#include <cwctype>
#include <string>
#include <vector>

#include "neovision/ansi.h"

namespace neovision {
namespace ansi {

// AnsiParser ------------------------------------------------------------------

std::wstring AnsiParser::ControlPortion() const
{
    return m_controlPortion;
}

std::vector<std::wstring> AnsiParser::CsiParameters() const
{
    return m_csiParameters;
}

std::wstring AnsiParser::CsiPortion() const
{
    return m_csiPortion;
}

std::wstring AnsiParser::EscapePortion() const
{
    return m_escapePortion;
}

bool AnsiParser::Parse(wchar_t c)
{
    m_processedChars += c;
    if (m_state == ParseState::None) ParseNoneState(c);
    if (m_state == ParseState::Control)
    {
        ParseControlState(c);
    }
    else if (m_state == ParseState::Escape)
    {
        ParseEscapeState(c);
    }
    else if (m_state == ParseState::Csi)
    {
        ParseCsiState(c);
    }
    if (m_state == ParseState::Error) return false;
    if (m_state == ParseState::None) return false;
    return true;
}

void AnsiParser::ParseNoneState(wchar_t c)
{
    const std::wstring cwstr{c};
    if (ControlCharacters.count(cwstr))
    {
        m_state = ParseState::Control;
    }
    else
    {
        m_state = ParseState::Error;
    }
}

void AnsiParser::ParseControlState(wchar_t c)
{
    const std::wstring cwstr{c};
    if (ControlCharacters.count(cwstr))
    {
        m_controlPortion += cwstr;
        if (cwstr == ControlCharacter::CSI)
            m_state = ParseState::Csi;
        else if (cwstr == ControlCharacter::ESC)
            m_state = ParseState::Escape;
        else
            m_state = ParseState::None;
        return;
    }
    else
    {
        m_state = ParseState::Error;
    }
}

void AnsiParser::ParseEscapeState(wchar_t c)
{
    m_escapePortion += c;
    if (EscapeSequences.count(m_escapePortion))
    {
        if (m_escapePortion == EscapeSequence::CSI) 
            m_state = ParseState::Csi;
        else if (m_escapePortion == EscapeSequence::CSSI)
            m_state = ParseState::Cssi;
    }
    else
    {
        // Longest possible escape sequence start is 2 characters.
        if (m_escapePortion.length() > 2) m_state = ParseState::Error;
    }
}

void AnsiParser::ParseCsiState(wchar_t c)
{
    const std::wstring cwstr{c};
    m_csiPortion += cwstr;
    if (CsiSequences.count(cwstr))
    {
        // If c is a csi sequence char, that would mark the end of the sequence.
        if (!m_parameterBuffer.empty())
        {
            m_csiParameters.emplace_back(m_parameterBuffer);
            m_parameterBuffer.clear();
        }
        m_state = ParseState::None;
    }
    else
    {
        /* Characters in the range of 0x30-0x3f are part of a parameter.
           If the character is a semi-colon, then we're starting the next 
           parameter. */
        if (c == L';')
        {
            m_csiParameters.emplace_back(m_parameterBuffer);
            m_parameterBuffer.clear();
        }
        else if ((c >= 0x30) && (c <= 0x3f))
        {
            m_parameterBuffer += c;
        }
        else
        {
            m_state = ParseState::Error;
        }
    }
}

std::wstring AnsiParser::PmPortion() const
{
    return m_pmPortion;
}

std::wstring AnsiParser::ProcessedCharacters() const
{
    return m_processedChars;
}

void AnsiParser::Reset()
{
    m_controlPortion.clear();
    m_escapePortion.clear();
    m_csiPortion.clear();
    m_csiParameters.clear();
    m_csiParameterBuffer.clear();
    m_cssiPortion.clear();
    m_parameterBuffer.clear();
    m_pmPortion.clear();
    m_processedChars.clear();
    m_state = ParseState::None;
}

AnsiParser::ParseState AnsiParser::State() const
{
    return m_state;
}

// Functions -------------------------------------------------------------------

std::wstring MakeEscapeSequence(const std::wstring& sequence)
{
    return ControlCharacter::ESC + sequence;
}

std::wstring MakeCssiSequence(const wchar_t sequence)
{
    return MakeEscapeSequence(EscapeSequence::CSSI + sequence);
}

std::wstring MakeCsiSequence(const std::vector<std::wstring>& sequenceItems)
{
    std::wstring result;
    if (!sequenceItems.empty())
    {
        for (const std::wstring& item: sequenceItems)
        {
            result += item + L";";
        }
        result.pop_back();
    }
    return MakeEscapeSequence(EscapeSequence::CSI + result);
}

std::wstring MakeDecPmSequence(const std::wstring& sequence, const std::wstring& suffix)
{
    return MakeCsiSequence({
        std::wstring{CsiSequence::DECPM},
        sequence,
        suffix
    });
}

std::wstring MakeSgrSequence(const std::vector<std::wstring>& sequenceItems)
{
    std::wstring result;
    if (!sequenceItems.empty())
    {
        for (const std::wstring& item: sequenceItems)
        {
            result += item + L";";
        }
        result.pop_back();
    }
    result += CsiSequence::SGR;
    return MakeCsiSequence({result});
}

} // namespace ansi
} // namespace neovision