/*
 * The commit page, which shows one commit on its own and is where the log and
 * the ref listings link. It renders the idents, the object ids, the message
 * and any note, then hands off to ui-diff.c for the diff against the first
 * parent. Free text and addresses are written through the repository's commit
 * and email filters, so a site can rewrite either on the way out.
 */

#define USE_THE_REPOSITORY_VARIABLE

#include "cgit.h"
#include "filter.h"
#include "html.h"
#include "parsing.h"
#include "shared.h"
#include "ui-commit.h"
#include "ui-diff.h"
#include "ui-log.h"
#include "ui-shared.h"

// The diff below the message is always taken against the first parent alone,
// which says little about a merge of many branches, so a commit with this
// many parents or more is shown without a diff at all.
#define OCTOPUS_PARENTS 3

static void print_ident_row(const char *role, const char *name, const char *email,
	timestamp_t date, int tz)
{
	htmlf("<tr><th>%s</th><td>", role);
	cgit_open_filter(ctx.repo->email_filter, email, "commit");
	html_txt(name);
	if (ctx.cfg.enable_plain_email) {
		html(" ");
		html_txt(email);
	}
	cgit_close_filter(ctx.repo->email_filter);
	html("</td><td class='right'><time datetime='");
	html_attr(show_date(date, tz, cgit_date_mode(DATE_ISO8601_STRICT)));
	html("'>");
	html_txt(show_date(date, tz, cgit_date_mode(DATE_ISO8601)));
	html("</time></td></tr>\n");
}

static int print_parent_rows(struct commit *commit, const char *rev, const char *prefix)
{
	struct commit_list *p;
	struct commit *parent;
	const char *parent_hex, *label;
	int parents = 0;

	for (p = commit->parents; p; p = p->next) {
		parent = lookup_commit_reference(the_repository, &p->item->object.oid);
		if (!parent) {
			html("<tr><td colspan='3'>");
			cgit_print_error("Error reading parent commit");
			html("</td></tr>\n");
			continue;
		}
		html("<tr><th>parent</th><td colspan='2' class='oid'>");
		parent_hex = label = oid_to_hex(&p->item->object.oid);
		if (ctx.repo->enable_subject_links)
			label = cgit_parse_commit(parent)->subject;
		cgit_commit_link(label, NULL, NULL, ctx.qry.head, parent_hex, prefix);
		html(" (");
		cgit_diff_link("diff", NULL, NULL, ctx.qry.head, rev, oid_to_hex(&p->item->object.oid), prefix);
		html(")</td></tr>\n");
		parents++;
	}
	return parents;
}

static void print_filtered_text(const char *text)
{
	cgit_open_filter(ctx.repo->commit_filter);
	html_txt(text);
	cgit_close_filter(ctx.repo->commit_filter);
}

void cgit_print_commit(char *hex, const char *prefix)
{
	struct commit *commit;
	struct commitinfo *info;
	struct strbuf notes = STRBUF_INIT;
	struct object_id oid;
	const char *commit_hex, *first_parent;
	char *tree_rev;
	int parents;

	if (!hex)
		hex = ctx.qry.head;

	if (repo_get_oid(the_repository, hex, &oid)) {
		cgit_print_error_page(400, "Bad Request", "Bad object id: %s", hex);
		return;
	}
	commit = lookup_commit_reference(the_repository, &oid);
	if (!commit) {
		cgit_print_error_page(404, "Not Found", "Bad commit reference: %s", hex);
		return;
	}
	info = cgit_parse_commit(commit);

	format_display_notes(&oid, &notes, PAGE_ENCODING, 1);

	load_ref_decorations(NULL, DECORATE_FULL_REFS);

	ctx.page.title = cgit_fmtalloc("%s - %s", info->subject, ctx.page.title);
	cgit_print_layout_start();
	cgit_print_diff_ctrls();

	html("<table class='commit-info'>\n");
	print_ident_row("author", info->author, info->author_email, info->author_date, info->author_tz);
	print_ident_row("committer", info->committer, info->committer_email,
		info->committer_date, info->committer_tz);

	html("<tr><th>commit</th><td colspan='2' class='oid'>");
	commit_hex = oid_to_hex(&commit->object.oid);
	cgit_commit_link(commit_hex, NULL, NULL, ctx.qry.head, commit_hex, prefix);
	html(" (");
	cgit_patch_link("patch", NULL, NULL, NULL, commit_hex, prefix);
	html(")</td></tr>\n");

	// The parent rows follow the commit row so the commit hashes sit
	// together, leaving the tree beside the download links.
	parents = print_parent_rows(commit, hex, prefix);

	html("<tr><th>tree</th><td colspan='2' class='oid'>");
	tree_rev = xstrdup(hex);
	cgit_tree_link(oid_to_hex(get_commit_tree_oid(commit)), NULL, NULL, ctx.qry.head, tree_rev, NULL);
	if (prefix) {
		html(" /");
		cgit_tree_link(prefix, NULL, NULL, ctx.qry.head, tree_rev, prefix);
	}
	free(tree_rev);
	html("</td></tr>\n");

	if (ctx.repo->snapshots) {
		html("<tr><th>download</th><td colspan='2' class='oid'>");
		cgit_print_snapshot_links(ctx.repo, hex, "<br>");
		html("</td></tr>\n");
	}
	html("</table>\n");

	html("<div class='commit-subject'>");
	print_filtered_text(info->subject);
	cgit_print_commit_decorations(commit);
	html("</div>\n");
	html("<div class='commit-msg'>");
	print_filtered_text(info->msg);
	html("</div>\n");
	if (notes.len != 0) {
		html("<div class='notes-header'>Notes</div>\n");
		html("<div class='notes'>");
		print_filtered_text(notes.buf);
		html("</div>\n");
		html("<div class='notes-footer'></div>\n");
	}

	if (parents < OCTOPUS_PARENTS) {
		if (parents)
			first_parent = oid_to_hex(&commit->parents->item->object.oid);
		else
			first_parent = NULL;
		cgit_print_diff(ctx.qry.oid, first_parent, prefix, 0, 0);
	}

	strbuf_release(&notes);
	cgit_free_commitinfo(info);
	cgit_print_layout_end();
}