/*

 * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>

 * Copyright (c) 2022, Idan Horowitz <idan.horowitz@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#pragma once

#include <AK/Error.h>

#include <AK/Try.h>

#ifndef KERNEL

#    include <AK/JsonValue.h>

#endif

namespace AK {

template<typename Builder>

inline constexpr bool IsLegacyBuilder = requires(Builder builder) { builder.try_append('\0'); };

template<typename Builder = void>

class JsonObjectSerializer;

template<typename Builder = void>

class JsonArraySerializer {

public:

    static ErrorOr<JsonArraySerializer> try_create(Builder& builder)

    {

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(builder.try_append('['));

        else

            TRY(builder.append('['));

        return JsonArraySerializer { builder };

    }

    JsonArraySerializer(JsonArraySerializer&& other)

        : m_builder(other.m_builder)

        , m_empty(other.m_empty)

        , m_finished(exchange(other.m_finished, true))

    {

    }

    JsonArraySerializer(JsonArraySerializer const&) = delete;

#ifndef KERNEL

    ErrorOr<void> add(JsonValue const& value)

    {

        TRY(begin_item());

        value.serialize(m_builder);

        return {};

    }

#endif

    ErrorOr<void> add(StringView value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>) {

            TRY(m_builder.try_append('"'));

            TRY(m_builder.try_append_escaped_for_json(value));

            TRY(m_builder.try_append('"'));

        } else {

            TRY(m_builder.append('"'));

            TRY(m_builder.append_escaped_for_json(value));

            TRY(m_builder.append('"'));

        }

        return {};

    }

#ifndef KERNEL

    ErrorOr<void> add(ByteString const& value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>) {

            TRY(m_builder.try_append('"'));

            TRY(m_builder.try_append_escaped_for_json(value));

            TRY(m_builder.try_append('"'));

        } else {

            TRY(m_builder.append('"'));

            TRY(m_builder.append_escaped_for_json(value));

            TRY(m_builder.append('"'));

        }

        return {};

    }

#endif

    ErrorOr<void> add(char const* value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>) {

            TRY(m_builder.try_append('"'));

            TRY(m_builder.try_append_escaped_for_json(value));

            TRY(m_builder.try_append('"'));

        } else {

            TRY(m_builder.append('"'));

            TRY(m_builder.append_escaped_for_json(value));

            TRY(m_builder.append('"'));

        }

        return {};

    }

    ErrorOr<void> add(bool value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_append(value ? "true"sv : "false"sv));

        else

            TRY(m_builder.append(value ? "true"sv : "false"sv));

        return {};

    }

    ErrorOr<void> add(int value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_appendff("{}", value));

        else

            TRY(m_builder.appendff("{}", value));

        return {};

    }

    ErrorOr<void> add(unsigned value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_appendff("{}", value));

        else

            TRY(m_builder.appendff("{}", value));

        return {};

    }

    ErrorOr<void> add(long value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_appendff("{}", value));

        else

            TRY(m_builder.appendff("{}", value));

        return {};

    }

    ErrorOr<void> add(long unsigned value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_appendff("{}", value));

        else

            TRY(m_builder.appendff("{}", value));

        return {};

    }

    ErrorOr<void> add(long long value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_appendff("{}", value));

        else

            TRY(m_builder.appendff("{}", value));

        return {};

    }

    ErrorOr<void> add(long long unsigned value)

    {

        TRY(begin_item());

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_appendff("{}", value));

        else

            TRY(m_builder.appendff("{}", value));

        return {};

    }

    ErrorOr<JsonArraySerializer<Builder>> add_array()

    {

        TRY(begin_item());

        return JsonArraySerializer::try_create(m_builder);

    }

    // Implemented in JsonObjectSerializer.h

    ErrorOr<JsonObjectSerializer<Builder>> add_object();

    ErrorOr<void> finish()

    {

        VERIFY(!m_finished);

        m_finished = true;

        if constexpr (IsLegacyBuilder<Builder>)

            TRY(m_builder.try_append(']'));

        else

            TRY(m_builder.append(']'));

        return {};

    }

private:

    explicit JsonArraySerializer(Builder& builder)

        : m_builder(builder)

    {

    }

    ErrorOr<void> begin_item()

    {

        VERIFY(!m_finished);

        if (!m_empty) {

            if constexpr (IsLegacyBuilder<Builder>)

                TRY(m_builder.try_append(','));

            else

                TRY(m_builder.append(','));

        }

        m_empty = false;

        return {};

    }

    Builder& m_builder;

    bool m_empty { true };

    bool m_finished { false };

};

// Template magic to allow for JsonArraySerializer<>::try_create(...) - Blame CxByte

template<>

struct JsonArraySerializer<void> {

    template<typename Builder>

    static ErrorOr<JsonArraySerializer<Builder>> try_create(Builder& builder)

    {

        return JsonArraySerializer<Builder>::try_create(builder);

    }

};

}

#if USING_AK_GLOBALLY

using AK::JsonArraySerializer;

#endif