// Copyright 2026 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <map>
#include <string>

#include <gtest/gtest.h>

#include "StarOSPanicCheck.h"

namespace StarletBootstrapProbe
{
namespace
{
// MEM1 words by address; absent words read as zero.
class FakeMem1
{
public:
  std::map<u32, u32> words;
  u32 operator()(u32 address) const
  {
    const auto it = words.find(address);
    return it == words.end() ? 0 : it->second;
  }
};

// The record as the loader leaves it, before the image runs.
FakeMem1 CreatedRecord()
{
  FakeMem1 mem1;
  mem1.words[SBR1_BASE] = SBR1_MAGIC;
  mem1.words[SBR1_BASE + 0x04] = SBR1_VERSION;
  mem1.words[SBR1_BASE + 0x08] = SBR1_SIZE;
  mem1.words[SBR1_BASE + SBR1_EXI_OWNER] = SBR1_EXI_STARLET;
  mem1.words[SBR1_BASE + SBR1_RELAY_STATUS] = SBR1_RELAY_JUMPING;
  return mem1;
}

// The record once StarOS's panic path has published it.
FakeMem1 PanicRecord()
{
  FakeMem1 mem1 = CreatedRecord();
  mem1.words[SBR1_BASE + SBR1_STARLET_STATE] = SBR1_STATE_PANIC;
  mem1.words[SBR1_BASE + SBR1_EXI_OWNER] = SBR1_EXI_PPC;
  return mem1;
}

TEST(StarletProbePanicCheck, WaitsForTheCodeAfterTheGuard)
{
  const FakeMem1 none;
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::None, none), "");
  // The guard is stored before the code: a slice can end in between.
  EXPECT_EQ(UnmetPanicCondition(1, 0, SBR1Mode::None, none), "__panic_code is 0, not 1");
  EXPECT_EQ(UnmetPanicCondition(1, 2, SBR1Mode::None, none), "__panic_code is 2, not 1");
  EXPECT_EQ(UnmetPanicCondition(0, 1, SBR1Mode::None, none), "__panic_state is 0, not 1");
  EXPECT_EQ(UnmetPanicCondition(2, 1, SBR1Mode::None, none), "__panic_state is 2, not 1");
  // The words come first, whatever the record says.
  EXPECT_EQ(UnmetPanicCondition(1, 0, SBR1Mode::Record, PanicRecord()),
            "__panic_code is 0, not 1");
}

TEST(StarletProbePanicCheck, RecordNeedsPanicStateReasonAndEXIBack)
{
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Record, PanicRecord()), "");
  // Panic words set, record not yet published.
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Record, CreatedRecord()),
            "SBR1 STARLET_STATE is 0, not 5");
  FakeMem1 running = PanicRecord();
  running.words[SBR1_BASE + SBR1_STARLET_STATE] = 2;
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Record, running), "SBR1 STARLET_STATE is 2, not 5");
  FakeMem1 reason = PanicRecord();
  reason.words[SBR1_BASE + SBR1_FATAL_REASON] = 3;
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Record, reason), "SBR1 FATAL_REASON is 3, not 0");
  // State published, EXI not yet handed back to the PPC.
  FakeMem1 exi = PanicRecord();
  exi.words[SBR1_BASE + SBR1_EXI_OWNER] = SBR1_EXI_STARLET;
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Record, exi), "SBR1 EXI_OWNER is 2, not 1");
}

TEST(StarletProbePanicCheck, AbsentRecordAreaStaysZero)
{
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Absent, FakeMem1{}), "");
  for (const u32 offset : {0x0u, SBR1_STARLET_STATE, SBR1_EXI_OWNER, SBR1_SIZE - 4})
  {
    FakeMem1 written;
    written.words[SBR1_BASE + offset] = 5;
    EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Absent, written),
              fmt::format("SBR1 area word +{:#x} is 0x5 without a record", offset));
  }
  // Words outside the area are not the record's.
  FakeMem1 outside;
  outside.words[SBR1_BASE - 4] = 5;
  outside.words[SBR1_BASE + SBR1_SIZE] = 5;
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::Absent, outside), "");
  // Without an SBR1 option, a written area is not checked.
  EXPECT_EQ(UnmetPanicCondition(1, 1, SBR1Mode::None, PanicRecord()), "");
}
}  // namespace
}  // namespace StarletBootstrapProbe