#include <minix/fb.h>
#include <minix/chardriver.h>
#include <minix/drivers.h>
#include <minix/ds.h>
#include <minix/sysutil.h>
#include <minix/type.h>
#include <minix/vm.h>
#include <sys/ioc_fb.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <dev/videomode/videomode.h>
#include <dev/videomode/edidvar.h>
#include <dev/videomode/edidreg.h>

#include "logos.h"
#include "fb_edid.h"
#include "fb.h"

/*
 * Function prototypes for the fb driver.
 */
static int fb_open(devminor_t minor, int access, endpoint_t user_endpt);
static int fb_close(devminor_t minor);
static ssize_t fb_read(devminor_t minor, u64_t pos, endpoint_t ep,
	cp_grant_id_t gid, size_t size, int flags, cdev_id_t id);
static ssize_t fb_write(devminor_t minor, u64_t pos, endpoint_t ep,
	cp_grant_id_t gid, size_t size, int flags, cdev_id_t id);
static int fb_ioctl(devminor_t minor, unsigned long request, endpoint_t ep,
	cp_grant_id_t gid, int flags, endpoint_t user_ep, cdev_id_t id);
static void paint_bootlogo(int minor);
static void paint_restartlogo(int minor);
static void paint_centered(int minor, char *data, int width, int height);
static int do_get_varscreeninfo(int minor, endpoint_t ep, cp_grant_id_t gid);
static int do_put_varscreeninfo(int minor, endpoint_t ep, cp_grant_id_t gid);
static int do_get_fixscreeninfo(int minor, endpoint_t ep, cp_grant_id_t gid);
static int do_pan_display(int minor, endpoint_t ep, cp_grant_id_t gid);
static int keep_displaying_restarted(void);

/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init(int type, sef_init_info_t *info);
static int sef_cb_lu_state_save(int);
static int lu_state_restore(void);

/* Entry points to the fb driver. */
static struct chardriver fb_tab =
{
	.cdr_open	= fb_open,
	.cdr_close	= fb_close,
	.cdr_read	= fb_read,
	.cdr_write	= fb_write,
	.cdr_ioctl	= fb_ioctl
};

/** Represents the /dev/fb device. */
static int has_restarted = 0;
static u64_t has_restarted_t1, has_restarted_t2;

static int open_counter[FB_DEV_NR];		/* Open count */

static int
fb_open(devminor_t minor, int UNUSED(access), endpoint_t UNUSED(user_endpt))
{
	int r;
	static int initialized = 0;
	static struct edid_info info;
	static struct edid_info *infop = NULL;

	if (minor < 0 || minor >= FB_DEV_NR) return ENXIO;

	if (!initialized) {
		r = fb_edid_read(minor, &info);
		infop = (r == 0) ? &info : NULL;
	}

	if (arch_fb_init(minor, infop) == OK) {
		open_counter[minor]++;
		if (!initialized) {
			if (has_restarted) {
				read_frclock_64(&has_restarted_t1);
				paint_restartlogo(minor);
			} else {
				paint_bootlogo(minor);
			}
			initialized = 1;
		}
		return OK;
	}
	return ENXIO;
}

static int
fb_close(devminor_t minor)
{
	if (minor < 0 || minor >= FB_DEV_NR) return ENXIO;
	assert(open_counter[minor] > 0);
	open_counter[minor]--;
	return OK;
}

static ssize_t
fb_read(devminor_t minor, u64_t pos, endpoint_t ep, cp_grant_id_t gid,
	size_t size, int UNUSED(flags), cdev_id_t UNUSED(id))
{
	struct device dev;
	int r;

	if (minor < 0 || minor >= FB_DEV_NR) return ENXIO;
	assert(open_counter[minor] > 0);

	arch_get_device(minor, &dev);

	if (size == 0 || pos >= dev.dv_size) return 0;
	if (pos + size > dev.dv_size)
		size = (size_t)(dev.dv_size - pos);

	r = sys_safecopyto(ep, gid, 0, (vir_bytes)(dev.dv_base + (size_t)pos),
	    size);

	return (r != OK) ? r : size;
}

static int
fb_ioctl(devminor_t minor, unsigned long request, endpoint_t ep,
	cp_grant_id_t gid, int UNUSED(flags), endpoint_t UNUSED(user_ep),
	cdev_id_t UNUSED(id))
{
/* Process I/O control requests */
	int r;

	if (minor < 0 || minor >= FB_DEV_NR) return ENXIO;

	switch(request) {
	case FBIOGET_VSCREENINFO:
		r = do_get_varscreeninfo(minor, ep, gid);
		return r;
	case FBIOPUT_VSCREENINFO:
		r = do_put_varscreeninfo(minor, ep, gid);
		return r;
	case FBIOGET_FSCREENINFO:
		r = do_get_fixscreeninfo(minor, ep, gid);
		return r;
	case FBIOPAN_DISPLAY:
		r = do_pan_display(minor, ep, gid);
		return r;
	}

	return ENOTTY;
}

static int
do_get_varscreeninfo(int minor, endpoint_t ep, cp_grant_id_t gid)
{
	int r;
	struct fb_var_screeninfo fbvs;

	if ((r = arch_get_varscreeninfo(minor, &fbvs)) == OK) {
		r = sys_safecopyto(ep, gid, 0, (vir_bytes) &fbvs, sizeof(fbvs));
	}

	return r;
}

static int
do_put_varscreeninfo(int minor, endpoint_t ep, cp_grant_id_t gid)
{
	int r;
	struct fb_var_screeninfo fbvs_copy;

	if (has_restarted && keep_displaying_restarted()) {
		return EAGAIN;
	}

	if ((r = sys_safecopyfrom(ep, gid, 0, (vir_bytes) &fbvs_copy,
	    sizeof(fbvs_copy))) != OK) {
		return r;
	}

	return arch_put_varscreeninfo(minor, &fbvs_copy);
}

static int
do_pan_display(int minor, endpoint_t ep, cp_grant_id_t gid)
{
	int r;
        struct fb_var_screeninfo fbvs_copy;

	if (has_restarted && keep_displaying_restarted()) {
		return EAGAIN;
	}

        if ((r = sys_safecopyfrom(ep, gid, 0, (vir_bytes) &fbvs_copy,
            sizeof(fbvs_copy))) != OK) {
                return r;
        }

        return arch_pan_display(minor, &fbvs_copy);
}

static int
do_get_fixscreeninfo(int minor, endpoint_t ep, cp_grant_id_t gid)
{
        int r;
        struct fb_fix_screeninfo fbfs;

        if ((r = arch_get_fixscreeninfo(minor, &fbfs)) == OK) {
                r = sys_safecopyto(ep, gid, 0, (vir_bytes) &fbfs, sizeof(fbfs));
        }

        return r;
}

static ssize_t
fb_write(devminor_t minor, u64_t pos, endpoint_t ep, cp_grant_id_t gid,
	size_t size, int UNUSED(flags), cdev_id_t UNUSED(id))
{
	struct device dev;
	int r;

	if (minor < 0 || minor >= FB_DEV_NR) return ENXIO;
	assert(open_counter[minor] > 0);

	if (has_restarted && keep_displaying_restarted())
		return EAGAIN;

	arch_get_device(minor, &dev);

	if (size == 0 || pos >= dev.dv_size) return 0;
	if (pos + size > dev.dv_size)
		size = (size_t)(dev.dv_size - pos);

	r = sys_safecopyfrom(ep, gid, 0,
	    (vir_bytes)(dev.dv_base + (size_t)pos), size);

	return (r != OK) ? r : size;
}

static int
sef_cb_lu_state_save(int UNUSED(state)) {
/* Save the state. */
	ds_publish_u32("open_counter", open_counter[0], DSF_OVERWRITE);

	return OK;
}

static int
lu_state_restore() {
/* Restore the state. */
	u32_t value;

	ds_retrieve_u32("open_counter", &value);
	ds_delete_u32("open_counter");
	open_counter[0] = (int) value;

	return OK;
}

static void
sef_local_startup()
{
	/* Register init callbacks. Use the same function for all event types */
	sef_setcb_init_fresh(sef_cb_init);
	sef_setcb_init_lu(sef_cb_init);
	sef_setcb_init_restart(sef_cb_init);

	/* Register live update callbacks  */
	/* - Agree to update immediately when LU is requested in a valid state*/
	sef_setcb_lu_prepare(sef_cb_lu_prepare_always_ready);
	/* - Support live update starting from any standard state */
	sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid_standard);
	/* - Register a custom routine to save the state. */
	sef_setcb_lu_state_save(sef_cb_lu_state_save);

	/* Let SEF perform startup. */
	sef_startup();
}

static int
sef_cb_init(int type, sef_init_info_t *UNUSED(info))
{
/* Initialize the fb driver. */
	int do_announce_driver = TRUE;

	open_counter[0] = 0;
	switch(type) {
	case SEF_INIT_FRESH:
	    printf("framebuffer fresh: pid %d\n", getpid());
	    break;

	case SEF_INIT_LU:
	    /* Restore the state. */
	    lu_state_restore();
	    do_announce_driver = FALSE;

	    printf("framebuffer: I'm a new version!\n");
	    break;

	case SEF_INIT_RESTART:
	    printf("framebuffer restarted: pid %d\n", getpid());
	    has_restarted = 1;
	    break;
	}

	/* Announce we are up when necessary. */
	if (do_announce_driver) {
		chardriver_announce();
	}

	/* Initialization completed successfully. */
	return OK;
}

int
main(int argc, char *argv[])
{
	env_setargs(argc, argv);
	fb_edid_args_parse();

	sef_local_startup();
	chardriver_task(&fb_tab);
	return OK;
}

static int
keep_displaying_restarted()
{
	u64_t delta;
	u32_t micro_delta;

	read_frclock_64(&has_restarted_t2);
	delta = delta_frclock_64(has_restarted_t1, has_restarted_t2);
	micro_delta = frclock_64_to_micros(delta);

#define DISPLAY_1SEC 1000000	/* 1 second in microseconds */
	if (micro_delta < DISPLAY_1SEC) {
		return 1;
	}

	has_restarted = 0;
	return 0;
}

static void
paint_bootlogo(int minor)
{
	paint_centered(minor, bootlogo_data, bootlogo_width, bootlogo_height);
}

static void
paint_restartlogo(int minor)
{
	paint_centered(minor, restartlogo_data, restartlogo_width,
			restartlogo_height);
}

static void
paint_centered(int minor, char *data, int width, int height)
{
	u8_t pixel[3];
	u32_t i, min_x, min_y, max_x, max_y, x_painted = 0, rows = 0;
	int r, bytespp;
	struct device dev;
	struct fb_var_screeninfo fbvs;

	/* Put display in a known state to simplify positioning code below */
	if ((r = arch_get_varscreeninfo(minor, &fbvs)) != OK) {
		printf("fb: unable to get screen info: %d\n", r);
	}
	fbvs.yoffset = 0;
	if ((r = arch_pan_display(minor, &fbvs)) != OK) {
		printf("fb: unable to pan display: %d\n", r);
	}

	arch_get_device(minor, &dev);

	/* Paint on a white canvas */
	bytespp = fbvs.bits_per_pixel / 8;
	for (i = 0; i < fbvs.xres * fbvs.yres * bytespp; i+= bytespp)
		*((u32_t *)((u32_t) dev.dv_base + i)) = 0x00FFFFFF;

	/* First seek to start */
	min_x = fbvs.xres / 2 - width / 2;
	max_x = fbvs.xres / 2 + width / 2;
	min_y = fbvs.yres / 2 - height / 2;
	max_y = fbvs.yres / 2 + height / 2;
	i = min_x * fbvs.xres + min_y;

	/* Add the image data */
	for (i = ((min_y * fbvs.xres) + min_x) * bytespp; rows < height;) {
		GET_PIXEL(data, pixel);

		((unsigned char *)((u32_t) dev.dv_base + i))[0] = pixel[2];
		((unsigned char *)((u32_t) dev.dv_base + i))[1] = pixel[1];
                ((unsigned char *)((u32_t) dev.dv_base + i))[2] = pixel[0];
		((unsigned char *)((u32_t) dev.dv_base + i))[3] = 0;

		x_painted++;/* Keep tab of how many row pixels we've painted */
		if (x_painted == width) {
			/* We've reached the end of the row, carriage return
			 * and go to next line.
			 */
			x_painted = 0;
			rows++;
			i = (((min_y + rows) * fbvs.xres) + min_x) * 4;
		} else {
			i += 4;
		}
	}
}