/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id: button.c 18419 2008-09-04 21:19:09Z pixelma $
 *
 * Copyright (C) 2002 by Daniel Stenberg
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/*
 * Rockbox button functions
 */

#include <stdlib.h>
#include "config.h"
#include "system.h"
#include "button.h"
#include "kernel.h"
#include "thread.h"
#include "backlight.h"
#include "serial.h"
#include "power.h"
#include "powermgmt.h"
#include "button-target.h"

#ifdef HAVE_REMOTE_LCD
#include "lcd-remote.h"
#endif

#ifndef SIMULATOR
#if 0
/* Older than MAX_EVENT_AGE button events are going to be ignored.
 * Used to prevent for example volume going up uncontrollable when events
 * are getting queued and UI is lagging too much.
 */
#define MAX_EVENT_AGE  HZ
#endif

struct event_queue button_queue;

static long lastbtn;   /* Last valid button status */
static long last_read; /* Last button status, for debouncing/filtering */
static intptr_t button_data; /* data value from last message dequeued */
#ifdef HAVE_LCD_BITMAP
static bool flipped;  /* buttons can be flipped to match the LCD flip */
#endif
#ifdef HAVE_BACKLIGHT
static bool filter_first_keypress;
#ifdef HAVE_REMOTE_LCD
static bool remote_filter_first_keypress;
#endif
#endif /* HAVE_BACKLIGHT */
#ifdef HAVE_HEADPHONE_DETECTION
static bool phones_present = false;
#endif

/* how long until repeat kicks in, in ticks */
#define REPEAT_START      30

/* the speed repeat starts at, in ticks */
#define REPEAT_INTERVAL_START   16

/* speed repeat finishes at, in ticks */
#define REPEAT_INTERVAL_FINISH  5

#ifdef HAVE_BUTTON_DATA
static int button_read(int *data);
#else
static int button_read(void);
#endif

#if defined(HAVE_HEADPHONE_DETECTION)
static struct timeout hp_detect_timeout; /* Debouncer for headphone plug/unplug */
/* This callback can be used for many different functions if needed -
   just check to which object tmo points */
static bool btn_detect_callback(struct timeout *tmo)
{
    /* Try to post only transistions */
    const long id = tmo->data ? SYS_PHONE_PLUGGED : SYS_PHONE_UNPLUGGED;
    queue_remove_from_head(&button_queue, id);
    queue_post(&button_queue, id, 0);
    return false;
}
#endif

static void button_tick(void)
{
    static int count = 0;
    static int repeat_speed = REPEAT_INTERVAL_START;
    static int repeat_count = 0;
    static bool repeat = false;
    static bool post = false;
#ifdef HAVE_BACKLIGHT
    static bool skip_release = false;
#ifdef HAVE_REMOTE_LCD
    static bool skip_remote_release = false;
#endif
#endif
    int diff;
    int btn;
#ifdef HAVE_BUTTON_DATA
    int data = 0;
#else
    const int data = 0;
#endif

#ifdef HAS_SERIAL_REMOTE
    /* Post events for the remote control */
    btn = remote_control_rx();
    if(btn)
    {
        queue_post(&button_queue, btn, 0);
    }
#endif

#ifdef HAVE_BUTTON_DATA
    btn = button_read(&data);
#else
    btn = button_read();
#endif

#if defined(HAVE_HEADPHONE_DETECTION)
    if (headphones_inserted() != phones_present)
    {
        /* Use the autoresetting oneshot to debounce the detection signal */
        phones_present = !phones_present;
        timeout_register(&hp_detect_timeout, btn_detect_callback,
                         HZ, phones_present);
    }
#endif

    /* Find out if a key has been released */
    diff = btn ^ lastbtn;
    if(diff && (btn & diff) == 0)
    {
#ifdef HAVE_BACKLIGHT
#ifdef HAVE_REMOTE_LCD
        if(diff & BUTTON_REMOTE)
            if(!skip_remote_release)
                queue_post(&button_queue, BUTTON_REL | diff, data);
            else
                skip_remote_release = false;
        else
#endif
            if(!skip_release)
                queue_post(&button_queue, BUTTON_REL | diff, data);
            else
                skip_release = false;
#else
        queue_post(&button_queue, BUTTON_REL | diff, data);
#endif
    }
    else
    {
        if ( btn )
        {
            /* normal keypress */
            if ( btn != lastbtn )
            {
                post = true;
                repeat = false;
                repeat_speed = REPEAT_INTERVAL_START;
            }
            else /* repeat? */
            {
                if ( repeat )
                {
                    if (!post)
                        count--;
                    if (count == 0) {
                        post = true;
                        /* yes we have repeat */
                        if (repeat_speed > REPEAT_INTERVAL_FINISH)
                            repeat_speed--;
                        count = repeat_speed;

                        repeat_count++;

                        /* Send a SYS_POWEROFF event if we have a device
                           which doesn't shut down easily with the OFF
                           key */
#ifdef HAVE_SW_POWEROFF
                        if ((btn == POWEROFF_BUTTON
#ifdef RC_POWEROFF_BUTTON
                                    || btn == RC_POWEROFF_BUTTON
#endif
                                    ) &&
#if CONFIG_CHARGING && !defined(HAVE_POWEROFF_WHILE_CHARGING)
                                !charger_inserted() &&
#endif
                                repeat_count > POWEROFF_COUNT)
                        {
                            /* Tell the main thread that it's time to
                               power off */
                            sys_poweroff();

                            /* Safety net for players without hardware
                               poweroff */
                            if(repeat_count > POWEROFF_COUNT * 10)
                                power_off();
                        }
#endif
                    }
                }
                else
                {
                    if (count++ > REPEAT_START)
                    {
                        post = true;
                        repeat = true;
                        repeat_count = 0;
                        /* initial repeat */
                        count = REPEAT_INTERVAL_START;
                    }
                }
            }
            if ( post )
            {
                if (repeat)
                {
                    /* Only post repeat events if the queue is empty,
                     * to avoid afterscroll effects. */
                    if (queue_empty(&button_queue))
                    {
                        queue_post(&button_queue, BUTTON_REPEAT | btn, data);
#ifdef HAVE_BACKLIGHT
#ifdef HAVE_REMOTE_LCD
                        skip_remote_release = false;
#endif
                        skip_release = false;
#endif
                        post = false;
                    }
                }
                else
                {
#ifdef HAVE_BACKLIGHT
#ifdef HAVE_REMOTE_LCD
                    if (btn & BUTTON_REMOTE) {
                        if (!remote_filter_first_keypress 
                            || is_remote_backlight_on(false)
#if defined(IRIVER_H100_SERIES) || defined(IRIVER_H300_SERIES)
                            || (remote_type()==REMOTETYPE_H300_NONLCD)
#endif
                            )
                            queue_post(&button_queue, btn, data);
                        else
                            skip_remote_release = true;
                    }
                    else
#endif
                        if (!filter_first_keypress || is_backlight_on(false)
#if BUTTON_REMOTE
                                || (btn & BUTTON_REMOTE)
#endif
                           )
                            queue_post(&button_queue, btn, data);
                        else
                            skip_release = true;
#else /* no backlight, nothing to skip */
                    queue_post(&button_queue, btn, data);
#endif
                    post = false;
                }
#ifdef HAVE_REMOTE_LCD
                if(btn & BUTTON_REMOTE)
                    remote_backlight_on();
                else
#endif
                {
                    backlight_on();
#ifdef HAVE_BUTTON_LIGHT
                    buttonlight_on();
#endif
                }

                reset_poweroff_timer();
            }
        }
        else
        {
            repeat = false;
            count = 0;
        }
    }
    lastbtn = btn & ~(BUTTON_REL | BUTTON_REPEAT);
}

#ifdef HAVE_ADJUSTABLE_CPU_FREQ
static void button_boost(bool state)
{
    static bool boosted = false;
    
    if (state && !boosted)
    {
        cpu_boost(true);
        boosted = true;
    }
    else if (!state && boosted)
    {
        cpu_boost(false);
        boosted = false;
    }
}
#endif /* HAVE_ADJUSTABLE_CPU_FREQ */

int button_queue_count( void )
{
    return queue_count(&button_queue);
}

long button_get(bool block)
{
    struct queue_event ev;
    int pending_count = queue_count(&button_queue);

#ifdef HAVE_ADJUSTABLE_CPU_FREQ
    /* Control the CPU boost trying to keep queue empty. */
    if (pending_count == 0)
        button_boost(false);
    else if (pending_count > 2)
        button_boost(true);
#endif
    
    if ( block || pending_count )
    {
        queue_wait(&button_queue, &ev);
        
#if 0
        /* Ignore if the event was too old and for simplicity, just
         * wait for a new button_get() request. */
        if (current_tick - ev.tick > MAX_EVENT_AGE)
            return BUTTON_NONE;
#endif
        button_data = ev.data;
        return ev.id;
    }
    
    return BUTTON_NONE;
}

long button_get_w_tmo(int ticks)
{
    struct queue_event ev;
    
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
    /* Be sure to keep boosted state. */
    if (!queue_empty(&button_queue))
        return button_get(true);
    
    button_boost(false);
#endif
    
    queue_wait_w_tmo(&button_queue, &ev, ticks);
    if (ev.id == SYS_TIMEOUT)
        ev.id = BUTTON_NONE;
    else
        button_data = ev.data;

    return ev.id;
}

intptr_t button_get_data(void)
{
    return button_data;
}

void button_init(void)
{
    /* Init used objects first */
    queue_init(&button_queue, true);

#ifdef HAVE_BUTTON_DATA
    int temp;
#endif
    /* hardware inits */
    button_init_device();

#ifdef HAVE_BUTTON_DATA
    button_read(&temp);
    lastbtn = button_read(&temp);
#else
    button_read();
    lastbtn = button_read();
#endif
    
    reset_poweroff_timer();

#ifdef HAVE_LCD_BITMAP
    flipped = false;
#endif
#ifdef HAVE_BACKLIGHT
    filter_first_keypress = false;
#ifdef HAVE_REMOTE_LCD
    remote_filter_first_keypress = false;
#endif    
#endif

    /* Start polling last */
    tick_add_task(button_tick);
}

#ifdef BUTTON_DRIVER_CLOSE
void button_close(void)
{
    tick_remove_task(button_tick);
}
#endif /* BUTTON_DRIVER_CLOSE */

#ifdef HAVE_LCD_BITMAP /* only bitmap displays can be flipped */
/*
 * helper function to swap LEFT/RIGHT, UP/DOWN (if present), and F1/F3 (Recorder)
 */
static int button_flip(int button)
{
    int newbutton;

    newbutton = button &
        ~(BUTTON_LEFT | BUTTON_RIGHT
#if defined(BUTTON_UP) && defined(BUTTON_DOWN)
        | BUTTON_UP | BUTTON_DOWN
#endif
#if defined(BUTTON_SCROLL_BACK) && defined(BUTTON_SCROLL_FWD)
        | BUTTON_SCROLL_BACK | BUTTON_SCROLL_FWD
#endif
#if CONFIG_KEYPAD == RECORDER_PAD
        | BUTTON_F1 | BUTTON_F3
#endif
#if CONFIG_KEYPAD == SANSA_C200_PAD
        | BUTTON_VOL_UP | BUTTON_VOL_DOWN
#endif
        );

    if (button & BUTTON_LEFT)
        newbutton |= BUTTON_RIGHT;
    if (button & BUTTON_RIGHT)
        newbutton |= BUTTON_LEFT;
#if defined(BUTTON_UP) && defined(BUTTON_DOWN)
    if (button & BUTTON_UP)
        newbutton |= BUTTON_DOWN;
    if (button & BUTTON_DOWN)
        newbutton |= BUTTON_UP;
#endif
#if defined(BUTTON_SCROLL_BACK) && defined(BUTTON_SCROLL_FWD)
    if (button & BUTTON_SCROLL_BACK)
        newbutton |= BUTTON_SCROLL_FWD;
    if (button & BUTTON_SCROLL_FWD)
        newbutton |= BUTTON_SCROLL_BACK;
#endif
#if CONFIG_KEYPAD == RECORDER_PAD
    if (button & BUTTON_F1)
        newbutton |= BUTTON_F3;
    if (button & BUTTON_F3)
        newbutton |= BUTTON_F1;
#endif
#if CONFIG_KEYPAD == SANSA_C200_PAD
    if (button & BUTTON_VOL_UP)
        newbutton |= BUTTON_VOL_DOWN;
    if (button & BUTTON_VOL_DOWN)
        newbutton |= BUTTON_VOL_UP;
#endif

    return newbutton;
}

/*
 * set the flip attribute
 * better only call this when the queue is empty
 */
void button_set_flip(bool flip)
{
    if (flip != flipped) /* not the current setting */
    {
        /* avoid race condition with the button_tick() */
        int oldlevel = disable_irq_save();
        lastbtn = button_flip(lastbtn);
        flipped = flip;
        restore_irq(oldlevel);
    }
}
#endif /* HAVE_LCD_BITMAP */

#ifdef HAVE_BACKLIGHT
void set_backlight_filter_keypress(bool value)
{
    filter_first_keypress = value;
}
#ifdef HAVE_REMOTE_LCD
void set_remote_backlight_filter_keypress(bool value)
{
    remote_filter_first_keypress = value;
}
#endif
#endif

/*
 * Get button pressed from hardware
 */
#ifdef HAVE_BUTTON_DATA
static int button_read(int *data)
{
    int btn = button_read_device(data);
#else
static int button_read(void)
{
    int btn = button_read_device();
#endif
    int retval;

#ifdef HAVE_LCD_BITMAP
    if (btn && flipped)
        btn = button_flip(btn); /* swap upside down */
#endif

    /* Filter the button status. It is only accepted if we get the same
       status twice in a row. */
#ifndef HAVE_TOUCHSCREEN
    if (btn != last_read)
            retval = lastbtn;
    else
#endif
        retval = btn;
    last_read = btn;

    return retval;
}


int button_status(void)
{
    return lastbtn;
}

void button_clear_queue(void)
{
    queue_clear(&button_queue);
}

#endif /* SIMULATOR */

#ifdef HAVE_SCROLLWHEEL
/* WHEEL_ACCEL_FACTOR = 2^16 / WHEEL_ACCEL_START */
#define WHEEL_ACCEL_FACTOR (1<<16)/WHEEL_ACCEL_START
/**
 * data:
 *    [31] Use acceleration
 * [30:24] Message post count (skipped + 1) (1-127)
 *  [23:0] Velocity - degree/sec
 *
 * WHEEL_ACCEL_FACTOR:
 * Value in degree/sec -- configurable via settings -- above which 
 * the accelerated scrolling starts. Factor is internally scaled by 
 * 1<<16 in respect to the following 32bit integer operations.
 */
int button_apply_acceleration(const unsigned int data)
{
    int delta = (data >> 24) & 0x7f;

    if ((data & (1 << 31)) != 0)
    {
        /* read driver's velocity from data */
        unsigned int v = data & 0xffffff;

        /* v = 28.4 fixed point */
        v = (WHEEL_ACCEL_FACTOR * v)>>(16-4);

        /* Calculate real numbers item to scroll based upon acceleration
         * setting, use correct roundoff */
#if   (WHEEL_ACCELERATION == 1)
        v = (v*v     + (1<< 7))>> 8;
#elif (WHEEL_ACCELERATION == 2)
        v = (v*v*v   + (1<<11))>>12;
#elif (WHEEL_ACCELERATION == 3)
        v = (v*v*v*v + (1<<15))>>16;
#endif

        if (v > 1)
            delta *= v;
    }

    return delta;
}
#endif /* HAVE_SCROLLWHEEL */
