#include "builtin.h"
#include "cache.h"
#include "config.h"
#include "parse-options.h"
#include "sequencer.h"
#include "rebase-interactive.h"
#include "argv-array.h"
#include "refs.h"
#include "rerere.h"
#include "run-command.h"

static GIT_PATH_FUNC(path_state_dir, "rebase-merge/")
static GIT_PATH_FUNC(path_squash_onto, "rebase-merge/squash-onto")
static GIT_PATH_FUNC(path_interactive, "rebase-merge/interactive")

static int add_exec_commands(struct string_list *commands)
{
        const char *todo_file = rebase_path_todo();
        struct todo_list todo_list = TODO_LIST_INIT;
        int res;

        if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
                return error_errno(_("could not read '%s'."), todo_file);

        if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
                                        &todo_list)) {
                todo_list_release(&todo_list);
                return error(_("unusable todo list: '%s'"), todo_file);
        }

        todo_list_add_exec_commands(&todo_list, commands);
        res = todo_list_write_to_file(the_repository, &todo_list,
                                      todo_file, NULL, NULL, -1, 0);
        todo_list_release(&todo_list);

        if (res)
                return error_errno(_("could not write '%s'."), todo_file);
        return 0;
}

static int get_revision_ranges(const char *upstream, const char *onto,
                               const char **head_hash,
                               char **revisions, char **shortrevisions)
{
        const char *base_rev = upstream ? upstream : onto, *shorthead;
        struct object_id orig_head;

        if (get_oid("HEAD", &orig_head))
                return error(_("no HEAD?"));

        *head_hash = find_unique_abbrev(&orig_head, GIT_MAX_HEXSZ);
        *revisions = xstrfmt("%s...%s", base_rev, *head_hash);

        shorthead = find_unique_abbrev(&orig_head, DEFAULT_ABBREV);

        if (upstream) {
                const char *shortrev;
                struct object_id rev_oid;

                get_oid(base_rev, &rev_oid);
                shortrev = find_unique_abbrev(&rev_oid, DEFAULT_ABBREV);

                *shortrevisions = xstrfmt("%s..%s", shortrev, shorthead);
        } else
                *shortrevisions = xstrdup(shorthead);

        return 0;
}

static int init_basic_state(struct replay_opts *opts, const char *head_name,
                            const char *onto, const char *orig_head)
{
        FILE *interactive;

        if (!is_directory(path_state_dir()) && mkdir_in_gitdir(path_state_dir()))
                return error_errno(_("could not create temporary %s"), path_state_dir());

        delete_reflog("REBASE_HEAD");

        interactive = fopen(path_interactive(), "w");
        if (!interactive)
                return error_errno(_("could not mark as interactive"));
        fclose(interactive);

        return write_basic_state(opts, head_name, onto, orig_head);
}

static int do_interactive_rebase(struct replay_opts *opts, unsigned flags,
                                 const char *switch_to, const char *upstream,
                                 const char *onto, const char *onto_name,
                                 const char *squash_onto, const char *head_name,
                                 const char *restrict_revision, char *raw_strategies,
                                 struct string_list *commands, unsigned autosquash)
{
        int ret;
        const char *head_hash = NULL;
        char *revisions = NULL, *shortrevisions = NULL;
        struct argv_array make_script_args = ARGV_ARRAY_INIT;
        struct todo_list todo_list = TODO_LIST_INIT;

        if (prepare_branch_to_be_rebased(opts, switch_to))
                return -1;

        if (get_revision_ranges(upstream, onto, &head_hash,
                                &revisions, &shortrevisions))
                return -1;

        if (raw_strategies)
                parse_strategy_opts(opts, raw_strategies);

        if (init_basic_state(opts, head_name, onto, head_hash)) {
                free(revisions);
                free(shortrevisions);

                return -1;
        }

        if (!upstream && squash_onto)
                write_file(path_squash_onto(), "%s\n", squash_onto);

        argv_array_pushl(&make_script_args, "", revisions, NULL);
        if (restrict_revision)
                argv_array_push(&make_script_args, restrict_revision);

        ret = sequencer_make_script(the_repository, &todo_list.buf,
                                    make_script_args.argc, make_script_args.argv,
                                    flags);

        if (ret)
                error(_("could not generate todo list"));
        else {
                discard_cache();
                if (todo_list_parse_insn_buffer(the_repository, todo_list.buf.buf,
                                                &todo_list))
                        BUG("unusable todo list");

                ret = complete_action(the_repository, opts, flags, shortrevisions, onto_name,
                                      onto, head_hash, commands, autosquash, &todo_list);
        }

        free(revisions);
        free(shortrevisions);
        todo_list_release(&todo_list);
        argv_array_clear(&make_script_args);

        return ret;
}

static const char * const builtin_rebase_interactive_usage[] = {
        N_("git rebase--interactive [<options>]"),
        NULL
};

int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
{
        struct replay_opts opts = REPLAY_OPTS_INIT;
        unsigned flags = 0, keep_empty = 0, rebase_merges = 0, autosquash = 0;
        int abbreviate_commands = 0, rebase_cousins = -1, ret = 0;
        const char *onto = NULL, *onto_name = NULL, *restrict_revision = NULL,
                *squash_onto = NULL, *upstream = NULL, *head_name = NULL,
                *switch_to = NULL, *cmd = NULL;
        struct string_list commands = STRING_LIST_INIT_DUP;
        char *raw_strategies = NULL;
        enum {
                NONE = 0, CONTINUE, SKIP, EDIT_TODO, SHOW_CURRENT_PATCH,
                SHORTEN_OIDS, EXPAND_OIDS, CHECK_TODO_LIST, REARRANGE_SQUASH, ADD_EXEC
        } command = 0;
        struct option options[] = {
                OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
                OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
                OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
                         N_("allow commits with empty messages")),
                OPT_BOOL(0, "rebase-merges", &rebase_merges, N_("rebase merge commits")),
                OPT_BOOL(0, "rebase-cousins", &rebase_cousins,
                         N_("keep original branch points of cousins")),
                OPT_BOOL(0, "autosquash", &autosquash,
                         N_("move commits that begin with squash!/fixup!")),
                OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
                OPT__VERBOSE(&opts.verbose, N_("be verbose")),
                OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
                            CONTINUE),
                OPT_CMDMODE(0, "skip", &command, N_("skip commit"), SKIP),
                OPT_CMDMODE(0, "edit-todo", &command, N_("edit the todo list"),
                            EDIT_TODO),
                OPT_CMDMODE(0, "show-current-patch", &command, N_("show the current patch"),
                            SHOW_CURRENT_PATCH),
                OPT_CMDMODE(0, "shorten-ids", &command,
                        N_("shorten commit ids in the todo list"), SHORTEN_OIDS),
                OPT_CMDMODE(0, "expand-ids", &command,
                        N_("expand commit ids in the todo list"), EXPAND_OIDS),
                OPT_CMDMODE(0, "check-todo-list", &command,
                        N_("check the todo list"), CHECK_TODO_LIST),
                OPT_CMDMODE(0, "rearrange-squash", &command,
                        N_("rearrange fixup/squash lines"), REARRANGE_SQUASH),
                OPT_CMDMODE(0, "add-exec-commands", &command,
                        N_("insert exec commands in todo list"), ADD_EXEC),
                OPT_STRING(0, "onto", &onto, N_("onto"), N_("onto")),
                OPT_STRING(0, "restrict-revision", &restrict_revision,
                           N_("restrict-revision"), N_("restrict revision")),
                OPT_STRING(0, "squash-onto", &squash_onto, N_("squash-onto"),
                           N_("squash onto")),
                OPT_STRING(0, "upstream", &upstream, N_("upstream"),
                           N_("the upstream commit")),
                OPT_STRING(0, "head-name", &head_name, N_("head-name"), N_("head name")),
                { OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign, N_("key-id"),
                        N_("GPG-sign commits"),
                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
                OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
                           N_("rebase strategy")),
                OPT_STRING(0, "strategy-opts", &raw_strategies, N_("strategy-opts"),
                           N_("strategy options")),
                OPT_STRING(0, "switch-to", &switch_to, N_("switch-to"),
                           N_("the branch or commit to checkout")),
                OPT_STRING(0, "onto-name", &onto_name, N_("onto-name"), N_("onto name")),
                OPT_STRING(0, "cmd", &cmd, N_("cmd"), N_("the command to run")),
                OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_auto),
                OPT_END()
        };

        sequencer_init_config(&opts);
        git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);

        opts.action = REPLAY_INTERACTIVE_REBASE;
        opts.allow_ff = 1;
        opts.allow_empty = 1;

        if (argc == 1)
                usage_with_options(builtin_rebase_interactive_usage, options);

        argc = parse_options(argc, argv, NULL, options,
                        builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);

        opts.gpg_sign = xstrdup_or_null(opts.gpg_sign);

        flags |= keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
        flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
        flags |= rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
        flags |= rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
        flags |= command == SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;

        if (rebase_cousins >= 0 && !rebase_merges)
                warning(_("--[no-]rebase-cousins has no effect without "
                          "--rebase-merges"));

        if (cmd && *cmd) {
                string_list_split(&commands, cmd, '\n', -1);

                /* rebase.c adds a new line to cmd after every command,
                 * so here the last command is always empty */
                string_list_remove_empty_items(&commands, 0);
        }

        switch (command) {
        case NONE:
                if (!onto && !upstream)
                        die(_("a base commit must be provided with --upstream or --onto"));

                ret = do_interactive_rebase(&opts, flags, switch_to, upstream, onto,
                                            onto_name, squash_onto, head_name, restrict_revision,
                                            raw_strategies, &commands, autosquash);
                break;
        case SKIP: {
                struct string_list merge_rr = STRING_LIST_INIT_DUP;

                rerere_clear(the_repository, &merge_rr);
                /* fallthrough */
        case CONTINUE:
                ret = sequencer_continue(the_repository, &opts);
                break;
        }
        case EDIT_TODO:
                ret = edit_todo_list(the_repository, flags);
                break;
        case SHOW_CURRENT_PATCH: {
                struct child_process cmd = CHILD_PROCESS_INIT;

                cmd.git_cmd = 1;
                argv_array_pushl(&cmd.args, "show", "REBASE_HEAD", "--", NULL);
                ret = run_command(&cmd);

                break;
        }
        case SHORTEN_OIDS:
        case EXPAND_OIDS:
                ret = transform_todo_file(the_repository, flags);
                break;
        case CHECK_TODO_LIST:
                ret = check_todo_list_from_file(the_repository);
                break;
        case REARRANGE_SQUASH:
                ret = rearrange_squash_in_todo_file(the_repository);
                break;
        case ADD_EXEC:
                ret = add_exec_commands(&commands);
                break;
        default:
                BUG("invalid command '%d'", command);
        }

        string_list_clear(&commands, 0);
        return !!ret;
}