#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>
#include "log.h"

#define PLOT_LINES      6

static void log_add_ent(log_t *l, logent_t *le);
static void logent_destroy(logent_t *le);
static void fatal_error(const char *format, ...);
static f_t *finit(char *name, const char *mode);
static void fend(f_t *f);

/**
 * Get the time: function to use as logfunc_t
 **/
void gettime(unsigned long long *t) {
    struct timeval tp;
    unsigned long long ctime;

    gettimeofday( &tp, NULL );
    ctime = tp.tv_sec;
    ctime *= 1000000;
    ctime += tp.tv_usec;

    *t = ctime;
}

log_t *log_init(char *fn, const char *mode, char *xlabel, char *ylabel, logfunc_t func) {
    char buf[256];

    stat_t  st;
    log_t   *l = (log_t *) malloc(sizeof(log_t));
    
    if (l == NULL)
        fatal_error("Could not allocate memory for the new log [%s].", fn);

    if (stat(LOG_DIR, &st) != 0)
        if (mkdir(LOG_DIR, 0777))
            fatal_error("Could not create directory: %s", LOG_DIR);

    sprintf(buf, "%s/%s-%s", LOG_DIR, fn, LOG_PLT);
    l->file = finit(buf, mode);

    if (l->file->lines == 0)
        l->file->lines = PLOT_LINES;
    
    l->entries = 0;
    l->entry = NULL;
    l->xlabel = strdup(xlabel);
    l->ylabel = strdup(ylabel);
    l->func = func;

    return l;
}

logent_t *logent_init(log_t *l, char *desc, ...) {
    char buf[256];
    char *id;
    va_list vargs;
    logent_t *le = (logent_t *)malloc(sizeof(logent_t));

    if (l == NULL)
        fatal_error("Log is NULL\n");

    if (le == NULL)
        fatal_error("Could not allocate memory for log entry: %s:%s\n", l->file->fn, desc);

    le->desc = strdup(desc);

    va_start(vargs, desc);
    id = va_arg(vargs, char*);
    va_end(vargs);

    if (id != NULL)
        sprintf(buf, "%s-%d.data", l->file->fn, l->file->lines - PLOT_LINES + l->entries);
    else
        sprintf(buf, "%s-%s.data", l->file->fn, id);

    printf("FN: %s\n", buf);
    le->file = finit(buf, l->file->mode);

    log_add_ent(l, le);

    return le;
}

void logent_start(logent_t *le, ...) {
    va_list vargs;

    if (le == NULL)
        fatal_error("Log entry is NULL\n");

    va_start(vargs, le);
    le->log->func(&le->t1);
    va_end(vargs);
}

void logent_end(logent_t *le, int idx, int ent, ...) {
    int res;
    va_list vargs;
    
    if (le == NULL)
        fatal_error("Logentry is NULL\n");
    
    va_start(vargs, ent);
    le->log->func(&le->t2, vargs);
    va_end(vargs);

    if (ent <= 0)
        ent = 1;

    res = (int)(le->t2 - le->t1) / ent;

    fprintf(le->file->f, "%d %d\n", idx, res);
    fflush(le->file->f);
}

void log_destroy(log_t *l) {
    int i;

    if (ftell(l->file->f) == 0) {
        fprintf(l->file->f, "set terminal postscript color\n");
        fprintf(l->file->f, "set output \"%s-%s\"\n", l->file->fn, LOG_CMP);
        fprintf(l->file->f, "set autoscale\n");
        fprintf(l->file->f, "set xlabel \"%s\"\nset ylabel \"%s\"\n", l->xlabel, l->ylabel);
        fprintf(l->file->f, "set key right\nplot");
    }

    for (i = 0; i < l->entries; i++) {
        if (l->entry[i]->file->lines == 0) {
            fprintf(l->file->f, " \\\n\"%s\" w linespoints lw 2 t \"%s\",",
                l->entry[i]->file->fn, l->entry[i]->desc
            );
        }
        logent_destroy(l->entry[i]);
    }

    fflush(l->file->f);
    fend(l->file);
    free(l->xlabel);
    free(l->ylabel);

    if (l->entry != NULL)
        free(l->entry);
}

/** 
 * When something bad happens.... we end!
 **/
static void fatal_error(const char *format, ...) {
    va_list vargs;
    fprintf(stdout, "[FATAL] ");
    va_start(vargs, format);
    vfprintf(stdout, format, vargs);
    va_end(vargs);
	exit(EXIT_FAILURE);
}

static f_t *finit(char *name, const char *mode) {

    char c;

    f_t *f = (f_t *)malloc(sizeof(f_t));

    if (f == NULL)
        fatal_error("Could not allocate memory for %s\n", name);

    f->fn = strdup(name);
    f->f = fopen(f->fn, mode);
    f->lines = 0;
    f->mode = mode;

    if (f->f == NULL)
        fatal_error("Coult not open %s[%s]\n", name, mode);

    while ((c = fgetc(f->f)) != EOF)
        if (c == '\n')
            f->lines++;

    fseek(f->f, 0, SEEK_END);

    return f;
}

static void fend(f_t *f) {
    if (f == NULL)
        fatal_error("Cant close NULL-file\n");

    if (f->f == NULL)
        return;

    printf("[FILE] stored in: %s\n", f->fn);
    free(f->fn);
    fclose(f->f);
}

static void log_add_ent(log_t *l, logent_t *le) {
    int i;

    logent_t **entry = (logent_t **)malloc(sizeof(logent_t*) * (l->entries + 1));

    for (i = 0; i < l->entries; i++)
        entry[i] = l->entry[i];

    entry[l->entries++] = le;
    
    if (l->entry != NULL)
        free(l->entry);
    
    l->entry = entry;
    le->log = l;
}

static void logent_destroy(logent_t *le) {
    
    if (le == NULL)
        fatal_error("Cant close log entry 0x%p\n", le);

    if (le->file->f != NULL)
        fend(le->file);

    le->file->f = NULL;

    free(le->desc);
    free(le);
}