#include "builtin.h"

#include "config.h"

#include "environment.h"

#include "gettext.h"

#include "hex.h"

#include "lockfile.h"

#include "commit.h"

#include "tag.h"

#include "refs.h"

#include "object-name.h"

#include "parse-options.h"

#include "read-cache-ll.h"

#include "revision.h"

#include "diff.h"

#include "hashmap.h"

#include "setup.h"

#include "strvec.h"

#include "run-command.h"

#include "object-store-ll.h"

#include "list-objects.h"

#include "commit-slab.h"

#include "wildmatch.h"

#define MAX_TAGS  (FLAG_BITS - 1)

#define DEFAULT_CANDIDATES 10

define_commit_slab(commit_names, struct commit_name *);

static const char * const describe_usage[] = {

  N_("git describe [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]"),

  N_("git describe [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]"),

  N_("git describe <blob>"),

  NULL

};

static int debug; /* Display lots of verbose info */

static int all; /* Any valid ref can be used */

static int tags;  /* Allow lightweight tags */

static int longformat;

static int first_parent;

static int abbrev = -1; /* unspecified */

static int max_candidates = DEFAULT_CANDIDATES;

static struct hashmap names;

static int have_util;

static struct string_list patterns = STRING_LIST_INIT_NODUP;

static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;

static int always;

static const char *suffix, *dirty, *broken;

static struct commit_names commit_names;

/* diff-index command arguments to check if working tree is dirty. */

static const char *diff_index_args[] = {

  "diff-index", "--quiet", "HEAD", "--", NULL

};

static const char *update_index_args[] = {

  "update-index", "--unmerged", "-q", "--refresh", NULL

};

struct commit_name {

  struct hashmap_entry entry;

  struct object_id peeled;

  struct tag *tag;

  unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */

  unsigned name_checked:1;

  unsigned misnamed:1;

  struct object_id oid;

  char *path;

};

static const char *prio_names[] = {

  N_("head"), N_("lightweight"), N_("annotated"),

};

static int commit_name_neq(const void *cmp_data UNUSED,

         const struct hashmap_entry *eptr,

         const struct hashmap_entry *entry_or_key,

         const void *peeled)

{

  const struct commit_name *cn1, *cn2;

  cn1 = container_of(eptr, const struct commit_name, entry);

  cn2 = container_of(entry_or_key, const struct commit_name, entry);

  return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);

}

static inline struct commit_name *find_commit_name(const struct object_id *peeled)

{

  return hashmap_get_entry_from_hash(&names, oidhash(peeled), peeled,

            struct commit_name, entry);

}

static int replace_name(struct commit_name *e,

             int prio,

             const struct object_id *oid,

             struct tag **tag)

{

  if (!e || e->prio < prio)

    return 1;

  if (e->prio == 2 && prio == 2) {

    /* Multiple annotated tags point to the same commit.

     * Select one to keep based upon their tagger date.

     */

    struct tag *t;

    if (!e->tag) {

      t = lookup_tag(the_repository, &e->oid);

      if (!t || parse_tag(t))

        return 1;

      e->tag = t;

    }

    t = lookup_tag(the_repository, oid);

    if (!t || parse_tag(t))

      return 0;

    *tag = t;

    if (e->tag->date < t->date)

      return 1;

  }

  return 0;

}

static void add_to_known_names(const char *path,

             const struct object_id *peeled,

             int prio,

             const struct object_id *oid)

{

  struct commit_name *e = find_commit_name(peeled);

  struct tag *tag = NULL;

  if (replace_name(e, prio, oid, &tag)) {

    if (!e) {

      e = xmalloc(sizeof(struct commit_name));

      oidcpy(&e->peeled, peeled);

      hashmap_entry_init(&e->entry, oidhash(peeled));

      hashmap_add(&names, &e->entry);

      e->path = NULL;

    }

    e->tag = tag;

    e->prio = prio;

    e->name_checked = 0;

    e->misnamed = 0;

    oidcpy(&e->oid, oid);

    free(e->path);

    e->path = xstrdup(path);

  }

}

static int get_name(const char *path, const char *referent UNUSED, const struct object_id *oid,

        int flag UNUSED, void *cb_data UNUSED)

{

  int is_tag = 0;

  struct object_id peeled;

  int is_annotated, prio;

  const char *path_to_match = NULL;

  if (skip_prefix(path, "refs/tags/", &path_to_match)) {

    is_tag = 1;

  } else if (all) {

    if ((exclude_patterns.nr || patterns.nr) &&

        !skip_prefix(path, "refs/heads/", &path_to_match) &&

        !skip_prefix(path, "refs/remotes/", &path_to_match)) {

      /* Only accept reference of known type if there are match/exclude patterns */

      return 0;

    }

  } else {

    /* Reject anything outside refs/tags/ unless --all */

    return 0;

  }

  /*

   * If we're given exclude patterns, first exclude any tag which match

   * any of the exclude pattern.

   */

  if (exclude_patterns.nr) {

    struct string_list_item *item;

    for_each_string_list_item(item, &exclude_patterns) {

      if (!wildmatch(item->string, path_to_match, 0))

        return 0;

    }

  }

  /*

   * If we're given patterns, accept only tags which match at least one

   * pattern.

   */

  if (patterns.nr) {

    int found = 0;

    struct string_list_item *item;

    for_each_string_list_item(item, &patterns) {

      if (!wildmatch(item->string, path_to_match, 0)) {

        found = 1;

        break;

      }

    }

    if (!found)

      return 0;

  }

  /* Is it annotated? */

  if (!peel_iterated_oid(the_repository, oid, &peeled)) {

    is_annotated = !oideq(oid, &peeled);

  } else {

    oidcpy(&peeled, oid);

    is_annotated = 0;

  }

  /*

   * By default, we only use annotated tags, but with --tags

   * we fall back to lightweight ones (even without --tags,

   * we still remember lightweight ones, only to give hints

   * in an error message).  --all allows any refs to be used.

   */

  if (is_annotated)

    prio = 2;

  else if (is_tag)

    prio = 1;

  else

    prio = 0;

  add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);

  return 0;

}

struct possible_tag {

  struct commit_name *name;

  int depth;

  int found_order;

  unsigned flag_within;

};

static int compare_pt(const void *a_, const void *b_)

{

  struct possible_tag *a = (struct possible_tag *)a_;

  struct possible_tag *b = (struct possible_tag *)b_;

  if (a->depth != b->depth)

    return a->depth - b->depth;

  if (a->found_order != b->found_order)

    return a->found_order - b->found_order;

  return 0;

}

static unsigned long finish_depth_computation(

  struct commit_list **list,

  struct possible_tag *best)

{

  unsigned long seen_commits = 0;

  while (*list) {

    struct commit *c = pop_commit(list);

    struct commit_list *parents = c->parents;

    seen_commits++;

    if (c->object.flags & best->flag_within) {

      struct commit_list *a = *list;

      while (a) {

        struct commit *i = a->item;

        if (!(i->object.flags & best->flag_within))

          break;

        a = a->next;

      }

      if (!a)

        break;

    } else

      best->depth++;

    while (parents) {

      struct commit *p = parents->item;

      repo_parse_commit(the_repository, p);

      if (!(p->object.flags & SEEN))

        commit_list_insert_by_date(p, list);

      p->object.flags |= c->object.flags;

      parents = parents->next;

    }

  }

  return seen_commits;

}

static void append_name(struct commit_name *n, struct strbuf *dst)

{

  if (n->prio == 2 && !n->tag) {

    n->tag = lookup_tag(the_repository, &n->oid);

    if (!n->tag || parse_tag(n->tag))

      die(_("annotated tag %s not available"), n->path);

  }

  if (n->tag && !n->name_checked) {

    if (strcmp(n->tag->tag, all ? n->path + 5 : n->path)) {

      warning(_("tag '%s' is externally known as '%s'"),

        n->path, n->tag->tag);

      n->misnamed = 1;

    }

    n->name_checked = 1;

  }

  if (n->tag) {

    if (all)

      strbuf_addstr(dst, "tags/");

    strbuf_addstr(dst, n->tag->tag);

  } else {

    strbuf_addstr(dst, n->path);

  }

}

static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)

{

  strbuf_addf(dst, "-%d-g%s", depth,

        repo_find_unique_abbrev(the_repository, oid, abbrev));

}

static void describe_commit(struct object_id *oid, struct strbuf *dst)

{

  struct commit *cmit, *gave_up_on = NULL;

  struct commit_list *list;

  struct commit_name *n;

  struct possible_tag all_matches[MAX_TAGS];

  unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;

  unsigned long seen_commits = 0;

  unsigned int unannotated_cnt = 0;

  cmit = lookup_commit_reference(the_repository, oid);

  n = find_commit_name(&cmit->object.oid);

  if (n && (tags || all || n->prio == 2)) {

    /*

     * Exact match to an existing ref.

     */

    append_name(n, dst);

    if (n->misnamed || longformat)

      append_suffix(0, n->tag ? get_tagged_oid(n->tag) : oid, dst);

    if (suffix)

      strbuf_addstr(dst, suffix);

    return;

  }

  if (!max_candidates)

    die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));

  if (debug)

    fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));

  if (!have_util) {

    struct hashmap_iter iter;

    struct commit *c;

    struct commit_name *n;

    init_commit_names(&commit_names);

    hashmap_for_each_entry(&names, &iter, n,

          entry /* member name */) {

      c = lookup_commit_reference_gently(the_repository,

                 &n->peeled, 1);

      if (c)

        *commit_names_at(&commit_names, c) = n;

    }

    have_util = 1;

  }

  list = NULL;

  cmit->object.flags = SEEN;

  commit_list_insert(cmit, &list);

  while (list) {

    struct commit *c = pop_commit(&list);

    struct commit_list *parents = c->parents;

    struct commit_name **slot;

    seen_commits++;

    slot = commit_names_peek(&commit_names, c);

    n = slot ? *slot : NULL;

    if (n) {

      if (!tags && !all && n->prio < 2) {

        unannotated_cnt++;

      } else if (match_cnt < max_candidates) {

        struct possible_tag *t = &all_matches[match_cnt++];

        t->name = n;

        t->depth = seen_commits - 1;

        t->flag_within = 1u << match_cnt;

        t->found_order = match_cnt;

        c->object.flags |= t->flag_within;

        if (n->prio == 2)

          annotated_cnt++;

      }

      else {

        gave_up_on = c;

        break;

      }

    }

    for (cur_match = 0; cur_match < match_cnt; cur_match++) {

      struct possible_tag *t = &all_matches[cur_match];

      if (!(c->object.flags & t->flag_within))

        t->depth++;

    }

    /* Stop if last remaining path already covered by best candidate(s) */

    if (annotated_cnt && !list) {

      int best_depth = INT_MAX;

      unsigned best_within = 0;

      for (cur_match = 0; cur_match < match_cnt; cur_match++) {

        struct possible_tag *t = &all_matches[cur_match];

        if (t->depth < best_depth) {

          best_depth = t->depth;

          best_within = t->flag_within;

        } else if (t->depth == best_depth) {

          best_within |= t->flag_within;

        }

      }

      if ((c->object.flags & best_within) == best_within) {

        if (debug)

          fprintf(stderr, _("finished search at %s\n"),

            oid_to_hex(&c->object.oid));

        break;

      }

    }

    while (parents) {

      struct commit *p = parents->item;

      repo_parse_commit(the_repository, p);

      if (!(p->object.flags & SEEN))

        commit_list_insert_by_date(p, &list);

      p->object.flags |= c->object.flags;

      parents = parents->next;

      if (first_parent)

        break;

    }

  }

  if (!match_cnt) {

    struct object_id *cmit_oid = &cmit->object.oid;

    if (always) {

      strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);

      if (suffix)

        strbuf_addstr(dst, suffix);

      return;

    }

    if (unannotated_cnt)

      die(_("No annotated tags can describe '%s'.\n"

          "However, there were unannotated tags: try --tags."),

          oid_to_hex(cmit_oid));

    else

      die(_("No tags can describe '%s'.\n"

          "Try --always, or create some tags."),

          oid_to_hex(cmit_oid));

  }

  QSORT(all_matches, match_cnt, compare_pt);

  if (gave_up_on) {

    commit_list_insert_by_date(gave_up_on, &list);

    seen_commits--;

  }

  seen_commits += finish_depth_computation(&list, &all_matches[0]);

  free_commit_list(list);

  if (debug) {

    static int label_width = -1;

    if (label_width < 0) {

      int i, w;

      for (i = 0; i < ARRAY_SIZE(prio_names); i++) {

        w = strlen(_(prio_names[i]));

        if (label_width < w)

          label_width = w;

      }

    }

    for (cur_match = 0; cur_match < match_cnt; cur_match++) {

      struct possible_tag *t = &all_matches[cur_match];

      fprintf(stderr, " %-*s %8d %s\n",

        label_width, _(prio_names[t->name->prio]),

        t->depth, t->name->path);

    }

    fprintf(stderr, _("traversed %lu commits\n"), seen_commits);

    if (gave_up_on) {

      fprintf(stderr,

        _("more than %i tags found; listed %i most recent\n"

        "gave up search at %s\n"),

        max_candidates, max_candidates,

        oid_to_hex(&gave_up_on->object.oid));

    }

  }

  append_name(all_matches[0].name, dst);

  if (all_matches[0].name->misnamed || abbrev)

    append_suffix(all_matches[0].depth, &cmit->object.oid, dst);

  if (suffix)

    strbuf_addstr(dst, suffix);

}

struct process_commit_data {

  struct object_id current_commit;

  struct object_id looking_for;

  struct strbuf *dst;

  struct rev_info *revs;

};

static void process_commit(struct commit *commit, void *data)

{

  struct process_commit_data *pcd = data;

  pcd->current_commit = commit->object.oid;

}

static void process_object(struct object *obj, const char *path, void *data)

{

  struct process_commit_data *pcd = data;

  if (oideq(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {

    reset_revision_walk();

    describe_commit(&pcd->current_commit, pcd->dst);

    strbuf_addf(pcd->dst, ":%s", path);

    free_commit_list(pcd->revs->commits);

    pcd->revs->commits = NULL;

  }

}

static void describe_blob(struct object_id oid, struct strbuf *dst)

{

  struct rev_info revs;

  struct strvec args = STRVEC_INIT;

  struct process_commit_data pcd = { *null_oid(), oid, dst, &revs};

  strvec_pushl(&args, "internal: The first arg is not parsed",

         "--objects", "--in-commit-order", "--reverse", "HEAD",

         NULL);

  repo_init_revisions(the_repository, &revs, NULL);

  if (setup_revisions(args.nr, args.v, &revs, NULL) > 1)

    BUG("setup_revisions could not handle all args?");

  if (prepare_revision_walk(&revs))

    die("revision walk setup failed");

  traverse_commit_list(&revs, process_commit, process_object, &pcd);

  reset_revision_walk();

  release_revisions(&revs);

  strvec_clear(&args);

}

static void describe(const char *arg, int last_one)

{

  struct object_id oid;

  struct commit *cmit;

  struct strbuf sb = STRBUF_INIT;

  if (debug)

    fprintf(stderr, _("describe %s\n"), arg);

  if (repo_get_oid(the_repository, arg, &oid))

    die(_("Not a valid object name %s"), arg);

  cmit = lookup_commit_reference_gently(the_repository, &oid, 1);

  if (cmit)

    describe_commit(&oid, &sb);

  else if (oid_object_info(the_repository, &oid, NULL) == OBJ_BLOB)

    describe_blob(oid, &sb);

  else

    die(_("%s is neither a commit nor blob"), arg);

  puts(sb.buf);

  if (!last_one)

    clear_commit_marks(cmit, -1);

  strbuf_release(&sb);

}

static int option_parse_exact_match(const struct option *opt, const char *arg,

            int unset)

{

  int *val = opt->value;

  BUG_ON_OPT_ARG(arg);

  *val = unset ? DEFAULT_CANDIDATES : 0;

  return 0;

}

int cmd_describe(int argc, const char **argv, const char *prefix)

{

  int contains = 0;

  struct option options[] = {

    OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),

    OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),

    OPT_BOOL(0, "all",        &all, N_("use any ref")),

    OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),

    OPT_BOOL(0, "long",       &longformat, N_("always use long format")),

    OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),

    OPT__ABBREV(&abbrev),

    OPT_CALLBACK_F(0, "exact-match", &max_candidates, NULL,

             N_("only output exact matches"),

             PARSE_OPT_NOARG, option_parse_exact_match),

    OPT_INTEGER(0, "candidates", &max_candidates,

          N_("consider <n> most recent tags (default: 10)")),

    OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),

         N_("only consider tags matching <pattern>")),

    OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),

         N_("do not consider tags matching <pattern>")),

    OPT_BOOL(0, "always",        &always,

      N_("show abbreviated commit object as fallback")),

    {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),

      N_("append <mark> on dirty working tree (default: \"-dirty\")"),

      PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},

    {OPTION_STRING, 0, "broken",  &broken, N_("mark"),

      N_("append <mark> on broken working tree (default: \"-broken\")"),

      PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},

    OPT_END(),

  };

  git_config(git_default_config, NULL);

  argc = parse_options(argc, argv, prefix, options, describe_usage, 0);

  if (abbrev < 0)

    abbrev = DEFAULT_ABBREV;

  if (max_candidates < 0)

    max_candidates = 0;

  else if (max_candidates > MAX_TAGS)

    max_candidates = MAX_TAGS;

  save_commit_buffer = 0;

  if (longformat && abbrev == 0)

    die(_("options '%s' and '%s' cannot be used together"), "--long", "--abbrev=0");

  if (contains) {

    struct string_list_item *item;

    struct strvec args;

    const char **argv_copy;

    int ret;

    strvec_init(&args);

    strvec_pushl(&args, "name-rev",

           "--peel-tag", "--name-only", "--no-undefined",

           NULL);

    if (always)

      strvec_push(&args, "--always");

    if (!all) {

      strvec_push(&args, "--tags");

      for_each_string_list_item(item, &patterns)

        strvec_pushf(&args, "--refs=refs/tags/%s", item->string);

      for_each_string_list_item(item, &exclude_patterns)

        strvec_pushf(&args, "--exclude=refs/tags/%s", item->string);

    }

    if (argc)

      strvec_pushv(&args, argv);

    else

      strvec_push(&args, "HEAD");

    /*

     * `cmd_name_rev()` modifies the array, so we'd leak its

     * contained strings if we didn't do a copy here.

     */

    ALLOC_ARRAY(argv_copy, args.nr + 1);

    for (size_t i = 0; i < args.nr; i++)

      argv_copy[i] = args.v[i];

    argv_copy[args.nr] = NULL;

    ret = cmd_name_rev(args.nr, argv_copy, prefix);

    strvec_clear(&args);

    free(argv_copy);

    return ret;

  }

  hashmap_init(&names, commit_name_neq, NULL, 0);

  refs_for_each_rawref(get_main_ref_store(the_repository), get_name,

           NULL);

  if (!hashmap_get_size(&names) && !always)

    die(_("No names found, cannot describe anything."));

  if (argc == 0) {

    if (broken) {

      struct child_process cp = CHILD_PROCESS_INIT;

      strvec_pushv(&cp.args, update_index_args);

      cp.git_cmd = 1;

      cp.no_stdin = 1;

      cp.no_stdout = 1;

      run_command(&cp);

      child_process_init(&cp);

      strvec_pushv(&cp.args, diff_index_args);

      cp.git_cmd = 1;

      cp.no_stdin = 1;

      cp.no_stdout = 1;

      if (!dirty)

        dirty = "-dirty";

      switch (run_command(&cp)) {

      case 0:

        suffix = NULL;

        break;

      case 1:

        suffix = dirty;

        break;

      default:

        /* diff-index aborted abnormally */

        suffix = broken;

      }

    } else if (dirty) {

      struct lock_file index_lock = LOCK_INIT;

      struct rev_info revs;

      int fd;

      setup_work_tree();

      prepare_repo_settings(the_repository);

      the_repository->settings.command_requires_full_index = 0;

      repo_read_index(the_repository);

      refresh_index(the_repository->index, REFRESH_QUIET|REFRESH_UNMERGED,

              NULL, NULL, NULL);

      fd = repo_hold_locked_index(the_repository,

                &index_lock, 0);

      if (0 <= fd)

        repo_update_index_if_able(the_repository, &index_lock);

      repo_init_revisions(the_repository, &revs, prefix);

      if (setup_revisions(ARRAY_SIZE(diff_index_args) - 1,

              diff_index_args, &revs, NULL) != 1)

        BUG("malformed internal diff-index command line");

      run_diff_index(&revs, 0);

      if (!diff_result_code(&revs.diffopt))

        suffix = NULL;

      else

        suffix = dirty;

      release_revisions(&revs);

    }

    describe("HEAD", 1);

  } else if (dirty) {

    die(_("option '%s' and commit-ishes cannot be used together"), "--dirty");

  } else if (broken) {

    die(_("option '%s' and commit-ishes cannot be used together"), "--broken");

  } else {

    while (argc-- > 0)

      describe(*argv++, argc == 0);

  }

  return 0;

}