JSJP_Student/Pods/KTVHTTPCache/KTVHTTPCache/Classes/KTVHCCommon/KTVHCRange.m

//
//  KTVHCRange.m
//  KTVHTTPCache
//
//  Created by Single on 2018/5/20.
//  Copyright © 2018年 Single. All rights reserved.
//

#import "KTVHCRange.h"

BOOL KTVHCRangeIsFull(KTVHCRange range)
{
    return KTVHCEqualRanges(range, KTVHCRangeFull());
}

BOOL KTVHCRangeIsVaild(KTVHCRange range)
{
    return !KTVHCRangeIsInvaild(range);
}

BOOL KTVHCRangeIsInvaild(KTVHCRange range)
{
    return KTVHCEqualRanges(range, KTVHCRangeInvaild());
}

BOOL KTVHCEqualRanges(KTVHCRange range1, KTVHCRange range2)
{
    return range1.start == range2.start && range1.end == range2.end;
}

long long KTVHCRangeGetLength(KTVHCRange range)
{
    if (range.start == KTVHCNotFound || range.end == KTVHCNotFound) {
        return KTVHCNotFound;
    }
    return range.end - range.start + 1;
}

NSString *KTVHCStringFromRange(KTVHCRange range)
{
    return [NSString stringWithFormat:@"Range : {%lld, %lld}", range.start, range.end];
}

NSString *KTVHCRangeGetHeaderString(KTVHCRange range)
{
    NSMutableString *string = [NSMutableString stringWithFormat:@"bytes="];
    if (range.start != KTVHCNotFound) {
        [string appendFormat:@"%lld", range.start];
    }
    [string appendFormat:@"-"];
    if (range.end != KTVHCNotFound) {
        [string appendFormat:@"%lld", range.end];
    }
    return [string copy];
}

NSDictionary *KTVHCRangeFillToRequestHeaders(KTVHCRange range, NSDictionary *headers)
{
    NSMutableDictionary *ret = [NSMutableDictionary dictionaryWithDictionary:headers];
    [ret setObject:KTVHCRangeGetHeaderString(range) forKey:@"Range"];
    return ret;
}

NSDictionary *KTVHCRangeFillToRequestHeadersIfNeeded(KTVHCRange range, NSDictionary *headers)
{
    if ([headers objectForKey:@"Range"]) {
        return headers;
    }
    return KTVHCRangeFillToRequestHeaders(range, headers);
}

NSDictionary *KTVHCRangeFillToResponseHeaders(KTVHCRange range, NSDictionary *headers, long long totalLength)
{
    NSMutableDictionary *ret = [NSMutableDictionary dictionaryWithDictionary:headers];
    long long currentLength = KTVHCRangeGetLength(range);
    [ret setObject:[NSString stringWithFormat:@"%lld", currentLength] forKey:@"Content-Length"];
    [ret setObject:[NSString stringWithFormat:@"bytes %lld-%lld/%lld", range.start, range.end, totalLength] forKey:@"Content-Range"];
    return ret;
}

NSString *KTVHCResponseRangeStringWithContentLength(long long contentLength)
{
    return [NSString stringWithFormat:@"bytes 0-%lld/%lld", contentLength - 1, contentLength];
}

KTVHCRange KTVHCMakeRange(long long start, long long end)
{
    KTVHCRange range = {start, end};
    return range;
}

KTVHCRange KTVHCRangeZero(void)
{
    return KTVHCMakeRange(0, 0);
}

KTVHCRange KTVHCRangeFull(void)
{
    return KTVHCMakeRange(0, KTVHCNotFound);
}

KTVHCRange KTVHCRangeInvaild(void)
{
    return KTVHCMakeRange(KTVHCNotFound, KTVHCNotFound);
}

KTVHCRange KTVHCRangeWithSeparateValue(NSString *value)
{
    KTVHCRange range = KTVHCRangeInvaild();
    if (value.length > 0) {
        NSArray *components = [value componentsSeparatedByString:@","];
        if (components.count == 1) {
            components = [components.firstObject componentsSeparatedByString:@"-"];
            if (components.count == 2) {
                NSString *startString = [components objectAtIndex:0];
                NSInteger startValue = [startString integerValue];
                NSString *endString = [components objectAtIndex:1];
                NSInteger endValue = [endString integerValue];
                if (startString.length && (startValue >= 0) && endString.length && (endValue >= startValue)) {
                    // The second 500 bytes: "500-999"
                    range.start = startValue;
                    range.end = endValue;
                } else if (startString.length && (startValue >= 0)) {
                    // The bytes after 9500 bytes: "9500-"
                    range.start = startValue;
                    range.end = KTVHCNotFound;
                } else if (endString.length && (endValue > 0)) {
                    // The final 500 bytes: "-500"
                    range.start = KTVHCNotFound;
                    range.end = endValue;
                }
            }
        }
    }
    return range;
}

KTVHCRange KTVHCRangeWithRequestHeaderValue(NSString *value)
{
    if ([value hasPrefix:@"bytes="]) {
        NSString *rangeString = [value substringFromIndex:6];
        return KTVHCRangeWithSeparateValue(rangeString);
    }
    return KTVHCRangeInvaild();
}

KTVHCRange KTVHCRangeWithResponseHeaderValue(NSString *value, long long *totalLength)
{
    if ([value hasPrefix:@"bytes "]) {
        value = [value stringByReplacingOccurrencesOfString:@"bytes " withString:@""];
        NSRange range = [value rangeOfString:@"/"];
        if (range.location != NSNotFound) {
            NSString *rangeString = [value substringToIndex:range.location];
            NSString *totalLengthString = [value substringFromIndex:range.location + range.length];
            *totalLength = totalLengthString.longLongValue;
            return KTVHCRangeWithSeparateValue(rangeString);
        }
    }
    return KTVHCRangeInvaild();
}

KTVHCRange KTVHCRangeWithEnsureLength(KTVHCRange range, long long ensureLength)
{
    if (ensureLength > 0 &&
        (range.end == KTVHCNotFound || range.end >= ensureLength)) {
        return KTVHCMakeRange(range.start, ensureLength - 1);
    }
    return range;
}