#include "builtin.h"
#include "cache.h"
#include "commit.h"
#include "diff.h"
#include "string-list.h"
#include "revision.h"
#include "utf8.h"
#include "mailmap.h"
#include "shortlog.h"
#include "parse-options.h"

static char const * const shortlog_usage[] = {
        N_("git shortlog [<options>] [<revision-range>] [[--] [<path>...]]"),
        NULL
};

/*
 * The util field of our string_list_items will contain one of two things:
 *
 *   - if --summary is not in use, it will point to a string list of the
 *     oneline subjects assigned to this author
 *
 *   - if --summary is in use, we don't need that list; we only need to know
 *     its size. So we abuse the pointer slot to store our integer counter.
 *
 *  This macro accesses the latter.
 */
#define UTIL_TO_INT(x) ((intptr_t)(x)->util)

static int compare_by_counter(const void *a1, const void *a2)
{
        const struct string_list_item *i1 = a1, *i2 = a2;
        return UTIL_TO_INT(i2) - UTIL_TO_INT(i1);
}

static int compare_by_list(const void *a1, const void *a2)
{
        const struct string_list_item *i1 = a1, *i2 = a2;
        const struct string_list *l1 = i1->util, *l2 = i2->util;

        if (l1->nr < l2->nr)
                return 1;
        else if (l1->nr == l2->nr)
                return 0;
        else
                return -1;
}

static void insert_one_record(struct shortlog *log,
                              const char *author,
                              const char *oneline)
{
        struct string_list_item *item;
        const char *mailbuf, *namebuf;
        size_t namelen, maillen;
        struct strbuf namemailbuf = STRBUF_INIT;
        struct ident_split ident;

        if (split_ident_line(&ident, author, strlen(author)))
                return;

        namebuf = ident.name_begin;
        mailbuf = ident.mail_begin;
        namelen = ident.name_end - ident.name_begin;
        maillen = ident.mail_end - ident.mail_begin;

        map_user(&log->mailmap, &mailbuf, &maillen, &namebuf, &namelen);
        strbuf_add(&namemailbuf, namebuf, namelen);

        if (log->email)
                strbuf_addf(&namemailbuf, " <%.*s>", (int)maillen, mailbuf);

        item = string_list_insert(&log->list, namemailbuf.buf);

        if (log->summary)
                item->util = (void *)(UTIL_TO_INT(item) + 1);
        else {
                const char *dot3 = log->common_repo_prefix;
                char *buffer, *p;
                struct strbuf subject = STRBUF_INIT;
                const char *eol;

                /* Skip any leading whitespace, including any blank lines. */
                while (*oneline && isspace(*oneline))
                        oneline++;
                eol = strchr(oneline, '\n');
                if (!eol)
                        eol = oneline + strlen(oneline);
                if (starts_with(oneline, "[PATCH")) {
                        char *eob = strchr(oneline, ']');
                        if (eob && (!eol || eob < eol))
                                oneline = eob + 1;
                }
                while (*oneline && isspace(*oneline) && *oneline != '\n')
                        oneline++;
                format_subject(&subject, oneline, " ");
                buffer = strbuf_detach(&subject, NULL);

                if (dot3) {
                        int dot3len = strlen(dot3);
                        if (dot3len > 5) {
                                while ((p = strstr(buffer, dot3)) != NULL) {
                                        int taillen = strlen(p) - dot3len;
                                        memcpy(p, "/.../", 5);
                                        memmove(p + 5, p + dot3len, taillen + 1);
                                }
                        }
                }

                if (item->util == NULL)
                        item->util = xcalloc(1, sizeof(struct string_list));
                string_list_append(item->util, buffer);
        }
}

static void read_from_stdin(struct shortlog *log)
{
        struct strbuf author = STRBUF_INIT;
        struct strbuf oneline = STRBUF_INIT;

        while (strbuf_getline_lf(&author, stdin) != EOF) {
                const char *v;
                if (!skip_prefix(author.buf, "Author: ", &v) &&
                    !skip_prefix(author.buf, "author ", &v))
                        continue;
                while (strbuf_getline_lf(&oneline, stdin) != EOF &&
                       oneline.len)
                        ; /* discard headers */
                while (strbuf_getline_lf(&oneline, stdin) != EOF &&
                       !oneline.len)
                        ; /* discard blanks */
                insert_one_record(log, v, oneline.buf);
        }
        strbuf_release(&author);
        strbuf_release(&oneline);
}

void shortlog_add_commit(struct shortlog *log, struct commit *commit)
{
        struct strbuf author = STRBUF_INIT;
        struct strbuf oneline = STRBUF_INIT;
        struct pretty_print_context ctx = {0};

        ctx.fmt = CMIT_FMT_USERFORMAT;
        ctx.abbrev = log->abbrev;
        ctx.subject = "";
        ctx.after_subject = "";
        ctx.date_mode.type = DATE_NORMAL;
        ctx.output_encoding = get_log_output_encoding();

        format_commit_message(commit, "%an <%ae>", &author, &ctx);
        if (!log->summary) {
                if (log->user_format)
                        pretty_print_commit(&ctx, commit, &oneline);
                else
                        format_commit_message(commit, "%s", &oneline, &ctx);
        }

        insert_one_record(log, author.buf, oneline.len ? oneline.buf : "<none>");

        strbuf_release(&author);
        strbuf_release(&oneline);
}

static void get_from_rev(struct rev_info *rev, struct shortlog *log)
{
        struct commit *commit;

        if (prepare_revision_walk(rev))
                die(_("revision walk setup failed"));
        while ((commit = get_revision(rev)) != NULL)
                shortlog_add_commit(log, commit);
}

static int parse_uint(char const **arg, int comma, int defval)
{
        unsigned long ul;
        int ret;
        char *endp;

        ul = strtoul(*arg, &endp, 10);
        if (*endp && *endp != comma)
                return -1;
        if (ul > INT_MAX)
                return -1;
        ret = *arg == endp ? defval : (int)ul;
        *arg = *endp ? endp + 1 : endp;
        return ret;
}

static const char wrap_arg_usage[] = "-w[<width>[,<indent1>[,<indent2>]]]";
#define DEFAULT_WRAPLEN 76
#define DEFAULT_INDENT1 6
#define DEFAULT_INDENT2 9

static int parse_wrap_args(const struct option *opt, const char *arg, int unset)
{
        struct shortlog *log = opt->value;

        log->wrap_lines = !unset;
        if (unset)
                return 0;
        if (!arg) {
                log->wrap = DEFAULT_WRAPLEN;
                log->in1 = DEFAULT_INDENT1;
                log->in2 = DEFAULT_INDENT2;
                return 0;
        }

        log->wrap = parse_uint(&arg, ',', DEFAULT_WRAPLEN);
        log->in1 = parse_uint(&arg, ',', DEFAULT_INDENT1);
        log->in2 = parse_uint(&arg, '\0', DEFAULT_INDENT2);
        if (log->wrap < 0 || log->in1 < 0 || log->in2 < 0)
                return error(wrap_arg_usage);
        if (log->wrap &&
            ((log->in1 && log->wrap <= log->in1) ||
             (log->in2 && log->wrap <= log->in2)))
                return error(wrap_arg_usage);
        return 0;
}

void shortlog_init(struct shortlog *log)
{
        memset(log, 0, sizeof(*log));

        read_mailmap(&log->mailmap, &log->common_repo_prefix);

        log->list.strdup_strings = 1;
        log->wrap = DEFAULT_WRAPLEN;
        log->in1 = DEFAULT_INDENT1;
        log->in2 = DEFAULT_INDENT2;
}

int cmd_shortlog(int argc, const char **argv, const char *prefix)
{
        struct shortlog log = { STRING_LIST_INIT_NODUP };
        struct rev_info rev;
        int nongit = !startup_info->have_repository;

        const struct option options[] = {
                OPT_BOOL('n', "numbered", &log.sort_by_number,
                         N_("sort output according to the number of commits per author")),
                OPT_BOOL('s', "summary", &log.summary,
                         N_("Suppress commit descriptions, only provides commit count")),
                OPT_BOOL('e', "email", &log.email,
                         N_("Show the email address of each author")),
                { OPTION_CALLBACK, 'w', NULL, &log, N_("w[,i1[,i2]]"),
                        N_("Linewrap output"), PARSE_OPT_OPTARG, &parse_wrap_args },
                OPT_END(),
        };

        struct parse_opt_ctx_t ctx;

        git_config(git_default_config, NULL);
        shortlog_init(&log);
        init_revisions(&rev, prefix);
        parse_options_start(&ctx, argc, argv, prefix, options,
                            PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);

        for (;;) {
                switch (parse_options_step(&ctx, options, shortlog_usage)) {
                case PARSE_OPT_HELP:
                        exit(129);
                case PARSE_OPT_DONE:
                        goto parse_done;
                }
                parse_revision_opt(&rev, &ctx, options, shortlog_usage);
        }
parse_done:
        argc = parse_options_end(&ctx);

        if (setup_revisions(argc, argv, &rev, NULL) != 1) {
                error(_("unrecognized argument: %s"), argv[1]);
                usage_with_options(shortlog_usage, options);
        }

        log.user_format = rev.commit_format == CMIT_FMT_USERFORMAT;
        log.abbrev = rev.abbrev;
        log.file = rev.diffopt.file;

        /* assume HEAD if from a tty */
        if (!nongit && !rev.pending.nr && isatty(0))
                add_head_to_pending(&rev);
        if (rev.pending.nr == 0) {
                if (isatty(0))
                        fprintf(stderr, _("(reading log message from standard input)\n"));
                read_from_stdin(&log);
        }
        else
                get_from_rev(&rev, &log);

        shortlog_output(&log);
        if (log.file != stdout)
                fclose(log.file);
        return 0;
}

static void add_wrapped_shortlog_msg(struct strbuf *sb, const char *s,
                                     const struct shortlog *log)
{
        strbuf_add_wrapped_text(sb, s, log->in1, log->in2, log->wrap);
        strbuf_addch(sb, '\n');
}

void shortlog_output(struct shortlog *log)
{
        int i, j;
        struct strbuf sb = STRBUF_INIT;

        if (log->sort_by_number)
                qsort(log->list.items, log->list.nr, sizeof(struct string_list_item),
                      log->summary ? compare_by_counter : compare_by_list);
        for (i = 0; i < log->list.nr; i++) {
                const struct string_list_item *item = &log->list.items[i];
                if (log->summary) {
                        fprintf(log->file, "%6d\t%s\n",
                                (int)UTIL_TO_INT(item), item->string);
                } else {
                        struct string_list *onelines = item->util;
                        fprintf(log->file, "%s (%d):\n",
                                item->string, onelines->nr);
                        for (j = onelines->nr - 1; j >= 0; j--) {
                                const char *msg = onelines->items[j].string;

                                if (log->wrap_lines) {
                                        strbuf_reset(&sb);
                                        add_wrapped_shortlog_msg(&sb, msg, log);
                                        fwrite(sb.buf, sb.len, 1, log->file);
                                }
                                else
                                        fprintf(log->file, "      %s\n", msg);
                        }
                        putc('\n', log->file);
                        onelines->strdup_strings = 1;
                        string_list_clear(onelines, 0);
                        free(onelines);
                }

                log->list.items[i].util = NULL;
        }

        strbuf_release(&sb);
        log->list.strdup_strings = 1;
        string_list_clear(&log->list, 1);
        clear_mailmap(&log->mailmap);
}