/* Copyright (c) 2018, Curtis McEnroe <programble@gmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#import <Cocoa/Cocoa.h>
#import <err.h>
#import <stdbool.h>
#import <stdint.h>
#import <stdlib.h>
#import <sysexits.h>

#import "gfx.h"

#define UNUSED __attribute__((unused))

@interface BufferView : NSView {
	size_t bufSize;
	uint32_t *buf;
	CGColorSpaceRef colorSpace;
	CGDataProviderRef dataProvider;
}
@end

@implementation BufferView
- (instancetype) initWithFrame: (NSRect) frameRect {
	colorSpace = CGColorSpaceCreateDeviceRGB();
	return [super initWithFrame: frameRect];
}

- (void) setWindowTitle {
	[[self window] setTitle: [NSString stringWithUTF8String: status()]];
}

- (void) draw {
	draw(buf, [self frame].size.width, [self frame].size.height);
	[self setNeedsDisplay: YES];
}

- (void) setFrameSize: (NSSize) newSize {
	[super setFrameSize: newSize];
	size_t newBufSize = 4 * newSize.width * newSize.height;
	if (newBufSize > bufSize) {
		bufSize = newBufSize;
		buf = malloc(bufSize);
		if (!buf) err(EX_OSERR, "malloc(%zu)", bufSize);
		CGDataProviderRelease(dataProvider);
		dataProvider = CGDataProviderCreateWithData(NULL, buf, bufSize, NULL);
	}
	[self draw];
}

- (void) drawRect: (NSRect) UNUSED dirtyRect {
	NSSize size = [self frame].size;
	CGContextRef ctx = [[NSGraphicsContext currentContext] CGContext];
	CGImageRef image = CGImageCreate(
		size.width, size.height,
		8, 32, 4 * size.width,
		colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,
		dataProvider,
		NULL, false, kCGRenderingIntentDefault
	);
	CGContextDrawImage(ctx, [self frame], image);
	CGImageRelease(image);
}

- (BOOL) acceptsFirstResponder {
	return YES;
}

- (void) keyDown: (NSEvent *) event {
	char in;
	BOOL converted = [
		[event characters]
		getBytes: &in
		maxLength: 1
		usedLength: NULL
		encoding: NSASCIIStringEncoding
		options: 0
		range: NSMakeRange(0, 1)
		remainingRange: NULL
	];
	if (converted) {
		if (!input(in)) {
			[NSApp terminate: self];
		}
		[self draw];
		[self setWindowTitle];
	}
}
@end

@interface Delegate : NSObject <NSApplicationDelegate>
@end

@implementation Delegate
- (BOOL) applicationShouldTerminateAfterLastWindowClosed:
	(NSApplication *) UNUSED sender {
	return YES;
}
@end

int main(int argc, char *argv[]) {
	int error = init(argc, argv);
	if (error) return error;

	[NSApplication sharedApplication];
	[NSApp setActivationPolicy: NSApplicationActivationPolicyRegular];
	[NSApp setDelegate: [Delegate new]];

	NSString *name = [[NSProcessInfo processInfo] processName];
	NSMenu *menu = [NSMenu new];
	[
		menu
		addItemWithTitle: @"Close Window"
		action: @selector(performClose:)
		keyEquivalent: @"w"
	];
	[menu addItem: [NSMenuItem separatorItem]];
	[
		menu
		addItemWithTitle: [@"Quit " stringByAppendingString: name]
		action: @selector(terminate:)
		keyEquivalent: @"q"
	];
	NSMenuItem *menuItem = [NSMenuItem new];
	[menuItem setSubmenu: menu];
	[NSApp setMainMenu: [NSMenu new]];
	[[NSApp mainMenu] addItem: menuItem];

	NSUInteger style = NSTitledWindowMask
		| NSClosableWindowMask
		| NSMiniaturizableWindowMask
		| NSResizableWindowMask;
	NSWindow *window = [
		[NSWindow alloc]
		initWithContentRect: NSMakeRect(0, 0, 800, 600)
		styleMask: style
		backing: NSBackingStoreBuffered
		defer: YES
	];
	[window center];

	BufferView *view = [[BufferView alloc] initWithFrame: [window frame]];
	[window setContentView: view];
	[view setWindowTitle];

	[window makeKeyAndOrderFront: nil];
	[NSApp activateIgnoringOtherApps: YES];
	[NSApp run];
}