/* $Id$ */

/***
  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 <limits.h>
#include <dirent.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <ltdl.h>

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

#ifndef NM_LIBRARY_PATH
#define NM_LIBRARY_PATH "/home/lennart/projects/libnewmail/src"
#endif

#define NM_PRIVATE_CONFIG_PATH ".newmail"
#define NM_GLOBAL_CONFIG_PATH "/etc/newmail"

void* (*nm_malloc)(size_t) = malloc;
void* (*nm_realloc)(void *,size_t) = realloc;
void (*nm_free)(void *) = free;

enum nm_error nm_errno = 0;
const char *nm_explanation = 0;

static void _ltdl_init(int b) {
    static int n = 0;

    if (b) {
        if (n++ == 0) {
            lt_dlinit();
            lt_dladdsearchdir(NM_LIBRARY_PATH);
        }
    } else {
        if (--n == 0)
            lt_dlexit();
    }
}
    
    
int nm_list(nm_enum_cb_t cb, void*user) {
    static char p[PATH_MAX];
    DIR *d;
    struct dirent *de;
    int n = 0;
    
    if (!cb) {
        nm_error(NM_ERROR_INVPAR, NULL);
        return -1;
    }
    
    snprintf(p, sizeof(p), "%s/"NM_PRIVATE_CONFIG_PATH, getenv("HOME"));
    if (!(d = opendir(p)))
        if (!(d = opendir(NM_GLOBAL_CONFIG_PATH)))
            return 0;

    while ((de = readdir(d))) {
        static char fn[PATH_MAX];

        if (de->d_name[0] == '.')
            continue;

        snprintf(fn, sizeof(fn), "%s/%s", p, de->d_name);
        cb(fn, user);
        n++;
    }

    closedir(d);
    
    return n;
}

const char *nm_strerror(enum nm_error n, int e, const char *explanation) {
    char *p = NULL;
    static char t[256];

    switch (n & ~(NM_ERROR_SYSTEM|NM_ERROR_EXPLANATION)) {
        case NM_ERROR_SUCCESS:      p = "Success"; break;
        case NM_ERROR_NOCONFIG:     p = "No configuration available"; break;
        case NM_ERROR_INVPAR:       p  = "Invalid parameters"; break;
        case NM_ERROR_MEMORY:       p = "Not enough memory"; break;
        case NM_ERROR_INVNAME:      p = "Invalid name"; break;
        case NM_ERROR_DLFAIL:       p = "Module not found"; break;
        case NM_ERROR_NOTIMPL:      p = "Not implemented"; break;
        case NM_ERROR_NOFILE:       p = "Could not open file"; break;
        case NM_ERROR_FORK:         p = "fork() failure"; break;
        case NM_ERROR_ALREADY:      p = "Asynchronous check already scheduled"; break;
        case NM_ERROR_CONTEXT:      p = "Function call in wrong context"; break;
        case NM_ERROR_INTERNAL:     p = "Internal error"; break;
        case NM_ERROR_SERVFAIL:     p = "Server failure"; break;
        case NM_ERROR_SERVNOTFOUND: p = "Server not found"; break;
        default: p = "Unknown error"; break;
    }

    if (n & NM_ERROR_SYSTEM) {
        snprintf(t, sizeof(t), "%s (%s)", p, strerror(e));
        p = t;
    } else if (n & NM_ERROR_EXPLANATION) {
        snprintf(t, sizeof(t), "%s (Explanation: %s)", p, explanation);
        p = t;
    }
    
    return p;
}

void nm_perror(const char *s) {
    fprintf(stderr, "%s: %s\n", s, nm_strerror(nm_errno, errno, nm_explanation));
}

int nm_info(struct nm_spool *s, struct nm_info *i) {
    char *p;

    if (!s || !i) {
        nm_error(NM_ERROR_INVPAR, NULL);
        goto fail;
    }

    if (!s->info) {
        nm_error(NM_ERROR_NOTIMPL, NULL);
        goto fail;
    }

    memset(i, 0, sizeof(struct nm_info));

    strncpy(i->path, s->path ? s->path : "n/a", sizeof(i->path));
    i->path[sizeof(i->path)-1] = 0;

    if (!(p = strrchr(i->path, '/')))
        p = i->path;
    else
        p++;

    strncpy(i->name, p, sizeof(i->name));
    i->name[sizeof(i->name)-1] = 0;

    if ((p = strrchr(i->name, '.'))) {
        *p = 0;
        p++;

        strncpy(i->type, p, sizeof(i->type));
        i->type[sizeof(i->type)-1] = 0;
    }

    return s->info(s, i);
    
fail:
    
    return -1;
}

int nm_query(struct nm_spool *s, enum nm_query query, struct nm_status *st) {

    if (!s || !st) {
        nm_error(NM_ERROR_INVPAR, NULL);
        goto fail;
    }

    if (!s->query) {
        nm_error(NM_ERROR_NOTIMPL, NULL);
        goto fail;
    }

    return s->query(s, query, st);
    
fail:
    return -1;
}


int nm_query_submit(struct nm_spool *s, enum nm_query query, oop_source *oop, nm_query_cb_t cb, void *user) {

    if (!s || !cb || !oop) {
        nm_error(NM_ERROR_INVPAR, NULL);
        goto fail;
    }

    if (!s->query_submit) {
        nm_error(NM_ERROR_NOTIMPL, NULL);
        goto fail;
    }

    return s->query_submit(s, query, oop, cb, (void*) user);
    
fail:
    return -1;
}

static int _nm_load(struct nm_spool *s, char *p) {
    char t[PATH_MAX];
    nm_init_t init;

    _ltdl_init(1);
    

    snprintf(t, sizeof(t), "lib%s", p);
    if (!(s->dl = lt_dlopenext(t))) {
        nm_error(NM_ERROR_DLFAIL|NM_ERROR_EXPLANATION, lt_dlerror());
        goto fail;
    }

    if (!(init = lt_dlsym(s->dl, "nm_init"))) {
        nm_error(NM_ERROR_DLFAIL|NM_ERROR_EXPLANATION, lt_dlerror());
        goto fail;
    }

    if (init(s) < 0)
        goto fail;

    return 0;
    
fail:
    
    if (s->dl)
        lt_dlclose(s->dl);

    _ltdl_init(0);
    
    return -1;
}

struct nm_spool* nm_open(const char *spool) {
    struct nm_spool* s = NULL;
    static char p[PATH_MAX];
        
    if (!spool) {
        char *r;
        snprintf(p, sizeof(p), "%s/"NM_PRIVATE_CONFIG_PATH"/.default", getenv("HOME"));

        if ((r = realpath(p, NULL)))
            if ((s = nm_open(r))) {
                free(r);
                return s;
            }

        snprintf(p, sizeof(p), NM_GLOBAL_CONFIG_PATH"/.default");

        if ((r = realpath(p, NULL)))
            if ((s = nm_open(r))) {
                free(r);
                return s;
            }
    }
        
    if (!(s = nm_malloc(sizeof(struct nm_spool)))) {
        nm_error(NM_ERROR_MEMORY, NULL);
        goto fail;
    }
    memset(s, 0, sizeof(struct nm_spool));

    if (spool) {
        char *d;
        
        if (!(s->config = nm_config_open(spool)))
            goto fail;

        if (!(s->path = nm_strdup(spool))) {
            nm_error(NM_ERROR_MEMORY, NULL);
            goto fail;
        }

        if (!(d = strrchr(spool, '.'))) {
            nm_error(NM_ERROR_INVNAME, NULL);
            goto fail;
        }
        d++;

        if (_nm_load(s, d) < 0)
            goto fail;
        
    } else {
        if (_nm_load(s, "maildir") < 0)
            if (_nm_load(s, "unix") < 0)
                goto fail;
    }

    return s;
    
fail:
    if (s) {
        if (s->config)
            nm_config_close(s->config);
        

        if (s->path)
            nm_free(s->path);
        
        nm_free(s);
    }

    return NULL;
}

void nm_close(struct nm_spool *s) {
    
    if (!s) {
        nm_error(NM_ERROR_INVPAR, NULL);
        return;
    }

    if (s->done)
        s->done(s);

    if (s->config)
        nm_config_close(s->config);

    if (s->path)
        nm_free(s->path);
    
    if (s->dl)
        lt_dlclose(s->dl);

    nm_free(s);

    _ltdl_init(0);
}