/* $Id$ */

/***
  This file is part of libnewmail

  libnewmail 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.
  
  libnewmail 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 libnewmail; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA
***/

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

#include "module.h"
#include "newmail.h"
#include "util.h"

struct data {
    char *path;
    enum nm_query query;
    nm_query_cb_t cb;
    void *user;
    oop_source *oop;
};

static int _query(struct nm_spool *s, enum nm_query query, struct nm_status *status) {
    struct data *data = (struct data*) s->data;
    status->new = status->cur = -1;

    
    if (query & (NM_QUERY_NCUR|NM_QUERY_NNEW)) {
        FILE *f;
        struct stat st;
        int hdr=1, old=0;

        if (!(f = fopen(data->path, "r"))) {
            
            if (errno == ENOENT) {
                status->new = status->cur = 0;
                return 0;
            } else {
                nm_error(NM_ERROR_NOFILE|NM_ERROR_SYSTEM, NULL);
                return -1;
            }
        
        }

        if (fstat(fileno(f), &st) < 0) {
            nm_error(NM_ERROR_NOFILE|NM_ERROR_SYSTEM, "fstat() failed");
            fclose(f);
            return -1;
        }
        
        if (!S_ISREG(st.st_mode)) {
            nm_error(NM_ERROR_NOFILE, "Mailbox not a regular file");
            fclose(f);
            return -1;
        }

        status->cur = 0;
        
        while (!feof(f)) {
            static char ln[128];
	    char *eol;
            
            if (!fgets(ln, sizeof(ln), f))
                break;
            
            if (strncmp(ln, "From ", 5) == 0) {
                    hdr = 1;
                    status->cur++;
                } else if (hdr && strcmp(ln, "\n") == 0)
                    hdr = 0;
                else if (hdr && strncmp(ln, "Status: ", 8) == 0) {
                    old++;
                    hdr = 0;
                }

	    /* Position the cursor at the next newline */
	    do {
	    	if (eol = strchr(ln, '\n')) {
			fseek(f, -1 * strlen(eol + 1), SEEK_CUR);
			break;
		}
	    } while(fgets(ln, sizeof(ln), f));
	}
            
        fclose(f);
        
        status->new = status->cur-old;
        
        return 0;

    } else if (query & (NM_QUERY_CUR|NM_QUERY_NEW)) {
        struct stat st;

        if (stat(data->path, &st) < 0) {
            if (errno == ENOENT) {
                status->cur = status->new = 0;
                return 0;
            }

            nm_error(NM_ERROR_NOFILE|NM_ERROR_SYSTEM, NULL);
            return -1;
        }

        if (!S_ISREG(st.st_mode)) {
            nm_error(NM_ERROR_NOFILE, "Mailbox not a regular file");
            return -1;
        }

        status->cur = st.st_size != 0 ? 1 : 0;
        status->new = status->cur && (st.st_atime < st.st_mtime) ? 1 : 0;
        return 0;
    }

    return -1;
}

static void * _cb(oop_source *source, struct timeval tv, void *user) {
    struct nm_status status;
    struct nm_spool *s = (struct nm_spool *) user;
    struct data *data = (struct data*) s->data;

    if (_query(s, data->query, &status) < 0)
        data->cb(s, NULL, data->user);
    else
        data->cb(s, &status, data->user);

    data->cb = NULL;
    data->user = NULL;
    data->query = 0;
    data->oop = NULL;

    return OOP_CONTINUE;
}


static int _query_submit(struct nm_spool *s, enum nm_query query, oop_source *oop, nm_query_cb_t cb, void *user) {
    struct data *data = (struct data*) s->data;

    if (data->cb) {
        nm_error(NM_ERROR_ALREADY, NULL);
        return -1;
    }

    data->cb = cb;
    data->user = user;
    data->query = query;
    data->oop = oop;

    data->oop->on_time(data->oop, OOP_TIME_NOW, _cb, s);
    
    return 0;
}

static int _configure(struct nm_spool *s) {
    return -1;
}

static int _info(struct nm_spool *s, struct nm_info *i) {
    struct data *data = (struct data*) s->data;

    snprintf(i->text, sizeof(i->text), "Unix mail spool %s", data->path);
    i->flags = NM_FLAG_SYNCHRONOUS;
    
    return 0;
}

static void _done(struct nm_spool *s) {
    struct data *data = (struct data*) s->data;

    if (data) {
        if (data->cb && data->oop)
            data->oop->cancel_time(data->oop, OOP_TIME_NOW, _cb, s);
        
        nm_free(data->path);
        nm_free(data);
    }
}

int nm_init(struct nm_spool *s) {
    struct data *data;
    char *def;

    if (!(def = getenv("MAIL"))) {
        static char fn[PATH_MAX];
        static struct stat st;

        def = fn;
        
        snprintf(fn, sizeof(fn), "/var/mail/%s", getenv("USER"));
        if (stat(fn, &st) < 0 || !S_ISREG(st.st_mode))
            snprintf(fn, sizeof(fn), "/var/spool/mail/%s", getenv("USER"));
    }

    s->query = _query;
    s->query_submit = _query_submit;
    s->configure = _configure;
    s->info = _info;
    s->done = _done;

    if (!s->path)
        s->path = nm_strdup("@AUTOMATIC@.unix");
    
    data = nm_malloc(sizeof(struct data));
    memset(data, 0, sizeof(struct data));
    data->path = nm_strdup(nm_specials(nm_config_get(s->config, "Path", def)));
    s->data = (void*) data;
    return 0;
}