#include "git-compat-util.h"

#include "config.h"

#include "gettext.h"

#include "hex.h"

#include "odb.h"

#include "parse.h"

#include "run-command.h"

#include "sigchain.h"

#include "connected.h"

#include "transport.h"

#include "packfile.h"

#include "promisor-remote.h"

static int promised_object_cb(const struct object_id *oid UNUSED,

            struct object_info *oi UNUSED,

            void *payload)

{

  bool *found = payload;

  *found = true;

  return 1;

}

/*

 * For partial clones, we don't want to have to do a regular connectivity check

 * because we have to enumerate and exclude all promisor objects (slow), and

 * then the connectivity check itself becomes a no-op because in a partial

 * clone every object is a promisor object. Instead, just make sure we

 * received, in a promisor packfile, the objects pointed to by each wanted ref.

 *

 * Before checking for promisor packs, be sure we have the latest pack-files

 * loaded into memory.

 *

 * Returns 1 when all object IDs have been found in promisor packs, in which

 * case we're fully connected and thus done. Returns 0 when we have found

 * objects in non-promisor packs, in which case we'll have to fall back to the

 * rev-list-based connectivity checks. Returns a negative error code on error.

 */

static int check_connected_promisor(struct repository *repo,

            oid_iterate_fn fn,

            void *cb_data,

            const struct object_id **oid)

{

  struct odb_for_each_object_options opts = {

    .flags = ODB_FOR_EACH_OBJECT_PROMISOR_ONLY,

    .prefix_hex_len = repo->hash_algo->hexsz,

  };

  int err;

  odb_reprepare(repo->objects);

  do {

    bool found = false;

    opts.prefix = *oid;

    err = odb_for_each_object_ext(repo->objects, NULL,

                promised_object_cb, &found, &opts);

    if (err < 0)

      return err;

    /*

     * We have found an object that is not part of a promisor pack,

     * and thus we cannot skip the full connectivity check.

     */

    if (!found)

      return 0;

  } while ((*oid = fn(cb_data)) != NULL);

  return 1;

}

/*

 * Fills in the --connectivity-check mode to pass to rev-list.

 */

static void connectivity_check_mode(struct repository *repo,

            struct check_connected_options *opt,

            struct strbuf *mode)

{

  const char *algorithm = NULL, *cutoff;

  unsigned long max_commits;

  /*

   * Deepening fetches do not have the usual boundary of

   * existing references, so use the full check for them.

   */

  if (opt->is_deepening_fetch) {

    strbuf_addstr(mode, "full");

    return;

  }

  if (repo_config_get_string_tmp(repo,

               "transfer.connectivitycheck",

               &algorithm))

    algorithm = "full";

  if (!strcasecmp(algorithm, "full"))

    strbuf_addstr(mode, "full");

  else if (!strcasecmp(algorithm, "incremental"))

    strbuf_addstr(mode, "incremental");

  else if (!strcasecmp(algorithm, "auto"))

    strbuf_addstr(mode, "auto");

  else if (skip_iprefix(algorithm, "auto=", &cutoff) &&

     git_parse_ulong(cutoff, &max_commits))

    strbuf_addf(mode, "auto=%lu", max_commits);

  else {

    warning(_("unknown transfer.connectivityCheck algorithm '%s', "

        "using 'full'"), algorithm);

    strbuf_addstr(mode, "full");

  }

}

/*

 * If we feed all the commits we want to verify to this command

 *

 *  $ git rev-list --objects --stdin --not --all

 *

 * and if it does not error out, that means everything reachable from

 * these commits locally exists and is connected to our existing refs.

 * Note that this does _not_ validate the individual objects.

 *

 * Returns 0 if everything is connected, non-zero otherwise.

 */

int check_connected(struct repository *repo,

        oid_iterate_fn fn, void *cb_data,

        struct check_connected_options *opt)

{

  struct child_process rev_list = CHILD_PROCESS_INIT;

  FILE *rev_list_in;

  struct check_connected_options defaults = CHECK_CONNECTED_INIT;

  struct strbuf mode = STRBUF_INIT;

  const struct object_id *oid;

  int err = 0;

  struct packed_git *new_pack = NULL;

  struct transport *transport;

  size_t base_len;

  if (!opt)

    opt = &defaults;

  transport = opt->transport;

  oid = fn(cb_data);

  if (!oid) {

    if (opt->err_fd)

      close(opt->err_fd);

    return err;

  }

  if (repo_has_promisor_remote(repo)) {

    err = check_connected_promisor(repo, fn, cb_data, &oid);

    if (err) {

      if (opt->err_fd)

        close(opt->err_fd);

      if (err > 0)

        err = 0;

      return err;

    }

  }

  if (opt->shallow_file) {

    strvec_push(&rev_list.args, "--shallow-file");

    strvec_push(&rev_list.args, opt->shallow_file);

  }

  strvec_push(&rev_list.args,"rev-list");

  strvec_push(&rev_list.args, "--objects");

  strvec_push(&rev_list.args, "--stdin");

  if (repo_has_promisor_remote(repo))

    strvec_push(&rev_list.args, "--exclude-promisor-objects");

  /* define where the traversal should stop */

  strvec_push(&rev_list.args, "--not");

  if (!opt->is_deepening_fetch) {

    if (opt->exclude_hidden_refs_section)

      strvec_pushf(&rev_list.args, "--exclude-hidden=%s",

             opt->exclude_hidden_refs_section);

    strvec_push(&rev_list.args, "--all");

  }

  strvec_push(&rev_list.args, "--alternate-refs");

  strvec_push(&rev_list.args, "--quiet");

  if (opt->progress)

    strvec_pushf(&rev_list.args, "--progress=%s",

           _("Checking connectivity"));

  connectivity_check_mode(repo, opt, &mode);

  strvec_pushf(&rev_list.args, "--connectivity-check=%s", mode.buf);

  strbuf_release(&mode);

  rev_list.git_cmd = 1;

  if (opt->env)

    strvec_pushv(&rev_list.env, opt->env);

  rev_list.in = -1;

  rev_list.no_stdout = 1;

  if (opt->err_fd)

    rev_list.err = opt->err_fd;

  else

    rev_list.no_stderr = opt->quiet;

  if (start_command(&rev_list))

    return error(_("Could not run 'git rev-list'"));

  sigchain_push(SIGPIPE, SIG_IGN);

  rev_list_in = xfdopen(rev_list.in, "w");

  if (transport && transport->smart_options &&

      transport->smart_options->self_contained_and_connected &&

      transport->pack_lockfiles.nr == 1 &&

      strip_suffix(transport->pack_lockfiles.items[0].string,

       ".keep", &base_len)) {

    struct strbuf idx_file = STRBUF_INIT;

    strbuf_add(&idx_file, transport->pack_lockfiles.items[0].string,

         base_len);

    strbuf_addstr(&idx_file, ".idx");

    new_pack = add_packed_git(repo, idx_file.buf,

            idx_file.len, 1);

    strbuf_release(&idx_file);

  }

  do {

    /*

     * If index-pack already checked that:

     * - there are no dangling pointers in the new pack

     * - the pack is self contained

     * Then if the updated ref is in the new pack, then we

     * are sure the ref is good and not sending it to

     * rev-list for verification.

     */

    if (new_pack && find_pack_entry_one(oid, new_pack))

      continue;

    if (fprintf(rev_list_in, "%s\n", oid_to_hex(oid)) < 0)

      break;

  } while ((oid = fn(cb_data)) != NULL);

  if (ferror(rev_list_in) || fflush(rev_list_in)) {

    if (errno != EPIPE && errno != EINVAL)

      error_errno(_("failed write to rev-list"));

    err = -1;

  }

  if (fclose(rev_list_in))

    err = error_errno(_("failed to close rev-list's stdin"));

  sigchain_pop(SIGPIPE);

  if (new_pack) {

    close_pack(new_pack);

    free(new_pack);

  }

  return finish_command(&rev_list) || err;

}