/*

    File:       QCommandLineConnection.m

    Contains:   Manages a connection consisting of CR LF delimited lines.

    Written by: DTS

    Copyright:  Copyright (c) 2011 Apple Inc. All Rights Reserved.

    Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc.

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                this notice, no other rights or licenses, express or implied,

                are granted by Apple herein, including but not limited to any

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                The Apple Software is provided by Apple on an "AS IS" basis. 

                APPLE MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING

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*/

#import "QCommandLineConnection.h"

@implementation QCommandLineConnection

@synthesize commandDelegate = commandDelegate_;

#pragma mark * Overrides

// See comment in header for an explanation of what these routines are about.

- (void)willCloseWithError:(NSError *)error

{

    // error may be nil

    if ([self.commandDelegate respondsToSelector:@selector(commandLineConnection:willCloseWithError:)]) {

        [self.commandDelegate commandLineConnection:self willCloseWithError:error];

    }

    [super willCloseWithError:error];

}

- (void)logWithFormat:(NSString *)format arguments:(va_list)argList

{

    assert(format != nil);

    if ([self.commandDelegate respondsToSelector:@selector(commandLineConnection:logWithFormat:arguments:)]) {

        [self.commandDelegate commandLineConnection:self logWithFormat:format arguments:argList];

    }

    [super logWithFormat:format arguments:argList];

}

#pragma mark * Send

- (void)sendString:(NSString *)str

{

    assert(str != nil);

    [self sendCommand:[str dataUsingEncoding:NSUTF8StringEncoding]];

}

- (void)sendCommandLine:(NSString *)line

{

    assert(line != nil);

    [self sendString:[NSString stringWithFormat:@"%@\r\n", line]];

}

- (void)sendCommandLines:(NSArray *)lines

{

    NSString *  linesStr;

    assert(lines != nil);

    assert([lines count] != 0);

    if ([lines count] == 1) {

        assert( [[lines objectAtIndex:0] isKindOfClass:[NSString class]] );

        [self sendCommandLine:[lines objectAtIndex:0]];

    } else {

        linesStr = [NSString stringWithFormat:@"%@\r\n", [lines componentsJoinedByString:@"\r\n"]];

        assert(linesStr != nil);

        [self sendString:linesStr];

    }

}

#pragma mark * Parse

- (void)didReceiveCommandLine:(NSString *)commandLine

    // See comment in header.

{

    assert(commandLine != nil);

    if ( [self.commandDelegate respondsToSelector:@selector(commandLineConnection:didReceiveCommandLine:)] ) {

        [self.commandDelegate commandLineConnection:self didReceiveCommandLine:commandLine];

    }

}

- (NSUInteger)parseCommandData:(NSData *)commandData

    // Called by our superclass when data arrives.  We parse command lines out 

    // of the data buffer and pass them to our delegate, returning the number of 

    // bytes successfully parsed.

    //

    // Note: Earlier versions of this code used to call [super parseCommandData], 

    // to given the super class's delegate a crack at the data before we had a go. 

    // We no longer do this because our super class now fails 

    // kQCommandConnectionInputUnexpectedError if its delegate doesn't implement 

    // -connection:parseCommandData:.

{

    const uint8_t *     bufferBytes;

    NSUInteger          bufferLength;

    NSUInteger          offset;

    NSUInteger          cursor;

    NSError *           error;

    assert(commandData != nil);

    bufferBytes  = [commandData bytes];

    bufferLength = [commandData length];

    assert(bufferBytes != nil);

    assert(bufferLength != 0);

    offset = 0;

    error  = nil;

    do {

        assert(offset <= bufferLength);

        cursor = offset;

        while ( (cursor < bufferLength) && (bufferBytes[cursor] != '\n') ) {

            cursor += 1;

        }

        if (cursor == bufferLength) {

            // We got to the end of the buffer before we found a line ending. 

            // We return in this case.  We'll get called back when more data 

            // arrives (or the connection will fail if the command line is 

            // longer than our input buffer).

            break;

        } else {

            NSString *  commandLine;

            cursor += 1;        // include the LF in the command

            // Check that the command string is valid UTF-8 and that it's correctly terminated 

            // by CR LF.  If either of these fails, we just drop the connection.  It's brutal, 

            // but it's the only thing we can do at this layer (because we don't know how to 

            // format a 'you bozo' response and we don't want to pass malformed commands up 

            // to our delegate and an extra delegate callback to deal with this seems somewhat 

            // excessive).

            commandLine = [[NSString alloc] initWithBytes:&bufferBytes[offset] length:cursor - offset encoding:NSUTF8StringEncoding];

            if ( (commandLine == nil) || ( ([commandLine length] < 2) || ([commandLine characterAtIndex:[commandLine length] - 2] != '\r') ) ) {

                error = [[self class] errorWithCode:kQCommandConnectionInputCommandMalformedError];

            } else {

                [self didReceiveCommandLine:commandLine];

            }

            [commandLine release];

            if (error != nil) {

                break;

            } else {

                offset = cursor;

            }

        }

    } while (YES);

    if (error != nil) {

        [self closeWithError:error];

    }

    return offset;

}

@end