#include "git-compat-util.h"

#include "environment.h"

#include "string-list.h"

#include "mailmap.h"

#include "object-name.h"

#include "odb.h"

#include "setup.h"

#include "config.h"

struct mailmap_info {

  char *name;

  char *email;

};

struct mailmap_entry {

  /* name and email for the simple mail-only case */

  char *name;

  char *email;

  /* name and email for the complex mail and name matching case */

  struct string_list namemap;

};

static void free_mailmap_info(void *p, const char *s UNUSED)

{

  struct mailmap_info *mi = (struct mailmap_info *)p;

  free(mi->name);

  free(mi->email);

  free(mi);

}

static void free_mailmap_entry(void *p, const char *s UNUSED)

{

  struct mailmap_entry *me = (struct mailmap_entry *)p;

  free(me->name);

  free(me->email);

  me->namemap.strdup_strings = 1;

  string_list_clear_func(&me->namemap, free_mailmap_info);

  free(me);

}

/*

 * On some systems (e.g. MinGW 4.0), string.h has _only_ inline

 * definition of strcasecmp and no non-inline implementation is

 * supplied anywhere, which is, eh, "unusual"; we cannot take an

 * address of such a function to store it in namemap.cmp.  This is

 * here as a workaround---do not assign strcasecmp directly to

 * namemap.cmp until we know no systems that matter have such an

 * "unusual" string.h.

 */

static int namemap_cmp(const char *a, const char *b)

{

  return strcasecmp(a, b);

}

static void add_mapping(struct string_list *map,

      char *new_name, char *new_email,

      char *old_name, char *old_email)

{

  struct mailmap_entry *me;

  struct string_list_item *item;

  if (!old_email) {

    old_email = new_email;

    new_email = NULL;

  }

  item = string_list_insert(map, old_email);

  if (item->util) {

    me = (struct mailmap_entry *)item->util;

  } else {

    CALLOC_ARRAY(me, 1);

    me->namemap.strdup_strings = 1;

    me->namemap.cmp = namemap_cmp;

    item->util = me;

  }

  if (!old_name) {

    /* Replace current name and new email for simple entry */

    if (new_name) {

      free(me->name);

      me->name = xstrdup(new_name);

    }

    if (new_email) {

      free(me->email);

      me->email = xstrdup(new_email);

    }

  } else {

    struct mailmap_info *mi = xcalloc(1, sizeof(struct mailmap_info));

    mi->name = xstrdup_or_null(new_name);

    mi->email = xstrdup_or_null(new_email);

    string_list_insert(&me->namemap, old_name)->util = mi;

  }

}

static char *parse_name_and_email(char *buffer, char **name,

          char **email, int allow_empty_email)

{

  char *left, *right, *nstart, *nend;

  *name = *email = NULL;

  if (!(left = strchr(buffer, '<')))

    return NULL;

  if (!(right = strchr(left + 1, '>')))

    return NULL;

  if (!allow_empty_email && (left+1 == right))

    return NULL;

  /* remove whitespace from beginning and end of name */

  nstart = buffer;

  while (isspace(*nstart) && nstart < left)

    ++nstart;

  nend = left-1;

  while (nend > nstart && isspace(*nend))

    --nend;

  *name = (nstart <= nend ? nstart : NULL);

  *email = left+1;

  *(nend+1) = '\0';

  *right++ = '\0';

  return (*right == '\0' ? NULL : right);

}

static void read_mailmap_line(struct string_list *map, char *buffer)

{

  char *name1 = NULL, *email1 = NULL, *name2 = NULL, *email2 = NULL;

  if (buffer[0] == '#')

    return;

  if ((name2 = parse_name_and_email(buffer, &name1, &email1, 0)))

    parse_name_and_email(name2, &name2, &email2, 1);

  if (email1)

    add_mapping(map, name1, email1, name2, email2);

}

int read_mailmap_file(struct string_list *map, const char *filename,

          unsigned flags)

{

  char buffer[1024];

  FILE *f;

  int fd;

  if (!filename)

    return 0;

  if (flags & MAILMAP_NOFOLLOW)

    fd = open_nofollow(filename, O_RDONLY);

  else

    fd = open(filename, O_RDONLY);

  if (fd < 0) {

    if (errno == ENOENT)

      return 0;

    return error_errno("unable to open mailmap at %s", filename);

  }

  f = xfdopen(fd, "r");

  while (fgets(buffer, sizeof(buffer), f) != NULL)

    read_mailmap_line(map, buffer);

  fclose(f);

  return 0;

}

static void read_mailmap_string(struct string_list *map, char *buf)

{

  while (*buf) {

    char *end = strchrnul(buf, '\n');

    if (*end)

      *end++ = '\0';

    read_mailmap_line(map, buf);

    buf = end;

  }

}

int read_mailmap_blob(struct repository *repo, struct string_list *map,

          const char *name)

{

  struct object_id oid;

  char *buf;

  size_t size;

  enum object_type type;

  if (!name)

    return 0;

  if (repo_get_oid(repo, name, &oid) < 0)

    return 0;

  buf = odb_read_object(repo->objects, &oid, &type, &size);

  if (!buf)

    return error("unable to read mailmap object at %s", name);

  if (type != OBJ_BLOB) {

    free(buf);

    return error("mailmap is not a blob: %s", name);

  }

  read_mailmap_string(map, buf);

  free(buf);

  return 0;

}

int read_mailmap(struct repository *repo, struct string_list *map)

{

  int err = 0;

  char *mailmap_file = NULL, *mailmap_blob = NULL;

  repo_config_get_pathname(repo, "mailmap.file", &mailmap_file);

  repo_config_get_string(repo, "mailmap.blob", &mailmap_blob);

  map->strdup_strings = 1;

  map->cmp = namemap_cmp;

  if (!mailmap_blob && is_bare_repository(repo))

    mailmap_blob = xstrdup("HEAD:.mailmap");

  if (!startup_info->have_repository || !is_bare_repository(repo))

    err |= read_mailmap_file(map, ".mailmap",

           startup_info->have_repository ?

           MAILMAP_NOFOLLOW : 0);

  if (startup_info->have_repository)

    err |= read_mailmap_blob(repo, map, mailmap_blob);

  err |= read_mailmap_file(map, mailmap_file, 0);

  free(mailmap_file);

  free(mailmap_blob);

  return err;

}

void clear_mailmap(struct string_list *map)

{

  map->strdup_strings = 1;

  string_list_clear_func(map, free_mailmap_entry);

}

/*

 * Look for an entry in map that match string[0:len]; string[len]

 * does not have to be NUL (but it could be).

 */

static struct string_list_item *lookup_prefix(struct string_list *map,

                const char *string, size_t len)

{

  bool exact_match;

  size_t i = string_list_find_insert_index(map, string, &exact_match);

  if (exact_match) {

    if (!string[len])

      return &map->items[i];

    /*

     * that map entry matches exactly to the string, including

     * the cruft at the end beyond "len".  That is not a match

     * with string[0:len] that we are looking for.

     */

  } else if (!string[len]) {

    /*

     * asked with the whole string, and got nothing.  No

     * matching entry can exist in the map.

     */

    return NULL;

  }

  /*

   * i is at the exact match to an overlong key, or location the

   * overlong key would be inserted, which must come after the

   * real location of the key if one exists.

   */

  while (i-- && i < map->nr) {

    int cmp = strncasecmp(map->items[i].string, string, len);

    if (cmp < 0)

      /*

       * "i" points at a key definitely below the prefix;

       * the map does not have string[0:len] in it.

       */

      break;

    else if (!cmp && !map->items[i].string[len])

      /* found it */

      return &map->items[i];

    /*

     * otherwise, the string at "i" may be string[0:len]

     * followed by a string that sorts later than string[len:];

     * keep trying.

     */

  }

  return NULL;

}

int map_user(struct string_list *map,

       const char **email, size_t *emaillen,

       const char **name, size_t *namelen)

{

  struct string_list_item *item;

  struct mailmap_entry *me;

  item = lookup_prefix(map, *email, *emaillen);

  if (item) {

    me = (struct mailmap_entry *)item->util;

    if (me->namemap.nr) {

      /*

       * The item has multiple items, so we'll look up on

       * name too. If the name is not found, we choose the

       * simple entry.

       */

      struct string_list_item *subitem;

      subitem = lookup_prefix(&me->namemap, *name, *namelen);

      if (subitem)

        item = subitem;

    }

  }

  if (item) {

    struct mailmap_info *mi = (struct mailmap_info *)item->util;

    if (mi->name == NULL && mi->email == NULL)

      return 0;

    if (mi->email) {

        *email = mi->email;

        *emaillen = strlen(*email);

    }

    if (mi->name) {

        *name = mi->name;

        *namelen = strlen(*name);

    }

    return 1;

  }

  return 0;

}