/*

File: EntryController.m

Abstract: Use the PubSub framework to create a simple RSS news reader.

Version: 1.0

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*/

#import "EntryController.h"

#import <PubSub/PubSub.h>

#import <PubSub/PSEnclosure.h>

#import <WebKit/WebKit.h>

@interface EntryController (Private)

- (NSString*) currentHTML;

@end

@implementation EntryController

// The current entry

- (PSEntry*) currentEntry

{

    return _entry;

}

// Sets the current entry

- (void) setCurrentEntry: (PSEntry*)entry

{

    if( entry!=_entry && ! [entry isEqual: _entry] ) {   // Don't compare entries with ==

        _entry = entry;

        [self reload];

        // If this entry is displayed for 1 second, mark it read:

        // This is a simple mechanism to ensure that the user really intends to mark-as-read

        // when they're changing the selection in the table view (e.g. by arrowing up and down).

        if( _entry && ! [_entry isRead] )

            [self performSelector: @selector(_markRead:) withObject: _entry afterDelay: 1.0];

    }

}

// If the input PSEntry is equal to our current entry, change its status (using the PubSub API) to read

- (void) _markRead: (PSEntry*)entry

{

    if( [entry isEqual: _entry] )

        [_entry setRead: YES];

}

#pragma mark -

#pragma mark HTML GENERATION:

- (NSString*) enclosureHTML: (PSEnclosure*)encl

{

    static NSString *sTemplate;

    if( ! sTemplate ) {

        NSString *path = [[NSBundle mainBundle] pathForResource: @"EnclosureTemplate" ofType: @"html"];

        sTemplate = [[NSString alloc] initWithContentsOfFile: path];

        NSAssert(sTemplate,@"Can't load EnclosureTemplate.html");

    }

    NSString *urlStr = [[encl URL] absoluteString];

    NSString *name = [[[encl URL] path] lastPathComponent];

    NSString *type = [encl MIMEType];

    if( ! type )

        type = @"";

    long long length = [encl length];

    NSString *lengthStr = length ?[NSString stringWithFormat: @"(%.0f KB)", length/1024.0]

                                 : @"";

    NSMutableString *html = [[sTemplate mutableCopy] autorelease];

    [html replaceOccurrencesOfString: @"{URL}" withString: urlStr

                                options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{NAME}" withString: name

                                options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{TYPE}" withString: type

                                options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{LENGTH}" withString: lengthStr

                                options: 0 range: NSMakeRange(0,[html length])];

    return html;

}

- (NSString*) enclosuresHTML

{

    NSMutableString *html = [NSMutableString string];

    for( PSEnclosure *encl in [_entry enclosures] )

        [html appendString: [self enclosureHTML: encl]];

    return html;

}

// The HTML representation of the current entry

- (NSString*) currentHTML

{

    // Without an entry, use the empty string

    if( ! _entry )

        return @"";

    // Get the title, if any. Entries don't have to have titles, but usually do.

    NSString *title = [_entry title];

    if( ! title ) title = @"";

    // Get the content, if any. Some entries only have a summary, some have nothing.

    NSString *content = [[_entry content] HTMLString];

    if( ! content )

        content = [[_entry summary] HTMLString];

    if( ! content ) content = @"";

    // Get the alternateURL (sometimes also known as "permalink"). This is almost always

    // the url of the entry's web page.

    NSString *link = [[_entry alternateURL] absoluteString];

    if( ! link ) link = @"";

    // Set the <base> value in the HTML, so that relative URLs in the content

    // will be interpreted correctly.

    NSString *base = [[_entry baseURL] absoluteString];

    if( ! base )

        base = link;

    if( ! base )

        base = [[[_entry feed] alternateURL] absoluteString];

    // Generate HTML for any enclosures:

    NSString *encls = [self enclosuresHTML];

    // There follows a very dumb (but easy!) HTML templating engine:

    // We plug the above values in to our template HTML, stored in our application's bundle.

    static NSString *sTemplate, *sNoLinkTemplate;

    // First, grab our templates out of our application's Resources directory

    if( ! sTemplate ) {

        NSString *path = [[NSBundle mainBundle] pathForResource: @"EntryTemplate" ofType: @"html"];

        sTemplate = [[NSString alloc] initWithContentsOfFile: path];

        NSAssert(sTemplate,@"Can't load EntryTemplate.html");

        path = [[NSBundle mainBundle] pathForResource: @"EntryTemplate_NoLink" ofType: @"html"];

        sNoLinkTemplate = [[NSString alloc] initWithContentsOfFile: path];

        NSAssert(sNoLinkTemplate,@"Can't load EntryTemplate.html");

    }

    NSString *template = [link length] ?sTemplate :sNoLinkTemplate;

    NSMutableString *html = [[template mutableCopy] autorelease];

    // Now, replace some constants that occur in the templates with our entry's data

    [html replaceOccurrencesOfString: @"{BASE}" withString: base

    options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{LINK}" withString: link

    options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{TITLE}" withString: title

    options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{CONTENT}" withString: content

    options: 0 range: NSMakeRange(0,[html length])];

    [html replaceOccurrencesOfString: @"{ENCLOSURES}" withString: encls

    options: 0 range: NSMakeRange(0,[html length])];

    return html;

}

#pragma mark -

#pragma mark LOADING:

// Set the object value of the status text field to the input string

- (void) _setStatus: (NSString*)status

{

    [_statusField setObjectValue: status];

}

// Reloads the entry into the WebView

- (void) reload

{

    [self _setStatus: nil];

    [[_webView mainFrame] loadHTMLString: [self currentHTML] baseURL: [_entry alternateURL]];

}

// Start animating our progress indicator, and set our status field accordingly

- (void) startedLoading

{

    _loading = YES;

    [_loadingIndicator startAnimation: self];

    [self _setStatus: @"Loading..."];

}

// Stop animating our progress indicator, and set our status field accordingly (to nil

// if no error occurred, or to an error string if we've encountered an error)

- (void) stoppedLoading: (NSError*)error

{

    _loading = NO;

    NSString *status = nil;

    if( error )

        status = [@"Error: " stringByAppendingString: [error localizedDescription]];

    [_loadingIndicator stopAnimation: self];

    [self _setStatus: status];

}

#pragma mark -

#pragma mark WEBVIEW DELEGATES:

// WebView delegate methods

// Used to indicate that we've started loading (so that we can update our progress indicator

// and status text field)

- (void)webView:(WebView *)sender didStartProvisionalLoadForFrame:(WebFrame *)frame

{

    if( frame == [_webView mainFrame] )

        [self startedLoading];

}

// Used to indicate that we've finished loading (so that we can update our progress indicator

// and status text field)

- (void)webView:(WebView *)sender didFinishLoadForFrame:(WebFrame *)frame

{

    if( frame == [_webView mainFrame] )

        [self stoppedLoading: nil];

}

// Used to indicate that we've encountered an error during loading (so that we can update our 

// progress indicator and status text field)

- (void)webView:(WebView *)sender didFailLoadWithError:(NSError *)error forFrame:(WebFrame *)frame

{

    NSLog(@"EntryController: Failed load: %@",error);

    if( frame == [_webView mainFrame] )

        [self stoppedLoading: error];

}

// Also used to indicate that we've encountered an error during loading (so that we can update our 

// progress indicator and status text field)

- (void)webView:(WebView *)sender didFailProvisionalLoadWithError:(NSError *)error forFrame:(WebFrame *)frame

{

    NSLog(@"EntryController: Failed provisional load: %@",error);

    if( frame == [_webView mainFrame] )

        [self stoppedLoading: error];

}

// We simply log to Console when we've encountered a policy implementation failure within a WebFrame.

// (You might want to do more.)

- (void)webView:(WebView *)sender unableToImplementPolicyWithError:(NSError *)error frame:(WebFrame *)frame

{

    NSLog(@"EntryController: %s %@",_cmd,error);

}

// We simply log to Console when we've encountered an error loading a (sub)resource within the WebView.

// (You might want to do more.)

- (void)webView:(WebView *)sender 

       resource:(id)identifier 

        didFailLoadingWithError:(NSError *)error

 fromDataSource:(WebDataSource *)dataSource

{

    NSLog(@"EntryController: Failed to load <%@> -- %@",

        [[error userInfo] objectForKey: NSErrorFailingURLStringKey],

        [error localizedDescription]);

}

// Track the mouse to handle roll-over for links

// This allows us to set our status text field to something informative when the user's cursor

// is over a link.

- (void)webView:(WebView *)sender 

        mouseDidMoveOverElement:(NSDictionary *)elementInformation 

        modifierFlags:(unsigned int)modifierFlags

{

    if( ! _loading ) {

        NSString *status = nil;

        NSURL *link = [elementInformation objectForKey: WebElementLinkURLKey];

        if( link ) {

            WebFrame *target = [elementInformation objectForKey: WebElementLinkTargetFrameKey];

            // If the Command key is held down, the link will open in the web browser:

            if( (modifierFlags & NSCommandKeyMask) || target != [_webView mainFrame] )

                status = @"Open \"%@\" in browser";

            else

                status = @"Go to \"%@\"";

            status = [NSString stringWithFormat: status, [link absoluteString]];

        }

        [self _setStatus: status];

    }

}

// Used to send a URL to the user's default web browser. If they're holding down the <Shift> key,

// we'll send the URL without activating the receiving application.

- (BOOL) _sendBrowserRequest: (NSURLRequest*)request forAction: (NSDictionary*)actionInformation

{

    NSWorkspaceLaunchOptions options = NSWorkspaceLaunchDefault;

    unsigned modifiers = [[actionInformation objectForKey: WebActionModifierFlagsKey] unsignedIntValue];

    if( (modifiers & NSShiftKeyMask) )

        options |= NSWorkspaceLaunchWithoutActivation;

    BOOL ok = [[NSWorkspace sharedWorkspace] openURLs: [NSArray arrayWithObject: [request URL]]

                              withAppBundleIdentifier: nil

                                              options: options

                       additionalEventParamDescriptor: nil

                                    launchIdentifiers: NULL];

    if( ! ok )

        NSBeep();

    return ok;

}

// Intercept link clicks, and send them to the web browser if the user Cmd-clicked

- (void)webView:(WebView *)sender decidePolicyForNavigationAction:(NSDictionary *)actionInformation 

        request:(NSURLRequest *)request 

          frame:(WebFrame *)frame

         decisionListener:(id<WebPolicyDecisionListener>)listener

{

    WebNavigationType navType = [[actionInformation objectForKey: WebActionNavigationTypeKey] intValue];

    unsigned modifiers = [[actionInformation objectForKey: WebActionModifierFlagsKey] unsignedIntValue];

    if( navType == WebNavigationTypeLinkClicked && (modifiers & NSCommandKeyMask) ) {

        [self _sendBrowserRequest: request forAction: actionInformation];

        [listener ignore];

    } else {

        [listener use];

    }

}

// Intercept link clicks destined for new windows, and send them to the user's default web browser

- (void)webView:(WebView *)sender decidePolicyForNewWindowAction:(NSDictionary *)actionInformation

        request:(NSURLRequest *)request 

   newFrameName:(NSString *)frameName 

        decisionListener:(id<WebPolicyDecisionListener>)listener

{

    [self _sendBrowserRequest: request forAction: actionInformation];

    [listener ignore];

}

@end