/************************** BEGIN SimpleParser.h *********************
 FAUST Architecture File
 Copyright (C) 2003-2022 GRAME, Centre National de Creation Musicale
 ---------------------------------------------------------------------
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; either version 2.1 of the License, or
 (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU Lesser General Public License for more details.
 
 You should have received a copy of the GNU Lesser General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 EXCEPTION : As a special exception, you may create a larger work
 that contains this FAUST architecture section and distribute
 that work under terms of your choice, so long as this FAUST
 architecture section is not modified.
 ********************************************************************/

#ifndef SIMPLEPARSER_H
#define SIMPLEPARSER_H

// ---------------------------------------------------------------------
//                          Simple Parser
// A parser returns true if it was able to parse what it is
// supposed to parse and advance the pointer. Otherwise it returns false
// and the pointer is not advanced so that another parser can be tried.
// ---------------------------------------------------------------------

#include <vector>
#include <map>
#include <string>
#include <cmath>
#include <fstream>
#include <sstream>
#include <stdio.h> // We use the lighter fprintf code
#include <ctype.h>
#include <assert.h>

#ifndef _WIN32
# pragma GCC diagnostic ignored "-Wunused-function"
#endif

struct itemInfo {
    std::string type;
    std::string label;
    std::string varname;
    std::string shortname;
    std::string address;
    std::string url;
    int index;
    double init;
    double fmin;
    double fmax;
    double step;
    std::vector<std::pair<std::string, std::string> > meta;
    
    itemInfo():index(0), init(0.), fmin(0.), fmax(0.), step(0.)
    {}
};

// ---------------------------------------------------------------------
//                          Elementary parsers
// ---------------------------------------------------------------------

// Report a parsing error
static bool parseError(const char*& p, const char* errmsg)
{
    fprintf(stderr, "Parse error : %s here : %s\n", errmsg, p);
    return true;
}

/**
 * @brief skipBlank : advance pointer p to the first non blank character
 * @param p the string to parse, then the remaining string
 */
static void skipBlank(const char*& p)
{
    while (isspace(*p)) { p++; }
}

// Parse character x, but don't report error if fails
static bool tryChar(const char*& p, char x)
{
    skipBlank(p);
    if (x == *p) {
        p++;
        return true;
    } else {
        return false;
    }
}

/**
 * @brief parseChar : parse a specific character x
 * @param p the string to parse, then the remaining string
 * @param x the character to recognize
 * @return true if x was found at the begin of p
 */
static bool parseChar(const char*& p, char x)
{
    skipBlank(p);
    if (x == *p) {
        p++;
        return true;
    } else {
        return false;
    }
}

/**
 * @brief parseWord : parse a specific string w
 * @param p the string to parse, then the remaining string
 * @param w the string to recognize
 * @return true if string w was found at the begin of p
 */
static bool parseWord(const char*& p, const char* w)
{
    skipBlank(p);
    const char* saved = p;  // to restore position if we fail
    while ((*w == *p) && (*w)) {++w; ++p;}
    if (*w) {
        p = saved;
        return false;
    } else {
        return true;
    }
}

/**
 * @brief parseDouble : parse number [s]dddd[.dddd] or [s]d[.dddd][E|e][s][dddd] and store the result in x
 * @param p the string to parse, then the remaining string
 * @param x the float number found if any
 * @return true if a float number was found at the begin of p
 */
static bool parseDouble(const char*& p, double& x)
{
    double sign = 1.0;     // sign of the number
    double ipart = 0;      // integral part of the number
    double dpart = 0;      // decimal part of the number before division
    double dcoef = 1.0;    // division factor for the decimal part
    double expsign = 1.0;  // sign of the E|e part
    double expcoef = 0.0;  // multiplication factor of E|e part
    
    bool valid = false;    // true if the number contains at least one digit
    
    skipBlank(p);
    const char* saved = p;  // to restore position if we fail
    
    // Sign
    if (parseChar(p, '+')) {
        sign = 1.0;
    } else if (parseChar(p, '-')) {
        sign = -1.0;
    }
    
    // Integral part
    while (isdigit(*p)) {
        valid = true;
        ipart = ipart*10 + (*p - '0');
        p++;
    }
    
    // Possible decimal part
    if (parseChar(p, '.')) {
        while (isdigit(*p)) {
            valid = true;
            dpart = dpart*10 + (*p - '0');
            dcoef *= 10.0;
            p++;
        }
    }
    
    // Possible E|e part
    if (parseChar(p, 'E') || parseChar(p, 'e')) {
        if (parseChar(p, '+')) {
            expsign = 1.0;
        } else if (parseChar(p, '-')) {
            expsign = -1.0;
        }
        while (isdigit(*p)) {
            expcoef = expcoef*10 + (*p - '0');
            p++;
        }
    }
    
    if (valid)  {
        x = (sign*(ipart + dpart/dcoef)) * std::pow(10.0, expcoef*expsign);
    } else {
        p = saved;
    }
    return valid;
}

/**
 * @brief parseString, parse an arbitrary quoted string q...q and store the result in s
 * @param p the string to parse, then the remaining string
 * @param quote the character used to quote the string
 * @param s the (unquoted) string found if any
 * @return true if a string was found at the begin of p
 */
static bool parseString(const char*& p, char quote, std::string& s)
{
    std::string str;
    skipBlank(p);
    
    const char* saved = p;  // to restore position if we fail
    if (*p++ == quote) {
        while ((*p != 0) && (*p != quote)) {
            str += *p++;
        }
        if (*p++ == quote) {
            s = str;
            return true;
        }
    }
    p = saved;
    return false;
}

/**
 * @brief parseSQString, parse a single quoted string '...' and store the result in s
 * @param p the string to parse, then the remaining string
 * @param s the (unquoted) string found if any
 * @return true if a string was found at the begin of p
 */
static bool parseSQString(const char*& p, std::string& s)
{
    return parseString(p, '\'', s);
}

/**
 * @brief parseDQString, parse a double quoted string "..." and store the result in s
 * @param p the string to parse, then the remaining string
 * @param s the (unquoted) string found if any
 * @return true if a string was found at the begin of p
 */
static bool parseDQString(const char*& p, std::string& s)
{
    return parseString(p, '"', s);
}

// ---------------------------------------------------------------------
//
//                          IMPLEMENTATION
// 
// ---------------------------------------------------------------------

/**
 * @brief parseMenuItem, parse a menu item ...'low':440.0...
 * @param p the string to parse, then the remaining string
 * @param name the name found
 * @param value the value found
 * @return true if a nemu item was found
 */
static bool parseMenuItem(const char*& p, std::string& name, double& value)
{
    const char* saved = p;  // to restore position if we fail
    if (parseSQString(p, name) && parseChar(p, ':') && parseDouble(p, value)) {
        return true;
    } else {
        p = saved;
        return false;
    }
}

static bool parseMenuItem2(const char*& p, std::string& name)
{
    const char* saved = p;  // to restore position if we fail
    // single quoted
    if (parseSQString(p, name)) {
        return true;
    } else {
        p = saved;
        return false;
    }
}

/**
 * @brief parseMenuList, parse a menu list {'low' : 440.0; 'mid' : 880.0; 'hi' : 1760.0}...
 * @param p the string to parse, then the remaining string
 * @param names the vector of names found
 * @param values the vector of values found
 * @return true if a menu list was found
 */
static bool parseMenuList(const char*& p, std::vector<std::string>& names, std::vector<double>& values)
{
    std::vector<std::string> tmpnames;
    std::vector<double> tmpvalues;
    const char* saved = p; // to restore position if we fail

    if (parseChar(p, '{')) {
        do {
            std::string n;
            double v;
            if (parseMenuItem(p, n, v)) {
                tmpnames.push_back(n);
                tmpvalues.push_back(v);
            } else {
                p = saved;
                return false;
            }
        } while (parseChar(p, ';'));
        if (parseChar(p, '}')) {
            // we suceeded
            names = tmpnames;
            values = tmpvalues;
            return true;
        }
    }
    p = saved;
    return false;
}

static bool parseMenuList2(const char*& p, std::vector<std::string>& names, bool debug)
{
    std::vector<std::string> tmpnames;
    const char* saved = p;  // to restore position if we fail
    
    if (parseChar(p, '{')) {
        do {
            std::string n;
            if (parseMenuItem2(p, n)) {
                tmpnames.push_back(n);
            } else {
                goto error;
            }
        } while (parseChar(p, ';'));
        if (parseChar(p, '}')) {
            // we suceeded
            names = tmpnames;
            return true;
        }
    }
    
error:
    if (debug) { fprintf(stderr, "parseMenuList2 : (%s) is not a valid list !\n", p); }
    p = saved;
    return false;
}

/// ---------------------------------------------------------------------
// Parse list of strings
/// ---------------------------------------------------------------------
static bool parseList(const char*& p, std::vector<std::string>& items)
{
    const char* saved = p;  // to restore position if we fail
    if (parseChar(p, '[')) {
        do {
            std::string item;
            if (!parseDQString(p, item)) {
                p = saved;
                return false;
            }
            items.push_back(item);
        } while (tryChar(p, ','));
        return parseChar(p, ']');
    } else {
        p = saved;
        return false;
    }
}

static bool parseMetaData(const char*& p, std::map<std::string, std::string>& metadatas)
{
    const char* saved = p; // to restore position if we fail
    std::string metaKey, metaValue;
    if (parseChar(p, ':') && parseChar(p, '[')) {
        do { 
            if (parseChar(p, '{') && parseDQString(p, metaKey) && parseChar(p, ':') && parseDQString(p, metaValue) && parseChar(p, '}')) {
                metadatas[metaKey] = metaValue;
            }
        } while (tryChar(p, ','));
        return parseChar(p, ']');
    } else {
        p = saved;
        return false;
    }
}

static bool parseItemMetaData(const char*& p, std::vector<std::pair<std::string, std::string> >& metadatas)
{
    const char* saved = p; // to restore position if we fail
    std::string metaKey, metaValue;
    if (parseChar(p, ':') && parseChar(p, '[')) {
        do { 
            if (parseChar(p, '{') && parseDQString(p, metaKey) && parseChar(p, ':') && parseDQString(p, metaValue) && parseChar(p, '}')) {
                metadatas.push_back(std::make_pair(metaKey, metaValue));
            }
        } while (tryChar(p, ','));
        return parseChar(p, ']');
    } else {
        p = saved;
        return false;
    }
}

// ---------------------------------------------------------------------
// Parse metadatas of the interface:
// "name" : "...", "inputs" : "...", "outputs" : "...", ...
// and store the result as key/value
/// ---------------------------------------------------------------------
static bool parseGlobalMetaData(const char*& p, std::string& key, std::string& value, double& dbl, std::map<std::string, std::string>& metadatas, std::vector<std::string>& items)
{
    const char* saved = p; // to restore position if we fail
    if (parseDQString(p, key)) {
        if (key == "meta") {
            return parseMetaData(p, metadatas);
        } else {
            return parseChar(p, ':') && (parseDQString(p, value) || parseList(p, items) || parseDouble(p, dbl));
        }
    } else {
        p = saved;
        return false;
    }
}

// ---------------------------------------------------------------------
// Parse gui:
// "type" : "...", "label" : "...", "address" : "...", ...
// and store the result in uiItems Vector
/// ---------------------------------------------------------------------
static bool parseUI(const char*& p, std::vector<itemInfo>& uiItems, int& numItems)
{
    const char* saved = p; // to restore position if we fail
    if (parseChar(p, '{')) {
   
        std::string label;
        std::string value;
        double dbl = 0;
        
        do {
            if (parseDQString(p, label)) {
                if (label == "type") {
                    if (uiItems.size() != 0) {
                        numItems++;
                    }
                    if (parseChar(p, ':') && parseDQString(p, value)) {   
                        itemInfo item;
                        item.type = value;
                        uiItems.push_back(item);
                    }
                }
                
                else if (label == "label") {
                    if (parseChar(p, ':') && parseDQString(p, value)) {
                        uiItems[numItems].label = value;
                    }
                }
                
                else if (label == "varname") {
                    if (parseChar(p, ':') && parseDQString(p, value)) {
                        uiItems[numItems].varname = value;
                    }
                }
                
                else if (label == "shortname") {
                    if (parseChar(p, ':') && parseDQString(p, value)) {
                        uiItems[numItems].shortname = value;
                    }
                }
                
                else if (label == "address") {
                    if (parseChar(p, ':') && parseDQString(p, value)) {
                        uiItems[numItems].address = value;
                    }
                }
                
                else if (label == "url") {
                    if (parseChar(p, ':') && parseDQString(p, value)) {
                        uiItems[numItems].url = value;
                    }
                }
                
                else if (label == "index") {
                    if (parseChar(p, ':') && parseDouble(p, dbl)) {
                        uiItems[numItems].index = int(dbl);
                    }
                }
                
                else if (label == "meta") {
                    if (!parseItemMetaData(p, uiItems[numItems].meta)) {
                        return false;
                    }
                }
                
                else if (label == "init") {
                    if (parseChar(p, ':') && parseDouble(p, dbl)) {
                        uiItems[numItems].init = dbl;
                    }
                }
                
                else if (label == "min") {
                    if (parseChar(p, ':') && parseDouble(p, dbl)) {
                        uiItems[numItems].fmin = dbl;
                    }
                }
                
                else if (label == "max") {
                    if (parseChar(p, ':') && parseDouble(p, dbl)) {
                        uiItems[numItems].fmax = dbl;
                    }
                }
                
                else if (label == "step") {
                    if (parseChar(p, ':') && parseDouble(p, dbl)) {
                        uiItems[numItems].step = dbl;
                    }
                }
                
                else if (label == "items") {
                    if (parseChar(p, ':') && parseChar(p, '[')) {
                        do {
                            if (!parseUI(p, uiItems, numItems)) {
                                p = saved;
                                return false;
                            }
                        } while (tryChar(p, ','));
                        if (parseChar(p, ']')) {
                            itemInfo item;
                            item.type = "close";
                            uiItems.push_back(item);
                            numItems++;
                        }
                    }
            
                } else {
                    fprintf(stderr, "Parse error unknown : %s \n", label.c_str());
                    assert(false);
                }
            } else {
                p = saved;
                return false;
            }
            
        } while (tryChar(p, ','));
    
        return parseChar(p, '}');
    } else {
        return true; // "items": [] is valid
    }
}

// ---------------------------------------------------------------------
// Parse full JSON record describing a JSON/Faust interface :
// {"metadatas": "...", "ui": [{ "type": "...", "label": "...", "items": [...], "address": "...","init": "...", "min": "...", "max": "...","step": "..."}]}
//
// and store the result in map Metadatas and vector containing the items of the interface. Returns true if parsing was successfull.
/// ---------------------------------------------------------------------
static bool parseJson(const char*& p,
                      std::map<std::string, std::pair<std::string, double> >& metaDatas0,
                      std::map<std::string, std::string>& metaDatas1,
                      std::map<std::string, std::vector<std::string> >& metaDatas2,
                      std::vector<itemInfo>& uiItems)
{
    parseChar(p, '{');
    
    do {
        std::string key;
        std::string value;
        double dbl = 0;
        std::vector<std::string> items;
        if (parseGlobalMetaData(p, key, value, dbl, metaDatas1, items)) {
            if (key != "meta") {
                // keep "name", "inputs", "outputs" key/value pairs
                if (items.size() > 0) {
                    metaDatas2[key] = items;
                    items.clear();
                } else if (value != "") {
                    metaDatas0[key].first = value;
                } else {
                    metaDatas0[key].second = dbl;
                }
            }
        } else if (key == "ui") {
            int numItems = 0;
            parseChar(p, '[') && parseUI(p, uiItems, numItems);
        }
    } while (tryChar(p, ','));
    
    return parseChar(p, '}');
}

#endif // SIMPLEPARSER_H
/**************************  END  SimpleParser.h **************************/
