//
//  RNTTakeScreenshot.m
//  RNTester
//
//  Created by Eric Lewis on 3/1/19.
//  Copyright © 2019 Facebook. All rights reserved.
//

#import "Screenshot.h"

#import <React/RCTUIManager.h>

@implementation ScreenshotManager

RCT_EXPORT_MODULE();

RCT_EXPORT_METHOD(takeScreenshot:(id /* NSString or NSNumber */)target
                  withOptions:(NSDictionary *)options
                  resolve:(RCTPromiseResolveBlock)resolve
                  reject:(RCTPromiseRejectBlock)reject)
{
  [self.bridge.uiManager addUIBlock:^(__unused RCTUIManager *uiManager, NSDictionary<NSNumber *, UIView *> *viewRegistry) {

    // Get view
    UIView *view;
    if (target == nil || [target isEqual:@"window"]) {
      view = RCTKeyWindow();
    } else if ([target isKindOfClass:[NSNumber class]]) {
      view = viewRegistry[target];
      if (!view) {
        RCTLogError(@"No view found with reactTag: %@", target);
        return;
      }
    }

    // Get options
    CGSize size = [RCTConvert CGSize:options];
    NSString *format = [RCTConvert NSString:options[@"format"] ?: @"png"];

    // Capture image
    if (size.width < 0.1 || size.height < 0.1) {
      size = view.bounds.size;
    }
    UIGraphicsBeginImageContextWithOptions(size, NO, 0);
    BOOL success = [view drawViewHierarchyInRect:(CGRect){CGPointZero, size} afterScreenUpdates:YES];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    if (!success || !image) {
      reject(RCTErrorUnspecified, @"Failed to capture view snapshot.", nil);
      return;
    }

    // Convert image to data (on a background thread)
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

      NSData *data;
      if ([format isEqualToString:@"png"]) {
        data = UIImagePNGRepresentation(image);
      } else if ([format isEqualToString:@"jpeg"]) {
        CGFloat quality = [RCTConvert CGFloat:options[@"quality"] ?: @1];
        data = UIImageJPEGRepresentation(image, quality);
      } else {
        RCTLogError(@"Unsupported image format: %@", format);
        return;
      }

      // Save to a temp file
      NSError *error = nil;
      NSString *tempFilePath = RCTTempFilePath(format, &error);
      if (tempFilePath) {
        if ([data writeToFile:tempFilePath options:(NSDataWritingOptions)0 error:&error]) {
          resolve(tempFilePath);
          return;
        }
      }

      // If we reached here, something went wrong
      reject(RCTErrorUnspecified, error.localizedDescription, error);
    });
  }];
}

@end