#include "cache.h"
#include "builtin.h"
#include "parse-options.h"
#include "diff.h"
#include "revision.h"
#include "rerere.h"
#include "dir.h"
#include "sequencer.h"

/*
 * This implements the builtins revert and cherry-pick.
 *
 * Copyright (c) 2007 Johannes E. Schindelin
 *
 * Based on git-revert.sh, which is
 *
 * Copyright (c) 2005 Linus Torvalds
 * Copyright (c) 2005 Junio C Hamano
 */

static const char * const revert_usage[] = {
        N_("git revert [<options>] <commit-ish>..."),
        N_("git revert <subcommand>"),
        NULL
};

static const char * const cherry_pick_usage[] = {
        N_("git cherry-pick [<options>] <commit-ish>..."),
        N_("git cherry-pick <subcommand>"),
        NULL
};

static const char *action_name(const struct replay_opts *opts)
{
        return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
}

static const char * const *revert_or_cherry_pick_usage(struct replay_opts *opts)
{
        return opts->action == REPLAY_REVERT ? revert_usage : cherry_pick_usage;
}

static int option_parse_x(const struct option *opt,
                          const char *arg, int unset)
{
        struct replay_opts **opts_ptr = opt->value;
        struct replay_opts *opts = *opts_ptr;

        if (unset)
                return 0;

        ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
        opts->xopts[opts->xopts_nr++] = xstrdup(arg);
        return 0;
}

LAST_ARG_MUST_BE_NULL
static void verify_opt_compatible(const char *me, const char *base_opt, ...)
{
        const char *this_opt;
        va_list ap;

        va_start(ap, base_opt);
        while ((this_opt = va_arg(ap, const char *))) {
                if (va_arg(ap, int))
                        break;
        }
        va_end(ap);

        if (this_opt)
                die(_("%s: %s cannot be used with %s"), me, this_opt, base_opt);
}

static int run_sequencer(int argc, const char **argv, struct replay_opts *opts)
{
        const char * const * usage_str = revert_or_cherry_pick_usage(opts);
        const char *me = action_name(opts);
        int cmd = 0;
        struct option base_options[] = {
                OPT_CMDMODE(0, "quit", &cmd, N_("end revert or cherry-pick sequence"), 'q'),
                OPT_CMDMODE(0, "continue", &cmd, N_("resume revert or cherry-pick sequence"), 'c'),
                OPT_CMDMODE(0, "abort", &cmd, N_("cancel revert or cherry-pick sequence"), 'a'),
                OPT_BOOL('n', "no-commit", &opts->no_commit, N_("don't automatically commit")),
                OPT_BOOL('e', "edit", &opts->edit, N_("edit the commit message")),
                OPT_NOOP_NOARG('r', NULL),
                OPT_BOOL('s', "signoff", &opts->signoff, N_("add Signed-off-by:")),
                OPT_INTEGER('m', "mainline", &opts->mainline, N_("parent number")),
                OPT_RERERE_AUTOUPDATE(&opts->allow_rerere_auto),
                OPT_STRING(0, "strategy", &opts->strategy, N_("strategy"), N_("merge strategy")),
                OPT_CALLBACK('X', "strategy-option", &opts, N_("option"),
                        N_("option for merge strategy"), option_parse_x),
                { OPTION_STRING, 'S', "gpg-sign", &opts->gpg_sign, N_("key-id"),
                  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
                OPT_END()
        };
        struct option *options = base_options;

        if (opts->action == REPLAY_PICK) {
                struct option cp_extra[] = {
                        OPT_BOOL('x', NULL, &opts->record_origin, N_("append commit name")),
                        OPT_BOOL(0, "ff", &opts->allow_ff, N_("allow fast-forward")),
                        OPT_BOOL(0, "allow-empty", &opts->allow_empty, N_("preserve initially empty commits")),
                        OPT_BOOL(0, "allow-empty-message", &opts->allow_empty_message, N_("allow commits with empty messages")),
                        OPT_BOOL(0, "keep-redundant-commits", &opts->keep_redundant_commits, N_("keep redundant, empty commits")),
                        OPT_END(),
                };
                options = parse_options_concat(options, cp_extra);
        }

        argc = parse_options(argc, argv, NULL, options, usage_str,
                        PARSE_OPT_KEEP_ARGV0 |
                        PARSE_OPT_KEEP_UNKNOWN);

        /* implies allow_empty */
        if (opts->keep_redundant_commits)
                opts->allow_empty = 1;

        /* Check for incompatible command line arguments */
        if (cmd) {
                char *this_operation;
                if (cmd == 'q')
                        this_operation = "--quit";
                else if (cmd == 'c')
                        this_operation = "--continue";
                else {
                        assert(cmd == 'a');
                        this_operation = "--abort";
                }

                verify_opt_compatible(me, this_operation,
                                "--no-commit", opts->no_commit,
                                "--signoff", opts->signoff,
                                "--mainline", opts->mainline,
                                "--strategy", opts->strategy ? 1 : 0,
                                "--strategy-option", opts->xopts ? 1 : 0,
                                "-x", opts->record_origin,
                                "--ff", opts->allow_ff,
                                NULL);
        }

        if (opts->allow_ff)
                verify_opt_compatible(me, "--ff",
                                "--signoff", opts->signoff,
                                "--no-commit", opts->no_commit,
                                "-x", opts->record_origin,
                                "--edit", opts->edit,
                                NULL);

        if (cmd) {
                opts->revs = NULL;
        } else {
                struct setup_revision_opt s_r_opt;
                opts->revs = xmalloc(sizeof(*opts->revs));
                init_revisions(opts->revs, NULL);
                opts->revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
                if (argc < 2)
                        usage_with_options(usage_str, options);
                if (!strcmp(argv[1], "-"))
                        argv[1] = "@{-1}";
                memset(&s_r_opt, 0, sizeof(s_r_opt));
                s_r_opt.assume_dashdash = 1;
                argc = setup_revisions(argc, argv, opts->revs, &s_r_opt);
        }

        if (argc > 1)
                usage_with_options(usage_str, options);

        /* These option values will be free()d */
        opts->gpg_sign = xstrdup_or_null(opts->gpg_sign);
        opts->strategy = xstrdup_or_null(opts->strategy);

        if (cmd == 'q')
                return sequencer_remove_state(opts);
        if (cmd == 'c')
                return sequencer_continue(opts);
        if (cmd == 'a')
                return sequencer_rollback(opts);
        return sequencer_pick_revisions(opts);
}

int cmd_revert(int argc, const char **argv, const char *prefix)
{
        struct replay_opts opts = REPLAY_OPTS_INIT;
        int res;

        if (isatty(0))
                opts.edit = 1;
        opts.action = REPLAY_REVERT;
        git_config(git_default_config, NULL);
        res = run_sequencer(argc, argv, &opts);
        if (res < 0)
                die(_("revert failed"));
        return res;
}

int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
{
        struct replay_opts opts = REPLAY_OPTS_INIT;
        int res;

        opts.action = REPLAY_PICK;
        git_config(git_default_config, NULL);
        res = run_sequencer(argc, argv, &opts);
        if (res < 0)
                die(_("cherry-pick failed"));
        return res;
}