#include <doctest/doctest.h>

#include <vector>

#include "packeteer/net/icmp.hpp"

using namespace packeteer::net;

TEST_CASE("parse_icmpv4 decodes an echo request with identifier/sequence") {
    std::vector<unsigned char> bytes = {8, 0, 0x00, 0x00, 0x1c, 0x05, 0x00, 0x01};
    auto icmp = parse_icmpv4(bytes);
    REQUIRE(icmp.has_value());
    CHECK(icmp->type == 8);
    CHECK(icmp->code == 0);
    REQUIRE(icmp->identifier.has_value());
    CHECK(*icmp->identifier == 0x1c05);
    REQUIRE(icmp->sequence.has_value());
    CHECK(*icmp->sequence == 1);
}

TEST_CASE("parse_icmpv4 decodes an echo reply the same way as a request") {
    std::vector<unsigned char> bytes = {0, 0, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02};
    auto icmp = parse_icmpv4(bytes);
    REQUIRE(icmp.has_value());
    CHECK(icmp->type == 0);
    REQUIRE(icmp->identifier.has_value());
    CHECK(*icmp->identifier == 1);
}

TEST_CASE("parse_icmpv4 decodes a non-echo type without an identifier/sequence") {
    std::vector<unsigned char> bytes = {3, 1, 0x00, 0x00};  // dest unreachable, host unreachable
    auto icmp = parse_icmpv4(bytes);
    REQUIRE(icmp.has_value());
    CHECK(icmp->type == 3);
    CHECK(icmp->code == 1);
    CHECK_FALSE(icmp->identifier.has_value());
}

TEST_CASE("parse_icmpv4 rejects a buffer shorter than the fixed header") {
    std::vector<unsigned char> bytes(3, 0);
    CHECK_FALSE(parse_icmpv4(bytes).has_value());
}

TEST_CASE("icmpv4_type_name covers known types and falls back for unknown ones") {
    CHECK(icmpv4_type_name(8) == "Echo Request");
    CHECK(icmpv4_type_name(0) == "Echo Reply");
    CHECK(icmpv4_type_name(3) == "Destination Unreachable");
    CHECK(icmpv4_type_name(200) == "type=200");
}

TEST_CASE("parse_icmpv6 decodes an echo request with identifier/sequence") {
    std::vector<unsigned char> bytes = {128, 0, 0x00, 0x00, 0x1c, 0x05, 0x00, 0x01};
    auto icmp = parse_icmpv6(bytes);
    REQUIRE(icmp.has_value());
    CHECK(icmp->type == 128);
    REQUIRE(icmp->identifier.has_value());
    CHECK(*icmp->identifier == 0x1c05);
}

TEST_CASE("parse_icmpv6 decodes a non-echo type (e.g. Neighbor Solicitation) without id/seq") {
    std::vector<unsigned char> bytes = {135, 0, 0x00, 0x00};
    auto icmp = parse_icmpv6(bytes);
    REQUIRE(icmp.has_value());
    CHECK(icmp->type == 135);
    CHECK_FALSE(icmp->identifier.has_value());
}

TEST_CASE("icmpv6_type_name covers known types and falls back for unknown ones") {
    CHECK(icmpv6_type_name(128) == "Echo Request");
    CHECK(icmpv6_type_name(135) == "Neighbor Solicitation");
    CHECK(icmpv6_type_name(134) == "Router Advertisement");
    CHECK(icmpv6_type_name(250) == "type=250");
}

TEST_CASE("the same type number means something different in each protocol's table") {
    // The whole reason these are two separate tables, not one shared by
    // number: ICMPv4's echo request is type 8, but ICMPv6's type 8
    // isn't in its table at all (echo request is 128 there instead).
    CHECK(icmpv4_type_name(8) == "Echo Request");
    CHECK(icmpv6_type_name(8) == "type=8");
    // And type 4 means "Parameter Problem" in ICMPv6 but is unmapped
    // (falls back) in the ICMPv4 table.
    CHECK(icmpv6_type_name(4) == "Parameter Problem");
    CHECK(icmpv4_type_name(4) == "Source Quench");
}