/* ui-tree.c: functions for tree output
 *
 * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
 *
 * Licensed under GNU General Public License v2
 *   (see COPYING for full license text)
 */

#include "cgit.h"
#include "ui-tree.h"
#include "html.h"
#include "ui-shared.h"

struct walk_tree_context {
	char *curr_rev;
	char *match_path;
	int state;
	bool dir_mode;
};

struct flatten_walk_tree_context {
	int counter;
	int path_added;
	unsigned char last_sha1[20];
	char* path;
	char* last_path;
};

static void print_text_buffer(const char *name, char *buf, unsigned long size)
{
	unsigned long lineno, idx;
	const char *numberfmt = "<a id='n%1$d' href='#n%1$d'>%1$d</a>\n";

	html("<table summary='blob content' class='blob'>\n");

	if (ctx.cfg.enable_tree_linenumbers) {
		html("<tr><td class='linenumbers'><pre>");
		idx = 0;
		lineno = 0;

		if (size) {
			htmlf(numberfmt, ++lineno);
			while (idx < size - 1) { // skip absolute last newline
				if (buf[idx] == '\n')
					htmlf(numberfmt, ++lineno);
				idx++;
			}
		}
		html("</pre></td>\n");
	}
	else {
		html("<tr>\n");
	}

	if (ctx.repo->source_filter) {
		char *filter_arg = xstrdup(name);
		html("<td class='lines'><pre><code>");
		cgit_open_filter(ctx.repo->source_filter, filter_arg);
		html_raw(buf, size);
		cgit_close_filter(ctx.repo->source_filter);
		free(filter_arg);
		html("</code></pre></td></tr></table>\n");
		return;
	}

	html("<td class='lines'><pre><code>");
	html_txt(buf);
	html("</code></pre></td></tr></table>\n");
}

#define ROWLEN 32

static void print_binary_buffer(char *buf, unsigned long size)
{
	unsigned long ofs, idx;
	static char ascii[ROWLEN + 1];

	html("<table summary='blob content' class='bin-blob'>\n");
	html("<tr><th>ofs</th><th>hex dump</th><th>ascii</th></tr>");
	for (ofs = 0; ofs < size; ofs += ROWLEN, buf += ROWLEN) {
		htmlf("<tr><td class='right'>%04lx</td><td class='hex'>", ofs);
		for (idx = 0; idx < ROWLEN && ofs + idx < size; idx++)
			htmlf("%*s%02x",
			      idx == 16 ? 4 : 1, "",
			      buf[idx] & 0xff);
		html(" </td><td class='hex'>");
		for (idx = 0; idx < ROWLEN && ofs + idx < size; idx++)
			ascii[idx] = isgraph(buf[idx]) ? buf[idx] : '.';
		ascii[idx] = '\0';
		html_txt(ascii);
		html("</td></tr>\n");
	}
	html("</table>\n");
}

static void set_title_from_path(const char *path)
{
	size_t path_len;
	char *new_title;

	if (!path)
		return;

	path_len = strlen(path);
	new_title = xmalloc(path_len + 3 + strlen(ctx.page.title) + 1);
	new_title[0] = '\0';

	strcat(new_title, path);
	strcat(new_title, " - ");
	strcat(new_title, ctx.page.title);
	ctx.page.title = new_title;
}

static void print_object(const unsigned char *sha1, char *path, const char *basename, const char *rev)
{
	enum object_type type;
	char *buf;
	unsigned long size;

	type = sha1_object_info(sha1, &size);
	if (type == OBJ_BAD) {
		cgit_print_error_page(404, "Not found",
			"Bad object name: %s", sha1_to_hex(sha1));
		return;
	}

	buf = read_sha1_file(sha1, &type, &size);
	if (!buf) {
		cgit_print_error_page(500, "Internal server error",
			"Error reading object %s", sha1_to_hex(sha1));
		return;
	}

	set_title_from_path(path);

	cgit_print_layout_start();
	htmlf("blob: %s (", sha1_to_hex(sha1));
	cgit_plain_link("plain", NULL, NULL, ctx.qry.head,
		        rev, path);
	html(")\n");

	if (ctx.cfg.max_blob_size && size / 1024 > ctx.cfg.max_blob_size) {
		htmlf("<div class='error'>blob size (%ldKB) exceeds display size limit (%dKB).</div>",
				size / 1024, ctx.cfg.max_blob_size);
		return;
	}

	if (buffer_is_binary(buf, size))
		print_binary_buffer(buf, size);
	else
		print_text_buffer(basename, buf, size);
}

static int flatten_tree_item(const unsigned char *sha1, struct strbuf *base,
		const char *pathname, unsigned mode, int stage, void *cbdata)
{
	struct flatten_walk_tree_context* fwt_ctx = cbdata;
	// increment counter of child elements
	fwt_ctx->counter++;
	if (!S_ISDIR(mode) || fwt_ctx->counter > 1) {
		if (fwt_ctx->counter > 1) {
			// if the first child element was a directory we have to use the path before
			free(fwt_ctx->path);
			fwt_ctx->path = xstrdup(fwt_ctx->last_path);
		}
		// flag that we ended
		fwt_ctx->counter = -1;
		// -1 to break read_tree_recursive
		return -1;
	}
	// save last path and concatenate new one
	char* tmp = xstrdup(fwt_ctx->path);
	free(fwt_ctx->path);
	free(fwt_ctx->last_path);
	fwt_ctx->last_path = xstrdup(tmp);
	fwt_ctx->path = (char*) malloc(sizeof(char) * (2 + strlen(tmp) + strlen(pathname)));
	strcpy(fwt_ctx->path, tmp);
	strcat(fwt_ctx->path, "/");
	strcat(fwt_ctx->path, pathname);
	free(tmp);
	fwt_ctx->path_added++;
	// save hash of found element
	hashcpy(fwt_ctx->last_sha1, sha1);
	return 0;
}

static int ls_item(const unsigned char *sha1, struct strbuf *base,
		const char *pathname, unsigned mode, int stage, void *cbdata)
{
	struct walk_tree_context *walk_tree_ctx = cbdata;
	char *name;
	struct strbuf fullpath = STRBUF_INIT;
	struct strbuf class = STRBUF_INIT;
	enum object_type type;
	unsigned long size = 0;

	if ((!S_ISDIR(mode) && walk_tree_ctx->dir_mode) || (S_ISDIR(mode) && !walk_tree_ctx->dir_mode)) {
		return 0;
	}

	name = xstrdup(pathname);
	strbuf_addf(&fullpath, "%s%s%s", ctx.qry.path ? ctx.qry.path : "",
		    ctx.qry.path ? "/" : "", name);

	if (!S_ISGITLINK(mode)) {
		type = sha1_object_info(sha1, &size);
		if (type == OBJ_BAD) {
			htmlf("<tr><td colspan='3'>Bad object: %s %s</td></tr>",
			      name,
			      sha1_to_hex(sha1));
			free(name);
			return 0;
		}
	}

	html("<tr><td class='ls-mode'>");
	cgit_print_filemode(mode);
	html("</td><td>");
	if (S_ISGITLINK(mode)) {
		cgit_submodule_link("ls-mod", fullpath.buf, sha1_to_hex(sha1));
	} else if (S_ISDIR(mode)) {
		struct flatten_walk_tree_context fwt_ctx;
		// initialize paths
		fwt_ctx.path = (char*) malloc(sizeof(char) * 1);
		strcpy(fwt_ctx.path, "");
		fwt_ctx.last_path = (char*) malloc(sizeof(char) * 1);
		strcpy(fwt_ctx.last_path, "");
		// start at actual position
		hashcpy(fwt_ctx.last_sha1, sha1);
		do {
			fwt_ctx.counter = 0;
			struct tree* tree;
			struct pathspec path = {
				.nr = 0
			};
			tree = parse_tree_indirect(fwt_ctx.last_sha1);
			read_tree_recursive(tree, "", 0, 1, &path, flatten_tree_item, &fwt_ctx);
		} while (fwt_ctx.counter != -1);
		if (fwt_ctx.path_added) {
			// append found path to fullpath and name
			strbuf_addf(&fullpath, "%s", fwt_ctx.path);
			char* tmp = xstrdup(name);
			free(name);
			name = (char*) malloc(sizeof(char) * (1 + strlen(tmp) + strlen(fwt_ctx.path)));
			strcpy(name, tmp);
			strcat(name, fwt_ctx.path);
			free(tmp);
		}
		// cleanup
		free(fwt_ctx.path);
		free(fwt_ctx.last_path);
		cgit_tree_link(name, NULL, "ls-dir", ctx.qry.head,
			       walk_tree_ctx->curr_rev, fullpath.buf);
	} else {
		char *ext = strrchr(name, '.');
		strbuf_addstr(&class, "ls-blob");
		if (ext)
			strbuf_addf(&class, " %s", ext + 1);
		cgit_tree_link(name, NULL, class.buf, ctx.qry.head,
			       walk_tree_ctx->curr_rev, fullpath.buf);
	}
	htmlf("</td><td class='ls-size'>%li</td>", size);

	html("<td>");
	cgit_log_link("log", NULL, "button", ctx.qry.head,
		      walk_tree_ctx->curr_rev, fullpath.buf, 0, NULL, NULL,
		      ctx.qry.showmsg, 0);
	if (ctx.repo->max_stats)
		cgit_stats_link("stats", NULL, "button", ctx.qry.head,
				fullpath.buf);
	if (!S_ISGITLINK(mode))
		cgit_plain_link("plain", NULL, "button", ctx.qry.head,
				walk_tree_ctx->curr_rev, fullpath.buf);
	html("</td></tr>\n");
	free(name);
	strbuf_release(&fullpath);
	strbuf_release(&class);
	return 0;
}

static void ls_head(void)
{
	cgit_print_layout_start();
	html("<table summary='tree listing' class='list'>\n");
	html("<tr class='nohover'>");
	html("<th class='left'>Mode</th>");
	html("<th class='left'>Name</th>");
	html("<th class='right'>Size</th>");
	html("<th/>");
	html("</tr>\n");
}

static void ls_tail(void)
{
	html("</table>\n");
	cgit_print_layout_end();
}

static void ls_tree(const unsigned char *sha1, char *path, struct walk_tree_context *walk_tree_ctx)
{
	struct tree *tree;
	struct pathspec paths = {
		.nr = 0
	};

	tree = parse_tree_indirect(sha1);
	if (!tree) {
		cgit_print_error_page(404, "Not found",
			"Not a tree object: %s", sha1_to_hex(sha1));
		return;
	}

	ls_head();
	walk_tree_ctx->dir_mode = true;
	read_tree_recursive(tree, "", 0, 1, &paths, ls_item, walk_tree_ctx);
	walk_tree_ctx->dir_mode = false;
	read_tree_recursive(tree, "", 0, 1, &paths, ls_item, walk_tree_ctx);
	ls_tail();
}


static int walk_tree(const unsigned char *sha1, struct strbuf *base,
		const char *pathname, unsigned mode, int stage, void *cbdata)
{
	struct walk_tree_context *walk_tree_ctx = cbdata;
	static char buffer[PATH_MAX];

	if (walk_tree_ctx->state == 0) {
		memcpy(buffer, base->buf, base->len);
		strcpy(buffer + base->len, pathname);
		if (strcmp(walk_tree_ctx->match_path, buffer))
			return READ_TREE_RECURSIVE;

		if (S_ISDIR(mode)) {
			walk_tree_ctx->state = 1;
			if (walk_tree_ctx->dir_mode) {
				set_title_from_path(buffer);
				ls_head();
			}
			return READ_TREE_RECURSIVE;
		} else {
			walk_tree_ctx->state = 2;
			if (walk_tree_ctx->dir_mode) {
				print_object(sha1, buffer, pathname, walk_tree_ctx->curr_rev);
			}
			return 0;
		}
	}
	ls_item(sha1, base, pathname, mode, stage, walk_tree_ctx);
	return 0;
}

/*
 * Show a tree or a blob
 *   rev:  the commit pointing at the root tree object
 *   path: path to tree or blob
 */
void cgit_print_tree(const char *rev, char *path)
{
	unsigned char sha1[20];
	struct commit *commit;
	struct pathspec_item path_items = {
		.match = path,
		.len = path ? strlen(path) : 0
	};
	struct pathspec paths = {
		.nr = path ? 1 : 0,
		.items = &path_items
	};
	struct walk_tree_context walk_tree_ctx = {
		.match_path = path,
		.state = 0
	};

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

	if (get_sha1(rev, sha1)) {
		cgit_print_error_page(404, "Not found",
			"Invalid revision name: %s", rev);
		return;
	}
	commit = lookup_commit_reference(sha1);
	if (!commit || parse_commit(commit)) {
		cgit_print_error_page(404, "Not found",
			"Invalid commit reference: %s", rev);
		return;
	}

	walk_tree_ctx.curr_rev = xstrdup(rev);

	if (path == NULL) {
		ls_tree(commit->tree->object.oid.hash, NULL, &walk_tree_ctx);
		goto cleanup;
	}

	walk_tree_ctx.dir_mode = true;
	read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
	walk_tree_ctx.state = 0;
	walk_tree_ctx.dir_mode = false;
	read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
	if (walk_tree_ctx.state == 1)
		ls_tail();
	else if (walk_tree_ctx.state == 2)
		cgit_print_layout_end();
	else
		cgit_print_error_page(404, "Not found", "Path not found");

cleanup:
	free(walk_tree_ctx.curr_rev);
}