#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "common.h"
#include "appconfig.h"
#include "procfile.h"
#include "rrd.h"
#include "plugin_proc.h"
#include "log.h"

#define MAX_INTERRUPTS 256
#define MAX_INTERRUPT_CPUS 256
#define MAX_INTERRUPT_NAME 50

struct interrupt {
	int used;
	char *id;
	char name[MAX_INTERRUPT_NAME + 1];
	unsigned long long value[MAX_INTERRUPT_CPUS];
	unsigned long long total;
};

int do_proc_interrupts(int update_every, unsigned long long dt) {
	static procfile *ff = NULL;
	static int cpus = -1, do_per_core = -1;

	if(dt) {};

	if(do_per_core == -1) do_per_core = config_get_boolean("plugin:proc:/proc/interrupts", "interrupts per core", 1);

	if(!ff) {
		char filename[FILENAME_MAX + 1];
		snprintf(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/interrupts");
		ff = procfile_open(config_get("plugin:proc:/proc/interrupts", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
	}
	if(!ff) return 1;

	ff = procfile_readall(ff);
	if(!ff) return 0; // we return 0, so that we will retry to open it next time

	uint32_t lines = procfile_lines(ff), l;
	uint32_t words = procfile_linewords(ff, 0), w;

	// find how many CPUs are there
	if(cpus == -1) {
		cpus = 0;
		for(w = 0; w < words ; w++) {
			if(strncmp(procfile_lineword(ff, 0, w), "CPU", 3) == 0)
				cpus++;
		}

		if(cpus > MAX_INTERRUPT_CPUS) cpus = MAX_INTERRUPT_CPUS;
	}

	if(!cpus) {
		error("PLUGIN: PROC_INTERRUPTS: Cannot find the number of CPUs in /proc/interrupts");
		return 1;
	}

	// allocate the size we need;
	struct interrupt irrs[lines];
	irrs[0].used = 0;

	// loop through all lines
	for(l = 1; l < lines ;l++) {
		struct interrupt *irr = &irrs[l];
		irr->used = 0;
		irr->total = 0;

		words = procfile_linewords(ff, l);
		if(!words) continue;

		irr->id = procfile_lineword(ff, l, 0);
		if(!irr->id || !irr->id[0]) continue;

		int idlen = strlen(irr->id);
		if(irr->id[idlen - 1] == ':')
			irr->id[idlen - 1] = '\0';

		int c;
		for(c = 0; c < cpus ;c++) {
			if((c + 1) < (int)words)
				irr->value[c] = strtoull(procfile_lineword(ff, l, (uint32_t)(c + 1)), NULL, 10);
			else
				irr->value[c] = 0;

			irr->total += irr->value[c];
		}

		if(isdigit(irr->id[0]) && (uint32_t)(cpus + 2) < words) {
			strncpy(irr->name, procfile_lineword(ff, l, words - 1), MAX_INTERRUPT_NAME);
			irr->name[MAX_INTERRUPT_NAME] = '\0';
			int nlen = strlen(irr->name);
			if(nlen < (MAX_INTERRUPT_NAME-1)) {
				irr->name[nlen] = '_';
				strncpy(&irr->name[nlen + 1], irr->id, MAX_INTERRUPT_NAME - nlen);
				irr->name[MAX_INTERRUPT_NAME] = '\0';
			}
		}
		else {
			strncpy(irr->name, irr->id, MAX_INTERRUPT_NAME);
			irr->name[MAX_INTERRUPT_NAME] = '\0';
		}

		irr->used = 1;
	}

	RRDSET *st;

	// --------------------------------------------------------------------

	st = rrdset_find_bytype("system", "interrupts");
	if(!st) {
		st = rrdset_create("system", "interrupts", NULL, "interrupts", NULL, "System interrupts", "interrupts/s", 1000, update_every, RRDSET_TYPE_STACKED);

		for(l = 0; l < lines ;l++) {
			if(!irrs[l].used) continue;
			rrddim_add(st, irrs[l].id, irrs[l].name, 1, 1, RRDDIM_INCREMENTAL);
		}
	}
	else rrdset_next(st);

	for(l = 0; l < lines ;l++) {
		if(!irrs[l].used) continue;
		rrddim_set(st, irrs[l].id, irrs[l].total);
	}
	rrdset_done(st);

	if(do_per_core) {
		int c;

		for(c = 0; c < cpus ; c++) {
			char id[256];
			snprintf(id, 256, "cpu%d_interrupts", c);

			st = rrdset_find_bytype("cpu", id);
			if(!st) {
				char name[256], title[256];
				snprintf(name, 256, "cpu%d_interrupts", c);
				snprintf(title, 256, "CPU%d Interrupts", c);
				st = rrdset_create("cpu", id, name, "interrupts", "cpu.interrupts", title, "interrupts/s", 2000 + c, update_every, RRDSET_TYPE_STACKED);

				for(l = 0; l < lines ;l++) {
					if(!irrs[l].used) continue;
					rrddim_add(st, irrs[l].id, irrs[l].name, 1, 1, RRDDIM_INCREMENTAL);
				}
			}
			else rrdset_next(st);

			for(l = 0; l < lines ;l++) {
				if(!irrs[l].used) continue;
				rrddim_set(st, irrs[l].id, irrs[l].value[c]);
			}
			rrdset_done(st);
		}
	}

	return 0;
}