/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include <rtl/ustrbuf.hxx>
#include <svl/adrparse.hxx>

namespace
{

enum ElementType { ELEMENT_START, ELEMENT_DELIM, ELEMENT_ITEM, ELEMENT_END };

struct ParsedAddrSpec
{
    sal_Unicode const * m_pBegin;
    sal_Unicode const * m_pEnd;
    ElementType m_eLastElem;
    bool m_bAtFound;
    bool m_bReparse;

    ParsedAddrSpec() { reset(); }

    bool isPoorlyValid() const { return m_eLastElem >= ELEMENT_ITEM; }

    bool isValid() const { return isPoorlyValid() && m_bAtFound; }

    void reset();

    void finish();
};

void ParsedAddrSpec::reset()
{
    m_pBegin = nullptr;
    m_pEnd = nullptr;
    m_eLastElem = ELEMENT_START;
    m_bAtFound = false;
    m_bReparse = false;
}

void ParsedAddrSpec::finish()
{
    if (isPoorlyValid())
        m_eLastElem = ELEMENT_END;
    else
        reset();
}

}

class SvAddressParser_Impl
{
    enum State { BEFORE_COLON, BEFORE_LESS, AFTER_LESS, AFTER_GREATER };

    enum TokenType: sal_uInt32 {
        TOKEN_QUOTED = 0x80000000, TOKEN_DOMAIN, TOKEN_COMMENT, TOKEN_ATOM };

    sal_Unicode const * m_pInputPos;
    sal_Unicode const * m_pInputEnd;
    sal_uInt32 m_nCurToken;
    sal_Unicode const * m_pCurTokenBegin;
    sal_Unicode const * m_pCurTokenEnd;
    ParsedAddrSpec m_aOuterAddrSpec;
    ParsedAddrSpec m_aInnerAddrSpec;
    ParsedAddrSpec * m_pAddrSpec;
    State m_eState;
    TokenType m_eType;

    inline void reset();

    void addTokenToAddrSpec(ElementType eTokenElem);

    bool readToken();

    static OUString reparse(sal_Unicode const * pBegin,
                            sal_Unicode const * pEnd);

public:
    SvAddressParser_Impl(SvAddressParser * pParser, const OUString& rIn);
};

inline void SvAddressParser_Impl::reset()
{
    m_aOuterAddrSpec.reset();
    m_aInnerAddrSpec.reset();
    m_pAddrSpec = &m_aOuterAddrSpec;
    m_eState = BEFORE_COLON;
    m_eType = TOKEN_ATOM;
}

void SvAddressParser_Impl::addTokenToAddrSpec(ElementType eTokenElem)
{
    if (!m_pAddrSpec->m_pBegin)
        m_pAddrSpec->m_pBegin = m_pCurTokenBegin;
    else if (m_pAddrSpec->m_pEnd < m_pCurTokenBegin)
        m_pAddrSpec->m_bReparse = true;
    m_pAddrSpec->m_pEnd = m_pCurTokenEnd;
    m_pAddrSpec->m_eLastElem = eTokenElem;
}


//  SvAddressParser_Impl


bool SvAddressParser_Impl::readToken()
{
    m_nCurToken = m_eType;
    switch (m_eType)
    {
        case TOKEN_QUOTED:
        {
            m_pCurTokenBegin = m_pInputPos - 1;
            bool bEscaped = false;
            for (;;)
            {
                if (m_pInputPos >= m_pInputEnd)
                    return false;
                sal_Unicode cChar = *m_pInputPos++;
                if (bEscaped)
                {
                    bEscaped = false;
                }
                else if (cChar == '"')
                {
                    m_pCurTokenEnd = m_pInputPos;
                    return true;
                }
                else if (cChar == '\\')
                    bEscaped = true;
            }
        }

        case TOKEN_DOMAIN:
        {
            m_pCurTokenBegin = m_pInputPos - 1;
            bool bEscaped = false;
            for (;;)
            {
                if (m_pInputPos >= m_pInputEnd)
                    return false;
                sal_Unicode cChar = *m_pInputPos++;
                if (bEscaped)
                    bEscaped = false;
                else if (cChar == ']')
                {
                    m_pCurTokenEnd = m_pInputPos;
                    return true;
                }
                else if (cChar == '\\')
                    bEscaped = true;
            }
        }

        case TOKEN_COMMENT:
        {
            m_pCurTokenBegin = m_pInputPos - 1;
            bool bEscaped = false;
            int nLevel = 0;
            for (;;)
            {
                if (m_pInputPos >= m_pInputEnd)
                    return false;
                sal_Unicode cChar = *m_pInputPos++;
                if (bEscaped)
                {
                    bEscaped = false;
                }
                else if (cChar == '(')
                {
                    ++nLevel;
                }
                else if (cChar == ')')
                    if (nLevel)
                    {
                        --nLevel;
                    }
                    else
                        return true;
                else if (cChar == '\\')
                {
                    bEscaped = true;
                }
            }
        }

        default:
        {
            sal_Unicode cChar;
            for (;;)
            {
                if (m_pInputPos >= m_pInputEnd)
                    return false;
                cChar = *m_pInputPos++;
                if (cChar > ' ' && cChar != 0x7F) // DEL
                    break;
            }
            m_pCurTokenBegin = m_pInputPos - 1;
            if (cChar == '"' || cChar == '(' || cChar == ')' || cChar == ','
                || cChar == '.' || cChar == ':' || cChar == ';'
                || cChar == '<' || cChar == '>' || cChar == '@'
                || cChar == '[' || cChar == '\\' || cChar == ']')
            {
                m_nCurToken = cChar;
                m_pCurTokenEnd = m_pInputPos;
                return true;
            }
            else
                for (;;)
                {
                    if (m_pInputPos >= m_pInputEnd)
                    {
                        m_pCurTokenEnd = m_pInputPos;
                        return true;
                    }
                    cChar = *m_pInputPos++;
                    if (cChar <= ' ' || cChar == '"' || cChar == '('
                        || cChar == ')' || cChar == ',' || cChar == '.'
                        || cChar == ':' || cChar == ';' || cChar == '<'
                        || cChar == '>' || cChar == '@' || cChar == '['
                        || cChar == '\\' || cChar == ']'
                        || cChar == 0x7F) // DEL
                    {
                        m_pCurTokenEnd = --m_pInputPos;
                        return true;
                    }
                }
        }
    }
}

// static
OUString SvAddressParser_Impl::reparse(sal_Unicode const * pBegin,
                                       sal_Unicode const * pEnd)
{
    OUStringBuffer aResult;
    TokenType eMode = TOKEN_ATOM;
    bool bEscaped = false;
    int nLevel = 0;
    while (pBegin < pEnd)
    {
        sal_Unicode cChar = *pBegin++;
        switch (eMode)
        {
        case TOKEN_QUOTED:
            if (bEscaped)
            {
                aResult.append(cChar);
                bEscaped = false;
            }
            else if (cChar == '"')
            {
                aResult.append(cChar);
                eMode = TOKEN_ATOM;
            }
            else if (cChar == '\\')
            {
                aResult.append(cChar);
                bEscaped = true;
            }
            else
                aResult.append(cChar);
            break;

        case TOKEN_DOMAIN:
            if (bEscaped)
            {
                aResult.append(cChar);
                bEscaped = false;
            }
            else if (cChar == ']')
            {
                aResult.append(cChar);
                eMode = TOKEN_ATOM;
            }
            else if (cChar == '\\')
            {
                aResult.append(cChar);
                bEscaped = true;
            }
            else
                aResult.append(cChar);
            break;

        case TOKEN_COMMENT:
            if (bEscaped)
                bEscaped = false;
            else if (cChar == '(')
                ++nLevel;
            else if (cChar == ')')
                if (nLevel)
                    --nLevel;
                else
                    eMode = TOKEN_ATOM;
            else if (cChar == '\\')
                bEscaped = true;
            break;

        case TOKEN_ATOM:
            if (cChar <= ' ' || cChar == 0x7F) // DEL
            {
            }
            else if (cChar == '(')
            {
                eMode = TOKEN_COMMENT;
            }
            else
            {
                if (cChar == '"')
                {
                    aResult.append(cChar);
                    eMode = TOKEN_QUOTED;
                }
                else if (cChar == '[')
                {
                    aResult.append(cChar);
                    eMode = TOKEN_QUOTED;
                }
                else
                    aResult.append(cChar);
            }
            break;
        }
    }
    return aResult.makeStringAndClear();
}

SvAddressParser_Impl::SvAddressParser_Impl(SvAddressParser * pParser,
                                           const OUString& rInput)
    : m_pCurTokenBegin(nullptr)
    , m_pCurTokenEnd(nullptr)
{
    m_pInputPos = rInput.getStr();
    m_pInputEnd = m_pInputPos + rInput.getLength();

    reset();
    bool bDone = false;
    for (;;)
    {
        if (!readToken())
        {
            if (m_eState == AFTER_LESS)
                m_nCurToken = '>';
            else
            {
                m_nCurToken = ',';
                bDone = true;
            }
        }
        switch (m_nCurToken)
        {
        case TOKEN_QUOTED:
            if (m_pAddrSpec->m_eLastElem != ELEMENT_END)
            {
                if (m_pAddrSpec->m_bAtFound
                    || m_pAddrSpec->m_eLastElem <= ELEMENT_DELIM)
                    m_pAddrSpec->reset();
                addTokenToAddrSpec(ELEMENT_ITEM);
            }
            m_eType = TOKEN_ATOM;
            break;

        case TOKEN_DOMAIN:
            if (m_pAddrSpec->m_eLastElem != ELEMENT_END)
            {
                if (m_pAddrSpec->m_bAtFound && m_pAddrSpec->m_eLastElem == ELEMENT_DELIM)
                    addTokenToAddrSpec(ELEMENT_ITEM);
                else
                    m_pAddrSpec->reset();
            }
            m_eType = TOKEN_ATOM;
            break;

        case TOKEN_COMMENT:
            m_eType = TOKEN_ATOM;
            break;

        case TOKEN_ATOM:
            if (m_pAddrSpec->m_eLastElem != ELEMENT_END)
            {
                if (m_pAddrSpec->m_eLastElem != ELEMENT_DELIM)
                    m_pAddrSpec->reset();
                addTokenToAddrSpec(ELEMENT_ITEM);
            }
            break;

        case '(':
            m_eType = TOKEN_COMMENT;
            break;

        case ')':
        case '\\':
        case ']':
            m_pAddrSpec->finish();
            break;

        case '<':
            switch (m_eState)
            {
            case BEFORE_COLON:
            case BEFORE_LESS:
                m_aOuterAddrSpec.finish();
                m_pAddrSpec = &m_aInnerAddrSpec;
                m_eState = AFTER_LESS;
                break;

            case AFTER_LESS:
                m_aInnerAddrSpec.finish();
                break;

            case AFTER_GREATER:
                m_aOuterAddrSpec.finish();
                break;
            }
            break;

        case '>':
            if (m_eState == AFTER_LESS)
            {
                m_aInnerAddrSpec.finish();
                if (m_aInnerAddrSpec.isValid())
                    m_aOuterAddrSpec.m_eLastElem = ELEMENT_END;
                m_pAddrSpec = &m_aOuterAddrSpec;
                m_eState = AFTER_GREATER;
            }
            else
            {
                m_aOuterAddrSpec.finish();
            }
            break;

        case '@':
            if (m_pAddrSpec->m_eLastElem != ELEMENT_END)
            {
                if (!m_pAddrSpec->m_bAtFound
                    && m_pAddrSpec->m_eLastElem == ELEMENT_ITEM)
                {
                    addTokenToAddrSpec(ELEMENT_DELIM);
                    m_pAddrSpec->m_bAtFound = true;
                }
                else
                    m_pAddrSpec->reset();
            }
            break;

        case ',':
        case ';':
            if (m_eState == AFTER_LESS)
                if (m_nCurToken == ',')
                {
                    if (m_aInnerAddrSpec.m_eLastElem != ELEMENT_END)
                        m_aInnerAddrSpec.reset();
                }
                else
                    m_aInnerAddrSpec.finish();
            else
            {
                if(m_aInnerAddrSpec.isValid() || (!m_aOuterAddrSpec.isValid() && m_aInnerAddrSpec.isPoorlyValid()))
                {
                    m_pAddrSpec = &m_aInnerAddrSpec;
                }
                else if(m_aOuterAddrSpec.isPoorlyValid())
                {
                    m_pAddrSpec = &m_aOuterAddrSpec;
                }
                else
                {
                    m_pAddrSpec = nullptr;
                }

                if (m_pAddrSpec)
                {
                    OUString aTheAddrSpec;
                    if (m_pAddrSpec->m_bReparse)
                        aTheAddrSpec = reparse(m_pAddrSpec->m_pBegin, m_pAddrSpec->m_pEnd);
                    else
                    {
                        sal_Int32 nLen = m_pAddrSpec->m_pEnd - m_pAddrSpec->m_pBegin;
                        if (nLen == rInput.getLength())
                            aTheAddrSpec = rInput;
                        else
                            aTheAddrSpec = rInput.copy( (m_pAddrSpec->m_pBegin - rInput.getStr()),
                                                        nLen);
                    }
                    pParser->m_vAddresses.emplace_back( aTheAddrSpec );
                }
                if (bDone)
                    return;
                reset();
            }
            break;

        case ':':
            switch (m_eState)
            {
            case BEFORE_COLON:
                m_aOuterAddrSpec.reset();
                m_eState = BEFORE_LESS;
                break;

            case BEFORE_LESS:
            case AFTER_GREATER:
                m_aOuterAddrSpec.finish();
                break;

            case AFTER_LESS:
                m_aInnerAddrSpec.reset();
                break;
            }
            break;

        case '"':
            m_eType = TOKEN_QUOTED;
            break;

        case '.':
            if (m_pAddrSpec->m_eLastElem != ELEMENT_END)
            {
                if (m_pAddrSpec->m_eLastElem != ELEMENT_DELIM)
                    addTokenToAddrSpec(ELEMENT_DELIM);
                else
                    m_pAddrSpec->reset();
            }
            break;

        case '[':
            m_eType = TOKEN_DOMAIN;
            break;
        }
    }
}

SvAddressParser::SvAddressParser(const OUString& rInput)
{
    SvAddressParser_Impl aDoParse(this, rInput);
}

SvAddressParser::~SvAddressParser()
{
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */