#include "builtin.h"

#include "config.h"

#include "gettext.h"

#include "hex.h"

#include "refs/refs-internal.h"

#include "object-name.h"

#include "object-store-ll.h"

#include "object.h"

#include "string-list.h"

#include "parse-options.h"

static const char * const show_ref_usage[] = {

  N_("git show-ref [--head] [-d | --dereference]\n"

     "             [-s | --hash[=<n>]] [--abbrev[=<n>]] [--branches] [--tags]\n"

     "             [--] [<pattern>...]"),

  N_("git show-ref --verify [-q | --quiet] [-d | --dereference]\n"

     "             [-s | --hash[=<n>]] [--abbrev[=<n>]]\n"

     "             [--] [<ref>...]"),

  N_("git show-ref --exclude-existing[=<pattern>]"),

  N_("git show-ref --exists <ref>"),

  NULL

};

struct show_one_options {

  int quiet;

  int hash_only;

  int abbrev;

  int deref_tags;

};

static void show_one(const struct show_one_options *opts,

         const char *refname, const struct object_id *oid)

{

  const char *hex;

  struct object_id peeled;

  if (!repo_has_object_file(the_repository, oid))

    die("git show-ref: bad ref %s (%s)", refname,

        oid_to_hex(oid));

  if (opts->quiet)

    return;

  hex = repo_find_unique_abbrev(the_repository, oid, opts->abbrev);

  if (opts->hash_only)

    printf("%s\n", hex);

  else

    printf("%s %s\n", hex, refname);

  if (!opts->deref_tags)

    return;

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

    hex = repo_find_unique_abbrev(the_repository, &peeled, opts->abbrev);

    printf("%s %s^{}\n", hex, refname);

  }

}

struct show_ref_data {

  const struct show_one_options *show_one_opts;

  const char **patterns;

  int found_match;

  int show_head;

};

static int show_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid,

        int flag UNUSED, void *cbdata)

{

  struct show_ref_data *data = cbdata;

  if (data->show_head && !strcmp(refname, "HEAD"))

    goto match;

  if (data->patterns) {

    int reflen = strlen(refname);

    const char **p = data->patterns, *m;

    while ((m = *p++) != NULL) {

      int len = strlen(m);

      if (len > reflen)

        continue;

      if (memcmp(m, refname + reflen - len, len))

        continue;

      if (len == reflen)

        goto match;

      if (refname[reflen - len - 1] == '/')

        goto match;

    }

    return 0;

  }

match:

  data->found_match++;

  show_one(data->show_one_opts, refname, oid);

  return 0;

}

static int add_existing(const char *refname,

      const char *referent UNUSED,

      const struct object_id *oid UNUSED,

      int flag UNUSED, void *cbdata)

{

  struct string_list *list = (struct string_list *)cbdata;

  string_list_insert(list, refname);

  return 0;

}

struct exclude_existing_options {

  /*

   * We need an explicit `enabled` field because it is perfectly valid

   * for `pattern` to be `NULL` even if `--exclude-existing` was given.

   */

  int enabled;

  const char *pattern;

};

/*

 * read "^(?:<anything>\s)?<refname>(?:\^\{\})?$" from the standard input,

 * and

 * (1) strip "^{}" at the end of line if any;

 * (2) ignore if match is provided and does not head-match refname;

 * (3) warn if refname is not a well-formed refname and skip;

 * (4) ignore if refname is a ref that exists in the local repository;

 * (5) otherwise output the line.

 */

static int cmd_show_ref__exclude_existing(const struct exclude_existing_options *opts)

{

  struct string_list existing_refs = STRING_LIST_INIT_DUP;

  char buf[1024];

  int patternlen = opts->pattern ? strlen(opts->pattern) : 0;

  refs_for_each_ref(get_main_ref_store(the_repository), add_existing,

        &existing_refs);

  while (fgets(buf, sizeof(buf), stdin)) {

    char *ref;

    int len = strlen(buf);

    if (len > 0 && buf[len - 1] == '\n')

      buf[--len] = '\0';

    if (3 <= len && !strcmp(buf + len - 3, "^{}")) {

      len -= 3;

      buf[len] = '\0';

    }

    for (ref = buf + len; buf < ref; ref--)

      if (isspace(ref[-1]))

        break;

    if (opts->pattern) {

      int reflen = buf + len - ref;

      if (reflen < patternlen)

        continue;

      if (strncmp(ref, opts->pattern, patternlen))

        continue;

    }

    if (check_refname_format(ref, 0)) {

      warning("ref '%s' ignored", ref);

      continue;

    }

    if (!string_list_has_string(&existing_refs, ref)) {

      printf("%s\n", buf);

    }

  }

  string_list_clear(&existing_refs, 0);

  return 0;

}

static int cmd_show_ref__verify(const struct show_one_options *show_one_opts,

        const char **refs)

{

  if (!refs || !*refs)

    die("--verify requires a reference");

  while (*refs) {

    struct object_id oid;

    if ((starts_with(*refs, "refs/") || refname_is_safe(*refs)) &&

        !refs_read_ref(get_main_ref_store(the_repository), *refs, &oid)) {

      show_one(show_one_opts, *refs, &oid);

    }

    else if (!show_one_opts->quiet)

      die("'%s' - not a valid ref", *refs);

    else

      return 1;

    refs++;

  }

  return 0;

}

struct patterns_options {

  int show_head;

  int branches_only;

  int tags_only;

};

static int cmd_show_ref__patterns(const struct patterns_options *opts,

          const struct show_one_options *show_one_opts,

          const char **patterns)

{

  struct show_ref_data show_ref_data = {

    .show_one_opts = show_one_opts,

    .show_head = opts->show_head,

  };

  if (patterns && *patterns)

    show_ref_data.patterns = patterns;

  if (opts->show_head)

    refs_head_ref(get_main_ref_store(the_repository), show_ref,

            &show_ref_data);

  if (opts->branches_only || opts->tags_only) {

    if (opts->branches_only)

      refs_for_each_fullref_in(get_main_ref_store(the_repository),

             "refs/heads/", NULL,

             show_ref, &show_ref_data);

    if (opts->tags_only)

      refs_for_each_fullref_in(get_main_ref_store(the_repository),

             "refs/tags/", NULL, show_ref,

             &show_ref_data);

  } else {

    refs_for_each_ref(get_main_ref_store(the_repository),

          show_ref, &show_ref_data);

  }

  if (!show_ref_data.found_match)

    return 1;

  return 0;

}

static int cmd_show_ref__exists(const char **refs)

{

  struct strbuf unused_referent = STRBUF_INIT;

  struct object_id unused_oid;

  unsigned int unused_type;

  int failure_errno = 0;

  const char *ref;

  int ret = 0;

  if (!refs || !*refs)

    die("--exists requires a reference");

  ref = *refs++;

  if (*refs)

    die("--exists requires exactly one reference");

  if (refs_read_raw_ref(get_main_ref_store(the_repository), ref,

            &unused_oid, &unused_referent, &unused_type,

            &failure_errno)) {

    if (failure_errno == ENOENT || failure_errno == EISDIR) {

      error(_("reference does not exist"));

      ret = 2;

    } else {

      errno = failure_errno;

      error_errno(_("failed to look up reference"));

      ret = 1;

    }

    goto out;

  }

out:

  strbuf_release(&unused_referent);

  return ret;

}

static int hash_callback(const struct option *opt, const char *arg, int unset)

{

  struct show_one_options *opts = opt->value;

  struct option abbrev_opt = *opt;

  opts->hash_only = 1;

  /* Use full length SHA1 if no argument */

  if (!arg)

    return 0;

  abbrev_opt.value = &opts->abbrev;

  return parse_opt_abbrev_cb(&abbrev_opt, arg, unset);

}

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

             int unset)

{

  struct exclude_existing_options *opts = opt->value;

  BUG_ON_OPT_NEG(unset);

  opts->enabled = 1;

  opts->pattern = arg;

  return 0;

}

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

{

  struct exclude_existing_options exclude_existing_opts = {0};

  struct patterns_options patterns_opts = {0};

  struct show_one_options show_one_opts = {0};

  int verify = 0, exists = 0;

  const struct option show_ref_options[] = {

    OPT_BOOL(0, "tags", &patterns_opts.tags_only, N_("only show tags (can be combined with --branches)")),

    OPT_BOOL(0, "branches", &patterns_opts.branches_only, N_("only show branches (can be combined with --tags)")),

    OPT_HIDDEN_BOOL(0, "heads", &patterns_opts.branches_only,

        N_("deprecated synonym for --branches")),

    OPT_BOOL(0, "exists", &exists, N_("check for reference existence without resolving")),

    OPT_BOOL(0, "verify", &verify, N_("stricter reference checking, "

          "requires exact ref path")),

    OPT_HIDDEN_BOOL('h', NULL, &patterns_opts.show_head,

        N_("show the HEAD reference, even if it would be filtered out")),

    OPT_BOOL(0, "head", &patterns_opts.show_head,

      N_("show the HEAD reference, even if it would be filtered out")),

    OPT_BOOL('d', "dereference", &show_one_opts.deref_tags,

          N_("dereference tags into object IDs")),

    OPT_CALLBACK_F('s', "hash", &show_one_opts, N_("n"),

             N_("only show SHA1 hash using <n> digits"),

             PARSE_OPT_OPTARG, &hash_callback),

    OPT__ABBREV(&show_one_opts.abbrev),

    OPT__QUIET(&show_one_opts.quiet,

         N_("do not print results to stdout (useful with --verify)")),

    OPT_CALLBACK_F(0, "exclude-existing", &exclude_existing_opts,

             N_("pattern"), N_("show refs from stdin that aren't in local repository"),

             PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback),

    OPT_END()

  };

  git_config(git_default_config, NULL);

  argc = parse_options(argc, argv, prefix, show_ref_options,

           show_ref_usage, 0);

  die_for_incompatible_opt3(exclude_existing_opts.enabled, "--exclude-existing",

          verify, "--verify",

          exists, "--exists");

  if (exclude_existing_opts.enabled)

    return cmd_show_ref__exclude_existing(&exclude_existing_opts);

  else if (verify)

    return cmd_show_ref__verify(&show_one_opts, argv);

  else if (exists)

    return cmd_show_ref__exists(argv);

  else

    return cmd_show_ref__patterns(&patterns_opts, &show_one_opts, argv);

}