/*
    KSysGuard, the KDE System Guard

    Copyright (c) 1999 Chris Schlaeger <cs@kde.org>
    Copyright (c) 2010 David Naylor <naylor.b.david@gmail.com>

    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 program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

*/

#include <sys/types.h>

#include <sys/resource.h>
#include <sys/sysctl.h>

#include <devstat.h>
#include <fcntl.h>
#include <nlist.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "cpuinfo.h"
#include "Command.h"
#include "ksysguardd.h"

#define FREQ_LEVEL_BUFFER 256
#define SYSCTL_ID_LEN 35

static void get_mmfreq(int, int*, int*);

static long percentages(int cnt, long *out, long *new, long *old, long *diffs);

static long (*cp_time)[CPUSTATES] = NULL;
static long (*cp_old)[CPUSTATES] = NULL;
static long (*cp_diff)[CPUSTATES] = NULL;

static int maxcpus = 1;
static int cpus = 1;
static int cores = 1;
static int (*freq)[3] = NULL;
static int *temp = NULL;

static long (*cpu_states)[CPUSTATES] = NULL;

void
initCpuInfo(struct SensorModul* sm)
{
    size_t len;
    int id;
    char name[SYSCTL_ID_LEN];
    int minfreq, maxfreq;

    len = sizeof(cpus);
    // XXX: this is a guess
    sysctlbyname("kern.smp.active", &cpus, &len, NULL, 0);
    // NOTE: cpus may be 0, which implies 1
    cpus = cpus ? cpus : 1;

    len = sizeof(cores);
    sysctlbyname("kern.smp.cpus", &cores, &len, NULL, 0);

    len = sizeof(maxcpus);
    sysctlbyname("kern.smp.maxcpus", &maxcpus, &len, NULL, 0);

    /* Core/process count */
    registerMonitor("system/processors", "integer", printNumCpus, printNumCpusInfo, sm);
    registerMonitor("system/cores", "integer", printNumCores, printNumCoresInfo, sm);

    /*
     * CPU Loads
     */
    if ((cp_time = malloc(sizeof(long) * CPUSTATES * (cores * 4 + 1))) == NULL) {
        log_error("out of memory for cp_time");
        return;
    }
    cp_old = &cp_time[cores];
    cp_diff = &cp_old[cores];
    cpu_states = &cp_diff[cores];

    /* Total CPU load */
    registerMonitor("cpu/system/user", "float", printCPUUser, printCPUUserInfo, sm);
    registerMonitor("cpu/system/nice", "float", printCPUNice, printCPUNiceInfo, sm);
    registerMonitor("cpu/system/sys", "float", printCPUSys, printCPUSysInfo, sm);
    registerMonitor("cpu/system/TotalLoad", "float", printCPUTotalLoad, printCPUTotalLoadInfo, sm);
    registerMonitor("cpu/system/intr", "float", printCPUIntr, printCPUIntrInfo, sm);
    registerMonitor("cpu/system/idle", "float", printCPUIdle, printCPUIdleInfo, sm);

    /* Monitor names changed from kde3 => kde4. Remain compatible with legacy requests when possible. */
    registerLegacyMonitor("cpu/user", "float", printCPUUser, printCPUUserInfo, sm);
    registerLegacyMonitor("cpu/nice", "float", printCPUNice, printCPUNiceInfo, sm);
    registerLegacyMonitor("cpu/sys", "float", printCPUSys, printCPUSysInfo, sm);
    registerLegacyMonitor("cpu/idle", "float", printCPUIdle, printCPUIdleInfo, sm);

    for (id = 0; id < cores; ++id) {
        snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/user", id);
        registerMonitor(name, "float", printCPUxUser, printCPUxUserInfo, sm);
        snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/nice", id);
        registerMonitor(name, "float", printCPUxNice, printCPUxNiceInfo, sm);
        snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/sys", id);
        registerMonitor(name, "float", printCPUxSys, printCPUxSysInfo, sm);
        snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/TotalLoad", id);
        registerMonitor(name, "float", printCPUxTotalLoad, printCPUxTotalLoadInfo, sm);
        snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/intr", id);
        registerMonitor(name, "float", printCPUxIntr, printCPUxIntrInfo, sm);
        snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/idle", id);
        registerMonitor(name, "float", printCPUxIdle, printCPUxIdleInfo, sm);
    }

    /*
     * CPU frequencies
     */
    if ((freq = malloc(sizeof(int) * 3 * (cores + 1))) == NULL) {
        log_error("out of memory for freq");
        return;
    }

    registerMonitor("cpu/system/AverageClock", "float", printCPUClock, printCPUClockInfo, sm);
    for (id = 0; id < cores; ++id) {
        len = sizeof(int);
        snprintf(name, SYSCTL_ID_LEN, "dev.cpu.%d.freq", id);
        if (!sysctlbyname(name, &freq[id][0], &len, NULL, 0)) {
            get_mmfreq(id, &freq[id][1], &freq[id][2]);
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/clock", id);
            registerMonitor(name, "integer", printCPUxClock, printCPUxClockInfo, sm);
        } else {
            freq[id][0] = -1;
            freq[id][1] = 0;
            freq[id][2] = 0;
        }
    }

    minfreq = freq[0][1];
    maxfreq = freq[0][2];
    for (id = 1; id < cores; ++id)
        if (freq[id][0] != -1) {
            minfreq = minfreq > freq[id][1] ? freq[id][1] : minfreq;
            maxfreq = maxfreq < freq[id][2] ? freq[id][2] : maxfreq;
        }
    freq[cores][1] = minfreq;
    freq[cores][2] = maxfreq;

    /*
     * CPU temperature
     */
    if ((temp = malloc(sizeof(int) * (cores + 1))) == NULL) {
        log_error("out of memory for temp");
        return;
    }
    registerMonitor("cpu/system/AverageTemperature", "float", printCPUTemperature, printCPUTemperatureInfo, sm);
    for (id = 0; id < cores; ++id) {
        len = sizeof(int);
        snprintf(name, SYSCTL_ID_LEN, "dev.cpu.%d.temperature", id);
        if (!sysctlbyname(name, &temp[id], &len, NULL, 0)) {
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/temperature", id);
            registerMonitor(name, "float", printCPUxTemperature, printCPUxTemperatureInfo, sm);
        } else
            temp[id] = -1;
    }

    updateCpuInfo();
}

void
exitCpuInfo(void)
{
    int id;
    char name[SYSCTL_ID_LEN];

    removeMonitor("system/processors");
    removeMonitor("system/cores");

    if (cp_time != NULL) {
        removeMonitor("cpu/system/user");
        removeMonitor("cpu/system/nice");
        removeMonitor("cpu/system/sys");
        removeMonitor("cpu/system/TotalLoad");
        removeMonitor("cpu/system/intr");
        removeMonitor("cpu/system/idle");

        /* These were registered as legacy monitors */
        removeMonitor("cpu/user");
        removeMonitor("cpu/nice");
        removeMonitor("cpu/sys");
        removeMonitor("cpu/idle");

        for (id = 0; id < cores; ++id) {
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/user", id);
            removeMonitor(name);
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/nice", id);
            removeMonitor(name);
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/sys", id);
            removeMonitor(name);
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/TotalLoad", id);
            removeMonitor(name);
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/intr", id);
            removeMonitor(name);
            snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/idle", id);
            removeMonitor(name);

            if (freq != NULL && freq[id][0] != -1) {
                snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/clock", id);
                removeMonitor(name);
            }
            if (temp != NULL && temp[id] != -1) {
                snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/temperature", id);
                removeMonitor(name);
            }
        }

        free(cp_time);
        cp_time = NULL;
    }

    if (freq != NULL) {
        removeMonitor("cpu/system/AverageClock");
        for (id = 0; id < cores; ++id)
            if (freq[id][0] != -1) {
                snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/clock", id);
                removeMonitor(name);
            }
        free(freq);
        freq = NULL;
    }

    if (temp != NULL) {
        removeMonitor("cpu/system/AverageTemperature");
        for (id = 0; id < cores; ++id)
            if (temp[id] != -1) {
                snprintf(name, SYSCTL_ID_LEN, "cpu/cpu%d/temperature", id);
                removeMonitor(name);
            }
        free(temp);
        temp = NULL;
    }

}

int
updateCpuInfo(void)
{
    int sid, id, tot_freq = 0, tot_temp = 0, freq_count = 0, temp_count = 0;
    char name[SYSCTL_ID_LEN];

    if (cp_time == NULL || freq == NULL || temp == NULL)
        return (0);

        size_t len = sizeof(long) * CPUSTATES * cores;
        sysctlbyname("kern.cp_times", cp_time, &len, NULL, 0);
    for (sid = 0; sid < CPUSTATES; ++sid)
        cpu_states[cores][sid] = 0;
    for (id = 0; id < cores; ++id) {
        percentages(CPUSTATES, cpu_states[id], cp_time[id], cp_old[id], cp_diff[id]);
        for (sid = 0; sid < CPUSTATES; ++sid)
            cpu_states[cores][sid] += cpu_states[id][sid];
    }
    for (id = 0; id < cores; ++id) {
        if (freq[id][0] != -1) {
            len = sizeof(int);
            snprintf(name, SYSCTL_ID_LEN, "dev.cpu.%d.freq", id);
            freq[id][0] = 0;
            if (!sysctlbyname(name, &freq[id][0], &len, NULL, 0)) {
                freq_count += 1;
                tot_freq += freq[id][0];
            }
        }
        if (temp[id] != -1) {
            len = sizeof(int);
            snprintf(name, SYSCTL_ID_LEN, "dev.cpu.%d.temperature", id);
            temp[id] = 0.0;
            if (!sysctlbyname(name, &temp[id], &len, NULL, 0)) {
                temp_count += 1;
                tot_temp += temp[id];
            }
        }
    }
    freq[cores][0] = freq_count == 0 ? 0 : tot_freq * 100 / freq_count;
    temp[cores] = temp_count == 0 ? 0.0 : tot_temp * 100 / temp_count;

    return (0);
}

void
printCPUUser(const char* cmd)
{
    fprintf(CurrentClient, "%f\n", cpu_states[cores][CP_USER] / 10.0 / cores);
}

void
printCPUUserInfo(const char* cmd)
{
    fprintf(CurrentClient, "CPU User Load\t0\t100\t%%\n");
}

void
printCPUNice(const char* cmd)
{
    fprintf(CurrentClient, "%f\n", cpu_states[cores][CP_NICE] / 10.0 / cores);
}

void
printCPUNiceInfo(const char* cmd)
{
    fprintf(CurrentClient, "CPU Nice Load\t0\t100\t%%\n");
}

void
printCPUSys(const char* cmd)
{
    fprintf(CurrentClient, "%f\n", cpu_states[cores][CP_SYS] / 10.0 / cores);
}

void
printCPUSysInfo(const char* cmd)
{
    fprintf(CurrentClient, "CPU System Load\t0\t100\t%%\n");
}

void
printCPUTotalLoad(const char* cmd)
{
    fprintf(CurrentClient, "%f\n", (cpu_states[cores][CP_SYS] + cpu_states[cores][CP_USER] +
        cpu_states[cores][CP_NICE] + cpu_states[cores][CP_INTR]) / 10.0 / cores);
}

void
printCPUTotalLoadInfo(const char* cmd)
{
        fprintf(CurrentClient, "CPU Total Load\t0\t100\t%%\n");
}

void
printCPUIntr(const char* cmd)
{
        fprintf(CurrentClient, "%f\n", cpu_states[cores][CP_INTR] / 10.0 / cores);
}

void
printCPUIntrInfo(const char* cmd)
{
        fprintf(CurrentClient, "CPU Interrupt Load\t0\t100\t%%\n");
}

void
printCPUIdle(const char* cmd)
{
    fprintf(CurrentClient, "%f\n", cpu_states[cores][CP_IDLE] / 10.0 / cores);
}

void
printCPUIdleInfo(const char* cmd)
{
    fprintf(CurrentClient, "CPU Idle Load\t0\t100\t%%\n");
}

void
printCPUxUser(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%0.1f\n", cpu_states[id][CP_USER] / 10.0);
}

void
printCPUxUserInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d User Load\t0\t100\t%%\n", id + 1);
}

void
printCPUxNice(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%0.1f\n", cpu_states[id][CP_NICE] / 10.0);
}

void
printCPUxNiceInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d Nice Load\t0\t100\t%%\n", id + 1);
}

void
printCPUxSys(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%0.1f\n", cpu_states[id][CP_SYS] / 10.0);
}

void
printCPUxSysInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d System Load\t0\t100\t%%\n", id + 1);
}

void
printCPUxTotalLoad(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%f\n", (cpu_states[id][CP_SYS] + cpu_states[id][CP_USER] +
        cpu_states[id][CP_NICE] + cpu_states[id][CP_INTR]) / 10.0);
}

void
printCPUxTotalLoadInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d Total Load\t0\t100\t%%\n", id + 1);
}

void
printCPUxIntr(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
        fprintf(CurrentClient, "%0.1f\n", cpu_states[id][CP_INTR] / 10.0);
}

void
printCPUxIntrInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d Interrupt Load\t0\t100\t%%\n", id + 1);
}

void
printCPUxIdle(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%0.1f\n", cpu_states[id][CP_IDLE] / 10.0);
}

void
printCPUxIdleInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d Idle Load\t0\t100\t%%\n", id + 1);
}

void printCPUxClock(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%d\n", freq[id][0]);
}

void printCPUxClockInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d Clock Frequency\t%d\t%d\tMHz\n", id + 1,
        freq[id][1], freq[id][2]);
}

void printCPUClock(const char* cmd)
{
    fprintf(CurrentClient, "%f\n", freq[cores][0] / 100.0);
}

void printCPUClockInfo(const char* cmd)
{
    fprintf(CurrentClient, "CPU Clock Frequency\t%d\t%d\tMHz\n", freq[cores][1], freq[cores][2]);
}

void printCPUxTemperature(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "%0.1f\n", (temp[id] - 2732) / 10.0);
}

void printCPUxTemperatureInfo(const char* cmd)
{
    int id;

    sscanf(cmd + 7, "%d", &id);
    fprintf(CurrentClient, "CPU%d Temperature\t0\t0\tC\n", id + 1);
}

void printCPUTemperature(const char* cmd)
{
    fprintf(CurrentClient, "%0.3f\n", (temp[cores] - 273200) / 1000.0);
}

void printCPUTemperatureInfo(const char* cmd)
{
    fprintf(CurrentClient, "CPU Temperature\t0\t0\tC\n");
}

void printNumCpus(const char* cmd)
{
    fprintf(CurrentClient, "%d\n", cpus);
}

void printNumCpusInfo(const char* cmd)
{
    fprintf(CurrentClient, "Number of physical CPUs\t0\t%d\t\n", maxcpus);
}

void printNumCores(const char* cmd)
{
    fprintf(CurrentClient, "%d\n", cores);
}

void printNumCoresInfo(const char* cmd)
{
    fprintf(CurrentClient, "Total number of processor cores\t0\t%d\t\n", maxcpus);
}

void get_mmfreq(int id, int* minfreq, int* maxfreq)
{
    char buf[FREQ_LEVEL_BUFFER];
    char mid[SYSCTL_ID_LEN];
    size_t len = FREQ_LEVEL_BUFFER;

    *minfreq = 0;
    *maxfreq = 0;

    snprintf(mid, sizeof(mid), "dev.cpu.%d.freq_levels", id);
    if (!sysctlbyname(mid, buf, &len, NULL, 0))
    {
        char *start = buf;
        char *end;

        /*
         * The string is ([[freq]]/[[num]] )*([[freq]]/[[num]] ), so
         * for each frequency we get we must also skip over another
         * set of numbers
         */
        while (1)
        {
            // Get the first number
            int number = strtol(start, &end, 10);
            if (start == end)
                break;
            if (!*maxfreq)
                *maxfreq = number;
            else
                *minfreq = number;
            if (!*end)
                break;
            start = end + 1;

            // Skip over the next number
            strtol(start, &end, 10);
            if (start == end || !*end)
                break;
            start = end + 1;
        }
    }
}

/* The part ripped from top... */
/*
 *  Top users/processes display for Unix
 *  Version 3
 *
 *  This program may be freely redistributed,
 *  but this entire comment MUST remain intact.
 *
 *  Copyright (c) 1984, 1989, William LeFebvre, Rice University
 *  Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University
 */

/*
 *  percentages(cnt, out, new, old, diffs) - calculate percentage change
 *    between array "old" and "new", putting the percentages i "out".
 *    "cnt" is size of each array and "diffs" is used for scratch space.
 *    The array "old" is updated on each call.
 *    The routine assumes modulo arithmetic.  This function is especially
 *    useful on BSD mchines for calculating cpu state percentages.
 */
long percentages(int cnt, long *out, long *new, long *old, long *diffs)
{
    int i;
    long change;
    long total_change;
    long *dp;
    long half_total;

    /* initialization */
    total_change = 0;
    dp = diffs;

    /* calculate changes for each state and the overall change */
    for (i = 0; i < cnt; i++)
    {
    if ((change = *new - *old) < 0)
    {
        /* this only happens when the counter wraps */
        change = (int)
        ((unsigned long)*new-(unsigned long)*old);
    }
    total_change += (*dp++ = change);
    *old++ = *new++;
    }

    /* avoid divide by zero potential */
    if (total_change == 0)
    {
    total_change = 1;
    }

    /* calculate percentages based on overall change, rounding up */
    half_total = total_change / 2l;

    /* Do not divide by 0. Causes Floating point exception */
    for (i = 0; i < cnt; i++)
    {
    *out++ = (int)((*diffs++ * 1000 + half_total) / total_change);
    }

    /* return the total in case the caller wants to use it */
    return(total_change);
}
