/*
     File: WebViewController.m
 Abstract: Main web view controller.
  Version: 1.1
 
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 */

#import "WebViewController.h"

@import Security;

@interface WebViewController () <UIWebViewDelegate>

// stuff for IB

@property (nonatomic, strong, readwrite) IBOutlet UIWebView *   webView;

// private properties

@property (nonatomic, strong, readwrite) NSURLSessionDataTask * installDataTask;

@end

@implementation WebViewController

- (void)dealloc
{
    // All of these should be nil because the connection retains its delegate (that is, us) 
    // until it completes, and we clean these up when the connection completes.
    
    assert(self->_installDataTask == nil);
}

/*! Called to log various bits of information.  Will be called on the main thread.
 *  \param format A standard NSString-style format string; will not be nil.
 */

- (void)logWithFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1, 2)
{
    id<WebViewControllerDelegate>   strongDelegate;

    assert(format != nil);
    
    strongDelegate = self.delegate;
    if ([strongDelegate respondsToSelector:@selector(webViewController:logWithFormat:arguments:)]) {
        va_list     arguments;
        
        va_start(arguments, format);
        [strongDelegate webViewController:self logWithFormat:format arguments:arguments];
        va_end(arguments);
    }
}

/*! The error domain used by our installation error codes.
 */

static NSString * WebViewControllerInstallErrorDomain = @"WebViewControllerInstallErrorDomain";

/*! Our installation error codes.  Note that (positive) HTTP status codes are also possible.
 */

enum WebViewControllerInstallErrorCode {
    // positive numbers are HTTP status codes
    WebViewControllerInstallErrorUnsupportedMIMEType   = -1, 
    WebViewControllerInstallErrorCertificateDataTooBig = -2,
    WebViewControllerInstallErrorCertificateDataBad    = -3, 
    WebViewControllerInstallErrorNowhereToInstall      = -4
};

/*! Returns an error object in the domain WebViewControllerInstallErrorDomain with 
 *  the specified error code
 *  \param code The code to use for the error.
 */

- (NSError *)constructInstallErrorWithCode:(NSInteger)code
{
    assert(code != 0);

    return [NSError errorWithDomain:WebViewControllerInstallErrorDomain code:code userInfo:nil];
}

/*! Create and installs a certificate from the data returned by the install data task.
 *  \param data The data returned by the install data task; must not be nil.
 *  \param errorPtr If not NULL then, on error, *errorPtr will be the actual error.
 *  \returns Returns YES on success, NO on failure.
 */

- (BOOL)parseAndInstallCertificateData:(NSData *)data error:(__autoreleasing NSError **)errorPtr
{
    NSError *           error;
    SecCertificateRef   anchor;

    assert(data != nil);
    // errorPtr may be NULL
    assert([NSThread isMainThread]);
    
    // Try to create a certificate from the data we downloaded.  If that 
    // succeeds, tell our delegate.
    
    error = nil;
    anchor = SecCertificateCreateWithData(NULL, (__bridge CFDataRef) data);
    if (anchor == nil) {
        error = [self constructInstallErrorWithCode:WebViewControllerInstallErrorCertificateDataBad];
    }
    if (error == nil) {
        id<WebViewControllerDelegate>   strongDelegate;
        
        strongDelegate = self.delegate;
        if ( ! [strongDelegate respondsToSelector:@selector(webViewController:addTrustedAnchor:error:)] ) {
            error = [self constructInstallErrorWithCode:WebViewControllerInstallErrorNowhereToInstall];
        } else {
            BOOL                            success;
            NSError *                       delegateError;

            success = [strongDelegate webViewController:self addTrustedAnchor:anchor error:&delegateError];
            if ( ! success ) {
                error = delegateError;
            }
        }
    }

    // Clean up.
    
    if (anchor != NULL) {
        CFRelease(anchor);
    }
    if ( (error != nil) && (errorPtr != NULL) ) {
        *errorPtr = error;
    }
    
    return (error == nil);
}

@end