/* This file is part of the dynarmic project.
 * Copyright (c) 2018 MerryMage
 * This software may be used and distributed according to the terms of the GNU
 * General Public License version 2 or any later version.
 */

#include "A32/testenv.h"
#include "a32_unicorn.h"
#include "common/assert.h"

#define CHECKED(expr)                                                                              \
    do {                                                                                           \
        if (auto cerr_ = (expr)) {                                                                 \
            ASSERT_MSG(false, "Call " #expr " failed with error: {} ({})\n", cerr_,                \
                       uc_strerror(cerr_));                                                        \
        }                                                                                          \
    } while (0)

constexpr u32 BEGIN_ADDRESS = 0;
constexpr u32 END_ADDRESS = ~u32(0);

A32Unicorn::A32Unicorn(ArmTestEnv& testenv) : testenv(testenv) {
    CHECKED(uc_open(UC_ARCH_ARM, UC_MODE_ARM, &uc));
    CHECKED(uc_hook_add(uc, &intr_hook, UC_HOOK_INTR, (void*)InterruptHook, this, BEGIN_ADDRESS, END_ADDRESS));
    CHECKED(uc_hook_add(uc, &mem_invalid_hook, UC_HOOK_MEM_INVALID, (void*)UnmappedMemoryHook, this, BEGIN_ADDRESS, END_ADDRESS));
    CHECKED(uc_hook_add(uc, &mem_write_prot_hook, UC_HOOK_MEM_WRITE, (void*)MemoryWriteHook, this, BEGIN_ADDRESS, END_ADDRESS));
}

A32Unicorn::~A32Unicorn() {
    ClearPageCache();
    CHECKED(uc_hook_del(uc, intr_hook));
    CHECKED(uc_hook_del(uc, mem_invalid_hook));
    CHECKED(uc_close(uc));
}

void A32Unicorn::Run() {
    while (testenv.ticks_left > 0) {
        CHECKED(uc_emu_start(uc, GetPC(), END_ADDRESS, 0, 1));
        testenv.ticks_left--;
        if (!testenv.interrupts.empty() || testenv.code_mem_modified_by_guest) {
            return;
        }
    }
}

constexpr std::array<int, A32Unicorn::num_gprs> gpr_ids{
    UC_ARM_REG_R0, UC_ARM_REG_R1, UC_ARM_REG_R2, UC_ARM_REG_R3, UC_ARM_REG_R4, UC_ARM_REG_R5, UC_ARM_REG_R6, UC_ARM_REG_R7,
    UC_ARM_REG_R8, UC_ARM_REG_R9, UC_ARM_REG_R10, UC_ARM_REG_R11, UC_ARM_REG_R12, UC_ARM_REG_R13, UC_ARM_REG_R14, UC_ARM_REG_R15,
};

A32Unicorn::RegisterArray A32Unicorn::GetRegisters() const {
    RegisterArray regs;
    RegisterPtrArray ptrs;
    for (size_t i = 0; i < ptrs.size(); ++i)
        ptrs[i] = &regs[i];

    CHECKED(uc_reg_read_batch(uc, const_cast<int*>(gpr_ids.data()),
                              reinterpret_cast<void**>(ptrs.data()), num_gprs));
    return regs;
}

void A32Unicorn::SetRegisters(const RegisterArray& value) {
    RegisterConstPtrArray ptrs;
    for (size_t i = 0; i < ptrs.size(); ++i)
        ptrs[i] = &value[i];

    CHECKED(uc_reg_write_batch(uc, const_cast<int*>(gpr_ids.data()),
                               reinterpret_cast<void**>(const_cast<u32**>(ptrs.data())), ptrs.size()));
}

using DoubleExtRegPtrArray = std::array<A32Unicorn::ExtRegArray::pointer, A32Unicorn::num_ext_regs/2>;
using DoubleExtRegConstPtrArray = std::array<A32Unicorn::ExtRegArray::const_pointer, A32Unicorn::num_ext_regs/2>;

constexpr std::array<int, A32Unicorn::num_ext_regs/2> double_ext_reg_ids{
    UC_ARM_REG_D0, UC_ARM_REG_D1, UC_ARM_REG_D2, UC_ARM_REG_D3, UC_ARM_REG_D4, UC_ARM_REG_D5, UC_ARM_REG_D6, UC_ARM_REG_D7,
    UC_ARM_REG_D8, UC_ARM_REG_D9, UC_ARM_REG_D10, UC_ARM_REG_D11, UC_ARM_REG_D12, UC_ARM_REG_D13, UC_ARM_REG_D14, UC_ARM_REG_D15,
    UC_ARM_REG_D16, UC_ARM_REG_D17, UC_ARM_REG_D18, UC_ARM_REG_D19, UC_ARM_REG_D20, UC_ARM_REG_D21, UC_ARM_REG_D22, UC_ARM_REG_D23,
    UC_ARM_REG_D24, UC_ARM_REG_D25, UC_ARM_REG_D26, UC_ARM_REG_D27, UC_ARM_REG_D28, UC_ARM_REG_D29, UC_ARM_REG_D30, UC_ARM_REG_D31,
};

A32Unicorn::ExtRegArray A32Unicorn::GetExtRegs() const {
    ExtRegArray ext_regs;
    DoubleExtRegPtrArray ptrs;
    for (size_t i = 0; i < ptrs.size(); ++i)
        ptrs[i] = &ext_regs[i*2];

    CHECKED(uc_reg_read_batch(uc, const_cast<int*>(double_ext_reg_ids.data()),
                              reinterpret_cast<void**>(ptrs.data()), ptrs.size()));

    return ext_regs;
}

void A32Unicorn::SetExtRegs(const ExtRegArray& value) {
    DoubleExtRegConstPtrArray ptrs;
    for (size_t i = 0; i < ptrs.size(); ++i)
        ptrs[i] = &value[i*2];

    CHECKED(uc_reg_write_batch(uc, const_cast<int*>(double_ext_reg_ids.data()),
                               reinterpret_cast<void* const *>(const_cast<u32**>(ptrs.data())), ptrs.size()));
}

u32 A32Unicorn::GetPC() const {
    u32 pc;
    CHECKED(uc_reg_read(uc, UC_ARM_REG_R15, &pc));
    return pc;
}

u32 A32Unicorn::GetFpscr() const {
    u32 fpsr;
    CHECKED(uc_reg_read(uc, UC_ARM_REG_FPSCR, &fpsr));
    return fpsr;
}

void A32Unicorn::SetFpscr(u32 value) {
    CHECKED(uc_reg_write(uc, UC_ARM_REG_FPSCR, &value));
}

u32 A32Unicorn::GetCpsr() const {
    u32 pstate;
    CHECKED(uc_reg_read(uc, UC_ARM_REG_CPSR, &pstate));
    return pstate;
}

void A32Unicorn::SetCpsr(u32 value) {
    CHECKED(uc_reg_write(uc, UC_ARM_REG_CPSR, &value));
}

void A32Unicorn::ClearPageCache() {
    for (const auto& page : pages) {
        CHECKED(uc_mem_unmap(uc, page->address, 4096));
    }
    pages.clear();
}

void A32Unicorn::DumpMemoryInformation() {
    uc_mem_region* regions;
    u32 count;
    CHECKED(uc_mem_regions(uc, &regions, &count));

    for (u32 i = 0; i < count; ++i) {
        printf("region: start 0x%08x end 0x%08x perms 0x%08x\n", static_cast<u32>(regions[i].begin), static_cast<u32>(regions[i].end), regions[i].perms);
    }

    CHECKED(uc_free(regions));
}

void A32Unicorn::InterruptHook(uc_engine* /*uc*/, u32 int_number, void* user_data) {
    auto* this_ = static_cast<A32Unicorn*>(user_data);

    u32 esr = 0;
    //CHECKED(uc_reg_read(uc, UC_ARM_REG_ESR, &esr));

    auto ec = esr >> 26;
    auto iss = esr & 0xFFFFFF;

    switch (ec) {
    case 0x15: // SVC
        this_->testenv.CallSVC(iss);
        break;
    default:
        this_->testenv.interrupts.emplace_back(fmt::format("Unhandled interrupt: int_number: {:#x}, esr: {:#x} (ec: {:#x}, iss: {:#x})", int_number, esr, ec, iss));
        break;
    }
}

bool A32Unicorn::UnmappedMemoryHook(uc_engine* uc, uc_mem_type /*type*/, u32 start_address, int size, u64 /*value*/, void* user_data) {
    auto* this_ = static_cast<A32Unicorn*>(user_data);

    const auto generate_page = [&](u32 base_address) {
        // printf("generate_page(%x)\n", base_address);

        const u32 permissions = [&]() -> u32 {
            if (base_address < this_->testenv.code_mem.size() * 4)
                return UC_PROT_READ | UC_PROT_EXEC;
            return UC_PROT_READ;
        }();

        auto page = std::make_unique<Page>();
        page->address = base_address;
        for (size_t i = 0; i < page->data.size(); ++i)
            page->data[i] = this_->testenv.MemoryRead8(static_cast<u32>(base_address + i));

        uc_err err = uc_mem_map_ptr(uc, base_address, page->data.size(), permissions, page->data.data());
        if (err == UC_ERR_MAP)
            return; // page already exists
        CHECKED(err);

        this_->pages.emplace_back(std::move(page));
    };

    const auto is_in_range = [](u32 addr, u32 start, u32 end) {
        if (start <= end)
            return addr >= start && addr <= end; // fffff[tttttt]fffff
        return addr >= start || addr <= end;     // ttttt]ffffff[ttttt
    };

    const u32 start_address_page = start_address & ~u32(0xFFF);
    const u32 end_address = start_address + size - 1;

    u32 current_address = start_address_page;
    do {
        generate_page(current_address);
        current_address += 0x1000;
    } while (is_in_range(current_address, start_address_page, end_address) && current_address != start_address_page);

    return true;
}

bool A32Unicorn::MemoryWriteHook(uc_engine* /*uc*/, uc_mem_type /*type*/, u32 start_address, int size, u64 value, void* user_data) {
    auto* this_ = static_cast<A32Unicorn*>(user_data);

    switch (size) {
    case 1:
        this_->testenv.MemoryWrite8(start_address, static_cast<u8>(value));
        break;
    case 2:
        this_->testenv.MemoryWrite16(start_address, static_cast<u16>(value));
        break;
    case 4:
        this_->testenv.MemoryWrite32(start_address, static_cast<u32>(value));
        break;
    case 8:
        this_->testenv.MemoryWrite64(start_address, value);
        break;
    default:
        UNREACHABLE();
    }

    return true;
}