package Torello.Browser;

import java.util.*;
import javax.json.*;
import javax.json.stream.*;
import java.io.*;

import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
import java.util.function.Function;

import Torello.Java.Additional.*;
import Torello.Java.JSON.*;

import static Torello.Java.JSON.JFlag.*;

import Torello.Java.StrCmpr;
import Torello.JavaDoc.StaticFunctional;
import Torello.JavaDoc.JDHeaderBackgroundImg;
import Torello.JavaDoc.Excuse;

/**
 * <SPAN CLASS=COPIEDJDK><B>Input/Output operations for streams produced by DevTools.</B></SPAN>
 * 
 * <EMBED CLASS='external-html' DATA-FILE-ID=CODE_GEN_NOTE>
 */
@StaticFunctional(Excused={"counter"}, Excuses={Excuse.CONFIGURATION})
@JDHeaderBackgroundImg(EmbedTagFileID="WOOD_PLANK_NOTE")
public class IO
{
    // ********************************************************************************************
    // ********************************************************************************************
    // Class Header Stuff
    // ********************************************************************************************
    // ********************************************************************************************


    // No Pubic Constructors
    private IO () { }

    // These two Vector's are used by all the "Methods" exported by this class.  java.lang.reflect
    // is used to generate the JSON String's.  It saves thousands of lines of Auto-Generated Code.
    private static final Map<String, Vector<String>>    parameterNames = new HashMap<>();
    private static final Map<String, Vector<Class<?>>>  parameterTypes = new HashMap<>();

    // Some Methods do not take any parameters - for instance all the "enable()" and "disable()"
    // I simply could not get ride of RAW-TYPES and UNCHECKED warnings... so there are now,
    // offically, two empty-vectors.  One for String's, and the other for Classes.

    private static final Vector<String>     EMPTY_VEC_STR = new Vector<>();
    private static final Vector<Class<?>>   EMPTY_VEC_CLASS = new Vector<>();

    static
    {
        for (Method m : IO.class.getMethods())
        {
            // This doesn't work!  The parameter names are all "arg0" ... "argN"
            // It works for java.lang.reflect.Field, BUT NOT java.lang.reflect.Parameter!
            //
            // Vector<String> parameterNamesList = new Vector<>(); -- NOPE!

            Vector<Class<?>> parameterTypesList = new Vector<>();
        
            for (Parameter p : m.getParameters()) parameterTypesList.add(p.getType());

            parameterTypes.put(
                m.getName(),
                (parameterTypesList.size() > 0) ? parameterTypesList : EMPTY_VEC_CLASS
            );
        }
    }

    static
    {
        Vector<String> v = null;

        v = new Vector<String>(1);
        parameterNames.put("close", v);
        Collections.addAll(v, new String[]
        { "handle", });

        v = new Vector<String>(3);
        parameterNames.put("read", v);
        Collections.addAll(v, new String[]
        { "handle", "offset", "size", });

        v = new Vector<String>(1);
        parameterNames.put("resolveBlob", v);
        Collections.addAll(v, new String[]
        { "objectId", });
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // Types - Static Inner Classes
    // ********************************************************************************************
    // ********************************************************************************************

    // public static class StreamHandle => String
    
    
    // Counter for keeping the WebSocket Request ID's distinct.
    private static int counter = 1;
    
    /**
     * Close the stream, discard any temporary backing storage.
     * 
     * @param handle Handle of the stream to close.
     * 
     * @return An instance of <CODE>{@link Script}&lt;String, {@link JsonObject},
     * {@link Ret0}&gt;</CODE>
     *
     * <BR /><BR />This {@code Script} instance must be <B STYLE='color:red'>executed</B> before the
     * browser receives the invocation-request.
     *
     * <BR /><BR />This Browser-Function <I>does not have</I> a return-value.  You may choose to
     * <B STYLE='color: red'>await</B> the {@link Promise}{@code <JsonObject,} {@link Ret0}
     * {@code >} to ensure the Browser Function has run to completion.
     */
    public static Script<String, JsonObject, Ret0> close(String handle)
    {
        // Exception-Check(s) to ensure that if any parameters which are not declared as
        // 'Optional', but have a 'null' value anyway, that a NullPointerException shall throw.
        
        if (handle == null) BRDPC.throwNPE("handle");
        
        final int       webSocketID = 23000000 + counter++;
        final boolean[] optionals   = { false, };
        
        // Convert Method Parameters into JSON.  Build the JSON Request-Object (as a String)
        String requestJSON = WriteJSON.get(
            parameterTypes.get("close"),
            parameterNames.get("close"),
            optionals, webSocketID,
            "IO.close",
            handle
        );
        
        // This Remote Command does not have a Return-Value.
        return new Script<>
            (BRDPC.defaultSender, webSocketID, requestJSON, BRDPC.NoReturnValues);
    }
    
    /**
     * Read a chunk of the stream
     * 
     * @param handle Handle of the stream to read.
     * 
     * @param offset 
     * Seek to the specified offset before reading (if not specificed, proceed with offset
     * following the last read). Some types of streams may only support sequential reads.
     * <BR /><B>OPTIONAL</B>
     * 
     * @param size Maximum number of bytes to read (left upon the agent discretion if not specified).
     * <BR /><B>OPTIONAL</B>
     * 
     * @return An instance of <CODE>{@link Script}&lt;String, {@link JsonObject},
     * {@link Ret3}&gt;</CODE>
     *
     * <BR /><BR />This {@link Script} may be <B STYLE='color:red'>executed</B> (using 
     * {@link Script#exec()}), and a {@link Promise} returned.
     *
     * <BR /><BR />When the {@code Promise} is <B STYLE='color: red'>awaited</B>
     * (using {@link Promise#await()}), the {@code Ret3} will subsequently
     * be returned from that call.
     * 
     * <BR /><BR />The <B STYLE='color: red'>returned</B> values are encapsulated
     * in an instance of <B>{@link Ret3}</B>
     *
     * <BR /><BR /><UL CLASS=JDUL>
     * <LI><CODE><B>Ret3.a:</B> Boolean (<B>base64Encoded</B>)</CODE>
     *     <BR />Set if the data is base64-encoded
     *     <BR /><BR /></LI>
     * <LI><CODE><B>Ret3.b:</B> String (<B>data</B>)</CODE>
     *     <BR />Data that were read.
     *     <BR /><BR /></LI>
     * <LI><CODE><B>Ret3.c:</B> Boolean (<B>eof</B>)</CODE>
     *     <BR />Set if the end-of-file condition occurred while reading.
     *     </LI>
     * </UL>
     */
    public static Script<String, JsonObject, Ret3<Boolean, String, Boolean>> read
        (String handle, Integer offset, Integer size)
    {
        // Exception-Check(s) to ensure that if any parameters which are not declared as
        // 'Optional', but have a 'null' value anyway, that a NullPointerException shall throw.
        
        if (handle == null) BRDPC.throwNPE("handle");
        
        final int       webSocketID = 23001000 + counter++;
        final boolean[] optionals   = { false, true, true, };
        
        // Convert Method Parameters into JSON.  Build the JSON Request-Object (as a String)
        String requestJSON = WriteJSON.get(
            parameterTypes.get("read"),
            parameterNames.get("read"),
            optionals, webSocketID,
            "IO.read",
            handle, offset, size
        );
        
        // 'JSON Binding' ... Converts Browser Response-JSON into Java-Type 'Ret3'
        Function<JsonObject, Ret3<Boolean, String, Boolean>> 
            responseProcessor = (JsonObject jo) -> new Ret3<>(
                ReadBoxedJSON.getBoolean(jo, "base64Encoded", true),
                ReadJSON.getString(jo, "data", false, true),
                ReadBoxedJSON.getBoolean(jo, "eof", true)
            );
        
        // Pass the 'defaultSender' to Script-Constructor
        // The sender that is used can be changed before executing script.
        return new Script<>(BRDPC.defaultSender, webSocketID, requestJSON, responseProcessor);
    }
    
    /**
     * Return UUID of Blob object specified by a remote object id.
     * 
     * @param objectId Object id of a Blob object wrapper.
     * 
     * @return An instance of <CODE>{@link Script}&lt;String, {@link JsonObject},
     * String&gt;</CODE>
     * 
     * <BR /><BR />This <B>script</B> may be <B STYLE='color: red'>executed</B>, using
     * {@link Script#exec()}, and afterwards, a {@link Promise}<CODE>&lt;JsonObject,
     * String&gt;</CODE> will be returned.
     *
     * <BR /><BR />Finally, the <B>{@code Promise}</B> may be <B STYLE='color: red'>awaited</B>,
     * using {@link Promise#await()}, <I>and the returned result of this Browser Function may
      * may be retrieved.</I>
     *
     * <BR /><BR />This Browser Function <B STYLE='color: red'>returns</B>
     * <BR /><BR /><UL CLASS=JDUL>
     * <LI><CODE>String (<B>uuid</B></CODE>)
     *     <BR />UUID of the specified Blob.
     * </LI>
     * </UL> */
    public static Script<String, JsonObject, String> resolveBlob(String objectId)
    {
        // Exception-Check(s) to ensure that if any parameters which are not declared as
        // 'Optional', but have a 'null' value anyway, that a NullPointerException shall throw.
        
        if (objectId == null) BRDPC.throwNPE("objectId");
        
        final int       webSocketID = 23002000 + counter++;
        final boolean[] optionals   = { false, };
        
        // Convert Method Parameters into JSON.  Build the JSON Request-Object (as a String)
        String requestJSON = WriteJSON.get(
            parameterTypes.get("resolveBlob"),
            parameterNames.get("resolveBlob"),
            optionals, webSocketID,
            "IO.resolveBlob",
            objectId
        );
        
        // 'JSON Binding' ... Converts Browser Response-JSON to 'String'
        Function<JsonObject, String> responseProcessor = (JsonObject jo) ->
            ReadJSON.getString(jo, "uuid", false, true);
        
        // Pass the 'defaultSender' to Script-Constructor
        // The sender that is used can be changed before executing script.
        return new Script<>(BRDPC.defaultSender, webSocketID, requestJSON, responseProcessor);
    }
    
}