/*
 * "git add" builtin command
 *
 * Copyright (C) 2006 Linus Torvalds
 */
#include <fnmatch.h>

#include "cache.h"
#include "builtin.h"
#include "dir.h"
#include "cache-tree.h"

static const char builtin_add_usage[] =
"git-add [-n] [-v] <filepattern>...";

static int common_prefix(const char **pathspec)
{
        const char *path, *slash, *next;
        int prefix;

        if (!pathspec)
                return 0;

        path = *pathspec;
        slash = strrchr(path, '/');
        if (!slash)
                return 0;

        prefix = slash - path + 1;
        while ((next = *++pathspec) != NULL) {
                int len = strlen(next);
                if (len >= prefix && !memcmp(path, next, len))
                        continue;
                for (;;) {
                        if (!len)
                                return 0;
                        if (next[--len] != '/')
                                continue;
                        if (memcmp(path, next, len+1))
                                continue;
                        prefix = len + 1;
                        break;
                }
        }
        return prefix;
}

static int match_one(const char *match, const char *name, int namelen)
{
        int matchlen;

        /* If the match was just the prefix, we matched */
        matchlen = strlen(match);
        if (!matchlen)
                return 1;

        /*
         * If we don't match the matchstring exactly,
         * we need to match by fnmatch
         */
        if (strncmp(match, name, matchlen))
                return !fnmatch(match, name, 0);

        /*
         * If we did match the string exactly, we still
         * need to make sure that it happened on a path
         * component boundary (ie either the last character
         * of the match was '/', or the next character of
         * the name was '/' or the terminating NUL.
         */
        return  match[matchlen-1] == '/' ||
                name[matchlen] == '/' ||
                !name[matchlen];
}

static int match(const char **pathspec, const char *name, int namelen, int prefix, char *seen)
{
        int retval;
        const char *match;

        name += prefix;
        namelen -= prefix;

        for (retval = 0; (match = *pathspec++) != NULL; seen++) {
                if (retval & *seen)
                        continue;
                match += prefix;
                if (match_one(match, name, namelen)) {
                        retval = 1;
                        *seen = 1;
                }
        }
        return retval;
}

static void prune_directory(struct dir_struct *dir, const char **pathspec, int prefix)
{
        char *seen;
        int i, specs;
        struct dir_entry **src, **dst;

        for (specs = 0; pathspec[specs];  specs++)
                /* nothing */;
        seen = xmalloc(specs);
        memset(seen, 0, specs);

        src = dst = dir->entries;
        i = dir->nr;
        while (--i >= 0) {
                struct dir_entry *entry = *src++;
                if (!match(pathspec, entry->name, entry->len, prefix, seen)) {
                        free(entry);
                        continue;
                }
                *dst++ = entry;
        }
        dir->nr = dst - dir->entries;

        for (i = 0; i < specs; i++) {
                struct stat st;
                const char *match;
                if (seen[i])
                        continue;

                /* Existing file? We must have ignored it */
                match = pathspec[i];
                if (!match[0] || !lstat(match, &st))
                        continue;
                die("pathspec '%s' did not match any files", match);
        }
}

static void fill_directory(struct dir_struct *dir, const char **pathspec)
{
        const char *path, *base;
        int baselen;

        /* Set up the default git porcelain excludes */
        memset(dir, 0, sizeof(*dir));
        dir->exclude_per_dir = ".gitignore";
        path = git_path("info/exclude");
        if (!access(path, R_OK))
                add_excludes_from_file(dir, path);

        /*
         * Calculate common prefix for the pathspec, and
         * use that to optimize the directory walk
         */
        baselen = common_prefix(pathspec);
        path = ".";
        base = "";
        if (baselen) {
                char *common = xmalloc(baselen + 1);
                common = xmalloc(baselen + 1);
                memcpy(common, *pathspec, baselen);
                common[baselen] = 0;
                path = base = common;
        }

        /* Read the directory and prune it */
        read_directory(dir, path, base, baselen);
        if (pathspec)
                prune_directory(dir, pathspec, baselen);
}

static int add_file_to_index(const char *path, int verbose)
{
        int size, namelen;
        struct stat st;
        struct cache_entry *ce;

        if (lstat(path, &st))
                die("%s: unable to stat (%s)", path, strerror(errno));

        if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode))
                die("%s: can only add regular files or symbolic links", path);

        namelen = strlen(path);
        size = cache_entry_size(namelen);
        ce = xcalloc(1, size);
        memcpy(ce->name, path, namelen);
        ce->ce_flags = htons(namelen);
        fill_stat_cache_info(ce, &st);

        ce->ce_mode = create_ce_mode(st.st_mode);
        if (!trust_executable_bit) {
                /* If there is an existing entry, pick the mode bits
                 * from it.
                 */
                int pos = cache_name_pos(path, namelen);
                if (pos >= 0)
                        ce->ce_mode = active_cache[pos]->ce_mode;
        }

        if (index_path(ce->sha1, path, &st, 1))
                die("unable to index file %s", path);
        if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD))
                die("unable to add %s to index",path);
        if (verbose)
                printf("add '%s'\n", path);
        cache_tree_invalidate_path(active_cache_tree, path);
        return 0;
}

static struct cache_file cache_file;

int cmd_add(int argc, const char **argv, char **envp)
{
        int i, newfd;
        int verbose = 0, show_only = 0;
        const char *prefix = setup_git_directory();
        const char **pathspec;
        struct dir_struct dir;

        git_config(git_default_config);

        newfd = hold_index_file_for_update(&cache_file, get_index_file());
        if (newfd < 0)
                die("unable to create new cachefile");

        if (read_cache() < 0)
                die("index file corrupt");

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];

                if (arg[0] != '-')
                        break;
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (!strcmp(arg, "-n")) {
                        show_only = 1;
                        continue;
                }
                if (!strcmp(arg, "-v")) {
                        verbose = 1;
                        continue;
                }
                die(builtin_add_usage);
        }
        git_config(git_default_config);
        pathspec = get_pathspec(prefix, argv + i);

        fill_directory(&dir, pathspec);

        if (show_only) {
                const char *sep = "", *eof = "";
                for (i = 0; i < dir.nr; i++) {
                        printf("%s%s", sep, dir.entries[i]->name);
                        sep = " ";
                        eof = "\n";
                }
                fputs(eof, stdout);
                return 0;
        }

        for (i = 0; i < dir.nr; i++)
                add_file_to_index(dir.entries[i]->name, verbose);

        if (active_cache_changed) {
                if (write_cache(newfd, active_cache, active_nr) ||
                    commit_index_file(&cache_file))
                        die("Unable to write new index file");
        }

        return 0;
}