hello world!", buf[0..n]);
}

test "listen on a port, send bytes, receive bytes" {
    if (!std.io.is_async) return error.SkipZigTest;

    if (std.builtin.os.tag != .linux and !std.builtin.os.tag.isDarwin()) {
        // TODO build abstractions for other operating systems
        return error.SkipZigTest;
    }

    // TODO doing this at comptime crashed the compiler
    const localhost = try net.Address.parseIp("127.0.0.1", 0);

    var server = net.StreamServer.init(net.StreamServer.Options{});
    defer server.deinit();
    try server.listen(localhost);

    var server_frame = async testServer(&server);
    var client_frame = async testClient(server.listen_address);

    try await server_frame;
    try await client_frame;
}

test "listen on ipv4 try connect on ipv6 then ipv4" {
    if (!std.io.is_async) return error.SkipZigTest;

    if (std.builtin.os.tag != .linux and !std.builtin.os.tag.isDarwin()) {
        // TODO build abstractions for other operating systems
        return error.SkipZigTest;
    }

    // TODO doing this at comptime crashed the compiler
    const localhost = try net.Address.parseIp("127.0.0.1", 0);

    var server = net.StreamServer.init(net.StreamServer.Options{});
    defer server.deinit();
    try server.listen(localhost);

    var server_frame = async testServer(&server);
    var client_frame = async testClientToHost(
        testing.allocator,
        "localhost",
        server.listen_address.getPort(),
    );

    try await server_frame;
    try await client_frame;
}

fn testClientToHost(allocator: *mem.Allocator, name: []const u8, port: u16) anyerror!void {
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    const connection = try net.tcpConnectToHost(allocator, name, port);
    defer connection.close();

    var buf: [100]u8 = undefined;
    const len = try connection.read(&buf);
    const msg = buf[0..len];
    testing.expect(mem.eql(u8, msg, "hello from server\n"));
}

fn testClient(addr: net.Address) anyerror!void {
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    const socket_file = try net.tcpConnectToAddress(addr);
    defer socket_file.close();

    var buf: [100]u8 = undefined;
    const len = try socket_file.read(&buf);
    const msg = buf[0..len];
    testing.expect(mem.eql(u8, msg, "hello from server\n"));
}

fn testServer(server: *net.StreamServer) anyerror!void {
    if (builtin.os.tag == .wasi) return error.SkipZigTest;

    var client = try server.accept();

    const stream = client.file.writer();
    try stream.print("hello from server\n", .{});
}