/*
 * Copyright (c) 2002-2018, the original author or authors.
 *
 * This software is distributable under the BSD license. See the terms of the
 * BSD license in the documentation provided with this software.
 *
 * https://opensource.org/licenses/BSD-3-Clause
 */
package jdk.internal.org.jline.utils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

Attributed string builder
Author:
Guillaume Nodet/**
 * Attributed string builder
 *
 * @author <a href="mailto:gnodet@gmail.com">Guillaume Nodet</a>
 */
public class AttributedStringBuilder extends AttributedCharSequence implements Appendable {

    private char[] buffer;
    private int[] style;
    private int length;
    private TabStops tabs = new TabStops(0);
    private int lastLineLength = 0;
    private AttributedStyle current = AttributedStyle.DEFAULT;

    public static AttributedString append(CharSequence... strings) {
        AttributedStringBuilder sb = new AttributedStringBuilder();
        for (CharSequence s : strings) {
            sb.append(s);
        }
        return sb.toAttributedString();
    }

    public AttributedStringBuilder() {
        this(64);
    }

    public AttributedStringBuilder(int capacity) {
        buffer = new char[capacity];
        style = new int[capacity];
        length = 0;
    }

    @Override
    public int length() {
        return length;
    }

    @Override
    public char charAt(int index) {
        return buffer[index];
    }

    @Override
    public AttributedStyle styleAt(int index) {
        return new AttributedStyle(style[index], style[index]);
    }

    @Override
    int styleCodeAt(int index) {
        return style[index];
    }

    @Override
    protected char[] buffer() {
        return buffer;
    }

    @Override
    protected int offset() {
        return 0;
    }

    @Override
    public AttributedString subSequence(int start, int end) {
        return new AttributedString(
                Arrays.copyOfRange(buffer, start, end),
                Arrays.copyOfRange(style, start, end),
                0,
                end - start);
    }

    @Override
    public AttributedStringBuilder append(CharSequence csq) {
        return append(new AttributedString(csq, current));
    }

    @Override
    public AttributedStringBuilder append(CharSequence csq, int start, int end) {
        return append(csq.subSequence(start, end));
    }

    @Override
    public AttributedStringBuilder append(char c) {
        return append(Character.toString(c));
    }

    public AttributedStringBuilder append(CharSequence csq, AttributedStyle style) {
        return append(new AttributedString(csq, style));
    }

    public AttributedStringBuilder style(AttributedStyle style) {
        current = style;
        return this;
    }

    public AttributedStringBuilder style(Function<AttributedStyle,AttributedStyle> style) {
        current = style.apply(current);
        return this;
    }

    public AttributedStringBuilder styled(Function<AttributedStyle,AttributedStyle> style, CharSequence cs) {
        return styled(style, sb -> sb.append(cs));
    }

    public AttributedStringBuilder styled(AttributedStyle style, CharSequence cs) {
        return styled(s -> style, sb -> sb.append(cs));
    }

    public AttributedStringBuilder styled(Function<AttributedStyle,AttributedStyle> style, Consumer<AttributedStringBuilder> consumer) {
        AttributedStyle prev = current;
        current = style.apply(prev);
        consumer.accept(this);
        current = prev;
        return this;
    }

    public AttributedStyle style() {
        return current;
    }

    public AttributedStringBuilder append(AttributedString str) {
        return append((AttributedCharSequence) str, 0, str.length());
    }

    public AttributedStringBuilder append(AttributedString str, int start, int end) {
        return append((AttributedCharSequence) str, start, end);
    }

    public AttributedStringBuilder append(AttributedCharSequence str) {
        return append(str, 0, str.length());
    }

    public AttributedStringBuilder append(AttributedCharSequence str, int start, int end) {
        ensureCapacity(length + end - start);
        for (int i = start; i < end; i++) {
            char c = str.charAt(i);
            int s = str.styleCodeAt(i) & ~current.getMask() | current.getStyle();
            if (tabs.defined() && c == '\t') {
                insertTab(new AttributedStyle(s, 0));
            } else {
                ensureCapacity(length + 1);
                buffer[length] = c;
                style[length] = s;
                if (c == '\n') {
                    lastLineLength = 0;
                } else {
                    lastLineLength++;
                }
                length++;
            }
        }
        return this;
    }

    protected void ensureCapacity(int nl) {
        if (nl > buffer.length) {
            int s = Math.max(buffer.length, 1);
            while (s <= nl) {
                s *= 2;
            }
            buffer = Arrays.copyOf(buffer, s);
            style = Arrays.copyOf(style, s);
        }
    }

    public void appendAnsi(String ansi) {
        ansiAppend(ansi);
    }

    public AttributedStringBuilder ansiAppend(String ansi) {
        int ansiStart = 0;
        int ansiState = 0;
        ensureCapacity(length + ansi.length());
        for (int i = 0; i < ansi.length(); i++) {
            char c = ansi.charAt(i);
            if (ansiState == 0 && c == 27) {
                ansiState++;
            } else if (ansiState == 1 && c == '[') {
                ansiState++;
                ansiStart = i + 1;
            } else if (ansiState == 2) {
                if (c == 'm') {
                    String[] params = ansi.substring(ansiStart, i).split(";");
                    int j = 0;
                    while (j < params.length) {
                        int ansiParam = params[j].isEmpty() ? 0 : Integer.parseInt(params[j]);
                        switch (ansiParam) {
                            case 0:
                                current = AttributedStyle.DEFAULT;
                                break;
                            case 1:
                                current = current.bold();
                                break;
                            case 2:
                                current = current.faint();
                                break;
                            case 3:
                                current = current.italic();
                                break;
                            case 4:
                                current = current.underline();
                                break;
                            case 5:
                                current = current.blink();
                                break;
                            case 7:
                                current = current.inverse();
                                break;
                            case 8:
                                current = current.conceal();
                                break;
                            case 9:
                                current = current.crossedOut();
                                break;
                            case 22:
                                current = current.boldOff().faintOff();
                                break;
                            case 23:
                                current = current.italicOff();
                                break;
                            case 24:
                                current = current.underlineOff();
                                break;
                            case 25:
                                current = current.blinkOff();
                                break;
                            case 27:
                                current = current.inverseOff();
                                break;
                            case 28:
                                current = current.concealOff();
                                break;
                            case 29:
                                current = current.crossedOutOff();
                                break;
                            case 30:
                            case 31:
                            case 32:
                            case 33:
                            case 34:
                            case 35:
                            case 36:
                            case 37:
                                current = current.foreground(ansiParam - 30);
                                break;
                            case 39:
                                current = current.foregroundOff();
                                break;
                            case 40:
                            case 41:
                            case 42:
                            case 43:
                            case 44:
                            case 45:
                            case 46:
                            case 47:
                                current = current.background(ansiParam - 40);
                                break;
                            case 49:
                                current = current.backgroundOff();
                                break;
                            case 38:
                            case 48:
                                if (j + 1 < params.length) {
                                    int ansiParam2 = Integer.parseInt(params[++j]);
                                    if (ansiParam2 == 2) {
                                        if (j + 3 < params.length) {
                                            int r = Integer.parseInt(params[++j]);
                                            int g = Integer.parseInt(params[++j]);
                                            int b = Integer.parseInt(params[++j]);
                                            // convert to 256 colors
                                            int col = 16 + (r >> 3) * 36 + (g >> 3) * 6 + (b >> 3);
                                            if (ansiParam == 38) {
                                                current = current.foreground(col);
                                            } else {
                                                current = current.background(col);
                                            }
                                        }
                                    } else if (ansiParam2 == 5) {
                                        if (j + 1 < params.length) {
                                            int col = Integer.parseInt(params[++j]);
                                            if (ansiParam == 38) {
                                                current = current.foreground(col);
                                            } else {
                                                current = current.background(col);
                                            }
                                        }
                                    }
                                }
                                break;
                            case 90:
                            case 91:
                            case 92:
                            case 93:
                            case 94:
                            case 95:
                            case 96:
                            case 97:
                                current = current.foreground(ansiParam - 90 + 8);
                                break;
                            case 100:
                            case 101:
                            case 102:
                            case 103:
                            case 104:
                            case 105:
                            case 106:
                            case 107:
                                current = current.background(ansiParam - 100 + 8);
                                break;
                        }
                        j++;
                    }
                    ansiState = 0;
                } else if (!(c >= '0' && c <= '9' || c == ';')) {
                    // This is not a SGR code, so ignore
                    ansiState = 0;
                }
            } else if (c == '\t' && tabs.defined()) {
                insertTab(current);
            } else {
                ensureCapacity(length + 1);
                buffer[length] = c;
                style[length] = this.current.getStyle();
                if (c == '\n') {
                    lastLineLength = 0;
                } else {
                    lastLineLength++;
                }
                length++;
            }
        }
        return this;
    }

    protected void insertTab(AttributedStyle s) {
        int nb = tabs.spaces(lastLineLength);
        ensureCapacity(length + nb);
        for (int i = 0; i < nb; i++) {
            buffer[length] = ' ';
            style[length] = s.getStyle();
            length++;
        }
        lastLineLength += nb;
    }

    public void setLength(int l) {
        length = l;
    }

    
Set the number of spaces a tab is expanded to. Tab size cannot be changed
after text has been added to prevent inconsistent indentation.
If tab size is set to 0, tabs are not expanded (the default).
Params:
tabsize – Spaces per tab or 0 for no tab expansion. Must be non-negative
Returns:
this/**
     * Set the number of spaces a tab is expanded to. Tab size cannot be changed
     * after text has been added to prevent inconsistent indentation.
     *
     * If tab size is set to 0, tabs are not expanded (the default).
     * @param tabsize Spaces per tab or 0 for no tab expansion. Must be non-negative
     * @return this
     */
    public AttributedStringBuilder tabs(int tabsize) {
        if (tabsize < 0) {
            throw new IllegalArgumentException("Tab size must be non negative");
        }
        return tabs(Arrays.asList(tabsize));
    }

    public AttributedStringBuilder tabs(List<Integer> tabs) {
        if (length > 0) {
            throw new IllegalStateException("Cannot change tab size after appending text");
        }
        this.tabs = new TabStops(tabs);
        return this;
    }

    public AttributedStringBuilder styleMatches(Pattern pattern, AttributedStyle s) {
        Matcher matcher = pattern.matcher(this);
        while (matcher.find()) {
            for (int i = matcher.start(); i < matcher.end(); i++) {
                style[i] = (style[i] & ~s.getMask()) | s.getStyle();
            }
        }
        return this;
    }

    public AttributedStringBuilder styleMatches(Pattern pattern, List<AttributedStyle> styles) {
        Matcher matcher = pattern.matcher(this);
        while (matcher.find()) {
            for (int group = 0; group < matcher.groupCount(); group++) {
                AttributedStyle s = styles.get(group);
                for (int i = matcher.start(group + 1); i < matcher.end(group + 1); i++) {
                    style[i] = (style[i] & ~s.getMask()) | s.getStyle();
                }
            }
        }
        return this;
    }

    private class TabStops {
        private List<Integer> tabs = new ArrayList<>();
        private int lastStop = 0;
        private int lastSize = 0;

        public TabStops(int tabs) {
            this.lastSize = tabs;
        }

        public TabStops(List<Integer> tabs) {
            this.tabs = tabs;
            int p = 0;
            for (int s: tabs) {
                if (s <= p) {
                    continue;
                }
                lastStop = s;
                lastSize = s - p;
                p = s;
            }
        }

        boolean defined() {
            return lastSize > 0;
        }

        int spaces(int lastLineLength) {
            int out = 0;
            if (lastLineLength >= lastStop) {
                out = lastSize - (lastLineLength - lastStop) % lastSize;
            } else {
                for (int s: tabs) {
                    if (s > lastLineLength) {
                        out = s - lastLineLength;
                        break;
                    }
                }
            }
            return out;
        }

    }

}