//
//  P4TaggedDataTransformer.m
//  JobSuey
//
//  Created by Work on 4/17/09.
//  Copyright 2009 Numerical Garden, LLC. All rights reserved.
//

#import "P4TaggedDataInflaterTransformer.h"
#import "NGAUtilities.h"


// Split a key into its base name and its index. i.e. for a key "how1,0"
// the base name is "how" and they index is "1,0".

static void
SplitKey( NSString * key, NSString ** base, NSString ** index );

// Insert an element into the response structure. The element may need to
// be inserted into an array nested deeply within the enclosing hash.

static void
InsertItem( NSMutableDictionary * hash, NSString * var, NSString * val );



@implementation P4TaggedDataInflaterTransformer

SINGLETON_IMPLEMENTATION(P4TaggedDataInflaterTransformer, sharedInstance)


+ (Class)transformedValueClass
{
    return [NSDictionary class];
}

+ (BOOL)allowsReverseTransformation
{
    return NO;
}

-(NSDictionary*)transformedDictionary:(NSDictionary*)dictionary
{
    if ( ![dictionary isKindOfClass:[NSDictionary class]])
        return dictionary;
    
    NSMutableDictionary * hierarchy = [NSMutableDictionary dictionary];
    
    for (NSString * key in [dictionary allKeys])
        InsertItem( hierarchy, key, [dictionary objectForKey:key] );

    return hierarchy;
}

- (id)transformedValue:(id)value
{
    if ([value isKindOfClass:[NSDictionary class]])
        return [self transformedDictionary:value];

    if ([value isKindOfClass:[NSArray class]])
    {
        NSMutableArray * transformedArray = [NSMutableArray arrayWithCapacity:[value count]];
        for (NSDictionary * dictionary in value)
        {
            [transformedArray addObject:[self transformedDictionary:dictionary]];
        }
        return transformedArray;
    }

    return nil;
}


@end


void
SplitKey( NSString * key, NSString ** base, NSString ** index )
{
    NSScanner * scanner = [NSScanner scannerWithString:key];
    
    NSCharacterSet * keyCharacters = [NSCharacterSet characterSetWithCharactersInString:@",1234567890"];
    
    if (![scanner scanUpToCharactersFromSet:keyCharacters intoString:base])
        *base = nil;
    
    if (![scanner scanCharactersFromSet:keyCharacters intoString:index])
        *index = nil;
}

void
InsertItem( NSMutableDictionary * hash, NSString * var, NSString * val )
{
    NSString	*key;
    NSString    *base, *index;
    
    SplitKey( var, &base, &index );
    
    // If there's no index, then we insert into the top level hash 
    // but if the key is already defined then we need to rename the key. This
    // is probably one of those special keys like otherOpen which can be
    // both an array element and a scalar. The scalar comes last, so we
    // just rename it to "otherOpens" to avoid trashing the previous key
    // value
    if ( index == nil )
    {
        key = var;
        
	if ( [hash doesContain:key] )
            key = [key stringByAppendingString:@"s"];
        
        [hash setObject:val forKey:key];
	return;
    }
    
    //
    // Get or create the parent array from the hash.
    //
    key = base;
    NSMutableArray * ary = nil;
    NSMutableArray * tary = nil;
    
    ary = [hash objectForKey:key];
    
    if ( nil == ary )
    {
        ary = [NSMutableArray arrayWithCapacity:1];
        [hash setObject:ary forKey:key];
    }
    else if ( ![ary isKindOfClass:[NSArray class]] )
    {
	//
	// There's an index in our var name, but the name is already defined 
	// and the value it contains is not an array. This means we've got a 
	// name collision. This can happen in 'p4 diff2' for example, when 
	// one file gets 'depotFile' and the other gets 'depotFile2'. In 
	// these cases it makes sense to keep the structure flat so we
	// just use the raw variable name.
	//
	[hash setObject:val forKey:var];
	return;
    }
    
    // The index may be a simple digit, or it could be a comma separated
    // list of digits. For each "level" in the index, we need a containing
    // array.
    NSScanner * scanner = [NSScanner scannerWithString:index];
    NSCharacterSet * commaSet = [NSCharacterSet characterSetWithCharactersInString:@","];
    NSString * subIndexString = nil;
    while ( YES )
    {
        [scanner scanUpToCharactersFromSet:commaSet intoString:&subIndexString];
        [scanner scanCharactersFromSet:commaSet intoString:nil]; // skip comma
        NSUInteger subIndex = [subIndexString intValue];
        
	// Found another level so we need to get/create a nested array
	// under the current entry. We use the level as an index so that
	// missing entries are left empty deliberately.
	
        if ( [scanner isAtEnd] )
        {
            [ary NGA_setObject:val atIndex:subIndex];
            break;
        }
        
        if ( [ary count] > subIndex )
            tary = [ary objectAtIndex:subIndex];
        else
            tary = nil;

        if ( !tary )
        {
            tary = [NSMutableArray arrayWithCapacity:subIndex+1];
            [ary NGA_setObject:tary atIndex:subIndex];
        }
        
	ary = tary;
    }
}