/* jsmin.cpp
   2008-08-03
   2010-09
   2013-03-29

Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
Copyright (c) 2010 Sun Junwen

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 shall be used for Good, not Evil.

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 "jsmin.h"
#include <stdlib.h>
#include <stdio.h>
#include <stdexcept>

using namespace std;

void JSMin::error(char* s)
{
    fputs("JSMIN Error: ", stderr);
    fputs(s, stderr);
    fputc('\n', stderr);
    exit(1);
}

/* isAlphanum -- return true if the character is a letter, digit, underscore,
        dollar sign, or non-ASCII character.
*/

int JSMin::isAlphanum(int c)
{
    return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
        (c >= 'A' && c <= 'Z') || c == '_' || c == '$' || c == '\\' ||
        c > 126);
}

/* isBlank -- return true if the character is ' ', '\t', '\r' or '\n'.
*/
int JSMin::isBlank(int c)
{
    return (c == ' ' || c == '\t' || c == '\r' || c == '\n');
}

/* get -- return the next character from stdin. Watch out for lookahead. If
        the character is a control character, translate it to a space or
        linefeed.
*/

int JSMin::get()
{
    int c = theLookahead;
    theLookahead = EOF;
    if (c == EOF) {
        c = getChar();
    }
    if (c >= ' ' || c == '\n' || c == EOF) {
        return c;
    }
    if (c == '\r') {
        return keepFirstComt ? '\r' : '\n';
    }
    return ' ';
}

/* peek -- get the next character without getting it.
*/

int JSMin::peek()
{
    theLookahead = get();
    return theLookahead;
}


/* next -- get the next character, excluding comments. peek() is used to see
        if a '/' is followed by a '/' or '*'.
*/

int JSMin::next()
{
    int c = get();
    if (keepFirstComt && c != '/' && !isBlank(c)) {
        keepFirstComt = false;
    }
    if (c == '/') {
        switch (peek()) {
        case '/':
            keepFirstComt = false;
            for (;;) {
                c = get();
                if (c <= '\n') {
                    break;
                }
            }
            break;
        case '*':
            get();

            if (keepFirstComt) {
                put('/');
                put('*');
            }

            while (c != ' ') {
                char comtContent;
                switch (comtContent = get()) {
                case '*':
                    if (peek() == '/') {
                        if (keepFirstComt) {
                            put('*');
                            put('/');
                            //put('\n');
                            keepFirstComt = false;
                        }

                        get();
                        c = ' ';
                    }
                    break;
                case EOF:
                    throw runtime_error("Error: JSMIN Unterminated comment.");
                    /*fprintf(stderr, "Error: JSMIN Unterminated comment.\n");
                    exit(1);*/
                }
                if (keepFirstComt && comtContent != '\r') {
                    put(comtContent);
                }
            }
            break;
        }
    }
    theY = theX;
    theX = c;
    return c;
}


/* action -- do something! What you do is determined by the argument:
        1   Output A. Copy B to A. Get the next B.
        2   Copy B to A. Get the next B. (Delete A).
        3   Get the next B. (Delete B).
   action treats a string as a single character. Wow!
   action recognizes a regular expression if it is preceded by ( or , or =.
*/

void JSMin::action(int d)
{
    switch (d) {
    case 1:
        put(theA);
        if (
            (theY == '\n' || theY == ' ') &&
            (theA == '+' || theA == '-' || theA == '*' || theA == '/') &&
            (theB == '+' || theB == '-' || theB == '*' || theB == '/')
        ) {
            put(theY);
        }
    case 2:
        theA = theB;
        if (theA == '\'' || theA == '"' || theA == '`') {
            for (;;) {
                put(theA);
                theA = get();
                if (theA == theB) {
                    break;
                }
                if (theA == '\\') {
                    put(theA);
                    theA = get();
                }
                if (theA == EOF) {
                    throw runtime_error("Error: JSMIN unterminated string literal.");
                    /*fprintf(stderr, "Error: JSMIN unterminated string literal.");
                    exit(1);*/
                }
            }
        }
    case 3:
        theB = next();
        if (theB == '/' && (
            theA == '(' || theA == ',' || theA == '=' || theA == ':' ||
            theA == '[' || theA == '!' || theA == '&' || theA == '|' ||
            theA == '?' || theA == '+' || theA == '-' || theA == '~' ||
            theA == '*' || theA == '/' || theA == '{' || theA == '\n'
        )) {
            put(theA);
            if (theA == '/' || theA == '*') {
                put(' ');
            }
            put(theB);
            for (;;) {
                theA = get();
                if (theA == '[') {
                    for (;;) {
                        put(theA);
                        theA = get();
                        if (theA == ']') {
                            break;
                        }
                        if (theA == '\\') {
                            put(theA);
                            theA = get();
                        }
                        if (theA == EOF) {
                            throw runtime_error("Error: JSMIN Unterminated set in Regular Expression literal.");
                            //error("Unterminated set in Regular Expression literal.");
                        }
                    }
                } else if (theA == '/') {
                    switch (peek()) {
                    case '/':
                    case '*':
                        throw runtime_error("Error: JSMIN Unterminated set in Regular Expression literal.");
                        //error("Unterminated set in Regular Expression literal.");
                    }
                    break;
                } else if (theA =='\\') {
                    put(theA);
                    theA = get();
                }
                if (theA == EOF) {
                    throw runtime_error("Error: JSMIN Unterminated Regular Expression literal.");
                    //error("Unterminated Regular Expression literal.");
                }
                put(theA);
            }
            theB = next();
        }
    }
}


/* go -- Copy the input to the output, deleting the characters which are
        insignificant to JavaScript. Comments will be removed. Tabs will be
        replaced with spaces. Carriage returns will be replaced with linefeeds.
        Most spaces and linefeeds will be removed.
*/

void JSMin::go()
{
    if (peek() == 0xEF) {
        get();
        get();
        get();
    }
    theA = '\n';
    action(3);
    while (theA != EOF) {
        switch (theA) {
        case ' ':
            action(isAlphanum(theB) ? 1 : 2);
            break;
        case '\n':
            switch (theB) {
            case '{':
            case '[':
            case '(':
            case '+':
            case '-':
            case '!':
            case '~':
                action(1);
                break;
            case ' ':
                action(3);
                break;
            default:
                action(isAlphanum(theB) ? 1 : 2);
            }
            break;
        default:
            switch (theB) {
            case ' ':
                action(isAlphanum(theA) ? 1 : 3);
                break;
            case '\n':
                switch (theA) {
                case '}':
                case ']':
                case ')':
                case '+':
                case '-':
                case '"':
                case '\'':
                case '`':
                    action(1);
                    break;
                default:
                    action(isAlphanum(theA) ? 1 : 3);
                }
                break;
            default:
                action(1);
                break;
            }
        }
    }
}


/* main -- Output any command line arguments as comments
        and then minify the input.
*/
//extern int
//main(int argc, char* argv[])
//{
//    int i;
//    for (i = 1; i < argc; i += 1) {
//        fprintf(stdout, "// %s\n", argv[i]);
//    }
//    jsmin();
//    return 0;
//}
