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

static const char builtin_mv_usage[] =
"git-mv [-n] [-f] (<source> <destination> | [-k] <source>... <destination>)";

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] == '/') {
                        char *without_slash = xmalloc(length);
                        memcpy(without_slash, result[i], length - 1);
                        without_slash[length - 1] = '\0';
                        result[i] = without_slash;
                }
                if (base_name) {
                        const char *last_slash = strrchr(result[i], '/');
                        if (last_slash)
                                result[i] = last_slash + 1;
                }
        }
        return get_pathspec(prefix, result);
}

static void show_list(const char *label, struct path_list *list)
{
        if (list->nr > 0) {
                int i;
                printf("%s", label);
                for (i = 0; i < list->nr; i++)
                        printf("%s%s", i > 0 ? ", " : "", list->items[i].path);
                putchar('\n');
        }
}

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, count;
        int verbose = 0, show_only = 0, force = 0, ignore_errors = 0;
        const char **source, **destination, **dest_path;
        enum update_mode { BOTH = 0, WORKING_DIRECTORY, INDEX } *modes;
        struct stat st;
        struct path_list overwritten = {NULL, 0, 0, 0};
        struct path_list src_for_dst = {NULL, 0, 0, 0};
        struct path_list added = {NULL, 0, 0, 0};
        struct path_list deleted = {NULL, 0, 0, 0};
        struct path_list changed = {NULL, 0, 0, 0};

        git_config(git_default_config);

        newfd = hold_locked_index(&lock_file, 1);
        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, "-f")) {
                        force = 1;
                        continue;
                }
                if (!strcmp(arg, "-k")) {
                        ignore_errors = 1;
                        continue;
                }
                usage(builtin_mv_usage);
        }
        count = argc - i - 1;
        if (count < 1)
                usage(builtin_mv_usage);

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

        if (dest_path[0][0] == '\0')
                /* special case: "." was normalized to "" */
                destination = copy_pathspec(dest_path[0], argv + i, count, 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 + i, count, 1);
        } else {
                if (count != 1)
                        usage(builtin_mv_usage);
                destination = dest_path;
        }

        /* Checking */
        for (i = 0; i < count; 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,
                                                        (count + last - first)
                                                        * sizeof(char *));
                                        destination = xrealloc(destination,
                                                        (count + last - first)
                                                        * sizeof(char *));
                                        modes = xrealloc(modes,
                                                        (count + last - first)
                                                        * sizeof(enum update_mode));
                                }

                                dst = add_slash(dst);
                                dst_len = strlen(dst) - 1;

                                for (j = 0; j < last - first; j++) {
                                        const char *path =
                                                active_cache[first + j]->name;
                                        source[count + j] = path;
                                        destination[count + j] =
                                                prefix_path(dst, dst_len,
                                                        path + length);
                                        modes[count + j] = INDEX;
                                }
                                count += last - first;
                        }
                } 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)) {
                                        fprintf(stderr, "Warning: %s;"
                                                        " will overwrite!\n",
                                                        bad);
                                        bad = NULL;
                                        path_list_insert(dst, &overwritten);
                                } else
                                        bad = "Cannot overwrite";
                        }
                } else if (cache_name_pos(src, length) < 0)
                        bad = "not under version control";
                else if (path_list_has_path(&src_for_dst, dst))
                        bad = "multiple sources for the same target";
                else
                        path_list_insert(dst, &src_for_dst);

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

        for (i = 0; i < count; i++) {
                const char *src = source[i], *dst = destination[i];
                enum update_mode mode = modes[i];
                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;

                if (cache_name_pos(src, strlen(src)) >= 0) {
                        path_list_insert(src, &deleted);

                        /* destination can be a directory with 1 file inside */
                        if (path_list_has_path(&overwritten, dst))
                                path_list_insert(dst, &changed);
                        else
                                path_list_insert(dst, &added);
                } else
                        path_list_insert(dst, &added);
        }

        if (show_only) {
                show_list("Changed  : ", &changed);
                show_list("Adding   : ", &added);
                show_list("Deleting : ", &deleted);
        } else {
                for (i = 0; i < changed.nr; i++) {
                        const char *path = changed.items[i].path;
                        int j = cache_name_pos(path, strlen(path));
                        struct cache_entry *ce = active_cache[j];

                        if (j < 0)
                                die ("Huh? Cache entry for %s unknown?", path);
                        refresh_cache_entry(ce, 0);
                }

                for (i = 0; i < added.nr; i++) {
                        const char *path = added.items[i].path;
                        add_file_to_cache(path, verbose);
                }

                for (i = 0; i < deleted.nr; i++) {
                        const char *path = deleted.items[i].path;
                        remove_file_from_cache(path);
                        cache_tree_invalidate_path(active_cache_tree, path);
                }

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

        return 0;
}