#include <unity.h>

#include <cstring>
#include <string>

#include "meshtastic_header.h"
#include "meshtastic_presets.h"

using namespace roro::meshtastic;

void setUp() {}
void tearDown() {}

// The 16 bytes every Meshtastic packet starts with, little-endian, never encrypted.
static const uint8_t kHeader[] = {
    0xFF, 0xFF, 0xFF, 0xFF,  // to: broadcast
    0x78, 0x56, 0x34, 0x12,  // from: !12345678
    0xEF, 0xBE, 0xAD, 0xDE,  // id
    0x6B,                    // flags: hop start 3, want ack, hop limit 3
    0x08,                    // channel hash: LongFast with the default key
    0x00,                    // next hop: none
    0x42,                    // relay node: last byte of the Node that relayed it
};

void test_header_fields() {
    PacketHeader h;
    TEST_ASSERT_TRUE(parseHeader(kHeader, sizeof kHeader, h));
    TEST_ASSERT_EQUAL_HEX32(0xFFFFFFFF, h.to);
    TEST_ASSERT_EQUAL_HEX32(0x12345678, h.from);
    TEST_ASSERT_EQUAL_HEX32(0xDEADBEEF, h.id);
    TEST_ASSERT_EQUAL_UINT8(0x08, h.channelHash);
    TEST_ASSERT_EQUAL_UINT8(0x00, h.nextHop);
    TEST_ASSERT_EQUAL_UINT8(0x42, h.relayNode);
    TEST_ASSERT_TRUE(h.broadcast());
}

void test_header_flags() {
    PacketHeader h;
    parseHeader(kHeader, sizeof kHeader, h);
    TEST_ASSERT_EQUAL_UINT8(3, h.hopLimit());
    TEST_ASSERT_EQUAL_UINT8(3, h.hopStart());
    TEST_ASSERT_TRUE(h.wantAck());
    TEST_ASSERT_FALSE(h.viaMqtt());
    TEST_ASSERT_EQUAL_INT(0, h.hopsAway());

    uint8_t relayed[16];
    std::memcpy(relayed, kHeader, 16);
    relayed[12] = 0xF1 | 0x10;  // hop start 7, via MQTT, hop limit 1
    parseHeader(relayed, 16, h);
    TEST_ASSERT_EQUAL_UINT8(1, h.hopLimit());
    TEST_ASSERT_EQUAL_UINT8(7, h.hopStart());
    TEST_ASSERT_TRUE(h.viaMqtt());
    TEST_ASSERT_FALSE(h.wantAck());
    TEST_ASSERT_EQUAL_INT(6, h.hopsAway());
}

void test_header_from_old_firmware_has_no_hop_start() {
    uint8_t old[16];
    std::memcpy(old, kHeader, 16);
    old[12] = 0x02;  // hop limit 2, hop start 0: firmware before 2.3 didn't set it
    PacketHeader h;
    parseHeader(old, 16, h);
    TEST_ASSERT_EQUAL_INT(-1, h.hopsAway());  // unknown, not "2 hops below zero"
}

void test_header_too_short() {
    PacketHeader h;
    TEST_ASSERT_FALSE(parseHeader(kHeader, 15, h));
    TEST_ASSERT_FALSE(parseHeader(nullptr, 0, h));
}

void test_node_ids() {
    TEST_ASSERT_EQUAL_STRING("!12345678", nodeId(0x12345678).c_str());
    TEST_ASSERT_EQUAL_STRING("!0000abcd", nodeId(0xABCD).c_str());
    TEST_ASSERT_EQUAL_STRING("all", nodeId(kBroadcast).c_str());
}

// Meshtastic shows these hashes for the default key ("AQ==").
void test_channel_hash_with_default_key() {
    TEST_ASSERT_EQUAL_UINT8(8, channelHash("LongFast", kDefaultKey, sizeof kDefaultKey));
    TEST_ASSERT_EQUAL_UINT8(31, channelHash("MediumFast", kDefaultKey, sizeof kDefaultKey));
}

void test_djb2() {
    TEST_ASSERT_EQUAL_UINT32(5381, djb2(""));
    TEST_ASSERT_EQUAL_UINT32(130429955u, djb2("LongFast"));
}

void test_eu868_presets() {
    TEST_ASSERT_EQUAL_size_t(7, kEu868PresetCount);
    const Preset& lf = kEu868Presets[0];  // the default comes first
    TEST_ASSERT_EQUAL_STRING("LongFast", lf.name);
    TEST_ASSERT_EQUAL_FLOAT(250.0f, lf.bwKHz);
    TEST_ASSERT_EQUAL_UINT8(11, lf.sf);
    TEST_ASSERT_EQUAL_UINT8(5, lf.cr);
    const Preset* ls = findPreset("LongSlow");
    TEST_ASSERT_NOT_NULL(ls);
    TEST_ASSERT_EQUAL_FLOAT(125.0f, ls->bwKHz);
    TEST_ASSERT_EQUAL_UINT8(12, ls->sf);
    TEST_ASSERT_EQUAL_UINT8(8, ls->cr);
    TEST_ASSERT_NULL(findPreset("ShortTurbo"));  // 500 kHz doesn't fit the 250 kHz sub-band
}

// The frequency slot comes from the channel name's hash; an unnamed channel uses the preset's name.
void test_eu868_frequencies() {
    TEST_ASSERT_EQUAL_UINT32(869525000u, eu868FrequencyHz(*findPreset("LongFast")));
    TEST_ASSERT_EQUAL_UINT32(869525000u, eu868FrequencyHz(*findPreset("MediumFast")));
    TEST_ASSERT_EQUAL_UINT32(869462500u, eu868FrequencyHz(*findPreset("LongSlow")));
    TEST_ASSERT_EQUAL_UINT32(869587500u, eu868FrequencyHz(*findPreset("LongMod")));
    // A 250 kHz preset has one slot, whatever the channel's name.
    TEST_ASSERT_EQUAL_UINT32(869525000u, eu868FrequencyHz(*findPreset("LongFast"), "Belgium"));
}

void test_radio_constants() {
    TEST_ASSERT_EQUAL_HEX8(0x2B, kSyncWord);
    TEST_ASSERT_EQUAL_UINT16(16, kPreambleLength);
}

int main() {
    UNITY_BEGIN();
    RUN_TEST(test_header_fields);
    RUN_TEST(test_header_flags);
    RUN_TEST(test_header_from_old_firmware_has_no_hop_start);
    RUN_TEST(test_header_too_short);
    RUN_TEST(test_node_ids);
    RUN_TEST(test_channel_hash_with_default_key);
    RUN_TEST(test_djb2);
    RUN_TEST(test_eu868_presets);
    RUN_TEST(test_eu868_frequencies);
    RUN_TEST(test_radio_constants);
    return UNITY_END();
}