#include <array>

#include <gtest/gtest.h>
#include <prjxray/xilinx/xc7series/bitstream_reader.h>
#include <prjxray/xilinx/xc7series/configuration_packet.h>
#include <prjxray/xilinx/xc7series/configuration_register.h>

namespace xc7series = prjxray::xilinx::xc7series;

TEST(BitstreamReaderTest, InitWithEmptyBytesReturnsNull) {
	absl::Span<uint8_t> bitstream;
	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	EXPECT_FALSE(reader);
}

TEST(BitstreamReaderTest, InitWithOnlySyncReturnsObject) {
	std::vector<uint8_t> bitstream{0xAA, 0x99, 0x55, 0x66};
	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	EXPECT_TRUE(reader);
}

TEST(BitstreamReaderTest, InitWithSyncAfterNonWordSizedPaddingReturnsObject) {
	std::vector<uint8_t> bitstream{0xFF, 0xFE, 0xAA, 0x99, 0x55, 0x66};
	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	EXPECT_TRUE(reader);
}

TEST(BitstreamReaderTest, InitWithSyncAfterWordSizedPaddingReturnsObject) {
	std::vector<uint8_t> bitstream{0xFF, 0xFE, 0xFD, 0xFC,
	                               0xAA, 0x99, 0x55, 0x66};
	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	EXPECT_TRUE(reader);
}

TEST(BitstreamReaderTest, ParsesType1Packet) {
	std::vector<uint8_t> bitstream{
	    0xAA, 0x99, 0x55, 0x66,  // sync
	    0x20, 0x00, 0x00, 0x00,  // NOP
	};
	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	ASSERT_TRUE(reader);
	ASSERT_NE(reader->begin(), reader->end());

	auto first_packet = reader->begin();
	EXPECT_EQ(first_packet->opcode(),
	          xc7series::ConfigurationPacket::Opcode::NOP);

	EXPECT_EQ(++first_packet, reader->end());
}

TEST(BitstreamReaderTest, ParseType2PacketWithoutType1Fails) {
	std::vector<uint8_t> bitstream{
	    0xAA, 0x99, 0x55, 0x66,  // sync
	    0x40, 0x00, 0x00, 0x00,  // Type 2 NOP
	};
	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	ASSERT_TRUE(reader);
	EXPECT_EQ(reader->begin(), reader->end());
}

TEST(BitstreamReaderTest, ParsesType2AfterType1Packet) {
	std::vector<uint8_t> bitstream{
	    0xAA, 0x99, 0x55, 0x66,  // sync
	    0x28, 0x00, 0x60, 0x00,  // Type 1 Read zero bytes from 6
	    0x48, 0x00, 0x00, 0x04,  // Type 2 write of 4 words
	    0x1,  0x2,  0x3,  0x4,  0x5, 0x6, 0x7, 0x8,
	    0x9,  0xA,  0xB,  0xC,  0xD, 0xE, 0xF, 0x10,
	};
	std::vector<uint32_t> data_words{0x01020304, 0x05060708, 0x090A0B0C,
	                                 0x0D0E0F10};

	auto reader = xc7series::BitstreamReader::InitWithBytes(bitstream);
	ASSERT_TRUE(reader);
	ASSERT_NE(reader->begin(), reader->end());

	auto first_packet = reader->begin();
	EXPECT_EQ(first_packet->opcode(),
	          xc7series::ConfigurationPacket::Opcode::Read);
	EXPECT_EQ(first_packet->address(),
	          xc7series::ConfigurationRegister::FDRO);
	EXPECT_EQ(first_packet->data(), absl::Span<uint32_t>());

	auto second_packet = ++first_packet;
	ASSERT_NE(second_packet, reader->end());
	EXPECT_EQ(second_packet->opcode(),
	          xc7series::ConfigurationPacket::Opcode::Read);
	EXPECT_EQ(second_packet->address(),
	          xc7series::ConfigurationRegister::FDRO);
	EXPECT_EQ(first_packet->data(), absl::Span<uint32_t>(data_words));

	EXPECT_EQ(++first_packet, reader->end());
}