/*
  $Id: main.c 41 2006-02-04 12:41:09Z dewitge $
	
  MySQL Activity Report
  Lightweight process that monitors some relevant MySQL parameters

  Copyright 2004 Gert Dewit <gert.dewit@sos.be>
*/


#include <my_global.h>
#include <my_sys.h>
#include <m_string.h>
#include <mysql.h>
#include <errmsg.h>

#include <rrd.h>

#include <stdio.h>
#include <stdarg.h>
#include <unistd.h>
#include <time.h>
#include <getopt.h>
#include <string.h>
#include <dirent.h>
#include <syslog.h>

#ifndef CONFIG_H
#define CONFIG_H 1
#include "config.h"
#endif

/* Need global option for MySQL >= 5.x */
#if defined (MYSQL_VERSION_ID) && MYSQL_VERSION_ID >= 50000
#define VARIABLESFMTSTR "show global variables like '%s'"
#define STATUSFMTSTR "show global status like '%s'"
#else
#define VARIABLESFMTSTR "show variables like '%s'"
#define STATUSFMTSTR "show status like '%s'"
#endif

#define DEFDATADIR "/var/lib/mysqlard"
#define DEFPIDFILE "/var/run/mysqlard.pid"
#define DEFRRDKEY  "key_cache.rrd"
#define DEFRRDCON  "connections.rrd"
#define DEFRRDTAB  "table_cache.rrd"
#define DEFRRDQUERY  "queries.rrd"
#define DEFRRDSLAVE  "slave.rrd"

unsigned long long ar_get(MYSQL *mysql, char *varname, int var);
unsigned long long ar_get_var(MYSQL *mysql, char *varname);
unsigned long long ar_get_param(MYSQL *mysql, char *varname);
unsigned long long ar_get_sl_param(MYSQL *mysql, char *varname);
int update_rrdfile(char *filename, char *cmd);
void open_log(void);
void do_log(int level, char *fmt, ...);
void bye(int exitval);
void usage(void);

int verbose = 0;
int foreground = 0;
const char *pid_file = NULL;

int main(int argc, char *argv[]) {
  int c;
  
  MYSQL mysql;

  time_t now;

  pid_t pid;
  FILE *pidfile;

  char conrrdpath[PATH_MAX];
  char tabrrdpath[PATH_MAX];
  char keyrrdpath[PATH_MAX];
  char queryrrdpath[PATH_MAX];
  char slaverrdpath[PATH_MAX];

  char command[PATH_MAX];

  /* options */
  int dokey = 1;
  int dotab = 1;
  int docon = 1;
  int doquery = 1;
  int doslave = 0;
  unsigned int steptime = 60;
  const char *host = NULL;
  const char *user = NULL;
  const char *passwd = NULL;
  const char *db = NULL;
  const char *socket_file = NULL;
  const char *datadir = NULL;
  unsigned int port = 0;
  unsigned long client_flag = 0;
  /* Relevant variables */
  unsigned long long table_cache = 0;
  unsigned long long max_connections = 0;
  unsigned long long key_buffer_size = 0;
  /* Monitored parameters */
  unsigned long long open_tables = 0;
  unsigned long long created_tmp_tables = 0;
  unsigned long long created_tmp_disk_tables = 0;
  unsigned long long key_reads = 0;
  unsigned long long key_read_requests = 0;
  unsigned long long key_blocks_used = 0;
  unsigned long long select_full_join = 0;
  unsigned long long select_range_check = 0;
  unsigned long long handler_read_key = 0;
  unsigned long long handler_read_rnd = 0;
  unsigned long long slow_queries = 0;
  unsigned long long threads_connected = 0;
  unsigned long long questions = 0;
  unsigned long long select = 0;
  unsigned long long insert = 0;
  unsigned long long update = 0;
  unsigned long long delete = 0;
  unsigned long long read_master_log_pos = 0;
  unsigned long long exec_master_log_pos = 0;

  /* handle command line */
  while(1) {
    int option_index = 0;

    static struct option long_options[] = {
      {"nokey", 0, 0, 'k'},
      {"nocon", 0, 0, 'c'},
      {"notab", 0, 0, 't'},
      {"noquery", 0, 0, 'q'},
      {"slave", 0, 0, 'L'},
      {"step", 1, 0, 's'},
      {"datadir", 1, 0, 'd'},
      {"host", 1, 0, 'h'},
      {"password", 1, 0, 'p'},
      {"port", 1, 0, 'P'},
      {"socket", 1, 0, 'S'},
      {"pidfile", 1, 0, 'F'},
      {"user", 1, 0, 'u'},
      {"verbose", 0, 0, 'v'},
      {"foreground", 0, 0, 'f'},
      {0, 0, 0, 0}
    };

    c = getopt_long(argc, argv, "kctqLs::d:h:p:P:S:F:u:vf", long_options, &option_index);
    if(c == -1)
      break;

    switch(c) {
      case 'k':
        dokey = 0;
        break;
      case 'c':
        docon = 0;
        break;
      case 't':
        dotab = 0;
        break;
      case 'q':
        doquery = 0;
        break;
      case 'L':
        doslave = 1;
        break;
      case 's':
        steptime = atol(optarg);
        break;
      case 'd':
        datadir = optarg;
        break;
      case 'h':
        host = optarg;
        break;
      case 'p':
        passwd = optarg;
        break;
      case 'P':
        port = atol(optarg);
        break;
      case 'F':
        pid_file = optarg;
        break;
      case 'S':
        socket_file = optarg;
        break;
      case 'u':
        user = optarg;
        break;
      case 'v':
        verbose = 1;
        break;
      case 'f':
        foreground = 1;
        break;
      default:
        usage();
    }
  }

  if(optind < argc) {
    usage();
  }

  if(pid_file == NULL)
    pid_file = strdup(DEFPIDFILE);
  if(access(pid_file, F_OK) == 0) {
    fprintf(stderr, "PID file %s exists, exiting ...\n", pid_file);
    bye(2);
  }

  if(datadir == NULL)
    datadir = strdup(DEFDATADIR);

  open_log();
  
  if(! opendir(datadir)) {
    do_log(LOG_CRIT, "data directory \"%s\" does not exist or is inaccessible\n", datadir);
    bye(3);
  }
  
  if(dotab) {
    snprintf(tabrrdpath, PATH_MAX, "%s/%s", datadir, DEFRRDTAB);
    if(access(tabrrdpath, W_OK) < 0) {
      do_log(LOG_CRIT, "RRD file %s not writeable\n", tabrrdpath);
      bye(4);
    }
  }
  if(dokey) {
    snprintf(keyrrdpath, PATH_MAX, "%s/%s", datadir, DEFRRDKEY);
    if(access(keyrrdpath, W_OK) < 0) {
      do_log(LOG_CRIT, "RRD file %s not writeable\n", keyrrdpath);
      bye(5);
    }
  }
  if(docon) {
    snprintf(conrrdpath, PATH_MAX, "%s/%s", datadir, DEFRRDCON);
    if(access(conrrdpath, W_OK) < 0) {
      do_log(LOG_CRIT, "RRD file %s not writeable\n", conrrdpath);
      bye(6);
    }
  }
  if(doquery) {
    snprintf(queryrrdpath, PATH_MAX, "%s/%s", datadir, DEFRRDQUERY);
    if(access(queryrrdpath, W_OK) < 0) {
      do_log(LOG_CRIT, "RRD file %s not writeable\n", queryrrdpath);
      bye(7);
    }
  }
  if(doslave) {
    snprintf(slaverrdpath, PATH_MAX, "%s/%s", datadir, DEFRRDSLAVE);
    if(access(slaverrdpath, W_OK) < 0) {
      do_log(LOG_CRIT, "RRD file %s not writeable\n", slaverrdpath);
      bye(7); // Should change this
    }
  }

  if(! foreground) {
    if((pid = fork()) < 0) {
      do_log(LOG_CRIT, "Cannot fork\n");
      bye(8);
    } else {
      if (pid != 0)
        exit(0);
    }
    pidfile = fopen(pid_file, "w");
    if(! pidfile) {
      do_log(LOG_CRIT, "Cannot create PID file, exiting ...\n");
      exit(10);
    }
    fprintf(pidfile, "%i\n", getpid());
    fclose(pidfile);
    setsid();
    chdir(datadir);
    umask(0);
  }

  do_log(LOG_INFO, "Keytable logging = %d\n", dokey);
  do_log(LOG_INFO, "Connection logging = %d\n", docon);
  do_log(LOG_INFO, "Table cache logging = %d\n", dotab);
  do_log(LOG_INFO, "Slave logging = %d\n", doslave);
  do_log(LOG_INFO, "Step time = %d\n", steptime);
  do_log(LOG_INFO, "Data dir = %s\n", datadir);
  do_log(LOG_INFO, "PID file = %s\n", pid_file);
  do_log(LOG_INFO, "MySQL host = %s\n", host ? host : (char *) LOCAL_HOST);
  do_log(LOG_INFO, "MySQL port = %d\n", port ? port : 3306);
  do_log(LOG_INFO, "MySQL socket = %s\n", socket_file ? socket_file : "none");
  do_log(LOG_INFO, "MySQL user = %s\n", user ? user : "current user");
  do_log(LOG_DEBUG, "MySQL user password = %s\n", passwd ? passwd : "none");

  MY_INIT(argv[0]);
  mysql_init(&mysql);
  if (!mysql_real_connect(&mysql, host, user, passwd, db, port, socket_file, client_flag)) {
    do_log(LOG_EMERG, "connect to server at '%s' failed, error: '%s'", host ? host : (char *) LOCAL_HOST, mysql_error(&mysql));
    bye(11);
  }
  for(;;) {
    now = time(NULL);
    do_log(LOG_DEBUG, "Data at %d", (int) now); /* DEBUG */
    /* Table Cache */
    if(dotab) {
      table_cache = ar_get_var(&mysql, "table_cache");
      open_tables = ar_get_param(&mysql, "open_tables");
      created_tmp_tables = ar_get_param(&mysql, "created_tmp_tables");
      created_tmp_disk_tables = ar_get_param(&mysql, "created_tmp_disk_tables");
      if(foreground) {
        printf("update %s %d:%llu:%llu:%llu:%llu\n", tabrrdpath, (int) now, open_tables, table_cache, created_tmp_tables, created_tmp_disk_tables);
      }
      snprintf(command, PATH_MAX, "N:%llu:%llu:%llu:%llu", open_tables, table_cache, created_tmp_tables, created_tmp_disk_tables);
      update_rrdfile(tabrrdpath, command);
    }
    /* Key cache */
    if(dokey) {
      key_reads = ar_get_param(&mysql, "key_reads");
      key_read_requests = ar_get_param(&mysql, "key_read_requests");
      key_buffer_size = ar_get_var(&mysql, "key_buffer_size");
      key_blocks_used = ar_get_param(&mysql, "key_blocks_used") * 1024;
      select_full_join = ar_get_param(&mysql, "select_full_join");
      select_range_check = ar_get_param(&mysql, "select_range_check");
      handler_read_key = ar_get_param(&mysql, "handler_read_key");
      handler_read_rnd = ar_get_param(&mysql, "handler_read_rnd");
      slow_queries = ar_get_param(&mysql, "slow_queries");
      if(foreground) {
        printf("update %s %d:%llu:%llu:%llu:%llu:%llu:%llu:%llu:%llu:%llu\n", keyrrdpath, (int) now, key_reads, key_read_requests, key_buffer_size, key_blocks_used, select_full_join, select_range_check, handler_read_key, handler_read_rnd, slow_queries);
      }
      snprintf(command, PATH_MAX, "N:%llu:%llu:%llu:%llu:%llu:%llu:%llu:%llu:%llu", key_reads, key_read_requests, key_buffer_size, key_blocks_used, select_full_join, select_range_check, handler_read_key, handler_read_rnd, slow_queries);
      update_rrdfile(keyrrdpath, command);
    }
    /* Connections */
    if(docon) {
      max_connections = ar_get_var(&mysql, "max_connections");
      threads_connected = ar_get_param(&mysql, "threads_connected");
      if(foreground) {
        printf("update %s %d:%llu:%llu\n", conrrdpath, (int) now, threads_connected, max_connections);
      }
      snprintf(command, PATH_MAX, "N:%llu:%llu", threads_connected, max_connections);
      update_rrdfile(conrrdpath, command);
    }
    /* Queries */
    if(doquery) {
      questions = ar_get_param(&mysql, "questions");
      select = ar_get_param(&mysql, "com_select");
      insert = ar_get_param(&mysql, "com_insert");
      update = ar_get_param(&mysql, "com_update");
      delete = ar_get_param(&mysql, "com_delete");
      if(foreground) {
        printf("update %s %d:%llu:%llu:%llu:%llu:%llu\n", queryrrdpath, (int) now, questions, select, insert, update, delete);
      }
      snprintf(command, PATH_MAX, "N:%llu:%llu:%llu:%llu:%llu", questions, select, insert, update, delete);
      update_rrdfile(queryrrdpath, command);
    }
    /* Slave */
    if(doslave) {
      read_master_log_pos = ar_get_sl_param(&mysql, "read_master_log_pos");
      exec_master_log_pos = ar_get_sl_param(&mysql, "exec_master_log_pos");
      if(foreground) {
        printf("update %s %d:%llu:%llu\n", slaverrdpath, (int) now, read_master_log_pos, exec_master_log_pos);
      }
      snprintf(command, PATH_MAX, "N:%llu:%llu", read_master_log_pos, exec_master_log_pos);
      update_rrdfile(slaverrdpath, command);
    }
    sleep(steptime);
  }
  mysql_close(&mysql);
  return 0;
}

unsigned long long ar_get_var(MYSQL *mysql, char *varname) {
  return ar_get(mysql, varname, 1);
}

unsigned long long ar_get_param(MYSQL *mysql, char *varname) {
  return ar_get(mysql, varname, 0);
}

unsigned long long ar_get(MYSQL *mysql, char *varname, int var) {
  unsigned long long retval;
  MYSQL_RES *res;
  MYSQL_ROW row;
  char query[2048];
  if(var) {
    snprintf(query, 2048, VARIABLESFMTSTR, varname);
  } else {
    snprintf(query, 2048, STATUSFMTSTR, varname);
  }
  if (mysql_query(mysql, query) || !(res=mysql_store_result(mysql))) {
    do_log(LOG_ERR, "Query \"%s\" failed; error : \"%s\"", query, mysql_error(mysql));
    return 0;
  }
  row=mysql_fetch_row(res);
  if(row) {
    retval = strtoull(row[1], NULL, 10);
  }
  mysql_free_result(res);
  return retval;
}

unsigned long long ar_get_sl_param(MYSQL *mysql, char *varname) {
  unsigned long long retval;
  MYSQL_RES *res;
  MYSQL_ROW row;
  char query[100];
  unsigned int field_count;
  unsigned int col;
  MYSQL_FIELD *fields;
  snprintf(query, 100, "show slave status");
  if (mysql_query(mysql, query) || !(res=mysql_store_result(mysql))) {
    do_log(LOG_ERR, "Query \"%s\" failed; error : \"%s\"", query, mysql_error(mysql));
    return 0;
  }
  retval = 0;
  row = mysql_fetch_row(res);
  field_count = mysql_num_fields(res);
  fields = mysql_fetch_fields(res);
  for( col = 0 ; col < field_count ; col++ ) {
	  if( strcasecmp(varname, fields[col].name) == 0 ) {
		  retval = strtoull(row[col], NULL, 10);
		  // break;
	  }
  }
  mysql_free_result(res);
  return retval;
}

int update_rrdfile(char *filename, char *cmd) {
  char **argv;
  int retval = 0;

  if(rrd_test_error())
    rrd_clear_error();
  argv = (char **) malloc(4 * sizeof(char *));
  if(! argv)
    return -2;

  argv[0] = PACKAGE;
  argv[1] = strdup("update");
  argv[2] = strdup(filename);
  argv[3] = strdup(cmd);

  optind = 0; opterr = 0;
  if(rrd_update(3, &argv[1]) == -1) {
    fprintf(stderr, "%s\n", rrd_get_error());
    retval = -1;
  }
  free(argv[1]); free(argv[2]); free(argv[3]); free(argv);
  return retval;
}

void open_log(void) {
  if(! foreground)
    openlog(PACKAGE_NAME, 0, LOG_DAEMON);
}

void do_log(int level, char *fmt, ...) {
  va_list ap;
  va_start(ap, fmt);
  if(foreground) {
    if(verbose || (level == LOG_EMERG) || (level == LOG_ALERT) || 
      (level == LOG_CRIT) || (level == LOG_ERR))
      vfprintf(stderr, fmt, ap);
  } else {
    vsyslog(level, fmt, ap);
  }
}

void bye(int exitval) {
  if(access(pid_file, F_OK) == 0) {
    if(unlink(pid_file)) {
      do_log(LOG_CRIT, "Cannot remove PID file %s\n", pid_file);
    }
  }
  do_log(LOG_CRIT, "Exiting\n");
  exit(exitval);
}

void usage(void) {
  fprintf(stderr,"%s\nUsage : %s [-k | --nokey] [-c | --nocon] [-t | --notab] \
[-q | --noquery] [-L | --slave] [-s val | --step=val] [-d dir | --datadir=dir] \
[-h hostname | --host=hostname] [-p passwd | --password=passwd] \
[-P port | --port=port] [-S socket | --socket socket] \
[-F file | --pidfile=file] [-u user | --user=user] [-v | --verbose] \
[-f | --foreground]\n\nCheck the manpage for detailed usage information.\n", PACKAGE_STRING, PACKAGE);
  exit(1);
}