#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[] = {
        "git revert [options] <commit-ish>",
        "git revert <subcommand>",
        NULL
};

static const char * const cherry_pick_usage[] = {
        "git cherry-pick [options] <commit-ish>",
        "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;
}

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 void verify_opt_mutually_compatible(const char *me, ...)
{
        const char *opt1, *opt2 = NULL;
        va_list ap;

        va_start(ap, me);
        while ((opt1 = va_arg(ap, const char *))) {
                if (va_arg(ap, int))
                        break;
        }
        if (opt1) {
                while ((opt2 = va_arg(ap, const char *))) {
                        if (va_arg(ap, int))
                                break;
                }
        }

        if (opt1 && opt2)
                die(_("%s: %s cannot be used with %s"), me, opt1, opt2);
}

static void parse_args(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 remove_state = 0;
        int contin = 0;
        int rollback = 0;
        struct option options[] = {
                OPT_BOOLEAN(0, "quit", &remove_state, "end revert or cherry-pick sequence"),
                OPT_BOOLEAN(0, "continue", &contin, "resume revert or cherry-pick sequence"),
                OPT_BOOLEAN(0, "abort", &rollback, "cancel revert or cherry-pick sequence"),
                OPT_BOOLEAN('n', "no-commit", &opts->no_commit, "don't automatically commit"),
                OPT_BOOLEAN('e', "edit", &opts->edit, "edit the commit message"),
                OPT_NOOP_NOARG('r', NULL),
                OPT_BOOLEAN('s', "signoff", &opts->signoff, "add Signed-off-by:"),
                OPT_INTEGER('m', "mainline", &opts->mainline, "parent number"),
                OPT_RERERE_AUTOUPDATE(&opts->allow_rerere_auto),
                OPT_STRING(0, "strategy", &opts->strategy, "strategy", "merge strategy"),
                OPT_CALLBACK('X', "strategy-option", &opts, "option",
                        "option for merge strategy", option_parse_x),
                OPT_END(),
                OPT_END(),
                OPT_END(),
                OPT_END(),
        };

        if (opts->action == REPLAY_PICK) {
                struct option cp_extra[] = {
                        OPT_BOOLEAN('x', NULL, &opts->record_origin, "append commit name"),
                        OPT_BOOLEAN(0, "ff", &opts->allow_ff, "allow fast-forward"),
                        OPT_BOOLEAN(0, "allow-empty", &opts->allow_empty, "preserve empty commits"),
                        OPT_END(),
                };
                if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
                        die(_("program error"));
        }

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

        /* Check for incompatible subcommands */
        verify_opt_mutually_compatible(me,
                                "--quit", remove_state,
                                "--continue", contin,
                                "--abort", rollback,
                                NULL);

        /* Set the subcommand */
        if (remove_state)
                opts->subcommand = REPLAY_REMOVE_STATE;
        else if (contin)
                opts->subcommand = REPLAY_CONTINUE;
        else if (rollback)
                opts->subcommand = REPLAY_ROLLBACK;
        else
                opts->subcommand = REPLAY_NONE;

        /* Check for incompatible command line arguments */
        if (opts->subcommand != REPLAY_NONE) {
                char *this_operation;
                if (opts->subcommand == REPLAY_REMOVE_STATE)
                        this_operation = "--quit";
                else if (opts->subcommand == REPLAY_CONTINUE)
                        this_operation = "--continue";
                else {
                        assert(opts->subcommand == REPLAY_ROLLBACK);
                        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 (opts->subcommand != REPLAY_NONE) {
                opts->revs = NULL;
        } else {
                opts->revs = xmalloc(sizeof(*opts->revs));
                init_revisions(opts->revs, NULL);
                opts->revs->no_walk = 1;
                if (argc < 2)
                        usage_with_options(usage_str, options);
                argc = setup_revisions(argc, argv, opts->revs, NULL);
        }

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

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

        memset(&opts, 0, sizeof(opts));
        if (isatty(0))
                opts.edit = 1;
        opts.action = REPLAY_REVERT;
        git_config(git_default_config, NULL);
        parse_args(argc, argv, &opts);
        res = sequencer_pick_revisions(&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;
        int res;

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