package com.jsoniter;

import com.jsoniter.any.Any;
import com.jsoniter.spi.*;

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class JsonIterator implements Closeable {

    public Config configCache;
    private static boolean isStreamingEnabled = false;
    final static ValueType[] valueTypes = new ValueType[256];
    InputStream in;
    byte[] buf;
    // Whenever buf is not large enough new one is created with size of
    // buf.length + autoExpandBufferStep. Set to < 1 to disable auto expanding.
    int autoExpandBufferStep;
    int head;
    int tail;
    int skipStartedAt = -1; // skip should keep bytes starting at this pos

    Map tempObjects = null; // used in reflection object decoder
    final Slice reusableSlice = new Slice(null, 0, 0);
    char[] reusableChars = new char[32];
    Object existingObject = null; // the object should be bind to next

    static {
        for (int i = 0; i < valueTypes.length; i++) {
            valueTypes[i] = ValueType.INVALID;
        }
        valueTypes['"'] = ValueType.STRING;
        valueTypes['-'] = ValueType.NUMBER;
        valueTypes['0'] = ValueType.NUMBER;
        valueTypes['1'] = ValueType.NUMBER;
        valueTypes['2'] = ValueType.NUMBER;
        valueTypes['3'] = ValueType.NUMBER;
        valueTypes['4'] = ValueType.NUMBER;
        valueTypes['5'] = ValueType.NUMBER;
        valueTypes['6'] = ValueType.NUMBER;
        valueTypes['7'] = ValueType.NUMBER;
        valueTypes['8'] = ValueType.NUMBER;
        valueTypes['9'] = ValueType.NUMBER;
        valueTypes['t'] = ValueType.BOOLEAN;
        valueTypes['f'] = ValueType.BOOLEAN;
        valueTypes['n'] = ValueType.NULL;
        valueTypes['['] = ValueType.ARRAY;
        valueTypes['{'] = ValueType.OBJECT;
    }

    private JsonIterator(InputStream in, byte[] buf, int head, int tail) {
        this.in = in;
        this.buf = buf;
        this.head = head;
        this.tail = tail;
    }

    private JsonIterator(InputStream in, byte[] buf, int autoExpandBufferStep) {
        this(in, buf, 0, 0);
        this.autoExpandBufferStep = autoExpandBufferStep;
    }

    public JsonIterator() {
        this(null, new byte[0], 0, 0);
    }

    public static JsonIterator parse(InputStream in, int bufSize) {
        return parse(in, bufSize, bufSize);
    }

    public static JsonIterator parse(InputStream in, int bufSize, int autoExpandBufferStep) {
        enableStreamingSupport();
        return new JsonIterator(in, new byte[bufSize], autoExpandBufferStep);
    }

    public static JsonIterator parse(byte[] buf) {
        return new JsonIterator(null, buf, 0, buf.length);
    }

    public static JsonIterator parse(byte[] buf, int head, int tail) {
        return new JsonIterator(null, buf, head, tail);
    }

    public static JsonIterator parse(String str) {
        return parse(str.getBytes());
    }

    public static JsonIterator parse(Slice slice) {
        return new JsonIterator(null, slice.data(), slice.head(), slice.tail());
    }

    public final void reset(byte[] buf) {
        this.buf = buf;
        this.head = 0;
        this.tail = buf.length;
    }

    public final void reset(byte[] buf, int head, int tail) {
        this.buf = buf;
        this.head = head;
        this.tail = tail;
    }

    public final void reset(Slice value) {
        this.buf = value.data();
        this.head = value.head();
        this.tail = value.tail();
    }

    public final void reset(InputStream in) {
        JsonIterator.enableStreamingSupport();
        this.in = in;
        this.head = 0;
        this.tail = 0;
    }

    public final void close() throws IOException {
        if (in != null) {
            in.close();
        }
    }

    final void unreadByte() {
        if (head == 0) {
            throw reportError("unreadByte", "unread too many bytes");
        }
        head--;
    }

    public final JsonException reportError(String op, String msg) {
        int peekStart = head - 10;
        if (peekStart < 0) {
            peekStart = 0;
        }
        int peekSize = head - peekStart;
        if (head > tail) {
            peekSize = tail - peekStart;
        }
        String peek = new String(buf, peekStart, peekSize);
        throw new JsonException(op + ": " + msg + ", head: " + head + ", peek: " + peek + ", buf: " + new String(buf));
    }

    public final String currentBuffer() {
        int peekStart = head - 10;
        if (peekStart < 0) {
            peekStart = 0;
        }
        String peek = new String(buf, peekStart, head - peekStart);
        return "head: " + head + ", peek: " + peek + ", buf: " + new String(buf);
    }

    public final boolean readNull() throws IOException {
        byte c = IterImpl.nextToken(this);
        if (c != 'n') {
            unreadByte();
            return false;
        }
        IterImpl.skipFixedBytes(this, 3); // null
        return true;
    }

    public final boolean readBoolean() throws IOException {
        byte c = IterImpl.nextToken(this);
        if ('t' == c) {
            IterImpl.skipFixedBytes(this, 3); // true
            return true;
        }
        if ('f' == c) {
            IterImpl.skipFixedBytes(this, 4); // false
            return false;
        }
        throw reportError("readBoolean", "expect t or f, found: " + c);
    }

    public final short readShort() throws IOException {
        int v = readInt();
        if (Short.MIN_VALUE