#import <WebKit/WebKit.h>

typedef char *(*SettingsCallback)(const char *, const char *, const char *, bool);
typedef void (*SettingsFree)(char *);

@interface KanbanSettingsHandler : NSObject <WKScriptMessageHandlerWithReply>
@property(nonatomic, weak) WKWebView *webview;
@property(nonatomic, copy) NSString *label;
@property(nonatomic) SettingsCallback callback;
@property(nonatomic) SettingsFree releaseReply;
@end

@implementation KanbanSettingsHandler
- (void)userContentController:(WKUserContentController *)controller
      didReceiveScriptMessage:(WKScriptMessage *)message
                 replyHandler:(void (^)(id, NSString *))replyHandler {
    if (message.webView != self.webview || !message.frameInfo.isMainFrame ||
        ![message.body isKindOfClass:NSString.class]) {
        replyHandler(nil, @"untrustedFrame");
        return;
    }
    char *reply = self.callback(self.label.UTF8String,
        message.frameInfo.request.URL.absoluteString.UTF8String,
        [(NSString *)message.body UTF8String], message.frameInfo.isMainFrame);
    if (!reply) { replyHandler(nil, @"bridgeUnavailable"); return; }
    NSString *value = [NSString stringWithUTF8String:reply];
    self.releaseReply(reply);
    replyHandler(value, nil);
}
@end

void install_workspace_settings(void *pointer, const char *label, const char *script,
                                SettingsCallback callback, SettingsFree releaseReply) {
    WKWebView *webview = (__bridge WKWebView *)pointer;
    KanbanSettingsHandler *handler = [KanbanSettingsHandler new];
    handler.webview = webview;
    handler.label = [NSString stringWithUTF8String:label];
    handler.callback = callback;
    handler.releaseReply = releaseReply;
    [webview.configuration.userContentController addScriptMessageHandlerWithReply:handler
        contentWorld:WKContentWorld.pageWorld name:@"kanbanSettings"];
    [webview.configuration.userContentController addUserScript:[[WKUserScript alloc]
        initWithSource:[NSString stringWithUTF8String:script]
        injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:YES]];
    // The initial document may already have started loading before the handler is attached.
    [webview evaluateJavaScript:[NSString stringWithUTF8String:script] completionHandler:nil];
}