/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"
#include "config.h"
#include "refs.h"
#include "builtin.h"
#include "exec-cmd.h"
#include "parse-options.h"

#ifndef DEFAULT_GIT_TEMPLATE_DIR
#define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
#endif

#ifdef NO_TRUSTABLE_FILEMODE
#define TEST_FILEMODE 0
#else
#define TEST_FILEMODE 1
#endif

static int init_is_bare_repository = 0;
static int init_shared_repository = -1;
static const char *init_db_template_dir;

static void copy_templates_1(struct strbuf *path, struct strbuf *template_path,
                             DIR *dir)
{
        size_t path_baselen = path->len;
        size_t template_baselen = template_path->len;
        struct dirent *de;

        /* Note: if ".git/hooks" file exists in the repository being
         * re-initialized, /etc/core-git/templates/hooks/update would
         * cause "git init" to fail here.  I think this is sane but
         * it means that the set of templates we ship by default, along
         * with the way the namespace under .git/ is organized, should
         * be really carefully chosen.
         */
        safe_create_dir(path->buf, 1);
        while ((de = readdir(dir)) != NULL) {
                struct stat st_git, st_template;
                int exists = 0;

                strbuf_setlen(path, path_baselen);
                strbuf_setlen(template_path, template_baselen);

                if (de->d_name[0] == '.')
                        continue;
                strbuf_addstr(path, de->d_name);
                strbuf_addstr(template_path, de->d_name);
                if (lstat(path->buf, &st_git)) {
                        if (errno != ENOENT)
                                die_errno(_("cannot stat '%s'"), path->buf);
                }
                else
                        exists = 1;

                if (lstat(template_path->buf, &st_template))
                        die_errno(_("cannot stat template '%s'"), template_path->buf);

                if (S_ISDIR(st_template.st_mode)) {
                        DIR *subdir = opendir(template_path->buf);
                        if (!subdir)
                                die_errno(_("cannot opendir '%s'"), template_path->buf);
                        strbuf_addch(path, '/');
                        strbuf_addch(template_path, '/');
                        copy_templates_1(path, template_path, subdir);
                        closedir(subdir);
                }
                else if (exists)
                        continue;
                else if (S_ISLNK(st_template.st_mode)) {
                        struct strbuf lnk = STRBUF_INIT;
                        if (strbuf_readlink(&lnk, template_path->buf,
                                            st_template.st_size) < 0)
                                die_errno(_("cannot readlink '%s'"), template_path->buf);
                        if (symlink(lnk.buf, path->buf))
                                die_errno(_("cannot symlink '%s' '%s'"),
                                          lnk.buf, path->buf);
                        strbuf_release(&lnk);
                }
                else if (S_ISREG(st_template.st_mode)) {
                        if (copy_file(path->buf, template_path->buf, st_template.st_mode))
                                die_errno(_("cannot copy '%s' to '%s'"),
                                          template_path->buf, path->buf);
                }
                else
                        error(_("ignoring template %s"), template_path->buf);
        }
}

static void copy_templates(const char *template_dir)
{
        struct strbuf path = STRBUF_INIT;
        struct strbuf template_path = STRBUF_INIT;
        size_t template_len;
        struct repository_format template_format = REPOSITORY_FORMAT_INIT;
        struct strbuf err = STRBUF_INIT;
        DIR *dir;
        char *to_free = NULL;

        if (!template_dir)
                template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
        if (!template_dir)
                template_dir = init_db_template_dir;
        if (!template_dir)
                template_dir = to_free = system_path(DEFAULT_GIT_TEMPLATE_DIR);
        if (!template_dir[0]) {
                free(to_free);
                return;
        }

        strbuf_addstr(&template_path, template_dir);
        strbuf_complete(&template_path, '/');
        template_len = template_path.len;

        dir = opendir(template_path.buf);
        if (!dir) {
                warning(_("templates not found in %s"), template_dir);
                goto free_return;
        }

        /* Make sure that template is from the correct vintage */
        strbuf_addstr(&template_path, "config");
        read_repository_format(&template_format, template_path.buf);
        strbuf_setlen(&template_path, template_len);

        /*
         * No mention of version at all is OK, but anything else should be
         * verified.
         */
        if (template_format.version >= 0 &&
            verify_repository_format(&template_format, &err) < 0) {
                warning(_("not copying templates from '%s': %s"),
                          template_dir, err.buf);
                strbuf_release(&err);
                goto close_free_return;
        }

        strbuf_addstr(&path, get_git_common_dir());
        strbuf_complete(&path, '/');
        copy_templates_1(&path, &template_path, dir);
close_free_return:
        closedir(dir);
free_return:
        free(to_free);
        strbuf_release(&path);
        strbuf_release(&template_path);
        clear_repository_format(&template_format);
}

static int git_init_db_config(const char *k, const char *v, void *cb)
{
        if (!strcmp(k, "init.templatedir"))
                return git_config_pathname(&init_db_template_dir, k, v);

        if (starts_with(k, "core."))
                return platform_core_config(k, v, cb);

        return 0;
}

/*
 * If the git_dir is not directly inside the working tree, then git will not
 * find it by default, and we need to set the worktree explicitly.
 */
static int needs_work_tree_config(const char *git_dir, const char *work_tree)
{
        if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
                return 0;
        if (skip_prefix(git_dir, work_tree, &git_dir) &&
            !strcmp(git_dir, "/.git"))
                return 0;
        return 1;
}

static int create_default_files(const char *template_path,
                                const char *original_git_dir)
{
        struct stat st1;
        struct strbuf buf = STRBUF_INIT;
        char *path;
        char repo_version_string[10];
        char junk[2];
        int reinit;
        int filemode;
        struct strbuf err = STRBUF_INIT;

        /* Just look for `init.templatedir` */
        init_db_template_dir = NULL; /* re-set in case it was set before */
        git_config(git_init_db_config, NULL);

        /*
         * First copy the templates -- we might have the default
         * config file there, in which case we would want to read
         * from it after installing.
         *
         * Before reading that config, we also need to clear out any cached
         * values (since we've just potentially changed what's available on
         * disk).
         */
        copy_templates(template_path);
        git_config_clear();
        reset_shared_repository();
        git_config(git_default_config, NULL);

        /*
         * We must make sure command-line options continue to override any
         * values we might have just re-read from the config.
         */
        is_bare_repository_cfg = init_is_bare_repository;
        if (init_shared_repository != -1)
                set_shared_repository(init_shared_repository);

        /*
         * We would have created the above under user's umask -- under
         * shared-repository settings, we would need to fix them up.
         */
        if (get_shared_repository()) {
                adjust_shared_perm(get_git_dir());
        }

        /*
         * We need to create a "refs" dir in any case so that older
         * versions of git can tell that this is a repository.
         */
        safe_create_dir(git_path("refs"), 1);
        adjust_shared_perm(git_path("refs"));

        if (refs_init_db(&err))
                die("failed to set up refs db: %s", err.buf);

        /*
         * Create the default symlink from ".git/HEAD" to the "master"
         * branch, if it does not exist yet.
         */
        path = git_path_buf(&buf, "HEAD");
        reinit = (!access(path, R_OK)
                  || readlink(path, junk, sizeof(junk)-1) != -1);
        if (!reinit) {
                if (create_symref("HEAD", "refs/heads/master", NULL) < 0)
                        exit(1);
        }

        /* This forces creation of new config file */
        xsnprintf(repo_version_string, sizeof(repo_version_string),
                  "%d", GIT_REPO_VERSION);
        git_config_set("core.repositoryformatversion", repo_version_string);

        /* Check filemode trustability */
        path = git_path_buf(&buf, "config");
        filemode = TEST_FILEMODE;
        if (TEST_FILEMODE && !lstat(path, &st1)) {
                struct stat st2;
                filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
                                !lstat(path, &st2) &&
                                st1.st_mode != st2.st_mode &&
                                !chmod(path, st1.st_mode));
                if (filemode && !reinit && (st1.st_mode & S_IXUSR))
                        filemode = 0;
        }
        git_config_set("core.filemode", filemode ? "true" : "false");

        if (is_bare_repository())
                git_config_set("core.bare", "true");
        else {
                const char *work_tree = get_git_work_tree();
                git_config_set("core.bare", "false");
                /* allow template config file to override the default */
                if (log_all_ref_updates == LOG_REFS_UNSET)
                        git_config_set("core.logallrefupdates", "true");
                if (needs_work_tree_config(original_git_dir, work_tree))
                        git_config_set("core.worktree", work_tree);
        }

        if (!reinit) {
                /* Check if symlink is supported in the work tree */
                path = git_path_buf(&buf, "tXXXXXX");
                if (!close(xmkstemp(path)) &&
                    !unlink(path) &&
                    !symlink("testing", path) &&
                    !lstat(path, &st1) &&
                    S_ISLNK(st1.st_mode))
                        unlink(path); /* good */
                else
                        git_config_set("core.symlinks", "false");

                /* Check if the filesystem is case-insensitive */
                path = git_path_buf(&buf, "CoNfIg");
                if (!access(path, F_OK))
                        git_config_set("core.ignorecase", "true");
                probe_utf8_pathname_composition();
        }

        strbuf_release(&buf);
        return reinit;
}

static void create_object_directory(void)
{
        struct strbuf path = STRBUF_INIT;
        size_t baselen;

        strbuf_addstr(&path, get_object_directory());
        baselen = path.len;

        safe_create_dir(path.buf, 1);

        strbuf_setlen(&path, baselen);
        strbuf_addstr(&path, "/pack");
        safe_create_dir(path.buf, 1);

        strbuf_setlen(&path, baselen);
        strbuf_addstr(&path, "/info");
        safe_create_dir(path.buf, 1);

        strbuf_release(&path);
}

static void separate_git_dir(const char *git_dir, const char *git_link)
{
        struct stat st;

        if (!stat(git_link, &st)) {
                const char *src;

                if (S_ISREG(st.st_mode))
                        src = read_gitfile(git_link);
                else if (S_ISDIR(st.st_mode))
                        src = git_link;
                else
                        die(_("unable to handle file type %d"), (int)st.st_mode);

                if (rename(src, git_dir))
                        die_errno(_("unable to move %s to %s"), src, git_dir);
        }

        write_file(git_link, "gitdir: %s", git_dir);
}

int init_db(const char *git_dir, const char *real_git_dir,
            const char *template_dir, unsigned int flags)
{
        int reinit;
        int exist_ok = flags & INIT_DB_EXIST_OK;
        char *original_git_dir = real_pathdup(git_dir, 1);

        if (real_git_dir) {
                struct stat st;

                if (!exist_ok && !stat(git_dir, &st))
                        die(_("%s already exists"), git_dir);

                if (!exist_ok && !stat(real_git_dir, &st))
                        die(_("%s already exists"), real_git_dir);

                set_git_dir(real_path(real_git_dir));
                git_dir = get_git_dir();
                separate_git_dir(git_dir, original_git_dir);
        }
        else {
                set_git_dir(real_path(git_dir));
                git_dir = get_git_dir();
        }
        startup_info->have_repository = 1;

        /* Just look for `core.hidedotfiles` */
        git_config(git_init_db_config, NULL);

        safe_create_dir(git_dir, 0);

        init_is_bare_repository = is_bare_repository();

        /* Check to see if the repository version is right.
         * Note that a newly created repository does not have
         * config file, so this will not fail.  What we are catching
         * is an attempt to reinitialize new repository with an old tool.
         */
        check_repository_format();

        reinit = create_default_files(template_dir, original_git_dir);

        create_object_directory();

        if (get_shared_repository()) {
                char buf[10];
                /* We do not spell "group" and such, so that
                 * the configuration can be read by older version
                 * of git. Note, we use octal numbers for new share modes,
                 * and compatibility values for PERM_GROUP and
                 * PERM_EVERYBODY.
                 */
                if (get_shared_repository() < 0)
                        /* force to the mode value */
                        xsnprintf(buf, sizeof(buf), "0%o", -get_shared_repository());
                else if (get_shared_repository() == PERM_GROUP)
                        xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
                else if (get_shared_repository() == PERM_EVERYBODY)
                        xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
                else
                        BUG("invalid value for shared_repository");
                git_config_set("core.sharedrepository", buf);
                git_config_set("receive.denyNonFastforwards", "true");
        }

        if (!(flags & INIT_DB_QUIET)) {
                int len = strlen(git_dir);

                if (reinit)
                        printf(get_shared_repository()
                               ? _("Reinitialized existing shared Git repository in %s%s\n")
                               : _("Reinitialized existing Git repository in %s%s\n"),
                               git_dir, len && git_dir[len-1] != '/' ? "/" : "");
                else
                        printf(get_shared_repository()
                               ? _("Initialized empty shared Git repository in %s%s\n")
                               : _("Initialized empty Git repository in %s%s\n"),
                               git_dir, len && git_dir[len-1] != '/' ? "/" : "");
        }

        free(original_git_dir);
        return 0;
}

static int guess_repository_type(const char *git_dir)
{
        const char *slash;
        char *cwd;
        int cwd_is_git_dir;

        /*
         * "GIT_DIR=. git init" is always bare.
         * "GIT_DIR=`pwd` git init" too.
         */
        if (!strcmp(".", git_dir))
                return 1;
        cwd = xgetcwd();
        cwd_is_git_dir = !strcmp(git_dir, cwd);
        free(cwd);
        if (cwd_is_git_dir)
                return 1;
        /*
         * "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
         */
        if (!strcmp(git_dir, ".git"))
                return 0;
        slash = strrchr(git_dir, '/');
        if (slash && !strcmp(slash, "/.git"))
                return 0;

        /*
         * Otherwise it is often bare.  At this point
         * we are just guessing.
         */
        return 1;
}

static int shared_callback(const struct option *opt, const char *arg, int unset)
{
        BUG_ON_OPT_NEG(unset);
        *((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
        return 0;
}

static const char *const init_db_usage[] = {
        N_("git init [-q | --quiet] [--bare] [--template=<template-directory>] [--shared[=<permissions>]] [<directory>]"),
        NULL
};

/*
 * If you want to, you can share the DB area with any number of branches.
 * That has advantages: you can save space by sharing all the SHA1 objects.
 * On the other hand, it might just make lookup slower and messier. You
 * be the judge.  The default case is to have one DB per managed directory.
 */
int cmd_init_db(int argc, const char **argv, const char *prefix)
{
        const char *git_dir;
        const char *real_git_dir = NULL;
        const char *work_tree;
        const char *template_dir = NULL;
        unsigned int flags = 0;
        const struct option init_db_options[] = {
                OPT_STRING(0, "template", &template_dir, N_("template-directory"),
                                N_("directory from which templates will be used")),
                OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
                                N_("create a bare repository"), 1),
                { OPTION_CALLBACK, 0, "shared", &init_shared_repository,
                        N_("permissions"),
                        N_("specify that the git repository is to be shared amongst several users"),
                        PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
                OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
                OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
                           N_("separate git dir from working tree")),
                OPT_END()
        };

        argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);

        if (real_git_dir && !is_absolute_path(real_git_dir))
                real_git_dir = real_pathdup(real_git_dir, 1);

        if (argc == 1) {
                int mkdir_tried = 0;
        retry:
                if (chdir(argv[0]) < 0) {
                        if (!mkdir_tried) {
                                int saved;
                                /*
                                 * At this point we haven't read any configuration,
                                 * and we know shared_repository should always be 0;
                                 * but just in case we play safe.
                                 */
                                saved = get_shared_repository();
                                set_shared_repository(0);
                                switch (safe_create_leading_directories_const(argv[0])) {
                                case SCLD_OK:
                                case SCLD_PERMS:
                                        break;
                                case SCLD_EXISTS:
                                        errno = EEXIST;
                                        /* fallthru */
                                default:
                                        die_errno(_("cannot mkdir %s"), argv[0]);
                                        break;
                                }
                                set_shared_repository(saved);
                                if (mkdir(argv[0], 0777) < 0)
                                        die_errno(_("cannot mkdir %s"), argv[0]);
                                mkdir_tried = 1;
                                goto retry;
                        }
                        die_errno(_("cannot chdir to %s"), argv[0]);
                }
        } else if (0 < argc) {
                usage(init_db_usage[0]);
        }
        if (is_bare_repository_cfg == 1) {
                char *cwd = xgetcwd();
                setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
                free(cwd);
        }

        if (init_shared_repository != -1)
                set_shared_repository(init_shared_repository);

        /*
         * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
         * without --bare.  Catch the error early.
         */
        git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
        work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
        if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
                die(_("%s (or --work-tree=<directory>) not allowed without "
                          "specifying %s (or --git-dir=<directory>)"),
                    GIT_WORK_TREE_ENVIRONMENT,
                    GIT_DIR_ENVIRONMENT);

        /*
         * Set up the default .git directory contents
         */
        if (!git_dir)
                git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;

        if (is_bare_repository_cfg < 0)
                is_bare_repository_cfg = guess_repository_type(git_dir);

        if (!is_bare_repository_cfg) {
                const char *git_dir_parent = strrchr(git_dir, '/');
                if (git_dir_parent) {
                        char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
                        git_work_tree_cfg = real_pathdup(rel, 1);
                        free(rel);
                }
                if (!git_work_tree_cfg)
                        git_work_tree_cfg = xgetcwd();
                if (work_tree)
                        set_git_work_tree(work_tree);
                else
                        set_git_work_tree(git_work_tree_cfg);
                if (access(get_git_work_tree(), X_OK))
                        die_errno (_("Cannot access work tree '%s'"),
                                   get_git_work_tree());
        }
        else {
                if (work_tree)
                        set_git_work_tree(work_tree);
        }

        UNLEAK(real_git_dir);
        UNLEAK(git_dir);
        UNLEAK(work_tree);

        flags |= INIT_DB_EXIST_OK;
        return init_db(git_dir, real_git_dir, template_dir, flags);
}