/*
	BASS custom looping example
	Copyright (c) 2004-2014 Un4seen Developments Ltd.
*/

#include <gtk/gtk.h>
#include <glib/gthread.h>
#include <stdlib.h>
#include <string.h>
#include <regex.h>
#include <math.h>
#include "bass.h"

#define WIDTH 600	// display width
#define HEIGHT 201	// height (odd number for centre line)

#pragma pack(1)
typedef struct {
	BYTE rgbRed, rgbGreen, rgbBlue;
} RGB;
#pragma pack()

GtkWidget *win = 0;
GThread *scanthread = 0;
BOOL killscan = FALSE;

DWORD chan;
DWORD bpp;			// bytes per pixel
QWORD loop[2] = { 0 };	// loop start & end
HSYNC lsync;		// looping sync

GtkWidget *waveda;
GdkPixbuf *wavepb;
RGB palette[HEIGHT / 2 + 1];

// display error messages
void Error(const char *es)
{
	GtkWidget *dialog = gtk_message_dialog_new(GTK_WINDOW(win), GTK_DIALOG_DESTROY_WITH_PARENT,
		GTK_MESSAGE_ERROR, GTK_BUTTONS_OK, "%s\n(error code: %d)", es, BASS_ErrorGetCode());
	gtk_dialog_run(GTK_DIALOG(dialog));
	gtk_widget_destroy(dialog);
}

void WindowDestroy(GtkObject *obj, gpointer data)
{
	gtk_main_quit();
}

void CALLBACK LoopSyncProc(HSYNC handle, DWORD channel, DWORD data, void *user)
{
	if (!BASS_ChannelSetPosition(channel, loop[0], BASS_POS_BYTE)) // try seeking to loop start
		BASS_ChannelSetPosition(channel, 0, BASS_POS_BYTE); // failed, go to start of file instead
}

void SetLoopStart(QWORD pos)
{
	loop[0] = pos;
}

void SetLoopEnd(QWORD pos)
{
	loop[1] = pos;
	BASS_ChannelRemoveSync(chan, lsync); // remove old sync
	lsync = BASS_ChannelSetSync(chan, BASS_SYNC_POS | BASS_SYNC_MIXTIME, loop[1], LoopSyncProc, 0); // set new sync
}

// scan the peaks
void *ScanPeaks(void *p)
{
	DWORD decoder = (uintptr_t)p;
	RGB *wavebuf = (RGB*)gdk_pixbuf_get_pixels(wavepb);
	DWORD pos = 0;
	float spp = BASS_ChannelBytes2Seconds(decoder, bpp); // seconds per pixel
	while (!killscan) {
		float peak[2];
		if (spp > 1) { // more than 1 second per pixel, break it down...
			float todo = spp;
			peak[1] = peak[0] = 0;
			do {
				float level[2], step = (todo < 1 ? todo : 1);
				BASS_ChannelGetLevelEx(decoder, level, step, BASS_LEVEL_STEREO); // scan peaks
				if (peak[0] < level[0]) peak[0] = level[0];
				if (peak[1] < level[1]) peak[1] = level[1];
				todo -= step;
			} while (todo > 0);
		} else
			BASS_ChannelGetLevelEx(decoder, peak, spp, BASS_LEVEL_STEREO); // scan peaks
		{
			DWORD a;
			for (a = 0; a < peak[0] * (HEIGHT / 2); a++)
				wavebuf[(HEIGHT / 2 - 1 - a) * WIDTH + pos] = palette[1 + a]; // draw left peak
			for (a = 0; a < peak[1] * (HEIGHT / 2); a++)
				wavebuf[(HEIGHT / 2 + 1 + a) * WIDTH + pos] = palette[1 + a]; // draw right peak
		}
		pos++;
		if (pos >= WIDTH) break; // reached end of display
		if (!BASS_ChannelIsActive(decoder)) break; // reached end of channel
	}
	if (!killscan) {
		DWORD size;
		BASS_ChannelSetPosition(decoder, (QWORD)-1, BASS_POS_BYTE | BASS_POS_SCAN); // build seek table (scan to end)
		size = BASS_ChannelGetAttributeEx(decoder, BASS_ATTRIB_SCANINFO, 0, 0); // get seek table size
		if (size) { // got it
			void *info = malloc(size); // allocate a buffer
			BASS_ChannelGetAttributeEx(decoder, BASS_ATTRIB_SCANINFO, info, size); // get the seek table
			BASS_ChannelSetAttributeEx(chan, BASS_ATTRIB_SCANINFO, info, size); // apply it to the playback channel
			free(info);
		}
	}
	BASS_StreamFree(decoder); // free the decoder
	return NULL;
}

gboolean FileExtensionFilter(const GtkFileFilterInfo *info, gpointer data)
{
	return !regexec((regex_t*)data, info->filename, 0, NULL, 0);
}

// select a file to play, and start scanning it
BOOL PlayFile()
{
	BOOL ret = FALSE;
	regex_t fregex;
	GtkWidget *filesel; // file selector
	GtkFileFilter *filter;
	filesel = gtk_file_chooser_dialog_new("Open File", GTK_WINDOW(win), GTK_FILE_CHOOSER_ACTION_OPEN,
		GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL, GTK_STOCK_OPEN, GTK_RESPONSE_ACCEPT, NULL);
	filter = gtk_file_filter_new();
	gtk_file_filter_set_name(filter, "Playable files");
	regcomp(&fregex, "\\.(mo3|xm|mod|s3m|it|umx|mp[1-3]|ogg|wav|aif)$", REG_ICASE | REG_NOSUB | REG_EXTENDED);
	gtk_file_filter_add_custom(filter, GTK_FILE_FILTER_FILENAME, FileExtensionFilter, &fregex, NULL);
	gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(filesel), filter);
	filter = gtk_file_filter_new();
	gtk_file_filter_set_name(filter, "All files");
	gtk_file_filter_add_pattern(filter, "*");
	gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(filesel), filter);
	if (gtk_dialog_run(GTK_DIALOG(filesel)) == GTK_RESPONSE_ACCEPT) {
		char *file = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(filesel));
		gtk_widget_hide(filesel);
		if (!(chan = BASS_StreamCreateFile(FALSE, file, 0, 0, 0))
			&& !(chan = BASS_MusicLoad(FALSE, file, 0, 0, BASS_MUSIC_RAMP | BASS_MUSIC_POSRESET | BASS_MUSIC_PRESCAN, 1))) {
			Error("Can't play file");
		} else {
			// create the bitmap
			wavepb = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, WIDTH, HEIGHT);
			{ // setup palette
				RGB *pal = (RGB*)palette;
				int a;
				memset(palette, 0, sizeof(palette));
				for (a = 1; a <= HEIGHT / 2; a++) {
					pal[a].rgbRed = (255 * a) / (HEIGHT / 2);
					pal[a].rgbGreen = 255 - pal[a].rgbRed;
				}
			}
			bpp = BASS_ChannelGetLength(chan, BASS_POS_BYTE) / WIDTH; // bytes per pixel
			{
				DWORD bpp1 = BASS_ChannelSeconds2Bytes(chan, 0.001); // minimum 1ms per pixel
				if (bpp < bpp1) bpp = bpp1;
			}
			BASS_ChannelSetSync(chan, BASS_SYNC_END | BASS_SYNC_MIXTIME, 0, LoopSyncProc, 0); // set sync to loop at end
			BASS_ChannelPlay(chan, FALSE); // start playing
			{ // create another channel to scan
				DWORD chan2 = BASS_StreamCreateFile(FALSE, file, 0, 0, BASS_STREAM_DECODE);
				if (!chan2) chan2 = BASS_MusicLoad(FALSE, file, 0, 0, BASS_MUSIC_DECODE, 1);
#if GLIB_CHECK_VERSION(2,32,0)
				scanthread = g_thread_new(NULL, ScanPeaks, (void*)(uintptr_t)chan2); // start scanning in a new thread
#else
				scanthread = g_thread_create(ScanPeaks, (void*)(uintptr_t)chan2, TRUE, NULL); // start scanning in a new thread
#endif
			}
			ret = TRUE;
		}
		g_free(file);
	}
	gtk_widget_destroy(filesel);
	return ret;
}

void WindowButtonRelease(GtkWidget *obj, GdkEventButton *event, gpointer data)
{
	if (event->type == GDK_BUTTON_RELEASE) {
		if (event->button == 1) // set loop start
			SetLoopStart(event->x * bpp);
		else if (event->button == 3) // set loop end
			SetLoopEnd(event->x * bpp);
	}
}

void DrawTimeLine(QWORD pos, DWORD col, DWORD y)
{
	GdkGC *gc = waveda->style->fg_gc[GTK_WIDGET_STATE(waveda)];
	DWORD wpos = pos / bpp;
	GdkColor c = { 0,(col & 0xff) << 8,col & 0xff00,(col >> 8) & 0xff00 };
	gdk_gc_set_rgb_fg_color(gc, &c);
	gdk_draw_line(waveda->window, gc, wpos, 0, wpos, HEIGHT);
}

gboolean AreaExpose(GtkWidget *widget, GdkEventExpose *event, gpointer user)
{
	GdkGC *gc = widget->style->fg_gc[GTK_WIDGET_STATE(waveda)];
	GdkGCValues gcsave;
	gdk_gc_get_values(gc, &gcsave);
	gdk_draw_pixbuf(widget->window, gc, wavepb, 0, 0, 0, 0, -1, -1, GDK_RGB_DITHER_NONE, 0, 0);
	DrawTimeLine(loop[0], 0xffff00, 12); // loop start
	DrawTimeLine(loop[1], 0x00ffff, 24); // loop end
	DrawTimeLine(BASS_ChannelGetPosition(chan, BASS_POS_BYTE), 0xffffff, 0); // current pos
	gdk_gc_set_values(gc, &gcsave, GDK_GC_FOREGROUND);
	return FALSE;
}

gboolean TimerProc(gpointer data)
{
	// refresh window
	gtk_widget_queue_draw(waveda);
	return TRUE;
}

int main(int argc, char* argv[])
{
#if !GLIB_CHECK_VERSION(2,32,0)
	g_thread_init(NULL);
#endif
	gtk_init(&argc, &argv);

	// check the correct BASS was loaded
	if (HIWORD(BASS_GetVersion()) != BASSVERSION) {
		Error("An incorrect version of BASS was loaded");
		return 0;
	}

	// initialize BASS
	if (!BASS_Init(-1, 44100, 0, win, NULL)) {
		Error("Can't initialize device");
		return 0;
	}
	if (!PlayFile()) { // start a file playing
		BASS_Free();
		return 0;
	}

	// create the window
	win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	gtk_window_set_position(GTK_WINDOW(win), GTK_WIN_POS_CENTER);
	gtk_window_set_resizable(GTK_WINDOW(win), FALSE);
	gtk_window_set_title(GTK_WINDOW(win), "BASS custom looping example (left-click to set loop start, right-click to set end)");
	g_signal_connect(win, "destroy", GTK_SIGNAL_FUNC(WindowDestroy), NULL);

	GtkWidget *ebox = gtk_event_box_new();
	gtk_container_add(GTK_CONTAINER(win), ebox);
	g_signal_connect(ebox, "button-release-event", GTK_SIGNAL_FUNC(WindowButtonRelease), NULL);

	waveda = gtk_drawing_area_new();
	gtk_widget_set_size_request(waveda, WIDTH, HEIGHT);
	gtk_container_add(GTK_CONTAINER(ebox), waveda);
	g_signal_connect(waveda, "expose-event", GTK_SIGNAL_FUNC(AreaExpose), NULL);

	// setup update timer (10hz)
	g_timeout_add(100, TimerProc, NULL);

	gtk_widget_show_all(win);
	gtk_main();

	killscan = TRUE;
	g_thread_join(scanthread); // wait for the scan thread

	g_object_unref(wavepb);

	BASS_Free();
	return 0;
}