/*
 * Copyright (c) 2015, Vicent Marti
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "redcarpet.h"

VALUE rb_mRedcarpet;
VALUE rb_cMarkdown;
VALUE rb_cRenderHTML_TOC;

extern VALUE rb_cRenderBase;

static void rb_redcarpet_md_flags(VALUE hash, unsigned int *enabled_extensions_p)
{
	unsigned int extensions = 0;

	Check_Type(hash, T_HASH);

	/**
	 * Markdown extensions -- all disabled by default
	 */
	if (rb_hash_lookup(hash, CSTR2SYM("no_intra_emphasis")) == Qtrue)
		extensions |= MKDEXT_NO_INTRA_EMPHASIS;

	if (rb_hash_lookup(hash, CSTR2SYM("tables")) == Qtrue)
		extensions |= MKDEXT_TABLES;

	if (rb_hash_lookup(hash, CSTR2SYM("fenced_code_blocks")) == Qtrue)
		extensions |= MKDEXT_FENCED_CODE;

	if (rb_hash_lookup(hash, CSTR2SYM("disable_indented_code_blocks")) == Qtrue)
		extensions |= MKDEXT_DISABLE_INDENTED_CODE;

	if (rb_hash_lookup(hash, CSTR2SYM("autolink")) == Qtrue)
		extensions |= MKDEXT_AUTOLINK;

	if (rb_hash_lookup(hash, CSTR2SYM("strikethrough")) == Qtrue)
		extensions |= MKDEXT_STRIKETHROUGH;

	if (rb_hash_lookup(hash, CSTR2SYM("underline")) == Qtrue)
		extensions |= MKDEXT_UNDERLINE;

	if (rb_hash_lookup(hash, CSTR2SYM("highlight")) == Qtrue)
		extensions |= MKDEXT_HIGHLIGHT;

	if (rb_hash_lookup(hash, CSTR2SYM("quote")) == Qtrue)
		extensions |= MKDEXT_QUOTE;

	if (rb_hash_lookup(hash, CSTR2SYM("lax_spacing")) == Qtrue)
		extensions |= MKDEXT_LAX_SPACING;

	if (rb_hash_lookup(hash, CSTR2SYM("space_after_headers")) == Qtrue)
		extensions |= MKDEXT_SPACE_HEADERS;

	if (rb_hash_lookup(hash, CSTR2SYM("superscript")) == Qtrue)
		extensions |= MKDEXT_SUPERSCRIPT;

	if (rb_hash_lookup(hash, CSTR2SYM("footnotes")) == Qtrue)
		extensions |= MKDEXT_FOOTNOTES;

	*enabled_extensions_p = extensions;
}

static void
rb_redcarpet_md__free(void *markdown)
{
	sd_markdown_free((struct sd_markdown *)markdown);
}

static VALUE rb_redcarpet_md__new(int argc, VALUE *argv, VALUE klass)
{
	VALUE rb_markdown, rb_rndr, hash, rndr_options;
	unsigned int extensions = 0;

	struct rb_redcarpet_rndr *rndr;
	struct sd_markdown *markdown;

	if (rb_scan_args(argc, argv, "11", &rb_rndr, &hash) == 2)
		rb_redcarpet_md_flags(hash, &extensions);

	if (rb_obj_is_kind_of(rb_rndr, rb_cClass))
		rb_rndr = rb_funcall(rb_rndr, rb_intern("new"), 0);

	if (!rb_obj_is_kind_of(rb_rndr, rb_cRenderBase))
		rb_raise(rb_eTypeError, "Invalid Renderer instance given");

	/**
	 * Automatically enable the `fenced_code_blocks` option if
	 * given a kind of `HTML_TOC` object since many languages
	 * like Ruby use the sharp to comment code so these comments
	 * would be processed as titles.
	 */
	if (rb_obj_is_kind_of(rb_rndr, rb_cRenderHTML_TOC))
		extensions |= MKDEXT_FENCED_CODE;

	Data_Get_Struct(rb_rndr, struct rb_redcarpet_rndr, rndr);

	/* Merge the current options in the @options hash */
	if (hash != Qnil) {
		rndr_options = rb_funcall(rb_iv_get(rb_rndr, "@options"), rb_intern("merge"), 1, hash);
		rb_iv_set(rb_rndr, "@options", rndr_options);
	}

	markdown = sd_markdown_new(extensions, 16, &rndr->callbacks, &rndr->options);
	if (!markdown)
		rb_raise(rb_eRuntimeError, "Failed to create new Renderer class");

	rb_markdown = Data_Wrap_Struct(klass, NULL, rb_redcarpet_md__free, markdown);
	rb_iv_set(rb_markdown, "@renderer", rb_rndr);

	return rb_markdown;
}

static VALUE rb_redcarpet_md_render(VALUE self, VALUE text)
{
	VALUE rb_rndr;
	struct buf *output_buf;
	struct sd_markdown *markdown;

	Check_Type(text, T_STRING);

	rb_rndr = rb_iv_get(self, "@renderer");
	Data_Get_Struct(self, struct sd_markdown, markdown);

	if (rb_respond_to(rb_rndr, rb_intern("preprocess")))
		text = rb_funcall(rb_rndr, rb_intern("preprocess"), 1, text);
	if (NIL_P(text))
		return Qnil;

	struct rb_redcarpet_rndr *renderer;
	Data_Get_Struct(rb_rndr, struct rb_redcarpet_rndr, renderer);
	renderer->options.active_enc = rb_enc_get(text);

	/* initialize buffers */
	output_buf = bufnew(128);

	/* render the magic */
	sd_markdown_render(
		output_buf,
		(const uint8_t*)RSTRING_PTR(text),
		RSTRING_LEN(text),
		markdown);

	/* build the Ruby string */
	text = rb_enc_str_new((const char*)output_buf->data, output_buf->size, rb_enc_get(text));

	bufrelease(output_buf);

	if (rb_respond_to(rb_rndr, rb_intern("postprocess")))
		text = rb_funcall(rb_rndr, rb_intern("postprocess"), 1, text);

	return text;
}

__attribute__((visibility("default")))
void Init_redcarpet()
{
	rb_mRedcarpet = rb_define_module("Redcarpet");

	rb_cMarkdown = rb_define_class_under(rb_mRedcarpet, "Markdown", rb_cObject);
	rb_undef_alloc_func(rb_cMarkdown);
	rb_define_singleton_method(rb_cMarkdown, "new", rb_redcarpet_md__new, -1);
	rb_define_method(rb_cMarkdown, "render", rb_redcarpet_md_render, 1);

	Init_redcarpet_rndr();
}