/*
 * The repository summary page and the about page. The summary stacks the
 * branch list, the tag list and the head of the log into one table and ends
 * with the clone urls, reusing the listings ui-refs.c and ui-log.c draw
 * elsewhere. The about page renders the readme that config parsing picked for
 * the repository, either through the configured about filter or escaped as
 * plain text, and it can serve a file sitting beside that readme so links
 * inside the readme resolve.
 */

#include "cgit.h"
#include "filter.h"
#include "html.h"
#include "shared.h"
#include "ui-blob.h"
#include "ui-log.h"
#include "ui-plain.h"
#include "ui-refs.h"
#include "ui-shared.h"
#include "ui-summary.h"

// Age, commit message and author, the three columns a log row always has.
// ui-log.c adds one more for each of the two optional counts, and the rows
// this page stretches across the table have to match that width.
#define LOG_BASE_COLUMNS 3

static int clone_urls_printed;

static int log_columns(void)
{
	int columns = LOG_BASE_COLUMNS;

	if (ctx.repo->enable_log_filecount)
		columns++;
	if (ctx.repo->enable_log_linecount)
		columns++;
	return columns;
}

static void print_clone_url(const char *url)
{
	int columns = log_columns();

	// cgit_add_clone_urls may call back no times at all, so the heading
	// waits for a first url rather than being printed ahead of the walk.
	if (clone_urls_printed++ == 0) {
		htmlf("<tr class='nohover'><td colspan='%d'>&nbsp;</td></tr>", columns);
		htmlf("<tr class='nohover'><th class='left' colspan='%d'>Clone</th></tr>\n", columns);
	}

	htmlf("<tr><td colspan='%d' class='clone-url'><a rel='vcs-git' href='", columns);
	html_url_path(url);
	html("' title='");
	html_attr(ctx.repo->name);
	html(" Git repository'>");
	html_txt(url);
	html("</a></td></tr>\n");
}

/*
 * Without the separator boundary a sibling directory that merely shares the
 * base as a name prefix, such as repo.git-backup beside repo.git, would pass.
 */
static int path_within(const char *base, const char *path)
{
	size_t len = strlen(base);

	return starts_with(path, base) &&
	       (path[len] == '\0' || path[len] == '/');
}

/*
 * Returns a path the caller must free, or NULL when the request cannot be
 * served. A null ref means the readme is a file on the server's disk rather
 * than a path inside a ref, and such a readme is confined to its own
 * directory, so one named without a directory has nothing to confine it to
 * and is refused.
 */
static char *resolve_about_path(const char *filename, const char *ref,
				const char *path)
{
	char *copy, *base_dir, *full_path;
	char *resolved_base = NULL, *resolved_full = NULL;

	// dirname is allowed to write into its argument and to return a
	// pointer into it, so base_dir borrows from a copy we keep alive.
	copy = xstrdup(filename);
	base_dir = dirname(copy);
	if (!strcmp(base_dir, ".") || !strcmp(base_dir, "..")) {
		if (!ref) {
			free(copy);
			return NULL;
		}
		full_path = xstrdup(path);
	} else
		full_path = cgit_fmtalloc("%s/%s", base_dir, path);

	if (!ref) {
		resolved_base = realpath(base_dir, NULL);
		resolved_full = realpath(full_path, NULL);
		if (!resolved_base || !resolved_full ||
		    !path_within(resolved_base, resolved_full)) {
			free(full_path);
			full_path = NULL;
		}
	}

	free(copy);
	free(resolved_base);
	free(resolved_full);

	return full_path;
}

void cgit_print_summary(void)
{
	int columns = log_columns();

	cgit_print_layout_start();
	html("<table class='list'>\n");
	cgit_print_branches(ctx.cfg.summary_branches);
	htmlf("<tr class='nohover'><td colspan='%d'>&nbsp;</td></tr>\n", columns);
	cgit_print_tags(ctx.cfg.summary_tags);
	if (ctx.cfg.summary_log > 0) {
		htmlf("<tr class='nohover'><td colspan='%d'>&nbsp;</td></tr>\n", columns);
		cgit_print_log(ctx.qry.head, 0, ctx.cfg.summary_log, NULL,
			       NULL, NULL, 0, 0, 0);
	}
	clone_urls_printed = 0;
	cgit_add_clone_urls(print_clone_url);
	html("</table>");
	cgit_print_layout_end();
}

void cgit_print_repo_readme(const char *path)
{
	char *filename, *ref, *mimetype;
	int free_filename = 0;

	mimetype = cgit_get_mimetype_for_filename(path);
	if (mimetype && (starts_with(mimetype, "image/") ||
			 starts_with(mimetype, "video/"))) {
		ctx.page.mimetype = mimetype;
		ctx.page.charset = NULL;
		cgit_print_plain();
		free(mimetype);
		return;
	}
	free(mimetype);

	cgit_print_layout_start();
	if (ctx.repo->readme.nr == 0)
		goto done;

	filename = ctx.repo->readme.items[0].string;
	ref = ctx.repo->readme.items[0].util;

	if (path) {
		free_filename = 1;
		filename = resolve_about_path(filename, ref, path);
		if (!filename)
			goto done;
	}

	html("<div id='summary'>");
	if (!ctx.repo->about_filter) {
		// With no about-filter configured there is nothing to turn the
		// readme source into safe HTML, so it is escaped rather than
		// served raw, which would let an untrusted repository put
		// script on this page.
		html("<pre class='plaintext'>");
		if (ref) {
			cgit_print_file(filename, ref, 1, 1);
		} else {
			struct strbuf sb = STRBUF_INIT;
			if (strbuf_read_file(&sb, filename, 0) >= 0)
				html_txt(sb.buf);
			strbuf_release(&sb);
		}
		html("</pre>");
	} else {
		// The filter is what makes the source safe here, so it is fed
		// through unescaped.
		cgit_open_filter(ctx.repo->about_filter, filename);
		if (ref)
			cgit_print_file(filename, ref, 1, 0);
		else
			html_include(filename);
		cgit_close_filter(ctx.repo->about_filter);
	}

	html("</div>");
	if (free_filename)
		free(filename);

done:
	cgit_print_layout_end();
}