/*
 * Builtin "git branch"
 *
 * Copyright (c) 2006 Kristian Høgsberg <krh@redhat.com>
 * Based on git-branch.sh by Junio C Hamano.
 */

#include "cache.h"
#include "color.h"
#include "refs.h"
#include "commit.h"
#include "builtin.h"
#include "remote.h"
#include "parse-options.h"
#include "branch.h"
#include "diff.h"
#include "revision.h"

static const char * const builtin_branch_usage[] = {
        "git branch [options] [-r | -a] [--merged | --no-merged]",
        "git branch [options] [-l] [-f] <branchname> [<start-point>]",
        "git branch [options] [-r] (-d | -D) <branchname>",
        "git branch [options] (-m | -M) [<oldbranch>] <newbranch>",
        NULL
};

#define REF_LOCAL_BRANCH    0x01
#define REF_REMOTE_BRANCH   0x02

static const char *head;
static unsigned char head_sha1[20];

static int branch_use_color = -1;
static char branch_colors[][COLOR_MAXLEN] = {
        "\033[m",       /* reset */
        "",             /* PLAIN (normal) */
        "\033[31m",     /* REMOTE (red) */
        "",             /* LOCAL (normal) */
        "\033[32m",     /* CURRENT (green) */
};
enum color_branch {
        COLOR_BRANCH_RESET = 0,
        COLOR_BRANCH_PLAIN = 1,
        COLOR_BRANCH_REMOTE = 2,
        COLOR_BRANCH_LOCAL = 3,
        COLOR_BRANCH_CURRENT = 4,
};

static enum merge_filter {
        NO_FILTER = 0,
        SHOW_NOT_MERGED,
        SHOW_MERGED,
} merge_filter;
static unsigned char merge_filter_ref[20];

static int parse_branch_color_slot(const char *var, int ofs)
{
        if (!strcasecmp(var+ofs, "plain"))
                return COLOR_BRANCH_PLAIN;
        if (!strcasecmp(var+ofs, "reset"))
                return COLOR_BRANCH_RESET;
        if (!strcasecmp(var+ofs, "remote"))
                return COLOR_BRANCH_REMOTE;
        if (!strcasecmp(var+ofs, "local"))
                return COLOR_BRANCH_LOCAL;
        if (!strcasecmp(var+ofs, "current"))
                return COLOR_BRANCH_CURRENT;
        die("bad config variable '%s'", var);
}

static int git_branch_config(const char *var, const char *value, void *cb)
{
        if (!strcmp(var, "color.branch")) {
                branch_use_color = git_config_colorbool(var, value, -1);
                return 0;
        }
        if (!prefixcmp(var, "color.branch.")) {
                int slot = parse_branch_color_slot(var, 13);
                if (!value)
                        return config_error_nonbool(var);
                color_parse(value, var, branch_colors[slot]);
                return 0;
        }
        return git_color_default_config(var, value, cb);
}

static const char *branch_get_color(enum color_branch ix)
{
        if (branch_use_color > 0)
                return branch_colors[ix];
        return "";
}

static int delete_branches(int argc, const char **argv, int force, int kinds)
{
        struct commit *rev, *head_rev = head_rev;
        unsigned char sha1[20];
        char *name = NULL;
        const char *fmt, *remote;
        char section[PATH_MAX];
        int i;
        int ret = 0;

        switch (kinds) {
        case REF_REMOTE_BRANCH:
                fmt = "refs/remotes/%s";
                remote = "remote ";
                force = 1;
                break;
        case REF_LOCAL_BRANCH:
                fmt = "refs/heads/%s";
                remote = "";
                break;
        default:
                die("cannot use -a with -d");
        }

        if (!force) {
                head_rev = lookup_commit_reference(head_sha1);
                if (!head_rev)
                        die("Couldn't look up commit object for HEAD");
        }
        for (i = 0; i < argc; i++) {
                if (kinds == REF_LOCAL_BRANCH && !strcmp(head, argv[i])) {
                        error("Cannot delete the branch '%s' "
                                "which you are currently on.", argv[i]);
                        ret = 1;
                        continue;
                }

                free(name);

                name = xstrdup(mkpath(fmt, argv[i]));
                if (!resolve_ref(name, sha1, 1, NULL)) {
                        error("%sbranch '%s' not found.",
                                        remote, argv[i]);
                        ret = 1;
                        continue;
                }

                rev = lookup_commit_reference(sha1);
                if (!rev) {
                        error("Couldn't look up commit object for '%s'", name);
                        ret = 1;
                        continue;
                }

                /* This checks whether the merge bases of branch and
                 * HEAD contains branch -- which means that the HEAD
                 * contains everything in both.
                 */

                if (!force &&
                    !in_merge_bases(rev, &head_rev, 1)) {
                        error("The branch '%s' is not an ancestor of "
                                "your current HEAD.\n"
                                "If you are sure you want to delete it, "
                                "run 'git branch -D %s'.", argv[i], argv[i]);
                        ret = 1;
                        continue;
                }

                if (delete_ref(name, sha1)) {
                        error("Error deleting %sbranch '%s'", remote,
                               argv[i]);
                        ret = 1;
                } else {
                        printf("Deleted %sbranch %s.\n", remote, argv[i]);
                        snprintf(section, sizeof(section), "branch.%s",
                                 argv[i]);
                        if (git_config_rename_section(section, NULL) < 0)
                                warning("Update of config-file failed");
                }
        }

        free(name);

        return(ret);
}

struct ref_item {
        char *name;
        unsigned int kind;
        struct commit *commit;
};

struct ref_list {
        struct rev_info revs;
        int index, alloc, maxwidth;
        struct ref_item *list;
        struct commit_list *with_commit;
        int kinds;
};

static int has_commit(struct commit *commit, struct commit_list *with_commit)
{
        if (!with_commit)
                return 1;
        while (with_commit) {
                struct commit *other;

                other = with_commit->item;
                with_commit = with_commit->next;
                if (in_merge_bases(other, &commit, 1))
                        return 1;
        }
        return 0;
}

static int append_ref(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
{
        struct ref_list *ref_list = (struct ref_list*)(cb_data);
        struct ref_item *newitem;
        struct commit *commit;
        int kind;
        int len;

        /* Detect kind */
        if (!prefixcmp(refname, "refs/heads/")) {
                kind = REF_LOCAL_BRANCH;
                refname += 11;
        } else if (!prefixcmp(refname, "refs/remotes/")) {
                kind = REF_REMOTE_BRANCH;
                refname += 13;
        } else
                return 0;

        commit = lookup_commit_reference_gently(sha1, 1);
        if (!commit)
                return error("branch '%s' does not point at a commit", refname);

        /* Filter with with_commit if specified */
        if (!has_commit(commit, ref_list->with_commit))
                return 0;

        /* Don't add types the caller doesn't want */
        if ((kind & ref_list->kinds) == 0)
                return 0;

        if (merge_filter != NO_FILTER)
                add_pending_object(&ref_list->revs,
                                   (struct object *)commit, refname);

        /* Resize buffer */
        if (ref_list->index >= ref_list->alloc) {
                ref_list->alloc = alloc_nr(ref_list->alloc);
                ref_list->list = xrealloc(ref_list->list,
                                ref_list->alloc * sizeof(struct ref_item));
        }

        /* Record the new item */
        newitem = &(ref_list->list[ref_list->index++]);
        newitem->name = xstrdup(refname);
        newitem->kind = kind;
        newitem->commit = commit;
        len = strlen(newitem->name);
        if (len > ref_list->maxwidth)
                ref_list->maxwidth = len;

        return 0;
}

static void free_ref_list(struct ref_list *ref_list)
{
        int i;

        for (i = 0; i < ref_list->index; i++)
                free(ref_list->list[i].name);
        free(ref_list->list);
}

static int ref_cmp(const void *r1, const void *r2)
{
        struct ref_item *c1 = (struct ref_item *)(r1);
        struct ref_item *c2 = (struct ref_item *)(r2);

        if (c1->kind != c2->kind)
                return c1->kind - c2->kind;
        return strcmp(c1->name, c2->name);
}

static void fill_tracking_info(char *stat, const char *branch_name)
{
        int ours, theirs;
        struct branch *branch = branch_get(branch_name);

        if (!stat_tracking_info(branch, &ours, &theirs) || (!ours && !theirs))
                return;
        if (!ours)
                sprintf(stat, "[behind %d] ", theirs);
        else if (!theirs)
                sprintf(stat, "[ahead %d] ", ours);
        else
                sprintf(stat, "[ahead %d, behind %d] ", ours, theirs);
}

static int matches_merge_filter(struct commit *commit)
{
        int is_merged;

        if (merge_filter == NO_FILTER)
                return 1;

        is_merged = !!(commit->object.flags & UNINTERESTING);
        return (is_merged == (merge_filter == SHOW_MERGED));
}

static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
                           int abbrev, int current)
{
        char c;
        int color;
        struct commit *commit = item->commit;

        if (!matches_merge_filter(commit))
                return;

        switch (item->kind) {
        case REF_LOCAL_BRANCH:
                color = COLOR_BRANCH_LOCAL;
                break;
        case REF_REMOTE_BRANCH:
                color = COLOR_BRANCH_REMOTE;
                break;
        default:
                color = COLOR_BRANCH_PLAIN;
                break;
        }

        c = ' ';
        if (current) {
                c = '*';
                color = COLOR_BRANCH_CURRENT;
        }

        if (verbose) {
                struct strbuf subject;
                const char *sub = " **** invalid ref ****";
                char stat[128];

                strbuf_init(&subject, 0);
                stat[0] = '\0';

                commit = item->commit;
                if (commit && !parse_commit(commit)) {
                        pretty_print_commit(CMIT_FMT_ONELINE, commit,
                                            &subject, 0, NULL, NULL, 0, 0);
                        sub = subject.buf;
                }

                if (item->kind == REF_LOCAL_BRANCH)
                        fill_tracking_info(stat, item->name);

                printf("%c %s%-*s%s %s %s%s\n", c, branch_get_color(color),
                       maxwidth, item->name,
                       branch_get_color(COLOR_BRANCH_RESET),
                       find_unique_abbrev(item->commit->object.sha1, abbrev),
                       stat, sub);
                strbuf_release(&subject);
        } else {
                printf("%c %s%s%s\n", c, branch_get_color(color), item->name,
                       branch_get_color(COLOR_BRANCH_RESET));
        }
}

static int calc_maxwidth(struct ref_list *refs)
{
        int i, l, w = 0;
        for (i = 0; i < refs->index; i++) {
                if (!matches_merge_filter(refs->list[i].commit))
                        continue;
                l = strlen(refs->list[i].name);
                if (l > w)
                        w = l;
        }
        return w;
}

static void print_ref_list(int kinds, int detached, int verbose, int abbrev, struct commit_list *with_commit)
{
        int i;
        struct ref_list ref_list;
        struct commit *head_commit = lookup_commit_reference_gently(head_sha1, 1);

        memset(&ref_list, 0, sizeof(ref_list));
        ref_list.kinds = kinds;
        ref_list.with_commit = with_commit;
        if (merge_filter != NO_FILTER)
                init_revisions(&ref_list.revs, NULL);
        for_each_ref(append_ref, &ref_list);
        if (merge_filter != NO_FILTER) {
                struct commit *filter;
                filter = lookup_commit_reference_gently(merge_filter_ref, 0);
                filter->object.flags |= UNINTERESTING;
                add_pending_object(&ref_list.revs,
                                   (struct object *) filter, "");
                ref_list.revs.limited = 1;
                prepare_revision_walk(&ref_list.revs);
                if (verbose)
                        ref_list.maxwidth = calc_maxwidth(&ref_list);
        }

        qsort(ref_list.list, ref_list.index, sizeof(struct ref_item), ref_cmp);

        detached = (detached && (kinds & REF_LOCAL_BRANCH));
        if (detached && head_commit && has_commit(head_commit, with_commit)) {
                struct ref_item item;
                item.name = xstrdup("(no branch)");
                item.kind = REF_LOCAL_BRANCH;
                item.commit = head_commit;
                if (strlen(item.name) > ref_list.maxwidth)
                        ref_list.maxwidth = strlen(item.name);
                print_ref_item(&item, ref_list.maxwidth, verbose, abbrev, 1);
                free(item.name);
        }

        for (i = 0; i < ref_list.index; i++) {
                int current = !detached &&
                        (ref_list.list[i].kind == REF_LOCAL_BRANCH) &&
                        !strcmp(ref_list.list[i].name, head);
                print_ref_item(&ref_list.list[i], ref_list.maxwidth, verbose,
                               abbrev, current);
        }

        free_ref_list(&ref_list);
}

static void rename_branch(const char *oldname, const char *newname, int force)
{
        char oldref[PATH_MAX], newref[PATH_MAX], logmsg[PATH_MAX*2 + 100];
        unsigned char sha1[20];
        char oldsection[PATH_MAX], newsection[PATH_MAX];

        if (!oldname)
                die("cannot rename the current branch while not on any.");

        if (snprintf(oldref, sizeof(oldref), "refs/heads/%s", oldname) > sizeof(oldref))
                die("Old branchname too long");

        if (check_ref_format(oldref))
                die("Invalid branch name: %s", oldref);

        if (snprintf(newref, sizeof(newref), "refs/heads/%s", newname) > sizeof(newref))
                die("New branchname too long");

        if (check_ref_format(newref))
                die("Invalid branch name: %s", newref);

        if (resolve_ref(newref, sha1, 1, NULL) && !force)
                die("A branch named '%s' already exists.", newname);

        snprintf(logmsg, sizeof(logmsg), "Branch: renamed %s to %s",
                 oldref, newref);

        if (rename_ref(oldref, newref, logmsg))
                die("Branch rename failed");

        /* no need to pass logmsg here as HEAD didn't really move */
        if (!strcmp(oldname, head) && create_symref("HEAD", newref, NULL))
                die("Branch renamed to %s, but HEAD is not updated!", newname);

        snprintf(oldsection, sizeof(oldsection), "branch.%s", oldref + 11);
        snprintf(newsection, sizeof(newsection), "branch.%s", newref + 11);
        if (git_config_rename_section(oldsection, newsection) < 0)
                die("Branch is renamed, but update of config-file failed");
}

static int opt_parse_with_commit(const struct option *opt, const char *arg, int unset)
{
        unsigned char sha1[20];
        struct commit *commit;

        if (!arg)
                return -1;
        if (get_sha1(arg, sha1))
                die("malformed object name %s", arg);
        commit = lookup_commit_reference(sha1);
        if (!commit)
                die("no such commit %s", arg);
        commit_list_insert(commit, opt->value);
        return 0;
}

static int opt_parse_merge_filter(const struct option *opt, const char *arg, int unset)
{
        merge_filter = ((opt->long_name[0] == 'n')
                        ? SHOW_NOT_MERGED
                        : SHOW_MERGED);
        if (unset)
                merge_filter = SHOW_NOT_MERGED; /* b/c for --no-merged */
        if (!arg)
                arg = "HEAD";
        if (get_sha1(arg, merge_filter_ref))
                die("malformed object name %s", arg);
        return 0;
}

int cmd_branch(int argc, const char **argv, const char *prefix)
{
        int delete = 0, rename = 0, force_create = 0;
        int verbose = 0, abbrev = DEFAULT_ABBREV, detached = 0;
        int reflog = 0;
        enum branch_track track;
        int kinds = REF_LOCAL_BRANCH;
        struct commit_list *with_commit = NULL;

        struct option options[] = {
                OPT_GROUP("Generic options"),
                OPT__VERBOSE(&verbose),
                OPT_SET_INT( 0 , "track",  &track, "set up tracking mode (see git-pull(1))",
                        BRANCH_TRACK_EXPLICIT),
                OPT_BOOLEAN( 0 , "color",  &branch_use_color, "use colored output"),
                OPT_SET_INT('r', NULL,     &kinds, "act on remote-tracking branches",
                        REF_REMOTE_BRANCH),
                {
                        OPTION_CALLBACK, 0, "contains", &with_commit, "commit",
                        "print only branches that contain the commit",
                        PARSE_OPT_LASTARG_DEFAULT,
                        opt_parse_with_commit, (intptr_t)"HEAD",
                },
                {
                        OPTION_CALLBACK, 0, "with", &with_commit, "commit",
                        "print only branches that contain the commit",
                        PARSE_OPT_HIDDEN | PARSE_OPT_LASTARG_DEFAULT,
                        opt_parse_with_commit, (intptr_t) "HEAD",
                },
                OPT__ABBREV(&abbrev),

                OPT_GROUP("Specific git-branch actions:"),
                OPT_SET_INT('a', NULL, &kinds, "list both remote-tracking and local branches",
                        REF_REMOTE_BRANCH | REF_LOCAL_BRANCH),
                OPT_BIT('d', NULL, &delete, "delete fully merged branch", 1),
                OPT_BIT('D', NULL, &delete, "delete branch (even if not merged)", 2),
                OPT_BIT('m', NULL, &rename, "move/rename a branch and its reflog", 1),
                OPT_BIT('M', NULL, &rename, "move/rename a branch, even if target exists", 2),
                OPT_BOOLEAN('l', NULL, &reflog, "create the branch's reflog"),
                OPT_BOOLEAN('f', NULL, &force_create, "force creation (when already exists)"),
                {
                        OPTION_CALLBACK, 0, "no-merged", &merge_filter_ref,
                        "commit", "print only not merged branches",
                        PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
                        opt_parse_merge_filter, (intptr_t) "HEAD",
                },
                {
                        OPTION_CALLBACK, 0, "merged", &merge_filter_ref,
                        "commit", "print only merged branches",
                        PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
                        opt_parse_merge_filter, (intptr_t) "HEAD",
                },
                OPT_END(),
        };

        git_config(git_branch_config, NULL);

        if (branch_use_color == -1)
                branch_use_color = git_use_color_default;

        track = git_branch_track;

        head = resolve_ref("HEAD", head_sha1, 0, NULL);
        if (!head)
                die("Failed to resolve HEAD as a valid ref.");
        head = xstrdup(head);
        if (!strcmp(head, "HEAD")) {
                detached = 1;
        } else {
                if (prefixcmp(head, "refs/heads/"))
                        die("HEAD not found below refs/heads!");
                head += 11;
        }
        hashcpy(merge_filter_ref, head_sha1);

        argc = parse_options(argc, argv, options, builtin_branch_usage, 0);
        if (!!delete + !!rename + !!force_create > 1)
                usage_with_options(builtin_branch_usage, options);

        if (delete)
                return delete_branches(argc, argv, delete > 1, kinds);
        else if (argc == 0)
                print_ref_list(kinds, detached, verbose, abbrev, with_commit);
        else if (rename && (argc == 1))
                rename_branch(head, argv[0], rename > 1);
        else if (rename && (argc == 2))
                rename_branch(argv[0], argv[1], rename > 1);
        else if (argc <= 2)
                create_branch(head, argv[0], (argc == 2) ? argv[1] : head,
                              force_create, reflog, track);
        else
                usage_with_options(builtin_branch_usage, options);

        return 0;
}