#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>

#include "config.h"
#include "cmark.h"
#include "node.h"
#include "buffer.h"
#include "houdini.h"

// Functions to convert cmark_nodes to XML strings.

static void escape_xml(cmark_strbuf *dest, const unsigned char *source, int length)
{
	if (source != NULL) {
		if (length < 0)
			length = strlen((char *)source);

		houdini_escape_html0(dest, source, (size_t)length, 0);
	}
}

struct render_state {
	cmark_strbuf* xml;
	int indent;
};

static inline void indent(struct render_state *state)
{
	int i;
	for (i = 0; i < state->indent; i++) {
		cmark_strbuf_putc(state->xml, ' ');
	}
}

static int
S_render_node(cmark_node *node, cmark_event_type ev_type,
              struct render_state *state, int options)
{
	cmark_strbuf *xml = state->xml;
	bool literal = false;
	cmark_delim_type delim;
	bool entering = (ev_type == CMARK_EVENT_ENTER);

	if (entering) {
		indent(state);
		cmark_strbuf_printf(xml, "<%s",
		                    cmark_node_get_type_string(node));

		if (options & CMARK_OPT_SOURCEPOS && node->start_line != 0) {
			cmark_strbuf_printf(xml, " sourcepos=\"%d:%d-%d:%d\"",
			                    node->start_line,
			                    node->start_column,
			                    node->end_line,
			                    node->end_column);
		}

		literal = false;

		switch (node->type) {
		case CMARK_NODE_TEXT:
		case CMARK_NODE_CODE:
		case CMARK_NODE_HTML:
		case CMARK_NODE_INLINE_HTML:
			cmark_strbuf_puts(xml, ">");
			escape_xml(xml, node->as.literal.data,
			           node->as.literal.len);
			cmark_strbuf_puts(xml, "</");
			cmark_strbuf_puts(xml,
			                  cmark_node_get_type_string(node));
			literal = true;
			break;
		case CMARK_NODE_LIST:
			switch (cmark_node_get_list_type(node)) {
			case CMARK_ORDERED_LIST:
				cmark_strbuf_puts(xml, " type=\"ordered\"");
				cmark_strbuf_printf(xml, " start=\"%d\"",
				                    cmark_node_get_list_start(node));
				delim = cmark_node_get_list_delim(node);
				if (delim == CMARK_PAREN_DELIM) {
					cmark_strbuf_puts(xml,
					                  " delim=\"paren\"");
				} else if (delim == CMARK_PERIOD_DELIM) {
					cmark_strbuf_puts(xml,
					                  " delim=\"period\"");
				}
				break;
			case CMARK_BULLET_LIST:
				cmark_strbuf_puts(xml, " type=\"bullet\"");
				break;
			default:
				break;
			}
			cmark_strbuf_printf(xml, " tight=\"%s\"",
			                    (cmark_node_get_list_tight(node) ?
			                     "true" : "false"));
			break;
		case CMARK_NODE_HEADER:
			cmark_strbuf_printf(xml, " level=\"%d\"",
			                    node->as.header.level);
			break;
		case CMARK_NODE_CODE_BLOCK:
			if (node->as.code.info.len > 0) {
				cmark_strbuf_puts(xml, " info=\"");
				escape_xml(xml, node->as.code.info.data,
				           node->as.code.info.len);
				cmark_strbuf_putc(xml, '"');
			}
			cmark_strbuf_puts(xml, ">");
			escape_xml(xml, node->as.code.literal.data,
			           node->as.code.literal.len);
			cmark_strbuf_puts(xml, "</");
			cmark_strbuf_puts(xml,
			                  cmark_node_get_type_string(node));
			literal = true;
			break;
		case CMARK_NODE_LINK:
		case CMARK_NODE_IMAGE:
			cmark_strbuf_puts(xml, " destination=\"");
			escape_xml(xml, node->as.link.url, -1);
			cmark_strbuf_putc(xml, '"');
			cmark_strbuf_puts(xml, " title=\"");
			escape_xml(xml, node->as.link.title, -1);
			cmark_strbuf_putc(xml, '"');
			break;
		default:
			break;
		}
		if (node->first_child) {
			state->indent += 2;
		} else if (!literal) {
			cmark_strbuf_puts(xml, " /");
		}
		cmark_strbuf_puts(xml, ">\n");


	} else if (node->first_child) {
		state->indent -= 2;
		indent(state);
		cmark_strbuf_printf(xml, "</%s>\n",
		                    cmark_node_get_type_string(node));
	}

	return 1;
}

char *cmark_render_xml(cmark_node *root, int options)
{
	char *result;
	cmark_strbuf xml = GH_BUF_INIT;
	cmark_event_type ev_type;
	cmark_node *cur;
	struct render_state state = { &xml, 0 };

	cmark_iter *iter = cmark_iter_new(root);

	cmark_strbuf_puts(state.xml,
	                  "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
	cmark_strbuf_puts(state.xml,
	                  "<!DOCTYPE CommonMark SYSTEM \"CommonMark.dtd\">\n");
	while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
		cur = cmark_iter_get_node(iter);
		S_render_node(cur, ev_type, &state, options);
	}
	result = (char *)cmark_strbuf_detach(&xml);

	cmark_iter_free(iter);
	return result;
}