/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

#include <linux/time.h>
#include <linux/reiserfs_fs.h>

// this contains item handlers for old item types: sd, direct,
// indirect, directory

/* and where are the comments? how about saying where we can find an
   explanation of each item handler method? -Hans */

//////////////////////////////////////////////////////////////////////////////
// stat data functions
//
static int sd_bytes_number(struct item_head *ih, int block_size)
{
        return 0;
}

static void sd_decrement_key(struct cpu_key *key)
{
        key->on_disk_key.k_objectid--;
        set_cpu_key_k_type(key, TYPE_ANY);
        set_cpu_key_k_offset(key, (loff_t)(~0ULL >> 1));
}

static int sd_is_left_mergeable(struct reiserfs_key *key, unsigned long bsize)
{
        return 0;
}

static char *print_time(time_t t)
{
        static char timebuf[256];

        sprintf(timebuf, "%ld", t);
        return timebuf;
}

static void sd_print_item(struct item_head *ih, char *item)
{
        printk("\tmode | size | nlinks | first direct | mtime\n");
        if (stat_data_v1(ih)) {
                struct stat_data_v1 *sd = (struct stat_data_v1 *)item;

                printk("\t0%-6o | %6u | %2u | %d | %s\n", sd_v1_mode(sd),
                       sd_v1_size(sd), sd_v1_nlink(sd),
                       sd_v1_first_direct_byte(sd),
                       print_time(sd_v1_mtime(sd)));
        } else {
                struct stat_data *sd = (struct stat_data *)item;

                printk("\t0%-6o | %6Lu | %2u | %d | %s\n", sd_v2_mode(sd),
                       (unsigned long long)sd_v2_size(sd), sd_v2_nlink(sd),
                       sd_v2_rdev(sd), print_time(sd_v2_mtime(sd)));
        }
}

static void sd_check_item(struct item_head *ih, char *item)
{
        // FIXME: type something here!
}

static int sd_create_vi(struct virtual_node *vn,
                        struct virtual_item *vi,
                        int is_affected, int insert_size)
{
        vi->vi_index = TYPE_STAT_DATA;
        //vi->vi_type |= VI_TYPE_STAT_DATA;// not needed?
        return 0;
}

static int sd_check_left(struct virtual_item *vi, int free,
                         int start_skip, int end_skip)
{
        BUG_ON(start_skip || end_skip);
        return -1;
}

static int sd_check_right(struct virtual_item *vi, int free)
{
        return -1;
}

static int sd_part_size(struct virtual_item *vi, int first, int count)
{
        BUG_ON(count);
        return 0;
}

static int sd_unit_num(struct virtual_item *vi)
{
        return vi->vi_item_len - IH_SIZE;
}

static void sd_print_vi(struct virtual_item *vi)
{
        reiserfs_warning(NULL, "reiserfs-16100",
                         "STATDATA, index %d, type 0x%x, %h",
                         vi->vi_index, vi->vi_type, vi->vi_ih);
}

static struct item_operations stat_data_ops = {
        .bytes_number = sd_bytes_number,
        .decrement_key = sd_decrement_key,
        .is_left_mergeable = sd_is_left_mergeable,
        .print_item = sd_print_item,
        .check_item = sd_check_item,

        .create_vi = sd_create_vi,
        .check_left = sd_check_left,
        .check_right = sd_check_right,
        .part_size = sd_part_size,
        .unit_num = sd_unit_num,
        .print_vi = sd_print_vi
};

//////////////////////////////////////////////////////////////////////////////
// direct item functions
//
static int direct_bytes_number(struct item_head *ih, int block_size)
{
        return ih_item_len(ih);
}

// FIXME: this should probably switch to indirect as well
static void direct_decrement_key(struct cpu_key *key)
{
        cpu_key_k_offset_dec(key);
        if (cpu_key_k_offset(key) == 0)
                set_cpu_key_k_type(key, TYPE_STAT_DATA);
}

static int direct_is_left_mergeable(struct reiserfs_key *key,
                                    unsigned long bsize)
{
        int version = le_key_version(key);
        return ((le_key_k_offset(version, key) & (bsize - 1)) != 1);
}

static void direct_print_item(struct item_head *ih, char *item)
{
        int j = 0;

//    return;
        printk("\"");
        while (j < ih_item_len(ih))
                printk("%c", item[j++]);
        printk("\"\n");
}

static void direct_check_item(struct item_head *ih, char *item)
{
        // FIXME: type something here!
}

static int direct_create_vi(struct virtual_node *vn,
                            struct virtual_item *vi,
                            int is_affected, int insert_size)
{
        vi->vi_index = TYPE_DIRECT;
        //vi->vi_type |= VI_TYPE_DIRECT;
        return 0;
}

static int direct_check_left(struct virtual_item *vi, int free,
                             int start_skip, int end_skip)
{
        int bytes;

        bytes = free - free % 8;
        return bytes ? : -1;
}

static int direct_check_right(struct virtual_item *vi, int free)
{
        return direct_check_left(vi, free, 0, 0);
}

static int direct_part_size(struct virtual_item *vi, int first, int count)
{
        return count;
}

static int direct_unit_num(struct virtual_item *vi)
{
        return vi->vi_item_len - IH_SIZE;
}

static void direct_print_vi(struct virtual_item *vi)
{
        reiserfs_warning(NULL, "reiserfs-16101",
                         "DIRECT, index %d, type 0x%x, %h",
                         vi->vi_index, vi->vi_type, vi->vi_ih);
}

static struct item_operations direct_ops = {
        .bytes_number = direct_bytes_number,
        .decrement_key = direct_decrement_key,
        .is_left_mergeable = direct_is_left_mergeable,
        .print_item = direct_print_item,
        .check_item = direct_check_item,

        .create_vi = direct_create_vi,
        .check_left = direct_check_left,
        .check_right = direct_check_right,
        .part_size = direct_part_size,
        .unit_num = direct_unit_num,
        .print_vi = direct_print_vi
};

//////////////////////////////////////////////////////////////////////////////
// indirect item functions
//

static int indirect_bytes_number(struct item_head *ih, int block_size)
{
        return ih_item_len(ih) / UNFM_P_SIZE * block_size;      //- get_ih_free_space (ih);
}

// decrease offset, if it becomes 0, change type to stat data
static void indirect_decrement_key(struct cpu_key *key)
{
        cpu_key_k_offset_dec(key);
        if (cpu_key_k_offset(key) == 0)
                set_cpu_key_k_type(key, TYPE_STAT_DATA);
}

// if it is not first item of the body, then it is mergeable
static int indirect_is_left_mergeable(struct reiserfs_key *key,
                                      unsigned long bsize)
{
        int version = le_key_version(key);
        return (le_key_k_offset(version, key) != 1);
}

// printing of indirect item
static void start_new_sequence(__u32 * start, int *len, __u32 new)
{
        *start = new;
        *len = 1;
}

static int sequence_finished(__u32 start, int *len, __u32 new)
{
        if (start == INT_MAX)
                return 1;

        if (start == 0 && new == 0) {
                (*len)++;
                return 0;
        }
        if (start != 0 && (start + *len) == new) {
                (*len)++;
                return 0;
        }
        return 1;
}

static void print_sequence(__u32 start, int len)
{
        if (start == INT_MAX)
                return;

        if (len == 1)
                printk(" %d", start);
        else
                printk(" %d(%d)", start, len);
}

static void indirect_print_item(struct item_head *ih, char *item)
{
        int j;
        __le32 *unp;
        __u32 prev = INT_MAX;
        int num = 0;

        unp = (__le32 *) item;

        if (ih_item_len(ih) % UNFM_P_SIZE)
                reiserfs_warning(NULL, "reiserfs-16102", "invalid item len");

        printk("%d pointers\n[ ", (int)I_UNFM_NUM(ih));
        for (j = 0; j < I_UNFM_NUM(ih); j++) {
                if (sequence_finished(prev, &num, get_block_num(unp, j))) {
                        print_sequence(prev, num);
                        start_new_sequence(&prev, &num, get_block_num(unp, j));
                }
        }
        print_sequence(prev, num);
        printk("]\n");
}

static void indirect_check_item(struct item_head *ih, char *item)
{
        // FIXME: type something here!
}

static int indirect_create_vi(struct virtual_node *vn,
                              struct virtual_item *vi,
                              int is_affected, int insert_size)
{
        vi->vi_index = TYPE_INDIRECT;
        //vi->vi_type |= VI_TYPE_INDIRECT;
        return 0;
}

static int indirect_check_left(struct virtual_item *vi, int free,
                               int start_skip, int end_skip)
{
        int bytes;

        bytes = free - free % UNFM_P_SIZE;
        return bytes ? : -1;
}

static int indirect_check_right(struct virtual_item *vi, int free)
{
        return indirect_check_left(vi, free, 0, 0);
}

// return size in bytes of 'units' units. If first == 0 - calculate from the head (left), otherwise - from tail (right)
static int indirect_part_size(struct virtual_item *vi, int first, int units)
{
        // unit of indirect item is byte (yet)
        return units;
}

static int indirect_unit_num(struct virtual_item *vi)
{
        // unit of indirect item is byte (yet)
        return vi->vi_item_len - IH_SIZE;
}

static void indirect_print_vi(struct virtual_item *vi)
{
        reiserfs_warning(NULL, "reiserfs-16103",
                         "INDIRECT, index %d, type 0x%x, %h",
                         vi->vi_index, vi->vi_type, vi->vi_ih);
}

static struct item_operations indirect_ops = {
        .bytes_number = indirect_bytes_number,
        .decrement_key = indirect_decrement_key,
        .is_left_mergeable = indirect_is_left_mergeable,
        .print_item = indirect_print_item,
        .check_item = indirect_check_item,

        .create_vi = indirect_create_vi,
        .check_left = indirect_check_left,
        .check_right = indirect_check_right,
        .part_size = indirect_part_size,
        .unit_num = indirect_unit_num,
        .print_vi = indirect_print_vi
};

//////////////////////////////////////////////////////////////////////////////
// direntry functions
//

static int direntry_bytes_number(struct item_head *ih, int block_size)
{
        reiserfs_warning(NULL, "vs-16090",
                         "bytes number is asked for direntry");
        return 0;
}

static void direntry_decrement_key(struct cpu_key *key)
{
        cpu_key_k_offset_dec(key);
        if (cpu_key_k_offset(key) == 0)
                set_cpu_key_k_type(key, TYPE_STAT_DATA);
}

static int direntry_is_left_mergeable(struct reiserfs_key *key,
                                      unsigned long bsize)
{
        if (le32_to_cpu(key->u.k_offset_v1.k_offset) == DOT_OFFSET)
                return 0;
        return 1;

}

static void direntry_print_item(struct item_head *ih, char *item)
{
        int i;
        int namelen;
        struct reiserfs_de_head *deh;
        char *name;
        static char namebuf[80];

        printk("\n # %-15s%-30s%-15s%-15s%-15s\n", "Name",
               "Key of pointed object", "Hash", "Gen number", "Status");

        deh = (struct reiserfs_de_head *)item;

        for (i = 0; i < I_ENTRY_COUNT(ih); i++, deh++) {
                namelen =
                    (i ? (deh_location(deh - 1)) : ih_item_len(ih)) -
                    deh_location(deh);
                name = item + deh_location(deh);
                if (name[namelen - 1] == 0)
                        namelen = strlen(name);
                namebuf[0] = '"';
                if (namelen > sizeof(namebuf) - 3) {
                        strncpy(namebuf + 1, name, sizeof(namebuf) - 3);
                        namebuf[sizeof(namebuf) - 2] = '"';
                        namebuf[sizeof(namebuf) - 1] = 0;
                } else {
                        memcpy(namebuf + 1, name, namelen);
                        namebuf[namelen + 1] = '"';
                        namebuf[namelen + 2] = 0;
                }

                printk("%d:  %-15s%-15d%-15d%-15Ld%-15Ld(%s)\n",
                       i, namebuf,
                       deh_dir_id(deh), deh_objectid(deh),
                       GET_HASH_VALUE(deh_offset(deh)),
                       GET_GENERATION_NUMBER((deh_offset(deh))),
                       (de_hidden(deh)) ? "HIDDEN" : "VISIBLE");
        }
}

static void direntry_check_item(struct item_head *ih, char *item)
{
        int i;
        struct reiserfs_de_head *deh;

        // FIXME: type something here!
        deh = (struct reiserfs_de_head *)item;
        for (i = 0; i < I_ENTRY_COUNT(ih); i++, deh++) {
                ;
        }
}

#define DIRENTRY_VI_FIRST_DIRENTRY_ITEM 1

/*
 * function returns old entry number in directory item in real node
 * using new entry number in virtual item in virtual node */
static inline int old_entry_num(int is_affected, int virtual_entry_num,
                                int pos_in_item, int mode)
{
        if (mode == M_INSERT || mode == M_DELETE)
                return virtual_entry_num;

        if (!is_affected)
                /* cut or paste is applied to another item */
                return virtual_entry_num;

        if (virtual_entry_num < pos_in_item)
                return virtual_entry_num;

        if (mode == M_CUT)
                return virtual_entry_num + 1;

        RFALSE(mode != M_PASTE || virtual_entry_num == 0,
               "vs-8015: old_entry_num: mode must be M_PASTE (mode = \'%c\'",
               mode);

        return virtual_entry_num - 1;
}

/* Create an array of sizes of directory entries for virtual
   item. Return space used by an item. FIXME: no control over
   consuming of space used by this item handler */
static int direntry_create_vi(struct virtual_node *vn,
                              struct virtual_item *vi,
                              int is_affected, int insert_size)
{
        struct direntry_uarea *dir_u = vi->vi_uarea;
        int i, j;
        int size = sizeof(struct direntry_uarea);
        struct reiserfs_de_head *deh;

        vi->vi_index = TYPE_DIRENTRY;

        BUG_ON(!(vi->vi_ih) || !vi->vi_item);

        dir_u->flags = 0;
        if (le_ih_k_offset(vi->vi_ih) == DOT_OFFSET)
                dir_u->flags |= DIRENTRY_VI_FIRST_DIRENTRY_ITEM;

        deh = (struct reiserfs_de_head *)(vi->vi_item);

        /* virtual directory item have this amount of entry after */
        dir_u->entry_count = ih_entry_count(vi->vi_ih) +
            ((is_affected) ? ((vn->vn_mode == M_CUT) ? -1 :
                              (vn->vn_mode == M_PASTE ? 1 : 0)) : 0);

        for (i = 0; i < dir_u->entry_count; i++) {
                j = old_entry_num(is_affected, i, vn->vn_pos_in_item,
                                  vn->vn_mode);
                dir_u->entry_sizes[i] =
                    (j ? deh_location(&(deh[j - 1])) : ih_item_len(vi->vi_ih)) -
                    deh_location(&(deh[j])) + DEH_SIZE;
        }

        size += (dir_u->entry_count * sizeof(short));

        /* set size of pasted entry */
        if (is_affected && vn->vn_mode == M_PASTE)
                dir_u->entry_sizes[vn->vn_pos_in_item] = insert_size;

#ifdef CONFIG_REISERFS_CHECK
        /* compare total size of entries with item length */
        {
                int k, l;

                l = 0;
                for (k = 0; k < dir_u->entry_count; k++)
                        l += dir_u->entry_sizes[k];

                if (l + IH_SIZE != vi->vi_item_len +
                    ((is_affected
                      && (vn->vn_mode == M_PASTE
                          || vn->vn_mode == M_CUT)) ? insert_size : 0)) {
                        reiserfs_panic(NULL, "vs-8025", "(mode==%c, "
                                       "insert_size==%d), invalid length of "
                                       "directory item",
                                       vn->vn_mode, insert_size);
                }
        }
#endif

        return size;

}

//
// return number of entries which may fit into specified amount of
// free space, or -1 if free space is not enough even for 1 entry
//
static int direntry_check_left(struct virtual_item *vi, int free,
                               int start_skip, int end_skip)
{
        int i;
        int entries = 0;
        struct direntry_uarea *dir_u = vi->vi_uarea;

        for (i = start_skip; i < dir_u->entry_count - end_skip; i++) {
                if (dir_u->entry_sizes[i] > free)
                        /* i-th entry doesn't fit into the remaining free space */
                        break;

                free -= dir_u->entry_sizes[i];
                entries++;
        }

        if (entries == dir_u->entry_count) {
                reiserfs_panic(NULL, "item_ops-1",
                               "free space %d, entry_count %d", free,
                               dir_u->entry_count);
        }

        /* "." and ".." can not be separated from each other */
        if (start_skip == 0 && (dir_u->flags & DIRENTRY_VI_FIRST_DIRENTRY_ITEM)
            && entries < 2)
                entries = 0;

        return entries ? : -1;
}

static int direntry_check_right(struct virtual_item *vi, int free)
{
        int i;
        int entries = 0;
        struct direntry_uarea *dir_u = vi->vi_uarea;

        for (i = dir_u->entry_count - 1; i >= 0; i--) {
                if (dir_u->entry_sizes[i] > free)
                        /* i-th entry doesn't fit into the remaining free space */
                        break;

                free -= dir_u->entry_sizes[i];
                entries++;
        }
        BUG_ON(entries == dir_u->entry_count);

        /* "." and ".." can not be separated from each other */
        if ((dir_u->flags & DIRENTRY_VI_FIRST_DIRENTRY_ITEM)
            && entries > dir_u->entry_count - 2)
                entries = dir_u->entry_count - 2;

        return entries ? : -1;
}

/* sum of entry sizes between from-th and to-th entries including both edges */
static int direntry_part_size(struct virtual_item *vi, int first, int count)
{
        int i, retval;
        int from, to;
        struct direntry_uarea *dir_u = vi->vi_uarea;

        retval = 0;
        if (first == 0)
                from = 0;
        else
                from = dir_u->entry_count - count;
        to = from + count - 1;

        for (i = from; i <= to; i++)
                retval += dir_u->entry_sizes[i];

        return retval;
}

static int direntry_unit_num(struct virtual_item *vi)
{
        struct direntry_uarea *dir_u = vi->vi_uarea;

        return dir_u->entry_count;
}

static void direntry_print_vi(struct virtual_item *vi)
{
        int i;
        struct direntry_uarea *dir_u = vi->vi_uarea;

        reiserfs_warning(NULL, "reiserfs-16104",
                         "DIRENTRY, index %d, type 0x%x, %h, flags 0x%x",
                         vi->vi_index, vi->vi_type, vi->vi_ih, dir_u->flags);
        printk("%d entries: ", dir_u->entry_count);
        for (i = 0; i < dir_u->entry_count; i++)
                printk("%d ", dir_u->entry_sizes[i]);
        printk("\n");
}

static struct item_operations direntry_ops = {
        .bytes_number = direntry_bytes_number,
        .decrement_key = direntry_decrement_key,
        .is_left_mergeable = direntry_is_left_mergeable,
        .print_item = direntry_print_item,
        .check_item = direntry_check_item,

        .create_vi = direntry_create_vi,
        .check_left = direntry_check_left,
        .check_right = direntry_check_right,
        .part_size = direntry_part_size,
        .unit_num = direntry_unit_num,
        .print_vi = direntry_print_vi
};

//////////////////////////////////////////////////////////////////////////////
// Error catching functions to catch errors caused by incorrect item types.
//
static int errcatch_bytes_number(struct item_head *ih, int block_size)
{
        reiserfs_warning(NULL, "green-16001",
                         "Invalid item type observed, run fsck ASAP");
        return 0;
}

static void errcatch_decrement_key(struct cpu_key *key)
{
        reiserfs_warning(NULL, "green-16002",
                         "Invalid item type observed, run fsck ASAP");
}

static int errcatch_is_left_mergeable(struct reiserfs_key *key,
                                      unsigned long bsize)
{
        reiserfs_warning(NULL, "green-16003",
                         "Invalid item type observed, run fsck ASAP");
        return 0;
}

static void errcatch_print_item(struct item_head *ih, char *item)
{
        reiserfs_warning(NULL, "green-16004",
                         "Invalid item type observed, run fsck ASAP");
}

static void errcatch_check_item(struct item_head *ih, char *item)
{
        reiserfs_warning(NULL, "green-16005",
                         "Invalid item type observed, run fsck ASAP");
}

static int errcatch_create_vi(struct virtual_node *vn,
                              struct virtual_item *vi,
                              int is_affected, int insert_size)
{
        reiserfs_warning(NULL, "green-16006",
                         "Invalid item type observed, run fsck ASAP");
        return 0;               // We might return -1 here as well, but it won't help as create_virtual_node() from where
        // this operation is called from is of return type void.
}

static int errcatch_check_left(struct virtual_item *vi, int free,
                               int start_skip, int end_skip)
{
        reiserfs_warning(NULL, "green-16007",
                         "Invalid item type observed, run fsck ASAP");
        return -1;
}

static int errcatch_check_right(struct virtual_item *vi, int free)
{
        reiserfs_warning(NULL, "green-16008",
                         "Invalid item type observed, run fsck ASAP");
        return -1;
}

static int errcatch_part_size(struct virtual_item *vi, int first, int count)
{
        reiserfs_warning(NULL, "green-16009",
                         "Invalid item type observed, run fsck ASAP");
        return 0;
}

static int errcatch_unit_num(struct virtual_item *vi)
{
        reiserfs_warning(NULL, "green-16010",
                         "Invalid item type observed, run fsck ASAP");
        return 0;
}

static void errcatch_print_vi(struct virtual_item *vi)
{
        reiserfs_warning(NULL, "green-16011",
                         "Invalid item type observed, run fsck ASAP");
}

static struct item_operations errcatch_ops = {
        errcatch_bytes_number,
        errcatch_decrement_key,
        errcatch_is_left_mergeable,
        errcatch_print_item,
        errcatch_check_item,

        errcatch_create_vi,
        errcatch_check_left,
        errcatch_check_right,
        errcatch_part_size,
        errcatch_unit_num,
        errcatch_print_vi
};

//////////////////////////////////////////////////////////////////////////////
//
//
#if ! (TYPE_STAT_DATA == 0 && TYPE_INDIRECT == 1 && TYPE_DIRECT == 2 && TYPE_DIRENTRY == 3)
#error Item types must use disk-format assigned values.
#endif

struct item_operations *item_ops[TYPE_ANY + 1] = {
        &stat_data_ops,
        &indirect_ops,
        &direct_ops,
        &direntry_ops,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        &errcatch_ops           /* This is to catch errors with invalid type (15th entry for TYPE_ANY) */
};