/* 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 <stdint.h>
#import <stdlib.h>

extern int init(int argc, char *argv[]);
extern void draw(uint32_t *buf, size_t xres, size_t yres);
extern void input(char in);

#define WIDTH (640)
#define HEIGHT (480)

static size_t size = 4 * WIDTH * HEIGHT;
static uint32_t buf[WIDTH * HEIGHT];

@interface BufferView : NSView
@end

@implementation BufferView
- (void)drawRect:(NSRect)dirtyRect {
    CGContextRef ctx = [[NSGraphicsContext currentContext] CGContext];
    CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
    CGDataProviderRef data =
        CGDataProviderCreateWithData(NULL, buf, size, NULL);
    CGImageRef image =
        CGImageCreate(WIDTH, HEIGHT, 8, 32, WIDTH * 4, rgb,
                      kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,
                      data, NULL, false, kCGRenderingIntentDefault);
    CGContextDrawImage(ctx, CGRectMake(0, 0, WIDTH, HEIGHT), image);
    CGImageRelease(image);
    CGDataProviderRelease(data);
    CGColorSpaceRelease(rgb);
}

- (BOOL)acceptsFirstResponder {
    return YES;
}

- (void)keyDown:(NSEvent *)event {
    char in;
    [[event characters] getBytes:&in
                       maxLength:1
                      usedLength:NULL
                        encoding:NSASCIIStringEncoding
                         options:NSStringEncodingConversionAllowLossy
                           range:NSMakeRange(0, 1)
                  remainingRange:NULL];
    input(in);
    draw(buf, WIDTH, HEIGHT);
    [self setNeedsDisplay:YES];
}
@end

@interface Delegate : NSObject <NSApplicationDelegate>
@end

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

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

    draw(buf, WIDTH, HEIGHT);

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

    NSWindow *window = [[NSWindow alloc]
        initWithContentRect:NSMakeRect(0, 0, WIDTH, HEIGHT)
                  styleMask:NSTitledWindowMask | NSClosableWindowMask |
                            NSMiniaturizableWindowMask | NSResizableWindowMask
                    backing:NSBackingStoreBuffered
                      defer:YES];

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

    [window setTitle:[NSString stringWithUTF8String:argv[0]]];
    [window center];
    [window makeKeyAndOrderFront:nil];
    [NSApp activateIgnoringOtherApps:YES];
    [NSApp run];
}