/*
 * GraphLCD driver library
 *
 * common.c  -  various functions
 *
 * parts were taken from graphlcd plugin for the Video Disc Recorder
 * (c) 2001-2004 Carsten Siebholz <c.siebholz AT t-online.de>
 *
 * This file is released under the GNU General Public License. Refer
 * to the COPYING file distributed with this package.
 *
 * (c) 2004 Andreas Regel <andreas.regel AT powarman.de>
 */

#include <ctype.h>
#include <sched.h>
#include <time.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/resource.h>

#include "common.h"
#include "config.h"


namespace GLCD
{

static const int BitReverseTable[256] =
{
    0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
    0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
    0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
    0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
    0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
    0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
    0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
    0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
    0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
    0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
    0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
    0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
    0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
    0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
    0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
    0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
    0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
    0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
    0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
    0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
    0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
    0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
    0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
    0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
    0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
    0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
    0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
    0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
    0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
    0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
    0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
    0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
};

int nSleepInit()
{
    int ret = 0;

    if (Config.waitPriority != 0)
    {
        ret = setpriority(PRIO_PROCESS, 0, Config.waitPriority);
    }

    if (!ret)
    {
        switch (Config.waitMethod)
        {
            case kWaitUsleep: // usleep
                break;
            case kWaitNanosleep: // nanosleep
                break;
            case kWaitNanosleepRR: // nanosleep (sched_rr)
                // set sched algorithm
                struct sched_param param;

                param.sched_priority=1;
                ret = sched_setscheduler(0, SCHED_RR, &param);
                break;
            case kWaitGettimeofday: // gettimeofday
                break;
        }
    }
    return ret;
}

int nSleepDeInit()
{
    int ret = 0;

    if (Config.waitPriority != 0)
    {
        ret = setpriority(PRIO_PROCESS, 0, 0);
    }

    if (!ret)
    {
        switch (Config.waitMethod)
        {
            case kWaitUsleep: // usleep
                break;
            case kWaitNanosleep: // nanosleep
                break;
            case kWaitNanosleepRR: // nanosleep (sched_rr)
                // set sched algorithm
                struct sched_param param;

                param.sched_priority=0;
                ret = sched_setscheduler(0, SCHED_OTHER, &param);
                break;
            case kWaitGettimeofday: // gettimeofday
                break;
        }
    }
    return ret;
}

void nSleep(long ns)
{
    switch (Config.waitMethod)
    {
        case kWaitUsleep: // usleep
            if (ns > 0)
            {
                usleep(std::max(1L, ns/1000));
            }
            break;
        case kWaitNanosleep: // nanosleep
        case kWaitNanosleepRR: // nanosleep(sched_rr)
            struct timespec delay, remaining;
            if (ns > 0)
            {
                delay.tv_sec = ns/1000000000;
                delay.tv_nsec = ns%1000000000;
                while (nanosleep(&delay, &remaining) == -1)
                {
                    delay.tv_sec  = remaining.tv_sec;
                    delay.tv_nsec = remaining.tv_nsec;
                }
            }
            break;
        case kWaitGettimeofday: //getTimeofday for Kernel 2.6
            long us;
            struct timeval tv1, tv2;
            suseconds_t us2;
            if (ns > 0)
            {
                us = ns / 1000;
                if (us == 0)
                    us = 1;
                gettimeofday(&tv1, 0);
                do
                {
                    gettimeofday(&tv2, 0);
                    us2 = tv2.tv_usec + ((tv2.tv_sec - tv1.tv_sec) * 1000000);
                } while (us2 - tv1.tv_usec < us);
            }
    }
}

void uSleep(long us)
{
    if (Config.waitMethod == kWaitUsleep)
    {
        // usleep
        if (us > 0)
            usleep(std::max(1L, us));
    }
    else
    {
        nSleep(us * 1000);
    }
}



unsigned char ReverseBits(unsigned char value)
{
    return BitReverseTable[value];
}

void clip(int & value, int min, int max)
{
    if (value < min)
        value = min;
    if (value > max)
        value = max;
}

void sort(int & value1, int & value2)
{
    if (value2 < value1)
    {
        int tmp;
        tmp = value2;
        value2 = value1;
        value1 = tmp;
    }
}

std::string trim(const std::string & s)
{
    std::string::size_type start, end;

    start = 0;
    while (start < s.length())
    {
        if (!isspace(s[start]))
            break;
        start++;
    }
    end = s.length() - 1;
    while (end >= 0)
    {
        if (!isspace(s[end]))
            break;
        end--;
    }
    return s.substr(start, end - start + 1);
}

} // end of namespace