source: trunk/PrefsPane/src/Xml.m @ 1046

/* Copyright (C) 2008-2009 Peter Speck
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#import "Xml.h"

@implementation Xml

+ (BOOL)isSimpleName:(NSString*)name startIndex:(int)startIndex
{
    NSInteger len = [name length];
    for (int i = startIndex; i < len; i++) {
        unichar ch = [name characterAtIndex:i];
        if (ch == '-' || (ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'z'))
            continue;
        return NO;
    }
    return len > 0;
}

+ (BOOL)isSimpleName:(NSString*)name
{
    return [Xml isSimpleName:name startIndex:0];
}

#pragma mark -------------- Create elements

+ (NSXMLElement*)createElementWithName:(NSString*)name
{
    return (NSXMLElement*)[NSXMLNode elementWithName:name];
}

#pragma mark -------------- Singletons

+ (NSXMLElement*)singletonElementForXPath:(NSString*)xpath
                                forParent:(NSXMLElement*)parentE
{
    return [self singletonElementForXPath:xpath forParent:parentE asFirstChild:NO];
}

+ (NSXMLElement*)singletonElementForXPath:(NSString*)xpath
                                forParent:(NSXMLElement*)parentE
                             asFirstChild:(BOOL)asFirstChild
{
    NSArray* pathItems = [xpath componentsSeparatedByString:@"/"];
    NSUInteger compCount = [pathItems count];
    NSXMLElement* e = parentE;
    for (NSUInteger compIdx = 0; true; compIdx++) {
        NSString* s = [pathItems objectAtIndex:compIdx];
        if (![Xml isSimpleName:s]) {
            [NSException raise:@"Invalid element name in singleton xpath"
                        format:@"xpath = '%@'", xpath];
        }
        BOOL leaf = (compIdx == compCount - 1);
        NSArray* childs = [e elementsForName:s];
        NSInteger numChilds = [childs count];
        if (leaf && numChilds > 1) {
            for (int x = 1; x < numChilds; x++)
                [[childs objectAtIndex:compIdx] detach];
        }
        if (numChilds) {
            e = [childs objectAtIndex:0];
        } else {
            NSXMLElement* newE = [Xml createElementWithName:s];
            if (leaf && asFirstChild)
                [e insertChild:newE atIndex:0];
            else
                [e addChild:newE];
            e = newE;
        }
        if (leaf)
            return e;
    }
    [NSException raise:@"shouldn't fell through" format:@"xpath = '%@'", xpath];
}

+ (NSXMLElement*)singletonDateElement:(NSDate*)date
                             forXPath:(NSString*)xpath
                            fromParent:(NSXMLElement*)parentE
                       updateExisting:(BOOL)updateExisting
{
    NSXMLElement* e = [Xml singletonElementForXPath:xpath forParent:parentE asFirstChild:YES];
    if (!updateExisting && [Xml getAttribute:e withName:@"msecs"])
        return e;
    NSString* msecs = [NSString stringWithFormat:@"%.0f", [date timeIntervalSince1970] * 1000];
    [Xml setAttribute:msecs withName:@"msecs" inElement:e];
    [Xml setAttribute:[date description] withName:@"iso" inElement:e];
    return e;
}

#pragma mark -------------- Attributes

+ (NSString*)getAttribute:(NSXMLElement*)e withName:(NSString*)name
{
    return [[e attributeForName:name] stringValue];
}

+ (int)getBoolAttribute:(NSXMLElement*)e withName:(NSString*)name
{
    return [Xml getIntAttribute:e withName:name] ? YES : NO;
}

+ (int)getIntAttribute:(NSXMLElement*)e withName:(NSString*)name
{
    return [[Xml getAttribute:e withName:name] intValue];
}

+ (void)setAttribute:(NSString*)value withName:(NSString*)name inElement:(NSXMLElement*)e
{
    NSXMLNode* attr = [e attributeForName:name];
    if ([value length]) {
        if (![[attr stringValue] isEqual:value]) {
            [attr detach];
            [e addAttribute:[NSXMLNode attributeWithName:name stringValue:value]];
        }
    } else {
        [attr detach];
    }
}

+ (void)setBool:(BOOL)value withName:(NSString*)name inElement:(NSXMLElement*)e
{
    [Xml setAttribute:(value ? @"1" : NULL) withName:name inElement:e];
}

+ (void)setInt:(int)value withName:(NSString*)name inElement:(NSXMLElement*)e
{
    [Xml setAttribute:[NSString stringWithFormat:@"%d", value] withName:name inElement:e];
}

+ (void)reorderChilds:(NSArray*)childs
{
    if ([childs count] <= 1)
        return;
    for (NSUInteger i = 0; i < [childs count]; i++) {
        NSXMLElement *childE = [childs objectAtIndex:i];
        if (!childE) {
            NSLog(@"NULL element in array in reorder childs");
            continue;
        }
        NSXMLElement *parentE = (NSXMLElement*)[childE parent];
        if (!parentE) {
            NSLog(@"Element without parent in reorder childs.");
            continue;
        }
        [childE retain];
        [childE detach];
        [parentE addChild:childE];
        [childE release];
    }
}

#pragma mark -------------------------------- XPath

+ (NSArray *)nodesForXPath:(NSString *)xpath withRoot:(NSXMLElement*)rootE
{
    NSAssert(rootE, @"rootE");
    NSError *error = NULL;
    NSArray* a = [rootE nodesForXPath:xpath error:&error];
    if (error)
        NSLog(@"Xml.nodesForXPath failed with '%@' for xpath '%@' at location '%@'",
              error, xpath, [rootE XPath]);
    if (!a)
        a = [NSArray array];
    return a;
}

+ (NSXMLNode *)nodeForXPath:(NSString *)xpath withRoot:(NSXMLElement*)rootE
{
    NSArray* a = [self nodesForXPath:xpath withRoot:rootE];
    return [a count] > 0 ? [a objectAtIndex:0] : NULL;
}

+ (void)remove:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    NSArray* a = [self nodesForXPath:xpath withRoot:rootE];
    for (NSUInteger i = 0; i < [a count]; i++) {
        NSXMLNode* e = [a objectAtIndex:i];
        [e detach];
    }
}

+ (void)zapChildsAndAttributes:(NSXMLElement*)e
{
    for (NSXMLNode* a in [e attributes]) {
        if (![[a name] isEqual:@"rule-id"]) {
            //NSLog(@"Zaps attr: %@", a);
            [a detach];
        }
    }
    [e setChildren:[NSArray array]];
}

#pragma mark -------------------------------- simple get/set

+ (NSString*)stringForXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    NSArray* a = [Xml nodesForXPath:xpath withRoot:rootE];
    return [a count] ? [[a objectAtIndex:0] stringValue] : NULL;
}

+ (void)setText:(NSString*)value
       forXPath:(NSString*)xpath
       withRoot:(NSXMLElement*)rootE
     usingCDATA:(BOOL)usingCDATA
{
    NSArray* pathItems = [xpath componentsSeparatedByString:@"/"];
    NSUInteger num = [pathItems count];
    NSXMLElement* e = rootE;
    for (NSUInteger i = 0; i < num; i++) {
        NSString* s = [pathItems objectAtIndex:i];
        if (![s length]) {
            [NSException raise:@"Invalid setString xpath"
                        format:@"xpath = '%@'", xpath];
        }
        if ([s isEqual:@"."])
            continue;
        if ([s hasPrefix:@"@"]) {
            if (i + 1 < num) {
                [NSException raise:@"Invalid setString xpath"
                            format:@"xpath = '%@'", xpath];
            }
            if (![Xml isSimpleName:s startIndex:1]) {
                [NSException raise:@"Invalid attribute name in setString xpath"
                            format:@"xpath = '%@'", xpath];
            }
            NSString* attrName = [s substringFromIndex:1];
            [Xml setAttribute:value withName:attrName inElement:e];
            return;
        }
        if (![Xml isSimpleName:s]) {
            [NSException raise:@"Invalid element name in setString xpath"
                        format:@"xpath = '%@'", xpath];
        }
        NSArray* childs = [e elementsForName:s];
        if ([childs count]) {
            e = [childs objectAtIndex:0];
        } else {
            NSXMLElement* newE = [Xml createElementWithName:s];
            [e addChild:newE];
            e = newE;
        }
    }
    for (NSXMLElement* zapE in [e children])
        [zapE detach];
    if (![value length])
        return;
    if (usingCDATA) {
        //NSLog(@"SetCDATA in %@: {{{%@}}}", [e name], value);
        NSXMLNode* cdata = [[NSXMLNode alloc] initWithKind:NSXMLTextKind options:NSXMLNodeIsCDATA];
        [cdata setStringValue:value];
        [e addChild:cdata];
        [cdata release];
    } else {
        [e setStringValue:value];
    }
}

+ (void)setString:(NSString*)value forXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    [self setText:value forXPath:xpath withRoot:rootE usingCDATA:NO];
}

+ (void)setCData:(NSString*)value forXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    [self setText:value forXPath:xpath withRoot:rootE usingCDATA:YES];
}

+ (double)doubleForXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    return [[Xml stringForXPath:xpath withRoot:rootE] doubleValue];
}

+ (void)setDouble:(double)value forXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    [Xml setString:[NSString stringWithFormat:@"%f", value] forXPath:xpath withRoot:rootE];
}

+ (int)intForXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    return [[Xml stringForXPath:xpath withRoot:rootE] intValue];
}

+ (void)setInt:(int)value forXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    [Xml setString:[NSString stringWithFormat:@"%d", value] forXPath:xpath withRoot:rootE];
}

+ (BOOL)boolForXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    NSString* s = [Xml stringForXPath:xpath withRoot:rootE];
    return s && [s length] && ![s isEqual:@"false"] && ![s isEqual:@"0"];
}

+ (void)setBool:(BOOL)value forXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    [Xml setString:(value ? @"1" : NULL) forXPath:xpath withRoot:rootE];
}

+ (NSString*)dateFromMillisecsXPath:(NSString*)xpath withRoot:(NSXMLElement*)rootE
{
    double msecs = [Xml doubleForXPath:xpath withRoot:rootE];
    if (!msecs)
        return NULL;
    NSDate* date = [NSDate dateWithTimeIntervalSince1970:msecs / 1000.0];
    //
    NSDateFormatter* fmt = [[[NSDateFormatter alloc] init] autorelease];
    [fmt setDateStyle:NSDateFormatterMediumStyle];
    [fmt setTimeStyle:NSDateFormatterShortStyle];
    return [fmt stringFromDate:date];
}

#pragma mark -------------------------------- regexp

+ (BOOL)regex:(NSString*)regex matchesString:(NSString*)text
{
    NSString *fmt = [NSString stringWithFormat:@"SELF MATCHES '%@'", regex];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:fmt];
    return [predicate evaluateWithObject:text];
}

+ (NSString*)getHttpUrlSyntaxError:(NSString*)url
{
    if (![url length])
        return @"No URL was specified";
    if (![url hasPrefix:@"http://"] && ![url hasPrefix:@"https://"])
        return @"URL must start with 'http://' or 'https://'";
    if (![NSURL URLWithString:url])
        return @"Invalid URL (NSURL)";
    if (![Xml regex:@"^https?://[^:/]+(:[0-9]+)?(/[^[:space:]]*)?[:space:]*$" matchesString:url])
        return @"Invalid URL syntax";
    return NULL;
}

#pragma mark -------------------------------- unqiue id

// Faster than using XPath. Was bottleneck in loading new filters.
+ (BOOL)hasAttribute:(NSString*)attrName inSubtree:(NSXMLElement*)parentE withValue:(NSString*)value
{
    NSString* s = [[parentE attributeForName:attrName] stringValue];
    if (s && [s isEqualToString:value])
        return YES;
    for (NSXMLNode* childN in [parentE children]) {
        if ([childN kind] == NSXMLElementKind
            && [Xml hasAttribute:attrName inSubtree:(NSXMLElement*)childN withValue:value]) {
            return YES;
        }
    }
    return NO;
}

+ (int)makeUniqueIdWithRoot:(NSXMLElement*)rootE withAttributeName:(NSString*)attrName
{
    while (true) {
        int r = (int)arc4random() & 0x3FFFFFFF;
        if (r < 1234567)
            continue;
        NSString* value = [NSString stringWithFormat:@"%d", r];
        if (![Xml hasAttribute:attrName inSubtree:rootE withValue:value])
            return r;
    }
}

+ (int)makeUniqueIdWithRoot:(NSXMLElement*)rootE
{
    return [Xml makeUniqueIdWithRoot:rootE withAttributeName:@"id"];
}

#pragma mark -------------------------------- print-to-string

+ (NSData*)documentToData:(NSXMLDocument*)doc
{
    int options = NSXMLNodePrettyPrint|NSXMLNodePreserveCDATA;
    NSMutableData* data = [NSMutableData dataWithData:[doc XMLDataWithOptions:options]];
    [data appendBytes:"\n" length:1]; // XMLDataWithOptions doesn't end with newline.
    return data;
}

+ (NSString*)documentToString:(NSXMLDocument*)doc;
{
    NSData* data = [Xml documentToData:doc];
    return [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
}

// Cocoa doesn't support this for anything but full documents,
// and using [NSString stringWithFormat:@"%@", rootE] is dubious long-term.
+ (NSData*)subtreeToData:(NSXMLElement*)parentE;
{
    parentE = [parentE copy];
    NSXMLDocument* doc = [[NSXMLDocument alloc] initWithRootElement:parentE];
    NSData* data = [Xml documentToData:doc];
    [doc release];
    [parentE release];
    return data;
}

+ (NSString*)subtreeToString:(NSXMLElement*)parentE
{
    NSData* data = [Xml subtreeToData:parentE];
    return [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
}

@end