#include "cache.h"
#include "diff.h"
#include "commit.h"
#include "tag.h"
#include "graph.h"
#include "log-tree.h"
#include "reflog-walk.h"
#include "refs.h"
#include "string-list.h"

struct decoration name_decoration = { "object names" };

static void add_name_decoration(const char *prefix, const char *name, struct object *obj)
{
        int plen = strlen(prefix);
        int nlen = strlen(name);
        struct name_decoration *res = xmalloc(sizeof(struct name_decoration) + plen + nlen);
        memcpy(res->name, prefix, plen);
        memcpy(res->name + plen, name, nlen + 1);
        res->next = add_decoration(&name_decoration, obj, res);
}

static int add_ref_decoration(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
{
        struct object *obj = parse_object(sha1);
        if (!obj)
                return 0;
        refname = prettify_refname(refname);
        add_name_decoration("", refname, obj);
        while (obj->type == OBJ_TAG) {
                obj = ((struct tag *)obj)->tagged;
                if (!obj)
                        break;
                add_name_decoration("tag: ", refname, obj);
        }
        return 0;
}

void load_ref_decorations(void)
{
        static int loaded;
        if (!loaded) {
                loaded = 1;
                for_each_ref(add_ref_decoration, NULL);
        }
}

static void show_parents(struct commit *commit, int abbrev)
{
        struct commit_list *p;
        for (p = commit->parents; p ; p = p->next) {
                struct commit *parent = p->item;
                printf(" %s", find_unique_abbrev(parent->object.sha1, abbrev));
        }
}

void show_decorations(struct rev_info *opt, struct commit *commit)
{
        const char *prefix;
        struct name_decoration *decoration;

        if (opt->show_source && commit->util)
                printf("\t%s", (char *) commit->util);
        if (!opt->show_decorations)
                return;
        decoration = lookup_decoration(&name_decoration, &commit->object);
        if (!decoration)
                return;
        prefix = " (";
        while (decoration) {
                printf("%s%s", prefix, decoration->name);
                prefix = ", ";
                decoration = decoration->next;
        }
        putchar(')');
}

/*
 * Search for "^[-A-Za-z]+: [^@]+@" pattern. It usually matches
 * Signed-off-by: and Acked-by: lines.
 */
static int detect_any_signoff(char *letter, int size)
{
        char *cp;
        int seen_colon = 0;
        int seen_at = 0;
        int seen_name = 0;
        int seen_head = 0;

        cp = letter + size;
        while (letter <= --cp && *cp == '\n')
                continue;

        while (letter <= cp) {
                char ch = *cp--;
                if (ch == '\n')
                        break;

                if (!seen_at) {
                        if (ch == '@')
                                seen_at = 1;
                        continue;
                }
                if (!seen_colon) {
                        if (ch == '@')
                                return 0;
                        else if (ch == ':')
                                seen_colon = 1;
                        else
                                seen_name = 1;
                        continue;
                }
                if (('A' <= ch && ch <= 'Z') ||
                    ('a' <= ch && ch <= 'z') ||
                    ch == '-') {
                        seen_head = 1;
                        continue;
                }
                /* no empty last line doesn't match */
                return 0;
        }
        return seen_head && seen_name;
}

static void append_signoff(struct strbuf *sb, const char *signoff)
{
        static const char signed_off_by[] = "Signed-off-by: ";
        size_t signoff_len = strlen(signoff);
        int has_signoff = 0;
        char *cp;

        cp = sb->buf;

        /* First see if we already have the sign-off by the signer */
        while ((cp = strstr(cp, signed_off_by))) {

                has_signoff = 1;

                cp += strlen(signed_off_by);
                if (cp + signoff_len >= sb->buf + sb->len)
                        break;
                if (strncmp(cp, signoff, signoff_len))
                        continue;
                if (!isspace(cp[signoff_len]))
                        continue;
                /* we already have him */
                return;
        }

        if (!has_signoff)
                has_signoff = detect_any_signoff(sb->buf, sb->len);

        if (!has_signoff)
                strbuf_addch(sb, '\n');

        strbuf_addstr(sb, signed_off_by);
        strbuf_add(sb, signoff, signoff_len);
        strbuf_addch(sb, '\n');
}

static unsigned int digits_in_number(unsigned int number)
{
        unsigned int i = 10, result = 1;
        while (i <= number) {
                i *= 10;
                result++;
        }
        return result;
}

static int has_non_ascii(const char *s)
{
        int ch;
        if (!s)
                return 0;
        while ((ch = *s++) != '\0') {
                if (non_ascii(ch))
                        return 1;
        }
        return 0;
}

void get_patch_filename(struct commit *commit, int nr, const char *suffix,
                        struct strbuf *buf)
{
        int suffix_len = strlen(suffix) + 1;
        int start_len = buf->len;

        strbuf_addf(buf, commit ? "%04d-" : "%d", nr);
        if (commit) {
                int max_len = start_len + FORMAT_PATCH_NAME_MAX - suffix_len;

                format_commit_message(commit, "%f", buf, DATE_NORMAL);
                if (max_len < buf->len)
                        strbuf_setlen(buf, max_len);
                strbuf_addstr(buf, suffix);
        }
}

void log_write_email_headers(struct rev_info *opt, struct commit *commit,
                             const char **subject_p,
                             const char **extra_headers_p,
                             int *need_8bit_cte_p)
{
        const char *subject = NULL;
        const char *extra_headers = opt->extra_headers;
        const char *name = sha1_to_hex(commit->object.sha1);

        *need_8bit_cte_p = 0; /* unknown */
        if (opt->total > 0) {
                static char buffer[64];
                snprintf(buffer, sizeof(buffer),
                         "Subject: [%s %0*d/%d] ",
                         opt->subject_prefix,
                         digits_in_number(opt->total),
                         opt->nr, opt->total);
                subject = buffer;
        } else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
                static char buffer[256];
                snprintf(buffer, sizeof(buffer),
                         "Subject: [%s] ",
                         opt->subject_prefix);
                subject = buffer;
        } else {
                subject = "Subject: ";
        }

        printf("From %s Mon Sep 17 00:00:00 2001\n", name);
        graph_show_oneline(opt->graph);
        if (opt->message_id) {
                printf("Message-Id: <%s>\n", opt->message_id);
                graph_show_oneline(opt->graph);
        }
        if (opt->ref_message_ids && opt->ref_message_ids->nr > 0) {
                int i, n;
                n = opt->ref_message_ids->nr;
                printf("In-Reply-To: <%s>\n", opt->ref_message_ids->items[n-1].string);
                for (i = 0; i < n; i++)
                        printf("%s<%s>\n", (i > 0 ? "\t" : "References: "),
                               opt->ref_message_ids->items[i].string);
                graph_show_oneline(opt->graph);
        }
        if (opt->mime_boundary) {
                static char subject_buffer[1024];
                static char buffer[1024];
                struct strbuf filename =  STRBUF_INIT;
                *need_8bit_cte_p = -1; /* NEVER */
                snprintf(subject_buffer, sizeof(subject_buffer) - 1,
                         "%s"
                         "MIME-Version: 1.0\n"
                         "Content-Type: multipart/mixed;"
                         " boundary=\"%s%s\"\n"
                         "\n"
                         "This is a multi-part message in MIME "
                         "format.\n"
                         "--%s%s\n"
                         "Content-Type: text/plain; "
                         "charset=UTF-8; format=fixed\n"
                         "Content-Transfer-Encoding: 8bit\n\n",
                         extra_headers ? extra_headers : "",
                         mime_boundary_leader, opt->mime_boundary,
                         mime_boundary_leader, opt->mime_boundary);
                extra_headers = subject_buffer;

                get_patch_filename(opt->numbered_files ? NULL : commit, opt->nr,
                                    opt->patch_suffix, &filename);
                snprintf(buffer, sizeof(buffer) - 1,
                         "\n--%s%s\n"
                         "Content-Type: text/x-patch;"
                         " name=\"%s\"\n"
                         "Content-Transfer-Encoding: 8bit\n"
                         "Content-Disposition: %s;"
                         " filename=\"%s\"\n\n",
                         mime_boundary_leader, opt->mime_boundary,
                         filename.buf,
                         opt->no_inline ? "attachment" : "inline",
                         filename.buf);
                opt->diffopt.stat_sep = buffer;
                strbuf_release(&filename);
        }
        *subject_p = subject;
        *extra_headers_p = extra_headers;
}

void show_log(struct rev_info *opt)
{
        struct strbuf msgbuf = STRBUF_INIT;
        struct log_info *log = opt->loginfo;
        struct commit *commit = log->commit, *parent = log->parent;
        int abbrev = opt->diffopt.abbrev;
        int abbrev_commit = opt->abbrev_commit ? opt->abbrev : 40;
        const char *subject = NULL, *extra_headers = opt->extra_headers;
        int need_8bit_cte = 0;

        opt->loginfo = NULL;
        if (!opt->verbose_header) {
                graph_show_commit(opt->graph);

                if (!opt->graph) {
                        if (commit->object.flags & BOUNDARY)
                                putchar('-');
                        else if (commit->object.flags & UNINTERESTING)
                                putchar('^');
                        else if (opt->left_right) {
                                if (commit->object.flags & SYMMETRIC_LEFT)
                                        putchar('<');
                                else
                                        putchar('>');
                        }
                }
                fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
                if (opt->print_parents)
                        show_parents(commit, abbrev_commit);
                show_decorations(opt, commit);
                if (opt->graph && !graph_is_commit_finished(opt->graph)) {
                        putchar('\n');
                        graph_show_remainder(opt->graph);
                }
                putchar(opt->diffopt.line_termination);
                return;
        }

        /*
         * If use_terminator is set, we already handled any record termination
         * at the end of the last record.
         * Otherwise, add a diffopt.line_termination character before all
         * entries but the first.  (IOW, as a separator between entries)
         */
        if (opt->shown_one && !opt->use_terminator) {
                /*
                 * If entries are separated by a newline, the output
                 * should look human-readable.  If the last entry ended
                 * with a newline, print the graph output before this
                 * newline.  Otherwise it will end up as a completely blank
                 * line and will look like a gap in the graph.
                 *
                 * If the entry separator is not a newline, the output is
                 * primarily intended for programmatic consumption, and we
                 * never want the extra graph output before the entry
                 * separator.
                 */
                if (opt->diffopt.line_termination == '\n' &&
                    !opt->missing_newline)
                        graph_show_padding(opt->graph);
                putchar(opt->diffopt.line_termination);
        }
        opt->shown_one = 1;

        /*
         * If the history graph was requested,
         * print the graph, up to this commit's line
         */
        graph_show_commit(opt->graph);

        /*
         * Print header line of header..
         */

        if (opt->commit_format == CMIT_FMT_EMAIL) {
                log_write_email_headers(opt, commit, &subject, &extra_headers,
                                        &need_8bit_cte);
        } else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
                fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), stdout);
                if (opt->commit_format != CMIT_FMT_ONELINE)
                        fputs("commit ", stdout);

                if (!opt->graph) {
                        if (commit->object.flags & BOUNDARY)
                                putchar('-');
                        else if (commit->object.flags & UNINTERESTING)
                                putchar('^');
                        else if (opt->left_right) {
                                if (commit->object.flags & SYMMETRIC_LEFT)
                                        putchar('<');
                                else
                                        putchar('>');
                        }
                }
                fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit),
                      stdout);
                if (opt->print_parents)
                        show_parents(commit, abbrev_commit);
                if (parent)
                        printf(" (from %s)",
                               find_unique_abbrev(parent->object.sha1,
                                                  abbrev_commit));
                show_decorations(opt, commit);
                printf("%s", diff_get_color_opt(&opt->diffopt, DIFF_RESET));
                if (opt->commit_format == CMIT_FMT_ONELINE) {
                        putchar(' ');
                } else {
                        putchar('\n');
                        graph_show_oneline(opt->graph);
                }
                if (opt->reflog_info) {
                        /*
                         * setup_revisions() ensures that opt->reflog_info
                         * and opt->graph cannot both be set,
                         * so we don't need to worry about printing the
                         * graph info here.
                         */
                        show_reflog_message(opt->reflog_info,
                                    opt->commit_format == CMIT_FMT_ONELINE,
                                    opt->date_mode);
                        if (opt->commit_format == CMIT_FMT_ONELINE)
                                return;
                }
        }

        if (!commit->buffer)
                return;

        /*
         * And then the pretty-printed message itself
         */
        if (need_8bit_cte >= 0)
                need_8bit_cte = has_non_ascii(opt->add_signoff);
        pretty_print_commit(opt->commit_format, commit, &msgbuf,
                            abbrev, subject, extra_headers, opt->date_mode,
                            need_8bit_cte);

        if (opt->add_signoff)
                append_signoff(&msgbuf, opt->add_signoff);
        if (opt->show_log_size) {
                printf("log size %i\n", (int)msgbuf.len);
                graph_show_oneline(opt->graph);
        }

        /*
         * Set opt->missing_newline if msgbuf doesn't
         * end in a newline (including if it is empty)
         */
        if (!msgbuf.len || msgbuf.buf[msgbuf.len - 1] != '\n')
                opt->missing_newline = 1;
        else
                opt->missing_newline = 0;

        if (opt->graph)
                graph_show_commit_msg(opt->graph, &msgbuf);
        else
                fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
        if (opt->use_terminator) {
                if (!opt->missing_newline)
                        graph_show_padding(opt->graph);
                putchar('\n');
        }

        strbuf_release(&msgbuf);
}

int log_tree_diff_flush(struct rev_info *opt)
{
        diffcore_std(&opt->diffopt);

        if (diff_queue_is_empty()) {
                int saved_fmt = opt->diffopt.output_format;
                opt->diffopt.output_format = DIFF_FORMAT_NO_OUTPUT;
                diff_flush(&opt->diffopt);
                opt->diffopt.output_format = saved_fmt;
                return 0;
        }

        if (opt->loginfo && !opt->no_commit_id) {
                /* When showing a verbose header (i.e. log message),
                 * and not in --pretty=oneline format, we would want
                 * an extra newline between the end of log and the
                 * output for readability.
                 */
                show_log(opt);
                if ((opt->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT) &&
                    opt->verbose_header &&
                    opt->commit_format != CMIT_FMT_ONELINE) {
                        int pch = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_PATCH;
                        if ((pch & opt->diffopt.output_format) == pch)
                                printf("---");
                        putchar('\n');
                }
        }
        diff_flush(&opt->diffopt);
        return 1;
}

static int do_diff_combined(struct rev_info *opt, struct commit *commit)
{
        unsigned const char *sha1 = commit->object.sha1;

        diff_tree_combined_merge(sha1, opt->dense_combined_merges, opt);
        return !opt->loginfo;
}

/*
 * Show the diff of a commit.
 *
 * Return true if we printed any log info messages
 */
static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log_info *log)
{
        int showed_log;
        struct commit_list *parents;
        unsigned const char *sha1 = commit->object.sha1;

        if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
                return 0;

        /* Root commit? */
        parents = commit->parents;
        if (!parents) {
                if (opt->show_root_diff) {
                        diff_root_tree_sha1(sha1, "", &opt->diffopt);
                        log_tree_diff_flush(opt);
                }
                return !opt->loginfo;
        }

        /* More than one parent? */
        if (parents && parents->next) {
                if (opt->ignore_merges)
                        return 0;
                else if (opt->combine_merges)
                        return do_diff_combined(opt, commit);

                /* If we show individual diffs, show the parent info */
                log->parent = parents->item;
        }

        showed_log = 0;
        for (;;) {
                struct commit *parent = parents->item;

                diff_tree_sha1(parent->object.sha1, sha1, "", &opt->diffopt);
                log_tree_diff_flush(opt);

                showed_log |= !opt->loginfo;

                /* Set up the log info for the next parent, if any.. */
                parents = parents->next;
                if (!parents)
                        break;
                log->parent = parents->item;
                opt->loginfo = log;
        }
        return showed_log;
}

int log_tree_commit(struct rev_info *opt, struct commit *commit)
{
        struct log_info log;
        int shown;

        log.commit = commit;
        log.parent = NULL;
        opt->loginfo = &log;

        shown = log_tree_diff(opt, commit, &log);
        if (!shown && opt->loginfo && opt->always_show_header) {
                log.parent = NULL;
                show_log(opt);
                shown = 1;
        }
        opt->loginfo = NULL;
        maybe_flush_or_die(stdout, "stdout");
        return shown;
}