/* audio volume control for x11 (c) firk 2020-2021
   please respect the authorship
   feel free to use this code for anything */
#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/extensions/XShm.h>
#include <X11/keysym.h>
#include <X11/XF86keysym.h>
#include "mixer.h"

Display * display;
Screen * screen;
static winprops wp0;
static Window rootwin, miniwin;
static unsigned long colors[16];
static GC gc;
static int X0, Y0;
static unsigned int W0, H0;
static int sw, sh, redraw_needed;

static void init_colors(void) {
  XColor c;
  unsigned int n;
  for(n=0;n<16;n++) {
    c.flags = DoRed|DoGreen|DoBlue;
    c.red = ((n&8)?0x5500:0) + ((n&4)?0xAA00:0);
    c.green = ((n&8)?0x5500:0) + ((n&2)?0xAA00:0);
    c.blue = ((n&8)?0x5500:0) + ((n&1)?0xAA00:0);
    if(n==6) c.green=0x5500;
    if(!XAllocColor(display, DefaultColormapOfScreen(screen), &c)) { fprintf(stderr, "color[%d] alloc failed\n", n); exit(-1); }
    colors[n] = c.pixel;
  }
}

static void free_colors(void) {
  XFreeColors(display, DefaultColormapOfScreen(screen), colors, 16, 0);
}

extern unsigned long base_color(unsigned char c) {
  return colors[c&15];
}

static int calc_sizes(int _sw, int _sh) {
  int x, y;
  sw = _sw; sh = _sw;
  if((x=wp0.x0)<0) x = x+sw-wp0.w+1;
  if((y=wp0.y0)<0) y = y+sh-wp0.h+1;
  if(x==X0 && y==Y0 && wp0.w==(int)W0 && wp0.h==(int)H0) return 0;
  W0 = wp0.w; H0 = wp0.h;
  X0 = x; Y0 = y;
  return 1;
}

extern void x11_init(char const * display_name, winprops *wp) {
  XSetWindowAttributes wa;

  if(!(display = XOpenDisplay(display_name))) { fprintf(stderr, "fwm-mixer: XOpenDisplay(%s) failed\n", display_name); exit(-1); }
  if(!(screen = DefaultScreenOfDisplay(display))) { fprintf(stderr, "fwm-mixer: DefaultScreenOfDisplay() failed\n"); exit(-1); }
  wp0 = *wp;
  init_colors();
  if(wp0.w<=0) wp0.w = 100; if(wp0.h<=0) wp0.h = 10;
  if(wp0.w>10000) wp0.w = 10000; if(wp0.h>10000) wp0.h = 10000;
  if(wp0.bw<0) wp0.bw = 0; if(wp0.bw>100) wp0.bw = 100;
  calc_sizes(WidthOfScreen(screen), HeightOfScreen(screen));
  
  rootwin = DefaultRootWindow(display);
  wa.override_redirect = wp0.o?True:False;
  wa.event_mask = ExposureMask|ButtonPressMask|ButtonReleaseMask|PointerMotionMask|LeaveWindowMask;
  wa.background_pixel = base_color(0);
  wa.border_pixel = base_color(15);
  miniwin = XCreateWindow(display, rootwin,
    X0, Y0, W0, H0, wp0.bw,
    CopyFromParent, CopyFromParent, CopyFromParent,
    CWOverrideRedirect|CWEventMask|CWBackPixel|CWBorderPixel, &wa);
    
#if 0
  miniwin = XCreateSimpleWindow(display, rootwin, 0, 0, W0, H0, 0/*border*/, base_color(15), base_color(0));

  XChangeWindowAttributes(display, miniwin, CWOverrideRedirect|CWEventMask, &wa);
#endif

  XSetStandardProperties(display, miniwin, "MIXER", "MIXER", None, NULL, 0, NULL);

  // TODO: is this same as wa.event_mask ?
  XSelectInput(display, miniwin,
       ExposureMask|                                 // window redraw requests
       ButtonPressMask|ButtonReleaseMask|            // mouse buttons click
       KeyPressMask|KeyReleaseMask|KeymapStateMask|  // keyboard clicks / resync pressed state on getting focus
       PointerMotionMask|                            // mouse moving
       StructureNotifyMask                           // window moving/resizing
       );
  XSelectInput(display, rootwin, StructureNotifyMask);
  gc = XCreateGC(display, miniwin, 0, NULL);
  XSetForeground(display, gc, base_color(15));
  XSetBackground(display, gc, base_color(0));
#ifdef TASKBAR_FONT_NAME
  XSetFont(display, gc, XLoadFont(display, TASKBAR_FONT_NAME)); // TODO?
#endif
  XClearWindow(display, miniwin);
  XMapRaised(display, miniwin);
  XSync(display, False);
}

static void do_redraw(void) {
  redraw_needed = 0;
  if(W0<3 || H0<3) return;
  XSetForeground(display, gc, base_color(0));
  XFillRectangle(display, miniwin, gc, 0, 0, W0, H0);
  XSetForeground(display, gc, base_color(mute?7:15));
  XFillRectangle(display, miniwin, gc, 1, 1, (W0-2)*volume/1000, H0-2);
  XSetForeground(display, gc, base_color(15));
  XDrawRectangle(display, miniwin, gc, 0, 0, W0-1, H0-1);
  if(mute) {
    XDrawLine(display, miniwin, gc, 0, 0, W0-1, H0-1);
    XDrawLine(display, miniwin, gc, 0, H0-1, W0-1, 0);
  }
}


static unsigned int int_to_usize(int v) { if(v<=0) return 0; if(v>=1000) return 1000; return (unsigned int)v; }

extern void x11_redraw(void) {
  redraw_needed = 1;
}

extern void x11_event_cycle(int do_wait) {
  XEvent ev;
  if(do_wait || XPending(display)) {
    XNextEvent(display, &ev);
    switch(ev.type) {
    case ConfigureNotify:
      if(ev.xconfigure.window==rootwin) {
        if(calc_sizes(ev.xconfigure.width, ev.xconfigure.height)) {
          XMoveWindow(display, miniwin, X0, Y0);
        }
      }
      if(ev.xconfigure.window==miniwin) {
        W0 = int_to_usize(ev.xconfigure.width);
        H0 = int_to_usize(ev.xconfigure.height);
        redraw_needed = 1;
      }
      break;
    case Expose:
      if(ev.xexpose.window==miniwin && ev.xexpose.count==0) redraw_needed = 1;
      break;
    case ButtonPress:
      if(W0<2 || ev.xbutton.x<0) return;
      ev.xbutton.x = ((unsigned long)ev.xbutton.x)*100/(W0-1);
    }
    key_hook_handler(&ev);
  }
  if(redraw_needed) do_redraw();
}