/*
 * "git mv" builtin command
 *
 * Copyright (C) 2006 Johannes Schindelin
 */
#include "cache.h"
#include "builtin.h"
#include "dir.h"
#include "cache-tree.h"
#include "string-list.h"
#include "parse-options.h"

static const char * const builtin_mv_usage[] = {
        "git mv [options] <source>... <destination>",
        NULL
};

static const char **copy_pathspec(const char *prefix, const char **pathspec,
                                  int count, int base_name)
{
        int i;
        const char **result = xmalloc((count + 1) * sizeof(const char *));
        memcpy(result, pathspec, count * sizeof(const char *));
        result[count] = NULL;
        for (i = 0; i < count; i++) {
                int length = strlen(result[i]);
                if (length > 0 && result[i][length - 1] == '/') {
                        result[i] = xmemdupz(result[i], length - 1);
                }
                if (base_name) {
                        const char *last_slash = strrchr(result[i], '/');
                        if (last_slash)
                                result[i] = last_slash + 1;
                }
        }
        return get_pathspec(prefix, result);
}

static const char *add_slash(const char *path)
{
        int len = strlen(path);
        if (path[len - 1] != '/') {
                char *with_slash = xmalloc(len + 2);
                memcpy(with_slash, path, len);
                with_slash[len++] = '/';
                with_slash[len] = 0;
                return with_slash;
        }
        return path;
}

static struct lock_file lock_file;

int cmd_mv(int argc, const char **argv, const char *prefix)
{
        int i, newfd;
        int verbose = 0, show_only = 0, force = 0, ignore_errors = 0;
        struct option builtin_mv_options[] = {
                OPT__DRY_RUN(&show_only),
                OPT_BOOLEAN('f', NULL, &force, "force move/rename even if target exists"),
                OPT_BOOLEAN('k', NULL, &ignore_errors, "skip move/rename errors"),
                OPT_END(),
        };
        const char **source, **destination, **dest_path;
        enum update_mode { BOTH = 0, WORKING_DIRECTORY, INDEX } *modes;
        struct stat st;
        struct string_list src_for_dst = {NULL, 0, 0, 0};

        git_config(git_default_config, NULL);

        newfd = hold_locked_index(&lock_file, 1);
        if (read_cache() < 0)
                die("index file corrupt");

        argc = parse_options(argc, argv, prefix, builtin_mv_options,
                             builtin_mv_usage, 0);
        if (--argc < 1)
                usage_with_options(builtin_mv_usage, builtin_mv_options);

        source = copy_pathspec(prefix, argv, argc, 0);
        modes = xcalloc(argc, sizeof(enum update_mode));
        dest_path = copy_pathspec(prefix, argv + argc, 1, 0);

        if (dest_path[0][0] == '\0')
                /* special case: "." was normalized to "" */
                destination = copy_pathspec(dest_path[0], argv, argc, 1);
        else if (!lstat(dest_path[0], &st) &&
                        S_ISDIR(st.st_mode)) {
                dest_path[0] = add_slash(dest_path[0]);
                destination = copy_pathspec(dest_path[0], argv, argc, 1);
        } else {
                if (argc != 1)
                        usage_with_options(builtin_mv_usage, builtin_mv_options);
                destination = dest_path;
        }

        /* Checking */
        for (i = 0; i < argc; i++) {
                const char *src = source[i], *dst = destination[i];
                int length, src_is_dir;
                const char *bad = NULL;

                if (show_only)
                        printf("Checking rename of '%s' to '%s'\n", src, dst);

                length = strlen(src);
                if (lstat(src, &st) < 0)
                        bad = "bad source";
                else if (!strncmp(src, dst, length) &&
                                (dst[length] == 0 || dst[length] == '/')) {
                        bad = "can not move directory into itself";
                } else if ((src_is_dir = S_ISDIR(st.st_mode))
                                && lstat(dst, &st) == 0)
                        bad = "cannot move directory over file";
                else if (src_is_dir) {
                        const char *src_w_slash = add_slash(src);
                        int len_w_slash = length + 1;
                        int first, last;

                        modes[i] = WORKING_DIRECTORY;

                        first = cache_name_pos(src_w_slash, len_w_slash);
                        if (first >= 0)
                                die ("Huh? %.*s is in index?",
                                                len_w_slash, src_w_slash);

                        first = -1 - first;
                        for (last = first; last < active_nr; last++) {
                                const char *path = active_cache[last]->name;
                                if (strncmp(path, src_w_slash, len_w_slash))
                                        break;
                        }
                        free((char *)src_w_slash);

                        if (last - first < 1)
                                bad = "source directory is empty";
                        else {
                                int j, dst_len;

                                if (last - first > 0) {
                                        source = xrealloc(source,
                                                        (argc + last - first)
                                                        * sizeof(char *));
                                        destination = xrealloc(destination,
                                                        (argc + last - first)
                                                        * sizeof(char *));
                                        modes = xrealloc(modes,
                                                        (argc + last - first)
                                                        * sizeof(enum update_mode));
                                }

                                dst = add_slash(dst);
                                dst_len = strlen(dst);

                                for (j = 0; j < last - first; j++) {
                                        const char *path =
                                                active_cache[first + j]->name;
                                        source[argc + j] = path;
                                        destination[argc + j] =
                                                prefix_path(dst, dst_len,
                                                        path + length + 1);
                                        modes[argc + j] = INDEX;
                                }
                                argc += last - first;
                        }
                } else if (cache_name_pos(src, length) < 0)
                        bad = "not under version control";
                else if (lstat(dst, &st) == 0) {
                        bad = "destination exists";
                        if (force) {
                                /*
                                 * only files can overwrite each other:
                                 * check both source and destination
                                 */
                                if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
                                        fprintf(stderr, "Warning: %s;"
                                                        " will overwrite!\n",
                                                        bad);
                                        bad = NULL;
                                } else
                                        bad = "Cannot overwrite";
                        }
                } else if (string_list_has_string(&src_for_dst, dst))
                        bad = "multiple sources for the same target";
                else
                        string_list_insert(dst, &src_for_dst);

                if (bad) {
                        if (ignore_errors) {
                                if (--argc > 0) {
                                        memmove(source + i, source + i + 1,
                                                (argc - i) * sizeof(char *));
                                        memmove(destination + i,
                                                destination + i + 1,
                                                (argc - i) * sizeof(char *));
                                        i--;
                                }
                        } else
                                die ("%s, source=%s, destination=%s",
                                     bad, src, dst);
                }
        }

        for (i = 0; i < argc; i++) {
                const char *src = source[i], *dst = destination[i];
                enum update_mode mode = modes[i];
                int pos;
                if (show_only || verbose)
                        printf("Renaming %s to %s\n", src, dst);
                if (!show_only && mode != INDEX &&
                                rename(src, dst) < 0 && !ignore_errors)
                        die ("renaming %s failed: %s", src, strerror(errno));

                if (mode == WORKING_DIRECTORY)
                        continue;

                pos = cache_name_pos(src, strlen(src));
                assert(pos >= 0);
                if (!show_only)
                        rename_cache_entry_at(pos, dst);
        }

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

        return 0;
}