/* $Id: rrdtool_main.c,v 1.1 2008/03/11 22:47:06 dbach Exp $
 * Substantial penalty for early withdrawal.
 */

#include <unistd.h>
#include <math.h>   /* for isnan */
#include <ruby.h>
#include <rrd.h>
#include "rrd_info.h"

typedef struct string_arr_t {
    int len;
    char **strings;
} string_arr;

VALUE mRRD;
VALUE rb_eRRDError;

typedef int (*RRDFUNC)(int argc, char ** argv);
#define RRD_CHECK_ERROR  \
    if (rrd_test_error()) \
      rb_raise(rb_eRRDError, rrd_get_error()); \
    rrd_clear_error();

string_arr string_arr_new(VALUE rb_strings)
{
    string_arr a;
    char buf[64];
    int i;
   
    Check_Type(rb_strings, T_ARRAY);
    a.len = RARRAY_LEN(rb_strings) + 1;

    a.strings = malloc(a.len * sizeof(char *));
    a.strings[0] = "dummy";     /* first element is a dummy element */

    for (i = 0; i < a.len - 1; i++) {
        VALUE v = rb_ary_entry(rb_strings, i);
        switch (TYPE(v)) {
        case T_STRING:
            a.strings[i + 1] = strdup(STR2CSTR(v));
            break;
        case T_FIXNUM:
            snprintf(buf, 63, "%d", FIX2INT(v));
            a.strings[i + 1] = strdup(buf);
            break;
        default:
            rb_raise(rb_eTypeError, "invalid argument - %s, expected T_STRING or T_FIXNUM on index %d", rb_class2name(CLASS_OF(v)), i);
            break;
        }
    }

    return a;
}

void string_arr_delete(string_arr a)
{
    int i;

    /* skip dummy first entry */
    for (i = 1; i < a.len; i++) {
        free(a.strings[i]);
    }

    free(a.strings);
}

void reset_rrd_state()
{
    optind = 0; 
    opterr = 0;
    rrd_clear_error();
}

VALUE rrd_call(RRDFUNC func, VALUE args)
{
    string_arr a;

    a = string_arr_new(args);
    reset_rrd_state();
    func(a.len, a.strings);
    string_arr_delete(a);

    RRD_CHECK_ERROR

    return Qnil;
}

VALUE rb_rrd_create(VALUE self, VALUE args)
{
    return rrd_call(rrd_create, args);
}

VALUE rb_rrd_dump(VALUE self, VALUE args)
{
    return rrd_call(rrd_dump, args);
}

VALUE rb_rrd_fetch(VALUE self, VALUE args)
{
    string_arr a;
    unsigned long i, j, k, step, ds_cnt;
    rrd_value_t *raw_data;
    char **raw_names;
    VALUE data, names, result;
    time_t start, end;

    a = string_arr_new(args);
    reset_rrd_state();
    rrd_fetch(a.len, a.strings, &start, &end, &step, &ds_cnt, &raw_names, &raw_data);
    string_arr_delete(a);

    RRD_CHECK_ERROR

    names = rb_ary_new();
    for (i = 0; i < ds_cnt; i++) {
        rb_ary_push(names, rb_str_new2(raw_names[i]));
        free(raw_names[i]);
    }
    free(raw_names);

    k = 0;
    data = rb_ary_new();
    for (i = start; i < end; i += step) {
        VALUE line = rb_ary_new2(ds_cnt);
        for (j = 0; j < ds_cnt; j++) {
            rb_ary_store(line, j, rb_float_new(raw_data[k]));
            k++;
        }
        rb_ary_push(data, line);
    }
    free(raw_data);
   
    result = rb_ary_new2(4);
    rb_ary_store(result, 0, INT2NUM(start));
    rb_ary_store(result, 1, INT2NUM(end));
    rb_ary_store(result, 2, names);
    rb_ary_store(result, 3, data);
    return result;
}

VALUE rb_rrd_graph(VALUE self, VALUE args)
{
    string_arr a;
    char **calcpr, **p;
    VALUE result, print_results;
    int xsize, ysize;
    double ymin, ymax;

    a = string_arr_new(args);
    reset_rrd_state();
    rrd_graph(a.len, a.strings, &calcpr, &xsize, &ysize, NULL, &ymin, &ymax);
    string_arr_delete(a);

    RRD_CHECK_ERROR

    result = rb_ary_new2(3);
    print_results = rb_ary_new();
    p = calcpr;
    for (p = calcpr; p && *p; p++) {
        rb_ary_push(print_results, rb_str_new2(*p));
        free(*p);
    }
    free(calcpr);
    rb_ary_store(result, 0, print_results);
    rb_ary_store(result, 1, INT2FIX(xsize));
    rb_ary_store(result, 2, INT2FIX(ysize));
    return result;
}

VALUE rb_rrd_info(VALUE self, VALUE args)
{
    string_arr a;
    info_t *p, *data;
    VALUE result;

    a = string_arr_new(args);
    data = rrd_info(a.len, a.strings);
    string_arr_delete(a);

    RRD_CHECK_ERROR

    result = rb_hash_new();
    while (data) {
        VALUE key = rb_str_new2(data->key);
        switch (data->type) {
        case RD_I_VAL:
            if (isnan(data->value.u_val)) {
                rb_hash_aset(result, key, Qnil);
            }
            else {
                rb_hash_aset(result, key, rb_float_new(data->value.u_val));
            }
            break;
        case RD_I_CNT:
            rb_hash_aset(result, key, INT2FIX(data->value.u_cnt));
            break;
        case RD_I_STR:
            rb_hash_aset(result, key, rb_str_new2(data->value.u_str));
            free(data->value.u_str);
            break;
        }
        p = data;
        data = data->next;
        free(p);
    }
    return result;
}

VALUE rb_rrd_last(VALUE self, VALUE args)
{
    string_arr a;
    time_t last;

    a = string_arr_new(args);
    reset_rrd_state();
    last = rrd_last(a.len, a.strings);
    string_arr_delete(a);

    RRD_CHECK_ERROR

    return rb_funcall(rb_cTime, rb_intern("at"), 1, INT2FIX(last));
}

VALUE rb_rrd_resize(VALUE self, VALUE args)
{
    return rrd_call(rrd_resize, args);
}

VALUE rb_rrd_restore(VALUE self, VALUE args)
{
    return rrd_call(rrd_restore, args);
}

VALUE rb_rrd_tune(VALUE self, VALUE args)
{
    return rrd_call(rrd_tune, args);
}

VALUE rb_rrd_update(VALUE self, VALUE args)
{
    return rrd_call(rrd_update, args);
}

void Init_errand_backend() 
{
    mRRD = rb_define_module("ErrandBackend");
    rb_eRRDError = rb_define_class("ErrandError", rb_eStandardError);

    rb_define_module_function(mRRD, "create", rb_rrd_create, -2);
    rb_define_module_function(mRRD, "dump", rb_rrd_dump, -2);
    rb_define_module_function(mRRD, "fetch", rb_rrd_fetch, -2);
    rb_define_module_function(mRRD, "graph", rb_rrd_graph, -2);
    rb_define_module_function(mRRD, "last", rb_rrd_last, -2);
    rb_define_module_function(mRRD, "resize", rb_rrd_resize, -2);
    rb_define_module_function(mRRD, "restore", rb_rrd_restore, -2);
    rb_define_module_function(mRRD, "tune", rb_rrd_tune, -2);
    rb_define_module_function(mRRD, "update", rb_rrd_update, -2);
    rb_define_module_function(mRRD, "info", rb_rrd_info, -2);
}