#include "cache.h"
#include "diff.h"
#include "commit.h"
#include "log-tree.h"
#include "reflog-walk.h"

struct decoration name_decoration = { "object names" };

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", diff_unique_abbrev(parent->object.sha1, abbrev));
        }
}

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

        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 ch, *cp;
        int seen_colon = 0;
        int seen_at = 0;
        int seen_name = 0;
        int seen_head = 0;

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

        while (letter <= cp) {
                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 show_log(struct rev_info *opt, const char *sep)
{
        struct strbuf msgbuf;
        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 *extra;
        const char *subject = NULL, *extra_headers = opt->extra_headers;

        opt->loginfo = NULL;
        if (!opt->verbose_header) {
                if (opt->left_right) {
                        if (commit->object.flags & BOUNDARY)
                                putchar('-');
                        else if (commit->object.flags & SYMMETRIC_LEFT)
                                putchar('<');
                        else
                                putchar('>');
                }
                fputs(diff_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
                if (opt->parents)
                        show_parents(commit, abbrev_commit);
                show_decorations(commit);
                putchar(opt->diffopt.line_termination);
                return;
        }

        /*
         * The "oneline" format has several special cases:
         *  - The pretty-printed commit lacks a newline at the end
         *    of the buffer, but we do want to make sure that we
         *    have a newline there. If the separator isn't already
         *    a newline, add an extra one.
         *  - unlike other log messages, the one-line format does
         *    not have an empty line between entries.
         */
        extra = "";
        if (*sep != '\n' && opt->commit_format == CMIT_FMT_ONELINE)
                extra = "\n";
        if (opt->shown_one && opt->commit_format != CMIT_FMT_ONELINE)
                putchar(opt->diffopt.line_termination);
        opt->shown_one = 1;

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

        if (opt->commit_format == CMIT_FMT_EMAIL) {
                char *sha1 = sha1_to_hex(commit->object.sha1);
                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", sha1);
                if (opt->message_id)
                        printf("Message-Id: <%s>\n", opt->message_id);
                if (opt->ref_message_id)
                        printf("In-Reply-To: <%s>\nReferences: <%s>\n",
                               opt->ref_message_id, opt->ref_message_id);
                if (opt->mime_boundary) {
                        static char subject_buffer[1024];
                        static char buffer[1024];
                        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;

                        snprintf(buffer, sizeof(buffer) - 1,
                                 "--%s%s\n"
                                 "Content-Type: text/x-patch;"
                                 " name=\"%s.diff\"\n"
                                 "Content-Transfer-Encoding: 8bit\n"
                                 "Content-Disposition: %s;"
                                 " filename=\"%s.diff\"\n\n",
                                 mime_boundary_leader, opt->mime_boundary,
                                 sha1,
                                 opt->no_inline ? "attachment" : "inline",
                                 sha1);
                        opt->diffopt.stat_sep = buffer;
                }
        } else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
                fputs(diff_get_color(opt->diffopt.color_diff, DIFF_COMMIT),
                      stdout);
                if (opt->commit_format != CMIT_FMT_ONELINE)
                        fputs("commit ", stdout);
                if (commit->object.flags & BOUNDARY)
                        putchar('-');
                else if (opt->left_right) {
                        if (commit->object.flags & SYMMETRIC_LEFT)
                                putchar('<');
                        else
                                putchar('>');
                }
                fputs(diff_unique_abbrev(commit->object.sha1, abbrev_commit),
                      stdout);
                if (opt->parents)
                        show_parents(commit, abbrev_commit);
                if (parent)
                        printf(" (from %s)",
                               diff_unique_abbrev(parent->object.sha1,
                                                  abbrev_commit));
                show_decorations(commit);
                printf("%s",
                       diff_get_color(opt->diffopt.color_diff, DIFF_RESET));
                putchar(opt->commit_format == CMIT_FMT_ONELINE ? ' ' : '\n');
                if (opt->reflog_info) {
                        show_reflog_message(opt->reflog_info,
                                    opt->commit_format == CMIT_FMT_ONELINE,
                                    opt->date_mode);
                        if (opt->commit_format == CMIT_FMT_ONELINE) {
                                printf("%s", sep);
                                return;
                        }
                }
        }

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

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

        if (msgbuf.len)
                printf("%s%s%s", msgbuf.buf, extra, sep);
        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, opt->diffopt.msg_sep);
                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)
                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;
}