#include <gtest/gtest.h>
#include <vector>
#include <memory>

#include "rom/rom.h"
#include "zelda3/dungeon/room.h"
#include "zelda3/dungeon/dungeon_rom_addresses.h"

namespace yaze {
namespace zelda3 {
namespace test {

class DungeonSaveTest : public ::testing::Test {
 protected:
  void SetUp() override {
    rom_ = std::make_unique<Rom>();
    // Create a minimal ROM for testing (2MB)
    std::vector<uint8_t> dummy_data(0x200000, 0);
    rom_->LoadFromData(dummy_data);

    SetupRoomObjectPointers();
    SetupSpritePointers();

    room_ = std::make_unique<Room>(0, rom_.get());
  }

  void SetupRoomObjectPointers() {
    // 1. Setup kRoomObjectPointer (0x874C) to point to our table at 0xF8000
    // The code reads 3 bytes from kRoomObjectPointer
    // int object_pointer = (rom_data[room_object_pointer + 2] << 16) + ...
    // We want object_pointer to be 0xF8000 (PC address)
    // 0xF8000 is 1F:8000 in LoROM (Bank 1F)
    // So we write 00 80 1F at 0x874C
    int ptr_loc = kRoomObjectPointer;
    rom_->mutable_data()[ptr_loc] = 0x00;
    rom_->mutable_data()[ptr_loc + 1] = 0x80;
    rom_->mutable_data()[ptr_loc + 2] = 0x1F;

    // 2. Setup Room 0 pointer at 0xF8000
    // We want Room 0 data to be at 0x100000 (Bank 20, PC 0x100000)
    // 0x100000 is 20:8000 in LoROM
    // Write 00 80 20 at 0xF8000
    int table_loc = 0xF8000;
    rom_->mutable_data()[table_loc] = 0x00;
    rom_->mutable_data()[table_loc + 1] = 0x80;
    rom_->mutable_data()[table_loc + 2] = 0x20;

    // 3. Setup Room 1 pointer at 0xF8003 (for size calculation)
    // We want Room 0 to have 0x100 bytes of space
    // So Room 1 starts at 0x100100 (20:8100)
    // Write 00 81 20 at 0xF8003
    rom_->mutable_data()[table_loc + 3] = 0x00;
    rom_->mutable_data()[table_loc + 4] = 0x81;
    rom_->mutable_data()[table_loc + 5] = 0x20;

    // 4. Setup Room 0 Object Data Header at 0x100000
    // The code reads tile_address from room_address (which is 0x100000)
    // int tile_address = (rom_data[room_address + 2] << 16) + ...
    // We want tile_address to be 0x100005 (just after this pointer)
    // 0x100005 is 20:8005
    int room_data_loc = 0x100000;
    rom_->mutable_data()[room_data_loc] = 0x05;
    rom_->mutable_data()[room_data_loc + 1] = 0x80;
    rom_->mutable_data()[room_data_loc + 2] = 0x20;

    // 5. Setup actual object data at 0x100005
    // Header (2 bytes) + Objects
    // 0x100005: Floor/Layout info (2 bytes)
    rom_->mutable_data()[0x100005] = 0x00;
    rom_->mutable_data()[0x100006] = 0x00;
    // 0x100007: Start of objects
    // Empty object list: FF FF (Layer 1) FF FF (Layer 2) FF FF (Layer 3) FF FF (End)
    // Total 8 bytes.
    // Available space is 0x100 - 5 = 0xFB bytes (approx)
    // Actually CalculateRoomSize uses the Room Pointers (0xF8000).
    // Room 0 Size = 0x100100 - 0x100000 = 0x100 (256 bytes).
    // Used by header/pointers: 5 bytes? No, CalculateRoomSize returns raw size between room starts.
    // So available is 256 bytes.
    // SaveObjects subtracts 2 for header. So 254 bytes for objects.
  }

  void SetupSpritePointers() {
    // 1. Setup kRoomsSpritePointer (0x4C298)
    // Points to table in Bank 09. Let's put table at 0x48000 (09:8000)
    int ptr_loc = kRoomsSpritePointer;
    rom_->mutable_data()[ptr_loc] = 0x00;
    rom_->mutable_data()[ptr_loc + 1] = 0x80; 
    // Bank is hardcoded to 0x09 in code, so we only write low 2 bytes.

    // 2. Setup Sprite Pointer Table at 0x48000 (09:8000)
    // Room 0 pointer -> sprite list at 0x49000 (09:9000)
    // Write 00 90 at 0x48000
    int table_loc = 0x48000;
    rom_->mutable_data()[table_loc] = 0x00;
    rom_->mutable_data()[table_loc + 1] = 0x90;

    // Room 1 pointer at 0x48002 (for size calculation)
    // Let's give 0x50 bytes for sprites.
    // Next room at 0x49050 (09:9050)
    // Write 50 90 at 0x48002
    rom_->mutable_data()[table_loc + 2] = 0x50;
    rom_->mutable_data()[table_loc + 3] = 0x90;

    // 3. Setup Sprite Data at 0x49000
    // Sortsprite byte (0 or 1)
    rom_->mutable_data()[0x49000] = 0x00;
    // End of sprites (0xFF)
    rom_->mutable_data()[0x49001] = 0xFF;
  }

  std::unique_ptr<Rom> rom_;
  std::unique_ptr<Room> room_;
};

TEST_F(DungeonSaveTest, SaveObjects_FitsInSpace) {
  // Add a few objects
  RoomObject obj1(0x10, 10, 10, 0, 0);
  room_->AddObject(obj1);

  auto status = room_->SaveObjects();
  EXPECT_TRUE(status.ok()) << status.message();
}

TEST_F(DungeonSaveTest, SaveObjects_TooLarge) {
  // Add MANY objects to exceed 256 bytes
  // Each object encodes to 3 bytes.
  // We need > 85 objects.
  for (int i = 0; i < 100; ++i) {
    RoomObject obj(0x10, 10, 10, 0, 0);
    room_->AddObject(obj);
  }

  auto status = room_->SaveObjects();
  EXPECT_FALSE(status.ok());
  EXPECT_EQ(status.code(), absl::StatusCode::kOutOfRange);
}

TEST_F(DungeonSaveTest, SaveSprites_FitsInSpace) {
  // Add a sprite
  zelda3::Sprite spr(0x10, 10, 10, 0, 0);
  room_->GetSprites().push_back(spr);

  auto status = room_->SaveSprites();
  EXPECT_TRUE(status.ok()) << status.message();
}

TEST_F(DungeonSaveTest, SaveSprites_TooLarge) {
  // Add MANY sprites to exceed 0x50 (80) bytes
  // Each sprite is 3 bytes.
  // We need > 26 sprites.
  for (int i = 0; i < 30; ++i) {
    zelda3::Sprite spr(0x10, 10, 10, 0, 0);
    room_->GetSprites().push_back(spr);
  }

  auto status = room_->SaveSprites();
  EXPECT_FALSE(status.ok());
  EXPECT_EQ(status.code(), absl::StatusCode::kOutOfRange);
}

}  // namespace test
}  // namespace zelda3
}  // namespace yaze