//
//  FontResolver.h
//  Tabris
//
//  Created by Jordi Böhme López on 23.07.12.
//  Copyright (c) 2012 EclipseSource.
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  which accompanies this distribution, and is available at
//  http://www.eclipse.org/legal/epl-v10.html
//

#import <Foundation/Foundation.h>

@interface FontResolver : NSObject

+(UIFont*)fontWithDescription:(NSString*)description;

@end

//
//  FontResolver.m
//  Tabris
//
//  Created by Jordi Böhme López on 23.07.12.
//  Copyright (c) 2012 EclipseSource.
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  which accompanies this distribution, and is available at
//  http://www.eclipse.org/legal/epl-v10.html
//

#import "FontResolver.h"
#import "FontRegistry.h"

@implementation FontResolver

NSString *const FONT_FAMILY = @"font-family";
NSString *const FONT_SIZE = @"font-size";
NSString *const FONT_WEIGHT = @"font-weight";
NSString *const FONT_STYLE = @"font-style";

NSString *const FAMILY_SANS_SERIF = @"Helvetica";
NSString *const FAMILY_SERIF = @"Times New Roman";
NSString *const FAMILY_MONOSPACE = @"Courier New";

CGFloat const DEFAULT_FONT_SIZE = 12;

#pragma mark - API Methods

+(UIFont*)fontWithDescription:(NSString*)description {
    UIFont *result = nil;
    CGFloat fontSize = [[self extractSize:description] floatValue];
    BOOL isBold = [[self extractWeight:description] boolValue];
    BOOL isItalic = [[self extractStyle:description] boolValue];
    result = [self computeFont:description forSize:fontSize andBold:isBold andItalic:isItalic];
    if( !result ) {
        result = [self computeFallbackFontForSize:fontSize andBold:isBold andItalic:isItalic];
    }
    return result;
}

#pragma mark - Internal Methods

+(UIFont *)computeFont:(NSString *)description forSize:(CGFloat)size andBold:(BOOL)isBold andItalic:(BOOL)isItalic {
    UIFont *result = nil;
    NSString *fontName = [self extractFontName:description forBold:isBold andItalic:isItalic];
    if( fontName ) {
        UIFont *foundFont = [UIFont fontWithName:fontName size:size];
        if( foundFont ) {
            result = foundFont;
        }
    }
    return result;
}

+(UIFont *)computeFallbackFontForSize:(CGFloat)size andBold:(BOOL)isBold andItalic:(BOOL)isItalic {
    UIFont *result = nil;
    if( isBold ) {
        result = [UIFont boldSystemFontOfSize:size];
    } else if( isItalic ) {
        result = [UIFont italicSystemFontOfSize:size];
    } else {
        result = [UIFont systemFontOfSize:size];
    }
    return result;
}

+(NSString *)extractFontName:(NSString *)description forBold:(BOOL)isBold andItalic:(BOOL)isItalic {
    NSString *result = nil;
    NSString *familyString = [self extractValue:FONT_FAMILY from:description];
    NSArray *families = [self splitFamilies:familyString];
    for (NSString *family in families) {
        NSString *foundFamily = [self findFamily:family];
        result = [[FontRegistry instance] fontForFamily:foundFamily forBold:isBold andItalic:isItalic]; //replace this with [UIFont fontWithMarkupDescription:] when it's public
        if( result ) {
            return result;
        }
    }
    return result;
}

+(NSArray *)splitFamilies:(NSString *)familiesString {
    NSMutableArray *result = [NSMutableArray array];
    NSArray *families = [familiesString componentsSeparatedByString:@","];
    for (NSString *family in families) {
        [result addObject:[self normalizeFamily:family]];
    }
    return result;
}

+(NSString *)normalizeFamily:(NSString *)family {
    NSString *result = trim(family);
    if( [[result lowercaseString] isEqualToString:@"sans-serif"] ) {
        result = FAMILY_SANS_SERIF;
    } else if( [[result lowercaseString] isEqualToString:@"serif"] ) {
        result = FAMILY_SERIF;
    } else if( [[result lowercaseString] isEqualToString:@"monospace"] ) {
        result = FAMILY_MONOSPACE;
    }
    return result;
}

+(NSString *)findFamily:(NSString *)definedFont {
    NSArray *familyNames = [UIFont familyNames];
    for (NSString *familyName in familyNames) {
        if( [familyName isEqualToString:definedFont] ) {
            return familyName;
        }
    }
    return nil;
}

+(NSNumber *)extractSize:(NSString *)description {
    CGFloat result = DEFAULT_FONT_SIZE;
    NSString *pixel = [self extractValue:FONT_SIZE from:description];
    if( pixel ) {
        CGFloat px = [pixel floatValue];
        result = px;
    }
    return [NSNumber numberWithFloat:result];
}

+(NSNumber *)extractWeight:(NSString *)description {
    BOOL result = NO;
    NSString *foundValue = [self extractValue:FONT_WEIGHT from:description];
    if( foundValue && [foundValue isEqualToString:@"bold"] ) {
        result = YES;
    }
    return [NSNumber numberWithBool:result];
}

+(NSNumber *)extractStyle:(NSString *)description {
    BOOL result = NO;
    NSString *foundValue = [self extractValue:FONT_STYLE from:description];
    if( foundValue && [foundValue isEqualToString:@"italic"] ) {
        result = YES;
    }
    return [NSNumber numberWithFloat:result];
}

+(NSString *)extractValue:(NSString *)key from:(NSString *)description {
    NSString *result = nil;
    NSArray *components = [description componentsSeparatedByString:@";"];
    for (NSString *component in components) {
        NSString *keyValue = trim(component);
        if( [keyValue hasPrefix:key] ) {
            result = [keyValue substringFromIndex:[key length]+1];
            result = trim(result);
        }
    }
    return result;
}

NSString * trim(NSString *string) {
    return [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
}

@end