/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include "clone.h"

#include "git2/clone.h"

#include "git2/remote.h"

#include "git2/revparse.h"

#include "git2/branch.h"

#include "git2/config.h"

#include "git2/checkout.h"

#include "git2/commit.h"

#include "git2/tree.h"

#include "remote.h"

#include "futils.h"

#include "refs.h"

#include "fs_path.h"

#include "repository.h"

#include "odb.h"

static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link);

static int create_branch(

  git_reference **branch,

  git_repository *repo,

  const git_oid *target,

  const char *name,

  const char *log_message)

{

  git_commit *head_obj = NULL;

  git_reference *branch_ref = NULL;

  git_str refname = GIT_STR_INIT;

  int error;

  /* Find the target commit */

  if ((error = git_commit_lookup(&head_obj, repo, target)) < 0)

    return error;

  /* Create the new branch */

  if ((error = git_str_printf(&refname, GIT_REFS_HEADS_DIR "%s", name)) < 0)

    return error;

  error = git_reference_create(&branch_ref, repo, git_str_cstr(&refname), target, 0, log_message);

  git_str_dispose(&refname);

  git_commit_free(head_obj);

  if (!error)

    *branch = branch_ref;

  else

    git_reference_free(branch_ref);

  return error;

}

static int setup_tracking_config(

  git_repository *repo,

  const char *branch_name,

  const char *remote_name,

  const char *merge_target)

{

  git_config *cfg;

  git_str remote_key = GIT_STR_INIT, merge_key = GIT_STR_INIT;

  int error = -1;

  if (git_repository_config__weakptr(&cfg, repo) < 0)

    return -1;

  if (git_str_printf(&remote_key, "branch.%s.remote", branch_name) < 0)

    goto cleanup;

  if (git_str_printf(&merge_key, "branch.%s.merge", branch_name) < 0)

    goto cleanup;

  if (git_config_set_string(cfg, git_str_cstr(&remote_key), remote_name) < 0)

    goto cleanup;

  if (git_config_set_string(cfg, git_str_cstr(&merge_key), merge_target) < 0)

    goto cleanup;

  error = 0;

cleanup:

  git_str_dispose(&remote_key);

  git_str_dispose(&merge_key);

  return error;

}

static int create_tracking_branch(

  git_reference **branch,

  git_repository *repo,

  const git_oid *target,

  const char *branch_name,

  const char *log_message)

{

  int error;

  if ((error = create_branch(branch, repo, target, branch_name, log_message)) < 0)

    return error;

  return setup_tracking_config(

    repo,

    branch_name,

    GIT_REMOTE_ORIGIN,

    git_reference_name(*branch));

}

static int update_head_to_new_branch(

  git_repository *repo,

  const git_oid *target,

  const char *name,

  const char *reflog_message)

{

  git_reference *tracking_branch = NULL;

  int error;

  if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR))

    name += strlen(GIT_REFS_HEADS_DIR);

  error = create_tracking_branch(&tracking_branch, repo, target, name,

      reflog_message);

  if (!error)

    error = git_repository_set_head(

      repo, git_reference_name(tracking_branch));

  git_reference_free(tracking_branch);

  /* if it already existed, then the user's refspec created it for us, ignore it' */

  if (error == GIT_EEXISTS)

    error = 0;

  return error;

}

static int update_head_to_default(git_repository *repo)

{

  git_str initialbranch = GIT_STR_INIT;

  const char *branch_name;

  int error = 0;

  if ((error = git_repository_initialbranch(&initialbranch, repo)) < 0)

    goto done;

  if (git__prefixcmp(initialbranch.ptr, GIT_REFS_HEADS_DIR) != 0) {

    git_error_set(GIT_ERROR_INVALID, "invalid initial branch '%s'", initialbranch.ptr);

    error = -1;

    goto done;

  }

  branch_name = initialbranch.ptr + strlen(GIT_REFS_HEADS_DIR);

  error = setup_tracking_config(repo, branch_name, GIT_REMOTE_ORIGIN,

    initialbranch.ptr);

done:

  git_str_dispose(&initialbranch);

  return error;

}

static int update_remote_head(

  git_repository *repo,

  git_remote *remote,

  git_str *target,

  const char *reflog_message)

{

  git_refspec *refspec;

  git_reference *remote_head = NULL;

  git_str remote_head_name = GIT_STR_INIT;

  git_str remote_branch_name = GIT_STR_INIT;

  int error;

  /* Determine the remote tracking ref name from the local branch */

  refspec = git_remote__matching_refspec(remote, git_str_cstr(target));

  if (refspec == NULL) {

    git_error_set(GIT_ERROR_NET, "the remote's default branch does not fit the refspec configuration");

    error = GIT_EINVALIDSPEC;

    goto cleanup;

  }

  if ((error = git_refspec__transform(

    &remote_branch_name,

    refspec,

    git_str_cstr(target))) < 0)

    goto cleanup;

  if ((error = git_str_printf(&remote_head_name,

    "%s%s/%s",

    GIT_REFS_REMOTES_DIR,

    git_remote_name(remote),

    GIT_HEAD_FILE)) < 0)

    goto cleanup;

  error = git_reference_symbolic_create(

    &remote_head,

    repo,

    git_str_cstr(&remote_head_name),

    git_str_cstr(&remote_branch_name),

    true,

    reflog_message);

cleanup:

  git_reference_free(remote_head);

  git_str_dispose(&remote_branch_name);

  git_str_dispose(&remote_head_name);

  return error;

}

static int update_head_to_remote(

    git_repository *repo,

    git_remote *remote,

    const char *reflog_message)

{

  int error = 0;

  size_t refs_len;

  const git_remote_head *remote_head, **refs;

  const git_oid *remote_head_id;

  git_str branch = GIT_STR_INIT;

  if ((error = git_remote_ls(&refs, &refs_len, remote)) < 0)

    return error;

  /* We cloned an empty repository or one with an unborn HEAD */

  if (refs_len == 0 || strcmp(refs[0]->name, GIT_HEAD_FILE))

    return update_head_to_default(repo);

  /* We know we have HEAD, let's see where it points */

  remote_head = refs[0];

  GIT_ASSERT(remote_head);

  remote_head_id = &remote_head->oid;

  error = git_remote__default_branch(&branch, remote);

  if (error == GIT_ENOTFOUND) {

    error = git_repository_set_head_detached(

      repo, remote_head_id);

    goto cleanup;

  }

  if ((error = update_remote_head(repo, remote, &branch, reflog_message)) < 0)

    goto cleanup;

  error = update_head_to_new_branch(

    repo,

    remote_head_id,

    git_str_cstr(&branch),

    reflog_message);

cleanup:

  git_str_dispose(&branch);

  return error;

}

static int update_head_to_branch(

    git_repository *repo,

    git_remote *remote,

    const char *branch,

    const char *reflog_message)

{

  int retcode;

  git_str remote_branch_name = GIT_STR_INIT;

  git_reference *remote_ref = NULL;

  git_str default_branch = GIT_STR_INIT;

  GIT_ASSERT_ARG(remote);

  GIT_ASSERT_ARG(branch);

  if ((retcode = git_str_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",

    git_remote_name(remote), branch)) < 0 )

    goto cleanup;

  if ((retcode = git_reference_lookup(&remote_ref, repo, git_str_cstr(&remote_branch_name))) < 0)

    goto cleanup;

  if ((retcode = update_head_to_new_branch(repo, git_reference_target(remote_ref), branch,

      reflog_message)) < 0)

    goto cleanup;

  retcode = git_remote__default_branch(&default_branch, remote);

  if (retcode == GIT_ENOTFOUND)

    retcode = 0;

  else if (retcode)

    goto cleanup;

  if (!git_remote__matching_refspec(remote, git_str_cstr(&default_branch)))

    goto cleanup;

  retcode = update_remote_head(repo, remote, &default_branch, reflog_message);

cleanup:

  git_reference_free(remote_ref);

  git_str_dispose(&remote_branch_name);

  git_str_dispose(&default_branch);

  return retcode;

}

static int default_repository_create(git_repository **out, const char *path, int bare, void *payload)

{

  GIT_UNUSED(payload);

  return git_repository_init(out, path, bare);

}

static int default_remote_create(

    git_remote **out,

    git_repository *repo,

    const char *name,

    const char *url,

    void *payload)

{

  GIT_UNUSED(payload);

  return git_remote_create(out, repo, name, url);

}

/*

 * submodules?

 */

static int create_and_configure_origin(

    git_remote **out,

    git_repository *repo,

    const char *url,

    const git_clone_options *options)

{

  int error;

  git_remote *origin = NULL;

  char buf[GIT_PATH_MAX];

  git_remote_create_cb remote_create = options->remote_cb;

  void *payload = options->remote_cb_payload;

  /* If the path exists and is a dir, the url should be the absolute path */

  if (git_fs_path_root(url) < 0 && git_fs_path_exists(url) && git_fs_path_isdir(url)) {

    if (p_realpath(url, buf) == NULL)

      return -1;

    url = buf;

  }

  if (!remote_create) {

    remote_create = default_remote_create;

    payload = NULL;

  }

  if ((error = remote_create(&origin, repo, "origin", url, payload)) < 0)

    goto on_error;

  *out = origin;

  return 0;

on_error:

  git_remote_free(origin);

  return error;

}

static bool should_checkout(

  git_repository *repo,

  bool is_bare,

  const git_checkout_options *opts)

{

  if (is_bare)

    return false;

  if (!opts)

    return false;

  if (opts->checkout_strategy == GIT_CHECKOUT_NONE)

    return false;

  return !git_repository_head_unborn(repo);

}

static int checkout_branch(git_repository *repo, git_remote *remote, const git_checkout_options *co_opts, const char *branch, const char *reflog_message)

{

  int error;

  if (branch)

    error = update_head_to_branch(repo, remote, branch, reflog_message);

  /* Point HEAD to the same ref as the remote's head */

  else

    error = update_head_to_remote(repo, remote, reflog_message);

  if (!error && should_checkout(repo, git_repository_is_bare(repo), co_opts))

    error = git_checkout_head(repo, co_opts);

  return error;

}

static int clone_into(

  git_repository *repo,

  git_remote *_remote,

  const git_fetch_options *opts,

  const git_checkout_options *co_opts,

  const char *branch)

{

  int error;

  git_str reflog_message = GIT_STR_INIT;

  git_remote_connect_options connect_opts = GIT_REMOTE_CONNECT_OPTIONS_INIT;

  git_fetch_options fetch_opts;

  git_remote *remote;

  git_oid_t oid_type;

  GIT_ASSERT_ARG(repo);

  GIT_ASSERT_ARG(_remote);

  if (!git_repository_is_empty(repo)) {

    git_error_set(GIT_ERROR_INVALID, "the repository is not empty");

    return -1;

  }

  if ((error = git_remote_dup(&remote, _remote)) < 0)

    return error;

  memcpy(&fetch_opts, opts, sizeof(git_fetch_options));

  fetch_opts.update_flags = ~GIT_REMOTE_UPDATE_FETCHHEAD;

  if (!opts->depth)

    fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;

  if ((error = git_remote_connect_options__from_fetch_opts(&connect_opts, remote, &fetch_opts)) < 0)

    goto cleanup;

  git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));

  /*

   * Connect to the server so that we can identify the remote

   * object format.

   */

  if ((error = git_remote_connect_ext(remote, GIT_DIRECTION_FETCH,

      &connect_opts)) < 0)

    goto cleanup;

  if ((error = git_remote_oid_type(&oid_type, remote)) < 0 ||

      (error = git_repository__set_objectformat(repo, oid_type)) < 0)

    goto cleanup;

  if ((error = git_remote_fetch(remote, NULL, &fetch_opts, git_str_cstr(&reflog_message))) != 0)

    goto cleanup;

  error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));

cleanup:

  git_remote_free(remote);

  git_remote_connect_options_dispose(&connect_opts);

  git_str_dispose(&reflog_message);

  return error;

}

int git_clone__should_clone_local(const char *url_or_path, git_clone_local_t local)

{

  git_str fromurl = GIT_STR_INIT;

  const char *path = url_or_path;

  bool is_url, is_local;

  if (local == GIT_CLONE_NO_LOCAL)

    return 0;

  if ((is_url = git_fs_path_is_local_file_url(url_or_path)) != 0) {

    if (git_fs_path_fromurl(&fromurl, url_or_path) < 0) {

      is_local = -1;

      goto done;

    }

    path = fromurl.ptr;

  }

  is_local = (!is_url || local != GIT_CLONE_LOCAL_AUTO) &&

    git_fs_path_isdir(path);

done:

  git_str_dispose(&fromurl);

  return is_local;

}

static int git__clone(

  git_repository **out,

  const char *url,

  const char *local_path,

  const git_clone_options *_options,

  int use_existing)

{

  int error = 0;

  git_repository *repo = NULL;

  git_remote *origin;

  git_clone_options options = GIT_CLONE_OPTIONS_INIT;

  uint32_t rmdir_flags = GIT_RMDIR_REMOVE_FILES;

  git_repository_create_cb repository_cb;

  GIT_ASSERT_ARG(out);

  GIT_ASSERT_ARG(url);

  GIT_ASSERT_ARG(local_path);

  if (_options)

    memcpy(&options, _options, sizeof(git_clone_options));

  GIT_ERROR_CHECK_VERSION(&options, GIT_CLONE_OPTIONS_VERSION, "git_clone_options");

  /* Only clone to a new directory or an empty directory */

  if (git_fs_path_exists(local_path) && !use_existing && !git_fs_path_is_empty_dir(local_path)) {

    git_error_set(GIT_ERROR_INVALID,

      "'%s' exists and is not an empty directory", local_path);

    return GIT_EEXISTS;

  }

  /* Only remove the root directory on failure if we create it */

  if (git_fs_path_exists(local_path))

    rmdir_flags |= GIT_RMDIR_SKIP_ROOT;

  if (options.repository_cb)

    repository_cb = options.repository_cb;

  else

    repository_cb = default_repository_create;

  if ((error = repository_cb(&repo, local_path, options.bare, options.repository_cb_payload)) < 0)

    return error;

  if (!(error = create_and_configure_origin(&origin, repo, url, &options))) {

    int clone_local = git_clone__should_clone_local(url, options.local);

    int link = options.local != GIT_CLONE_LOCAL_NO_LINKS;

    if (clone_local == 1)

      error = clone_local_into(

        repo, origin, &options.fetch_opts, &options.checkout_opts,

        options.checkout_branch, link);

    else if (clone_local == 0)

      error = clone_into(

        repo, origin, &options.fetch_opts, &options.checkout_opts,

        options.checkout_branch);

    else

      error = -1;

    git_remote_free(origin);

  }

  if (error != 0) {

    git_error *last_error;

    git_error_save(&last_error);

    git_repository_free(repo);

    repo = NULL;

    (void)git_futils_rmdir_r(local_path, NULL, rmdir_flags);

    git_error_restore(last_error);

  }

  *out = repo;

  return error;

}

int git_clone(

  git_repository **out,

  const char *url,

  const char *local_path,

  const git_clone_options *_options)

{

  return git__clone(out, url, local_path, _options, 0);

}

int git_clone__submodule(

  git_repository **out,

  const char *url,

  const char *local_path,

  const git_clone_options *_options)

{

  return git__clone(out, url, local_path, _options, 1);

}

int git_clone_options_init(git_clone_options *opts, unsigned int version)

{

  GIT_INIT_STRUCTURE_FROM_TEMPLATE(

    opts, version, git_clone_options, GIT_CLONE_OPTIONS_INIT);

  return 0;

}

#ifndef GIT_DEPRECATE_HARD

int git_clone_init_options(git_clone_options *opts, unsigned int version)

{

  return git_clone_options_init(opts, version);

}

#endif

static bool can_link(const char *src, const char *dst, int link)

{

#ifdef GIT_WIN32

  GIT_UNUSED(src);

  GIT_UNUSED(dst);

  GIT_UNUSED(link);

  return false;

#else

  struct stat st_src, st_dst;

  if (!link)

    return false;

  if (p_stat(src, &st_src) < 0)

    return false;

  if (p_stat(dst, &st_dst) < 0)

    return false;

  return st_src.st_dev == st_dst.st_dev;

#endif

}

static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link)

{

  int error, flags;

  git_repository *src;

  git_str src_odb = GIT_STR_INIT, dst_odb = GIT_STR_INIT, src_path = GIT_STR_INIT;

  git_str reflog_message = GIT_STR_INIT;

  GIT_ASSERT_ARG(repo);

  GIT_ASSERT_ARG(remote);

  if (!git_repository_is_empty(repo)) {

    git_error_set(GIT_ERROR_INVALID, "the repository is not empty");

    return -1;

  }

  /*

   * Let's figure out what path we should use for the source

   * repo, if it's not rooted, the path should be relative to

   * the repository's worktree/gitdir.

   */

  if ((error = git_fs_path_from_url_or_path(&src_path, git_remote_url(remote))) < 0)

    return error;

  /* Copy .git/objects/ from the source to the target */

  if ((error = git_repository_open(&src, git_str_cstr(&src_path))) < 0) {

    git_str_dispose(&src_path);

    return error;

  }

  if (git_repository__item_path(&src_odb, src, GIT_REPOSITORY_ITEM_OBJECTS) < 0 ||

      git_repository__item_path(&dst_odb, repo, GIT_REPOSITORY_ITEM_OBJECTS) < 0) {

    error = -1;

    goto cleanup;

  }

  flags = 0;

  if (can_link(git_repository_path(src), git_repository_path(repo), link))

    flags |= GIT_CPDIR_LINK_FILES;

  error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),

        flags, GIT_OBJECT_DIR_MODE);

  /*

   * can_link() doesn't catch all variations, so if we hit an

   * error and did want to link, let's try again without trying

   * to link.

   */

  if (error < 0 && link) {

    flags &= ~GIT_CPDIR_LINK_FILES;

    error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),

          flags, GIT_OBJECT_DIR_MODE);

  }

  if (error < 0)

    goto cleanup;

  git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));

  if ((error = git_remote_fetch(remote, NULL, fetch_opts, git_str_cstr(&reflog_message))) != 0)

    goto cleanup;

  error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));

cleanup:

  git_str_dispose(&reflog_message);

  git_str_dispose(&src_path);

  git_str_dispose(&src_odb);

  git_str_dispose(&dst_odb);

  git_repository_free(src);

  return error;

}