/**
 * @file EscapeSequence.cpp
 * @author apio (cloudapio.eu)
 * @brief ANSI escape sequence parsing.
 *
 * @copyright Copyright (c) 2023, the Luna authors.
 *
 */

#include <luna/CType.h>
#include <luna/Check.h>
#include <luna/EscapeSequence.h>
#include <luna/NumberParsing.h>

EscapeSequenceParser::EscapeSequenceParser(u8 begin)
{
    switch (begin)
    {
    case 0x1b: m_sequence_type = SequenceType::ESC; break;
    case 0x9b: m_sequence_type = SequenceType::CSI; break;
    case 0x90: m_sequence_type = SequenceType::DCS; break;
    case 0x9d: m_sequence_type = SequenceType::OSC; break;
    default: fail("Unrecognized escape sequence type");
    }
}

Result<bool> EscapeSequenceParser::advance(u8 byte)
{
    switch (m_sequence_type)
    {
    case SequenceType::ESC: {
        switch (byte)
        {
        case '[': {
            m_sequence_type = SequenceType::CSI;
            return false;
        };
        case 'P': {
            m_sequence_type = SequenceType::DCS;
            return false;
        };
        case ']': {
            m_sequence_type = SequenceType::OSC;
            return false;
        };
        case '7': {
            m_escape_code = EscapeCode::SaveCursor;
            m_valid = true;
            return true;
        };
        case '8': {
            m_escape_code = EscapeCode::RestoreCursor;
            m_valid = true;
            return true;
        };
        default: {
            m_valid = false;
            return true;
        }
        }
    };
    break;
    case SequenceType::CSI: {
        if (_isdigit(byte))
        {
            m_parsing_parameter = true;
            TRY(m_parameter.try_append(byte));
            return false;
        }

        if (!m_parsing_parameter && byte == ';')
        {
            TRY(m_parameters.try_append(0));
            return false;
        }

        if (m_parsing_parameter)
        {
            TRY(m_parameter.try_append(0));
            int value = static_cast<int>(parse_unsigned_integer((const char*)m_parameter.data(), nullptr, 10));
            m_parameter.clear();
            TRY(m_parameters.try_append(value));
        }

        switch (byte)
        {
        case 'A': {
            m_escape_code = EscapeCode::CursorUp;
            m_valid = true;
            return true;
        };
        case 'B': {
            m_escape_code = EscapeCode::CursorDown;
            m_valid = true;
            return true;
        };
        case 'C': {
            m_escape_code = EscapeCode::CursorForward;
            m_valid = true;
            return true;
        };
        case 'D': {
            m_escape_code = EscapeCode::CursorBack;
            m_valid = true;
            return true;
        };
        case 'E': {
            m_escape_code = EscapeCode::CursorNextLine;
            m_valid = true;
            return true;
        };
        case 'F': {
            m_escape_code = EscapeCode::CursorPreviousLine;
            m_valid = true;
            return true;
        };
        case 'G': {
            m_escape_code = EscapeCode::CursorHorizontalAbsolute;
            m_valid = true;
            return true;
        };
        case 'H': {
            m_escape_code = EscapeCode::SetCursorPosition;
            m_valid = true;
            return true;
        };
        case 'm': {
            m_escape_code = EscapeCode::SelectGraphicRendition;
            m_valid = true;
            return true;
        };
        case ';': {
            return false;
        };
        default: {
            m_valid = false;
            return true;
        }
        }
    };
    break;
    case SequenceType::DCS: todo();
    case SequenceType::OSC: todo();
    default: todo();
    }
}