Writer.hpp

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/*
    MIT No Attribution
 
    Copyright 2021-2023 Mr. Hands
 
    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to
    deal in the Software without restriction, including without limitation the
    rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
    sell copies of the Software, and to permit persons to whom the Software is
    furnished to do so.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/
 
#pragma once
 
#include "commands/Command.hpp"
#include "commands/IndentPop.hpp"
#include "commands/IndentPush.hpp"
#include "commands/NextLine.hpp"
#include "data/WriterConfig.hpp"
 
namespace panini
{
 
    class Writer
    {
 
    public:
        virtual ~Writer() = default;
 
        virtual const WriterConfig& GetConfig() const = 0;
 
        virtual BraceBreakingStyle GetBraceBreakingStyle() const = 0;
 
        virtual IncludeStyle GetIncludeStyle() const = 0;
 
        virtual bool IsOnNewLine() const = 0;
 
        virtual Writer& operator << (const std::string& chunk) = 0;
 
        virtual Writer& operator << (const char* chunkString) = 0;
 
        virtual Writer& operator << (const NextLine& command) = 0;
 
        virtual Writer& operator << (const IndentPush& command) = 0;
 
        virtual Writer& operator << (const IndentPop& command) = 0;
 
        virtual Writer& operator << (Command&& command) = 0;
 
        virtual void SetIsInCommentBlock(bool value) = 0;
 
        virtual bool IsChanged() const = 0;
 
        virtual bool Commit(bool force) = 0;
 
    protected:
        virtual void Write(const std::string& chunk) = 0;
 
        virtual void WriteNewLine() = 0;
 
        virtual bool OnCommit(bool force = false) = 0;
 
    };
 
    template <typename TConfig>
    class ConfiguredWriter
        : public Writer
    {
 
        static_assert(std::is_base_of<WriterConfig, TConfig>::value, "TConfig must inherit from WriterConfig");
 
    public:
        inline explicit ConfiguredWriter(const TConfig& config = TConfig{})
            : m_config(config)
        {
            // reserve cached strings
 
            const size_t indentReserveSize = 8 * m_config.chunkIndent.size();
            m_lineIndentCached.reserve(indentReserveSize);
            m_commentIndentCached.reserve(indentReserveSize);
 
            // inherit is not allowed on the config
 
            if (m_config.braceBreakingStyle == BraceBreakingStyle::Inherit)
            {
                TConfig defaultConfig;
                m_config.braceBreakingStyle = defaultConfig.braceBreakingStyle;
            }
 
            if (m_config.includeStyle == IncludeStyle::Inherit)
            {
                WriterConfig defaultConfig;
                m_config.includeStyle = defaultConfig.includeStyle;
            }
        }
 
        virtual ~ConfiguredWriter() = default;
 
        inline const WriterConfig& GetConfig() const override
        {
            return static_cast<const WriterConfig&>(m_config);
        }
 
        inline BraceBreakingStyle GetBraceBreakingStyle() const override
        {
            return m_config.braceBreakingStyle;
        }
 
        inline IncludeStyle GetIncludeStyle() const override
        {
            return m_config.includeStyle;
        }
 
        inline bool IsOnNewLine() const override
        {
            return m_state == State::NewLine;
        }
 
        inline Writer& operator << (const std::string& chunk) override
        {
            if (m_state == State::NewLine)
            {
                if (!m_lineIndentCached.empty())
                {
                    Write(m_lineIndentCached);
                }
                else
                {
                    // allow writers to act on new lines
 
                    Write("");
                }
 
                m_state = State::Chunk;
 
                if (m_isInCommentBlock)
                {
                    Write(" * ");
 
                    if (!m_commentIndentCached.empty())
                    {
                        Write(m_commentIndentCached);
                    }
                }
            }
 
            Write(chunk);
 
            m_lineChunkCountWritten += chunk.size();
 
            return *this;
        }
 
        inline Writer& operator << (const char* chunkString) override
        {
            return *this << std::string(chunkString);
        }
 
        inline Writer& operator << (const NextLine& command) override
        {
            (void)command;
 
            // edge-case for empty lines within a comment block
 
            if (m_isInCommentBlock &&
                m_lineChunkCountWritten == 0)
            {
                Write(" *");
            }
 
            WriteNewLine();
 
            m_state = State::NewLine;
 
            m_lineChunkCountWritten = 0;
 
            return *this;
        }
 
        inline Writer& operator << (const IndentPush& command) override
        {
            (void)command;
 
            if (!m_isInCommentBlock)
            {
                CacheIndentation(m_lineIndentCached, ++m_lineIndentCount);
            }
            else
            {
                CacheIndentation(m_commentIndentCached, ++m_commentIndentCount);
            }
 
            return *this;
        }
 
        inline Writer& operator << (const IndentPop& command) override
        {
            (void)command;
 
            if (!m_isInCommentBlock)
            {
                if (m_lineIndentCount > 0)
                {
                    CacheIndentation(
                        m_lineIndentCached,
                        --m_lineIndentCount
                    );
                }
            }
            else
            {
                if (m_commentIndentCount > 0)
                {
                    CacheIndentation(
                        m_commentIndentCached,
                        --m_commentIndentCount
                    );
                }
            }
 
            return *this;
        }
 
        inline Writer& operator << (Command&& command) override
        {
            command.Visit(*this);
 
            return *this;
        }
 
        inline void SetIsInCommentBlock(bool value) override
        {
            m_isInCommentBlock = value;
 
            m_commentIndentCount = 0;
            m_commentIndentCached.clear();
        }
 
        inline virtual bool IsChanged() const override
        {
            return false;
        }
 
        inline bool Commit(bool force = false) override
        {
            return (force || IsChanged()) && OnCommit(force);
        }
 
    protected:
        void WriteNewLine() override
        {
            Write(m_config.chunkNewLine);
        }
 
    protected:
        TConfig m_config;
 
    private:
        inline void CacheIndentation(std::string& target, int32_t count)
        {
            target.clear();
 
            for (int32_t i = 0; i < count; ++i)
            {
                target += m_config.chunkIndent;
            }
        }
 
    private:
        size_t m_lineChunkCountWritten = 0;
 
        int32_t m_lineIndentCount = 0;
        std::string m_lineIndentCached;
 
        enum class State
        {
            NewLine,
            Chunk
        };
        State m_state = State::NewLine;
 
        bool m_isInCommentBlock = false;
        int32_t m_commentIndentCount = 0;
        std::string m_commentIndentCached;
 
    };
 
    using WriterBase = Writer;
 
};