/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2000 Ximian, Inc.
 *
 * Authors: Michael Zucchi <notzed@ximian.com>
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of version 2 of the GNU Lesser General Public 
 * License as published by the Free Software Foundation.
 *
 * This program 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 * USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <glib/gi18n-lib.h>

#include "camel-exception.h"
#include "camel-private.h"
#include "camel-url.h"

#include "camel-maildir-folder.h"
#include "camel-maildir-store.h"
#include "camel-maildir-summary.h"

#define d(x)

static CamelLocalStoreClass *parent_class = NULL;

/* Returns the class for a CamelMaildirStore */
#define CMAILDIRS_CLASS(so) CAMEL_MAILDIR_STORE_CLASS (CAMEL_OBJECT_GET_CLASS(so))
#define CF_CLASS(so) CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(so))
#define CMAILDIRF_CLASS(so) CAMEL_MAILDIR_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(so))

static CamelFolder *get_folder(CamelStore * store, const char *folder_name, guint32 flags, CamelException * ex);
static CamelFolder *get_inbox (CamelStore *store, CamelException *ex);
static void delete_folder(CamelStore * store, const char *folder_name, CamelException * ex);
static void maildir_rename_folder(CamelStore *store, const char *old, const char *new, CamelException *ex);

static CamelFolderInfo * get_folder_info (CamelStore *store, const char *top, guint32 flags, CamelException *ex);

static gboolean maildir_compare_folder_name(const void *a, const void *b);
static guint maildir_hash_folder_name(const void *a);

static void camel_maildir_store_class_init(CamelObjectClass * camel_maildir_store_class)
{
	CamelStoreClass *camel_store_class = CAMEL_STORE_CLASS(camel_maildir_store_class);
	/*CamelServiceClass *camel_service_class = CAMEL_SERVICE_CLASS(camel_maildir_store_class);*/

	parent_class = (CamelLocalStoreClass *)camel_type_get_global_classfuncs(camel_local_store_get_type());

	/* virtual method overload, use defaults for most */
	camel_store_class->hash_folder_name = maildir_hash_folder_name;
	camel_store_class->compare_folder_name = maildir_compare_folder_name;
	camel_store_class->get_folder = get_folder;
	camel_store_class->get_inbox = get_inbox;
	camel_store_class->delete_folder = delete_folder;
	camel_store_class->rename_folder = maildir_rename_folder;

	camel_store_class->get_folder_info = get_folder_info;
	camel_store_class->free_folder_info = camel_store_free_folder_info_full;
}

CamelType camel_maildir_store_get_type(void)
{
	static CamelType camel_maildir_store_type = CAMEL_INVALID_TYPE;

	if (camel_maildir_store_type == CAMEL_INVALID_TYPE) {
		camel_maildir_store_type = camel_type_register(CAMEL_LOCAL_STORE_TYPE, "CamelMaildirStore",
							  sizeof(CamelMaildirStore),
							  sizeof(CamelMaildirStoreClass),
							  (CamelObjectClassInitFunc) camel_maildir_store_class_init,
							  NULL,
							  NULL,
							  NULL);
	}

	return camel_maildir_store_type;
}

/* This fixes up some historical cruft of names starting with "./" */
static const char *
md_canon_name(const char *a)
{
	if (a != NULL) {
		if (a[0] == '/')
			a++;
		if (a[0] == '.' && a[1] == '/')
			a+=2;
	}
	return a;
}

static guint maildir_hash_folder_name(const void *a)
{
	return g_str_hash(md_canon_name(a));
}

static gboolean maildir_compare_folder_name(const void *a, const void *b)
{
	return g_str_equal(md_canon_name(a), md_canon_name(b));
}

static CamelFolder *
get_folder(CamelStore * store, const char *folder_name, guint32 flags, CamelException * ex)
{
	char *name, *tmp, *cur, *new;
	struct stat st;
	CamelFolder *folder = NULL;

	folder_name = md_canon_name(folder_name);

	if (!((CamelStoreClass *)parent_class)->get_folder(store, folder_name, flags, ex))
		return NULL;

	name = g_strdup_printf("%s%s", CAMEL_LOCAL_STORE(store)->toplevel_dir, folder_name);
	tmp = g_strdup_printf("%s/tmp", name);
	cur = g_strdup_printf("%s/cur", name);
	new = g_strdup_printf("%s/new", name);

	if (!strcmp(folder_name, ".")) {
		/* special case "." (aka inbox), may need to be created */
		if (stat(tmp, &st) != 0 || !S_ISDIR(st.st_mode)
		    || stat(cur, &st) != 0 || !S_ISDIR(st.st_mode)
		    || stat(new, &st) != 0 || !S_ISDIR(st.st_mode)) {
			if (mkdir(tmp, 0700) != 0
			    || mkdir(cur, 0700) != 0
			    || mkdir(new, 0700) != 0) {
				camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
						     _("Cannot create folder `%s': %s"),
						     folder_name, g_strerror(errno));
				rmdir(tmp);
				rmdir(cur);
				rmdir(new);
				goto fail;
			}
		}
		folder = camel_maildir_folder_new(store, folder_name, flags, ex);
	} else if (stat(name, &st) == -1) {
		/* folder doesn't exist, see if we should create it */
		if (errno != ENOENT) {
			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
					      _("Cannot get folder `%s': %s"),
					      folder_name, g_strerror (errno));
		} else if ((flags & CAMEL_STORE_FOLDER_CREATE) == 0) {
			camel_exception_setv (ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
					      _("Cannot get folder `%s': folder does not exist."),
					      folder_name);
		} else {
			if (mkdir(name, 0700) != 0
			    || mkdir(tmp, 0700) != 0
			    || mkdir(cur, 0700) != 0
			    || mkdir(new, 0700) != 0) {
				camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
						      _("Cannot create folder `%s': %s"),
						      folder_name, g_strerror (errno));
				rmdir(tmp);
				rmdir(cur);
				rmdir(new);
				rmdir(name);
			} else {
				folder = camel_maildir_folder_new(store, folder_name, flags, ex);
			}
		}
	} else if (!S_ISDIR(st.st_mode)
		   || stat(tmp, &st) != 0 || !S_ISDIR(st.st_mode)
		   || stat(cur, &st) != 0 || !S_ISDIR(st.st_mode)
		   || stat(new, &st) != 0 || !S_ISDIR(st.st_mode)) {
		/* folder exists, but not maildir */
		camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
				     _("Cannot get folder `%s': not a maildir directory."), name);
	} else if (flags & CAMEL_STORE_FOLDER_EXCL) {
		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
				      _("Cannot create folder `%s': folder exists."),
				      folder_name);
	} else {
		folder = camel_maildir_folder_new(store, folder_name, flags, ex);
	}
fail:
	g_free(name);
	g_free(tmp);
	g_free(cur);
	g_free(new);

	return folder;
}

static CamelFolder *
get_inbox (CamelStore *store, CamelException *ex)
{
	return camel_store_get_folder(store, ".", CAMEL_STORE_FOLDER_CREATE, ex);
}

static void delete_folder(CamelStore * store, const char *folder_name, CamelException * ex)
{
	char *name, *tmp, *cur, *new;
	struct stat st;

	if (strcmp(folder_name, ".") == 0) {
		camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
				     _("Cannot delete folder: %s: Invalid operation"), _("Inbox"));
		return;
	}

	name = g_strdup_printf("%s%s", CAMEL_LOCAL_STORE(store)->toplevel_dir, folder_name);

	tmp = g_strdup_printf("%s/tmp", name);
	cur = g_strdup_printf("%s/cur", name);
	new = g_strdup_printf("%s/new", name);

	if (stat(name, &st) == -1 || !S_ISDIR(st.st_mode)
	    || stat(tmp, &st) == -1 || !S_ISDIR(st.st_mode)
	    || stat(cur, &st) == -1 || !S_ISDIR(st.st_mode)
	    || stat(new, &st) == -1 || !S_ISDIR(st.st_mode)) {
		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
				      _("Could not delete folder `%s': %s"),
				      folder_name, errno ? g_strerror (errno) :
				      _("not a maildir directory"));
	} else {
		int err = 0;

		/* remove subdirs first - will fail if not empty */
		if (rmdir(cur) == -1 || rmdir(new) == -1) {
			err = errno;
		} else {
			DIR *dir;
			struct dirent *d;

			/* for tmp (only), its contents is irrelevant */
			dir = opendir(tmp);
			if (dir) {
				while ( (d=readdir(dir)) ) {
					char *name = d->d_name, *file;

					if (!strcmp(name, ".") || !strcmp(name, ".."))
						continue;
					file = g_strdup_printf("%s/%s", tmp, name);
					unlink(file);
					g_free(file);
				}
				closedir(dir);
			}
			if (rmdir(tmp) == -1 || rmdir(name) == -1)
				err = errno;
		}

		if (err != 0) {
			/* easier just to mkdir all (and let them fail), than remember what we got to */
			mkdir(name, 0700);
			mkdir(cur, 0700);
			mkdir(new, 0700);
			mkdir(tmp, 0700);
			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
					      _("Could not delete folder `%s': %s"),
					      folder_name, g_strerror (err));
		} else {
			/* and remove metadata */
			((CamelStoreClass *)parent_class)->delete_folder(store, folder_name, ex);
		}
	}

	g_free(name);
	g_free(tmp);
	g_free(cur);
	g_free(new);
}

static void
maildir_rename_folder(CamelStore *store, const char *old, const char *new, CamelException *ex)
{
	if (strcmp(old, ".") == 0) {
		camel_exception_setv(ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
				     _("Cannot rename folder: %s: Invalid operation"), _("Inbox"));
		return;
	}

	((CamelStoreClass *)parent_class)->rename_folder(store, old, new, ex);
}

static void
fill_fi(CamelStore *store, CamelFolderInfo *fi, guint32 flags)
{
	CamelFolder *folder;

	folder = camel_object_bag_get(store->folders, fi->full_name);

	if (folder == NULL
	    && (flags & CAMEL_STORE_FOLDER_INFO_FAST) == 0)
		folder = camel_store_get_folder(store, fi->full_name, 0, NULL);

	if (folder) {
		if ((flags & CAMEL_STORE_FOLDER_INFO_FAST) == 0)
			camel_folder_refresh_info(folder, NULL);
		fi->unread = camel_folder_get_unread_message_count(folder);
		fi->total = camel_folder_get_message_count(folder);
		camel_object_unref(folder);
	} else {
		char *path, *folderpath;
		CamelFolderSummary *s;
		const char *root;

		/* This should be fast enough not to have to test for INFO_FAST */
		root = camel_local_store_get_toplevel_dir((CamelLocalStore *)store);
		path = g_strdup_printf("%s/%s.ev-summary", root, fi->full_name);
		folderpath = g_strdup_printf("%s/%s", root, fi->full_name);
		s = (CamelFolderSummary *)camel_maildir_summary_new(NULL, path, folderpath, NULL);
		if (camel_folder_summary_header_load(s) != -1) {
			fi->unread = s->unread_count;
			fi->total = s->saved_count;
		}
		camel_object_unref(s);
		g_free(folderpath);
		g_free(path);
	}
}

struct _scan_node {
	struct _scan_node *next;
	struct _scan_node *prev;

	CamelFolderInfo *fi;

	dev_t dnode;
	ino_t inode;
};

static guint scan_hash(const void *d)
{
	const struct _scan_node *v = d;

	return v->inode ^ v->dnode;
}

static gboolean scan_equal(const void *a, const void *b)
{
	const struct _scan_node *v1 = a, *v2 = b;
	
	return v1->inode == v2->inode && v1->dnode == v2->dnode;
}

static void scan_free(void *k, void *v, void *d)
{
	g_free(k);
}

static CamelFolderInfo *scan_fi(CamelStore *store, guint32 flags, CamelURL *url, const char *full, const char *name)
{
	CamelFolderInfo *fi;
	char *tmp, *cur, *new;
	struct stat st;

	fi = g_malloc0(sizeof(*fi));
	fi->full_name = g_strdup(full);
	fi->name = g_strdup(name);
	camel_url_set_fragment(url, fi->full_name);
	fi->uri = camel_url_to_string(url, 0);
	fi->unread = -1;
	fi->total = -1;
	/* we only calculate nochildren properly if we're recursive */
	if (((flags & CAMEL_STORE_FOLDER_INFO_RECURSIVE) != 0))
		fi->flags = CAMEL_FOLDER_NOCHILDREN;

	d(printf("Adding maildir info: '%s' '%s' '%s'\n", fi->name, fi->full_name, fi->uri));

	tmp = g_build_filename(url->path, fi->full_name, "tmp", NULL);
	cur = g_build_filename(url->path, fi->full_name, "cur", NULL);
	new = g_build_filename(url->path, fi->full_name, "new", NULL);

	if (!(stat(tmp, &st) == 0 && S_ISDIR(st.st_mode)
	      && stat(cur, &st) == 0 && S_ISDIR(st.st_mode)
	      && stat(new, &st) == 0 && S_ISDIR(st.st_mode)))
		fi->flags |= CAMEL_FOLDER_NOSELECT;

	g_free(new);
	g_free(cur);
	g_free(tmp);

	fill_fi(store, fi, flags);

	return fi;
}

static int
scan_dirs(CamelStore *store, guint32 flags, CamelFolderInfo *topfi, CamelURL *url, CamelException *ex)
{
	EDList queue = E_DLIST_INITIALISER(queue);
	struct _scan_node *sn;
	const char *root = ((CamelService *)store)->url->path;
	char *tmp;
	GHashTable *visited;
	struct stat st;
	int res = -1;

	visited = g_hash_table_new(scan_hash, scan_equal);

	sn = g_malloc0(sizeof(*sn));
	sn->fi = topfi;
	e_dlist_addtail(&queue, (EDListNode *)sn);
	g_hash_table_insert(visited, sn, sn);

	while (!e_dlist_empty(&queue)) {
		char *name;
		DIR *dir;
		struct dirent *d;
		CamelFolderInfo *last;

		sn = (struct _scan_node *)e_dlist_remhead(&queue);

		last = (CamelFolderInfo *)&sn->fi->child;

		if (!strcmp(sn->fi->full_name, "."))
			name = g_strdup(root);
		else
			name = g_build_filename(root, sn->fi->full_name, NULL);

		dir = opendir(name);
		if (dir == NULL) {
			g_free(name);
			camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM,
					     _("Could not scan folder `%s': %s"),
					     root, g_strerror(errno));
			goto fail;
		}

		while ( (d = readdir(dir)) ) {
			if (strcmp(d->d_name, "tmp") == 0
			    || strcmp(d->d_name, "cur") == 0
			    || strcmp(d->d_name, "new") == 0
			    || strcmp(d->d_name, ".") == 0
			    || strcmp(d->d_name, "..") == 0)
				continue;

			tmp = g_build_filename(name, d->d_name, NULL);
			if (stat(tmp, &st) == 0 && S_ISDIR(st.st_mode)) {
				struct _scan_node in;

				in.dnode = st.st_dev;
				in.inode = st.st_ino;

				/* see if we've visited already */
				if (g_hash_table_lookup(visited, &in) == NULL) {
					struct _scan_node *snew = g_malloc(sizeof(*snew));
					char *full;

					snew->dnode = in.dnode;
					snew->inode = in.inode;

					if (!strcmp(sn->fi->full_name, "."))
						full = g_strdup(d->d_name);
					else
						full = g_strdup_printf("%s/%s", sn->fi->full_name, d->d_name);
					snew->fi = scan_fi(store, flags, url, full, d->d_name);
					g_free(full);

					last->next =  snew->fi;
					last = snew->fi;
					snew->fi->parent = sn->fi;

					sn->fi->flags &= ~CAMEL_FOLDER_NOCHILDREN;
					sn->fi->flags |= CAMEL_FOLDER_CHILDREN;

					g_hash_table_insert(visited, snew, snew);

					if (((flags & CAMEL_STORE_FOLDER_INFO_RECURSIVE) != 0))
						e_dlist_addtail(&queue, (EDListNode *)snew);
				}
			}
			g_free(tmp);
		}
		closedir(dir);
	}

	res = 0;
fail:
	g_hash_table_foreach(visited, scan_free, NULL);
	g_hash_table_destroy(visited);

	return res;
}

static CamelFolderInfo *
get_folder_info (CamelStore *store, const char *top, guint32 flags, CamelException *ex)
{
	CamelFolderInfo *fi = NULL;
	CamelLocalStore *local_store = (CamelLocalStore *)store;
	CamelURL *url;

	url = camel_url_new("maildir:", NULL);
	camel_url_set_path(url, ((CamelService *)local_store)->url->path);

	if (top == NULL || top[0] == 0) {
		CamelFolderInfo *scan;

		/* create a dummy "." parent inbox, use to scan, then put back at the top level */
		fi = scan_fi(store, flags, url, ".", _("Inbox"));
		if (scan_dirs(store, flags, fi, url, ex) == -1)
			goto fail;
		fi->next = fi->child;
		scan = fi->child;
		fi->child = NULL;
		while (scan) {
			scan->parent = NULL;
			scan = scan->next;
		}
		fi->flags &= ~CAMEL_FOLDER_CHILDREN;
		fi->flags |= CAMEL_FOLDER_SYSTEM|CAMEL_FOLDER_NOCHILDREN|CAMEL_FOLDER_NOINFERIORS|CAMEL_FOLDER_TYPE_INBOX;
	} else if (!strcmp(top, ".")) {
		fi = scan_fi(store, flags, url, ".", _("Inbox"));
		fi->flags |= CAMEL_FOLDER_SYSTEM|CAMEL_FOLDER_NOCHILDREN|CAMEL_FOLDER_NOINFERIORS|CAMEL_FOLDER_TYPE_INBOX;
	} else {
		const char *name = strrchr(top, '/');

		fi = scan_fi(store, flags, url, top, name?name+1:top);
		if (scan_dirs(store, flags, fi, url, ex) == -1)
			goto fail;
	}

	camel_url_free(url);

	return fi;

fail:
	if (fi)
		camel_store_free_folder_info_full(store, fi);

	camel_url_free(url);

	return NULL;
}