/*
 * 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.
 */
package org.joni;

import org.jcodings.Encoding;
import org.joni.exception.ErrorMessages;
import org.joni.exception.ValueException;

public final class CodeRangeBuffer {
    private static final int INIT_MULTI_BYTE_RANGE_SIZE = 5;    
    private static final int ALL_MULTI_BYTE_RANGE = 0x7fffffff;
    
    int[]p; 
    int used;
    
    public CodeRangeBuffer(int[]ranges) {
        p = ranges;
        used = ranges[0] + 1;
    }
    
    public CodeRangeBuffer() {
        p = new int[INIT_MULTI_BYTE_RANGE_SIZE];
        writeCodePoint(0, 0);
    }
    
    public int[]getCodeRange() {
        return p;
    }
    
    private CodeRangeBuffer(CodeRangeBuffer orig) {
        p = new int[orig.p.length];
        System.arraycopy(orig.p, 0, p, 0, p.length);
        used = orig.used;
    }
    
    public String toString() {
        StringBuilder buf = new StringBuilder();
        buf.append("CodeRange");
        buf.append("\n  used: " + used);
        buf.append("\n  code point: " + p[0]);
        buf.append("\n  ranges: ");
        
        for (int i=0; i<p[0]; i++) {
            buf.append("[" + rangeNumToString(p[i * 2 + 1]) + ".." + rangeNumToString(p[i * 2 + 2]) + "]");
            if (i > 0 && i % 6 == 0) buf.append("\n          ");
        }
        
        return buf.toString();
    }
    
    private static String rangeNumToString(int num){
        return "0x" + Integer.toString(num, 16);
    }
    
    public void expand(int low) {
        int length = p.length;
        do { length <<= 1; } while (length < low);
        int[]tmp = new int[length];
        System.arraycopy(p, 0, tmp, 0, used);
        p = tmp;
    }
    
    public void ensureSize(int size) {
        int length = p.length;
        while (length < size ) { length <<= 1; }
        if (p.length != length) { 
            int[]tmp = new int[length];
            System.arraycopy(p, 0, tmp, 0, used);
            p = tmp;            
        }
    }   
    
    private void moveRight(int from, int to, int n) {
        if (to + n > p.length) expand(to + n);
        System.arraycopy(p, from, p, to, n);
        if (to + n > used) used = to + n;
    }
    
    protected void moveLeft(int from, int to, int n) {
        System.arraycopy(p, from, p, to, n);
    }
    
    private void moveLeftAndReduce(int from, int to) {
        System.arraycopy(p, from, p, to, used - from);
        used -= from - to;
    }

    public void writeCodePoint(int pos, int b) {
        int u = pos + 1;
        if (p.length < u) expand(u);
        p[pos] = b;
        if (used < u) used = u;
    }
    
    public CodeRangeBuffer clone() {
        return new CodeRangeBuffer(this);
    }
    
    // ugly part: these methods should be made OO
    // add_code_range_to_buf
    public static CodeRangeBuffer addCodeRangeToBuff(CodeRangeBuffer pbuf, int from, int to) {
        if (from > to) {
            int n = from;
            from = to;
            to = n;
        }
        
        if (pbuf == null) pbuf = new CodeRangeBuffer(); // move to CClassNode
        
        int[]p = pbuf.p;
        int n = p[0];
        
        int low = 0;
        int bound = n;
        
        while (low < bound) {
            int x = (low + bound) >>> 1;
            if (from > p[x * 2 + 2]) {
                low = x + 1;
            } else {
                bound = x;
            }
        }
        
        int high = low;
        bound = n;
        
        while (high < bound) {
            int x = (high + bound) >>> 1;
            if (to >= p[x * 2 + 1] - 1) {
                high = x + 1;
            } else {
                bound = x;
            }
        }
        
        int incN = low + 1 - high;

        if (n + incN > Config.MAX_MULTI_BYTE_RANGES_NUM) throw new ValueException(ErrorMessages.ERR_TOO_MANY_MULTI_BYTE_RANGES);        
        
        if (incN != 1) {
            if (from > p[low * 2 + 1]) from = p[low * 2 + 1];
            if (to < p[(high - 1) * 2 + 2]) to = p[(high - 1) * 2 + 2];
        }
        
        if (incN != 0 && high < n) {
            int fromPos = 1 + high * 2;
            int toPos = 1 + (low + 1) * 2;
            int size = (n - high) * 2;
            
            if (incN > 0) {
                pbuf.moveRight(fromPos, toPos, size);
            } else {
                pbuf.moveLeftAndReduce(fromPos, toPos);
            }
        }
        
        int pos = 1 + low * 2;
        // pbuf.ensureSize(pos + 2);
        pbuf.writeCodePoint(pos, from);
        pbuf.writeCodePoint(pos + 1, to);
        n += incN;
        pbuf.writeCodePoint(0, n);
        
        return pbuf;
    }
    
    // add_code_range, be aware of it returning null!
    public static CodeRangeBuffer addCodeRange(CodeRangeBuffer pbuf, ScanEnvironment env, int from, int to) {
        if (from >to) {
            if (env.syntax.allowEmptyRangeInCC()) {
                return pbuf;
            } else {
                throw new ValueException(ErrorMessages.ERR_EMPTY_RANGE_IN_CHAR_CLASS);
            }
        }
        return addCodeRangeToBuff(pbuf, from, to);
    }

    // SET_ALL_MULTI_BYTE_RANGE
    protected static CodeRangeBuffer setAllMultiByteRange(Encoding enc, CodeRangeBuffer pbuf) {
        return addCodeRangeToBuff(pbuf, enc.mbcodeStartPosition(), ALL_MULTI_BYTE_RANGE);
    }
    
    // ADD_ALL_MULTI_BYTE_RANGE
    public static CodeRangeBuffer addAllMultiByteRange(Encoding enc, CodeRangeBuffer pbuf) {
        if (!enc.isSingleByte()) return setAllMultiByteRange(enc, pbuf);
        return pbuf;
    }
    
    // not_code_range_buf
    public static CodeRangeBuffer notCodeRangeBuff(Encoding enc, CodeRangeBuffer bbuf) {
        CodeRangeBuffer pbuf = null;

        if (bbuf == null) return setAllMultiByteRange(enc, pbuf);
        
        int[]p = bbuf.p;
        int n = p[0];
        
        if (n <= 0) return setAllMultiByteRange(enc, pbuf);
        
        int pre = enc.mbcodeStartPosition();
        
        int from;
        int to = 0;
        for (int i=0; i<n; i++) {
            from = p[i * 2 + 1];
            to = p[i * 2 + 2];
            if (pre <= from - 1) {
                pbuf = addCodeRangeToBuff(pbuf, pre, from - 1);
            }
            if (to == ALL_MULTI_BYTE_RANGE) break;
            pre = to + 1;
        }
        
        if (to < ALL_MULTI_BYTE_RANGE) pbuf = addCodeRangeToBuff(pbuf, to + 1, ALL_MULTI_BYTE_RANGE);
        return pbuf;
    }
    
    // or_code_range_buf
    public static CodeRangeBuffer orCodeRangeBuff(Encoding enc, CodeRangeBuffer bbuf1, boolean not1,
                                                                CodeRangeBuffer bbuf2, boolean not2) {
        CodeRangeBuffer pbuf = null;
        
        if (bbuf1 == null && bbuf2 == null) {
            if (not1 || not2) {
                return setAllMultiByteRange(enc, pbuf);
            }
            return null;
        }

        if (bbuf2 == null) {
            CodeRangeBuffer tbuf;
            boolean tnot;
            // swap
            tnot = not1; not1 = not2; not2 = tnot;
            tbuf = bbuf1; bbuf1 = bbuf2; bbuf2 = tbuf; 
        }
        
        if (bbuf1 == null) {
            if (not1) {
                return setAllMultiByteRange(enc, pbuf);
            } else { 
                if (!not2) {
                    return bbuf2.clone();
                } else {
                    return notCodeRangeBuff(enc, bbuf2);
                }
            }
        }
        
        if (not1) {
            CodeRangeBuffer tbuf;
            boolean tnot;
            // swap
            tnot = not1; not1 = not2; not2 = tnot;
            tbuf = bbuf1; bbuf1 = bbuf2; bbuf2 = tbuf; 
        }

        if (!not2 && !not1) { /* 1 OR 2 */
            pbuf = bbuf2.clone();
        } else if (!not1) { /* 1 OR (not 2) */
            pbuf = notCodeRangeBuff(enc, bbuf2);
        }
        
        int[]p1 = bbuf1.p;
        int n1 = p1[0];
        
        for (int i=0; i<n1; i++) {
            int from = p1[i * 2 + 1];
            int to = p1[i * 2 + 2];
            pbuf = addCodeRangeToBuff(pbuf, from, to);
        }
        
        return pbuf;
    }
    
    // and_code_range1
    public static CodeRangeBuffer andCodeRange1(CodeRangeBuffer pbuf, int from1, int to1, int[]data, int n) {
        for (int i=0; i<n; i++) {
            int from2 = data[i * 2 + 1];
            int to2 = data[i * 2 + 2];
            if (from2 < from1) {
                if (to2 < from1) {
                    continue;
                } else {
                    from1 = to2 + 1;
                }
            } else if (from2 <= to1) {
                if (to2 < to1) {
                    if (from1 <= from2 - 1) {
                        pbuf = addCodeRangeToBuff(pbuf, from1, from2 - 1);
                    }
                    from1 = to2 + 1;
                } else {
                    to1 = from2 - 1;
                }
            } else {
                from1 = from2;
            }
            if (from1 > to1) break;
        }
        
        if (from1 <= to1) {
            pbuf = addCodeRangeToBuff(pbuf, from1, to1);
        }
        
        return pbuf;
    }
    
    // and_code_range_buf
    public static CodeRangeBuffer andCodeRangeBuff(CodeRangeBuffer bbuf1, boolean not1,
                                                   CodeRangeBuffer bbuf2, boolean not2) {
        CodeRangeBuffer pbuf = null;
        
        if (bbuf1 == null) { 
            if (not1 && bbuf2 != null) return bbuf2.clone(); /* not1 != 0 -> not2 == 0 */
            return null; 
        } else if (bbuf2 == null) {
            if (not2) return bbuf1.clone();
            return null;
        }
        
        if (not1) {
            CodeRangeBuffer tbuf;
            boolean tnot;
            // swap
            tnot = not1; not1 = not2; not2 = tnot;
            tbuf = bbuf1; bbuf1 = bbuf2; bbuf2 = tbuf;             
        }
        
        int[]p1 = bbuf1.p;
        int n1 = p1[0];
        int[]p2 = bbuf2.p;
        int n2 = p2[0];

        if (!not2 && !not1) { /* 1 AND 2 */
            for (int i=0; i<n1; i++) {
                int from1 = p1[i * 2 + 1];
                int to1 = p1[i * 2 + 2];

                for (int j=0; j<n2; j++) {
                    int from2 = p2[j * 2 + 1];
                    int to2 = p2[j * 2 + 2];

                    if (from2 > to1) break;
                    if (to2 < from1) continue;
                    int from = from1 > from2 ? from1 : from2;
                    int to = to1 < to2 ? to1 : to2;
                    pbuf = addCodeRangeToBuff(pbuf, from, to);
                }
            }
        } else if (!not1) { /* 1 AND (not 2) */
            for (int i=0; i<n1; i++) {
                int from1 = p1[i * 2 + 1];
                int to1 = p1[i * 2 + 2];
                pbuf = andCodeRange1(pbuf, from1, to1, p2, n2);
            }
        }

        return pbuf;
    }
}