/****************************************************************************
 Copyright (C) 2013 Henry van Merode. All rights reserved.
 Copyright (c) 2015-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

 https://axis-project.github.io/

 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, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 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.
 ****************************************************************************/

#include "CCPUScriptLexer.h"

NS_AX_BEGIN
PUScriptLexer::PUScriptLexer() {}

PUScriptLexer::~PUScriptLexer() {}

void PUScriptLexer::openLexer(std::string_view str, std::string_view source, PUScriptTokenList& tokens)
{
    enum
    {
        READY = 0,
        COMMENT,
        MULTICOMMENT,
        WORD,
        QUOTE,
        VAR,
        POSSIBLECOMMENT
    };

    const wchar_t varopener = '$', quote = '\"', slash = '/', backslash = '\\', openbrace = '{', closebrace = '}',
                  colon = ':', star = '*', cr = '\r', lf = '\n';
    char c = 0, lastc = 0;

    std::string lexeme;
    unsigned int line = 1, state = READY, lastQuote = 0;

    //    ScriptTokenListPtr tokens(OGRE_NEW_T(ScriptTokenList, MEMCATEGORY_GENERAL)(), SPFM_DELETE_T);
    //
    // Iterate over the input

    std::string_view::const_iterator i = str.begin(), end = str.end();
    while (i != end)
    {
        lastc = c;
        c     = *i;

        if (c == quote)
            lastQuote = line;

        switch (state)
        {
        case READY:
            if (c == slash && lastc == slash)
            {
                // Comment start, clear out the lexeme
                lexeme = "";
                state  = COMMENT;
            }
            else if (c == star && lastc == slash)
            {
                lexeme = "";
                state  = MULTICOMMENT;
            }
            else if (c == quote)
            {
                // Clear out the lexeme ready to be filled with quotes!
                lexeme = c;
                state  = QUOTE;
            }
            else if (c == varopener)
            {
                // Set up to read in a variable
                lexeme = c;
                state  = VAR;
            }
            else if (isNewline(c))
            {
                lexeme = c;
                setToken(lexeme, line, source, &tokens);
            }
            else if (!isWhitespace(c))
            {
                lexeme = c;
                if (c == slash)
                    state = POSSIBLECOMMENT;
                else
                    state = WORD;
            }
            break;
        case COMMENT:
            // This newline happens to be ignored automatically
            if (isNewline(c))
                state = READY;
            break;
        case MULTICOMMENT:
            if (c == slash && lastc == star)
                state = READY;
            break;
        case POSSIBLECOMMENT:
            if (c == slash && lastc == slash)
            {
                lexeme = "";
                state  = COMMENT;
                break;
            }
            else if (c == star && lastc == slash)
            {
                lexeme = "";
                state  = MULTICOMMENT;
                break;
            }
            else
            {
                state = WORD;
            }
        case WORD:
            if (isNewline(c))
            {
                setToken(lexeme, line, source, &tokens);
                lexeme = c;
                setToken(lexeme, line, source, &tokens);
                state = READY;
            }
            else if (isWhitespace(c))
            {
                setToken(lexeme, line, source, &tokens);
                state = READY;
            }
            else if (c == openbrace || c == closebrace || c == colon)
            {
                setToken(lexeme, line, source, &tokens);
                lexeme = c;
                setToken(lexeme, line, source, &tokens);
                state = READY;
            }
            else
            {
                lexeme += c;
            }
            break;
        case QUOTE:
            if (c != backslash)
            {
                // Allow embedded quotes with escaping
                if (c == quote && lastc == backslash)
                {
                    lexeme += c;
                }
                else if (c == quote)
                {
                    lexeme += c;
                    setToken(lexeme, line, source, &tokens);
                    state = READY;
                }
                else
                {
                    // Backtrack here and allow a backslash normally within the quote
                    if (lastc == backslash)
                        lexeme = lexeme + "\\" + c;
                    else
                        lexeme += c;
                }
            }
            break;
        case VAR:
            if (isNewline(c))
            {
                setToken(lexeme, line, source, &tokens);
                lexeme = c;
                setToken(lexeme, line, source, &tokens);
                state = READY;
            }
            else if (isWhitespace(c))
            {
                setToken(lexeme, line, source, &tokens);
                state = READY;
            }
            else if (c == openbrace || c == closebrace || c == colon)
            {
                setToken(lexeme, line, source, &tokens);
                lexeme = c;
                setToken(lexeme, line, source, &tokens);
                state = READY;
            }
            else
            {
                lexeme += c;
            }
            break;
        }

        // Separate check for newlines just to track line numbers
        if (c == cr || (c == lf && lastc != cr))
            line++;

        ++i;
    }

    // Check for valid exit states
    if (state == WORD || state == VAR)
    {
        if (!lexeme.empty())
            setToken(lexeme, line, source, &tokens);
    }
    else
    {
        if (state == QUOTE)
        {
            printf("Exception\n");

            //            OGRE_EXCEPT(Exception::ERR_INVALID_STATE,
            //                        Ogre::String("no matching \" found for \" at line ") +
            //                        Ogre::StringConverter::toString(lastQuote),
            //                        "ScriptLexer::tokenize");
        }
    }
}

void PUScriptLexer::setToken(std::string_view lexeme, int line, std::string_view source, PUScriptTokenList* tokens)
{

    const char openBracket = '{', closeBracket = '}', colon = ':', quote = '\"', var = '$';

    PUScriptToken* token = new PUScriptToken;

    token->lexeme = lexeme;
    token->line   = line;
    token->file   = source;
    bool ignore   = false;

    // Check the user token map first
    if (lexeme.size() == 1 && isNewline(lexeme[0]))
    {
        token->type = TID_NEWLINE;
        if (!tokens->empty() && tokens->back()->type == TID_NEWLINE)
        {
            ignore = true;
            delete token;
        }
    }
    else if (lexeme.size() == 1 && lexeme[0] == openBracket)
        token->type = TID_LBRACKET;
    else if (lexeme.size() == 1 && lexeme[0] == closeBracket)
        token->type = TID_RBRACKET;
    else if (lexeme.size() == 1 && lexeme[0] == colon)
        token->type = TID_COLON;
    else if (lexeme[0] == var)
        token->type = TID_VARIABLE;
    else
    {
        // This is either a non-zero length phrase or quoted phrase
        if (lexeme.size() >= 2 && lexeme[0] == quote && lexeme[lexeme.size() - 1] == quote)
        {
            token->type = TID_QUOTE;
        }
        else
        {
            token->type = TID_WORD;
        }
    }

    if (!ignore)
        tokens->push_back(token);
}

bool PUScriptLexer::isWhitespace(char c) const
{
    return c == ' ' || c == '\r' || c == '\t';
}

bool PUScriptLexer::isNewline(char c) const
{

    return c == '\n' || c == '\r';
}

NS_AX_END