const (
	HTML_SKIP_HTML                 = 1 << iota // skip preformatted HTML blocks
	HTML_SKIP_STYLE                            // skip embedded <style> elements
	HTML_SKIP_IMAGES                           // skip embedded images
	HTML_SKIP_LINKS                            // skip all links
	HTML_SAFELINK                              // only link to trusted protocols
	HTML_NOFOLLOW_LINKS                        // only link with rel="nofollow"
	HTML_HREF_TARGET_BLANK                     // add a blank target
	HTML_OMIT_CONTENTS                         // skip the main contents (for a standalone table of contents)
	HTML_COMPLETE_PAGE                         // generate a complete HTML page
	HTML_USE_SMARTYPANTS                       // enable smart punctuation substitutions
	HTML_SMARTYPANTS_FRACTIONS                 // enable smart fractions (with HTML_USE_SMARTYPANTS)
	HTML_SMARTYPANTS_DASHES                    // enable smart dashes (with HTML_USE_SMARTYPANTS)
	HTML_SMARTYPANTS_LATEX_DASHES              // enable LaTeX-style dashes (with HTML_USE_SMARTYPANTS and HTML_SMARTYPANTS_DASHES)
	HTML_SMARTYPANTS_ANGLED_QUOTES             // enable angled double quotes (with HTML_USE_SMARTYPANTS) for double quotes rendering
	HTML_FOOTNOTE_RETURN_LINKS                 // generate a link at the end of a footnote to return to the source
)

const (
	EXTENSION_ABBREVIATIONS              // Render abbreviations `*[HTML]: Hyper Text Markup Language`
	EXTENSION_AUTO_HEADER_IDS            // Create the header ID from the text
	EXTENSION_AUTOLINK                   // Detect embedded URLs that are not explicitly marked
	EXTENSION_CITATION                   // Support citations via the link syntax
	EXTENSION_EXAMPLE_LISTS              // Render '(@tag)  ' example lists
	EXTENSION_FENCED_CODE                // Render fenced code blocks
	EXTENSION_FOOTNOTES                  // Pandoc-style footnotes
	EXTENSION_HARD_LINE_BREAK            // Translate newlines into line breaks
	EXTENSION_HEADER_IDS                 // Specify header IDs with {#id}
	EXTENSION_INCLUDE                    // Include file with {{ syntax
	EXTENSION_INLINE_ATTR                // Detect CommonMark's IAL syntax
	EXTENSION_LAX_HTML_BLOCKS            // Loosen up HTML block parsing rules
	EXTENSION_MATH                       // Detect $$...$$ and parse as math
	EXTENSION_MATTER                     // Use {frontmatter} {mainmatter} {backmatter} (TODO(miek): not actually used)
	EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK // No need to insert an empty line to start a (code, quote, order list, unorder list)block
	EXTENSION_PARTS                      // Detect part headers (-#)
	EXTENSION_QUOTES                     // Allow A> as asides
	EXTENSION_SHORT_REF                  // (#id) will be a cross reference
	EXTENSION_SPACE_HEADERS              // Be strict about prefix header rules
	EXTENSION_TABLES                     // Render tables
	EXTENSION_TITLEBLOCK_TOML            // Titleblock in TOML
	EXTENSION_UNIQUE_HEADER_IDS          // When detecting identical anchors add a sequence number -1, -2 etc
	EXTENSION_BACKSLASH_LINE_BREAK       // Translate trailing backslashes into line breaks
	EXTENSION_RFC7328                    // Parse RFC 7328 markdown. Depends on FOOTNOTES extension.
	EXTENSION_DEFINITION_LISTS           // render definition lists

)

const (
	DefaultIpr  = "trust200902"
	DefaultArea = "Internet"
)

const Version = "1.3.6"

const (
	XML2_STANDALONE = 1 << iota // create standalone document
)

const (
	XML_STANDALONE = 1 << iota // create standalone document
)

var (
	// These have been known to change, these are the current ones (2015-08-27).
	CitationsBase = "https://xml2rfc.tools.ietf.org/public/rfc/"

	// CitationsRFC is the URL where the citations for RFCs are.
	CitationsRFC = CitationsBase + "bibxml/"

	// CitationsANSI is the URL where the citations for ANSI documents are.
	CitationsANSI = CitationsBase + "bibxml2/"

	// CitationsID is the URL where the citations for I-Ds are.
	CitationsID = CitationsBase + "bibxml3/"

	// CitationsW3C is the URL where the citations for W3C documents are.
	CitationsW3C = CitationsBase + "bibxml4/"
)

var PIs = []string{"toc", "symrefs", "sortrefs", "compact", "subcompact", "private", "topblock", "header", "footer", "comments"}

var SourceCodeTypes = map[string]bool{
	"abnf":       true,
	"asn.1":      true,
	"bash":       true,
	"c++":        true,
	"c":          true,
	"cbor":       true,
	"dtd":        true,
	"java":       true,
	"javascript": true,
	"json":       true,
	"mib":        true,
	"perl":       true,
	"pseudocode": true,
	"python":     true,
	"rnc":        true,
	"xml":        true,

	"go": true,
}

type HtmlRendererParameters struct {
	// Prepend this text to each relative URL.
	AbsolutePrefix string
	// Add this text to each footnote anchor, to ensure uniqueness.
	FootnoteAnchorPrefix string
	// Show this text inside the <a> tag for a footnote return link, if the
	// HTML_FOOTNOTE_RETURN_LINKS flag is enabled. If blank, the string
	// <sup>[return]</sup> is used.
	FootnoteReturnLinkContents string
}

type Markdown struct {
	// contains filtered or unexported fields
}

type Renderer interface {
	// block-level callbacks
	BlockCode(out *bytes.Buffer, text []byte, lang string, caption []byte, subfigure bool, callouts bool)
	BlockQuote(out *bytes.Buffer, text []byte, attribution []byte)
	BlockHtml(out *bytes.Buffer, text []byte)
	CommentHtml(out *bytes.Buffer, text []byte)
	// SpecialHeader is used for Abstract and Preface. The what string contains abstract or preface.
	SpecialHeader(out *bytes.Buffer, what []byte, text func() bool, id string)
	// Note is use for typesetting notes.
	Note(out *bytes.Buffer, text func() bool, id string)
	Part(out *bytes.Buffer, text func() bool, id string)
	Header(out *bytes.Buffer, text func() bool, level int, id string)
	HRule(out *bytes.Buffer)
	List(out *bytes.Buffer, text func() bool, flags, start int, group []byte)
	ListItem(out *bytes.Buffer, text []byte, flags int)
	Paragraph(out *bytes.Buffer, text func() bool, flags int)

	Table(out *bytes.Buffer, header []byte, body []byte, footer []byte, columnData []int, caption []byte)
	TableRow(out *bytes.Buffer, text []byte)
	TableHeaderCell(out *bytes.Buffer, text []byte, flags, colspan int)
	TableCell(out *bytes.Buffer, text []byte, flags, colspan int)

	Footnotes(out *bytes.Buffer, text func() bool)
	FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)
	TitleBlockTOML(out *bytes.Buffer, data *title)
	Aside(out *bytes.Buffer, text []byte)
	Figure(out *bytes.Buffer, text []byte, caption []byte)

	// Span-level callbacks
	AutoLink(out *bytes.Buffer, link []byte, kind int)
	CodeSpan(out *bytes.Buffer, text []byte)
	// CalloutText is called when a callout is seen in the text. Id is the text
	// seen between < and > and ids references the callout counter(s) in the code.
	CalloutText(out *bytes.Buffer, id string, ids []string)
	// Called when a callout is seen in a code block. Index is the callout counter, id
	// is the number seen between < and >.
	CalloutCode(out *bytes.Buffer, index, id string)
	DoubleEmphasis(out *bytes.Buffer, text []byte)
	Emphasis(out *bytes.Buffer, text []byte)
	Subscript(out *bytes.Buffer, text []byte)
	Superscript(out *bytes.Buffer, text []byte)
	Image(out *bytes.Buffer, link []byte, title []byte, alt []byte, subfigure bool)
	LineBreak(out *bytes.Buffer)
	Link(out *bytes.Buffer, link []byte, title []byte, content []byte)
	RawHtmlTag(out *bytes.Buffer, tag []byte)
	TripleEmphasis(out *bytes.Buffer, text []byte)
	StrikeThrough(out *bytes.Buffer, text []byte)
	FootnoteRef(out *bytes.Buffer, ref []byte, id int)
	Index(out *bytes.Buffer, primary, secondary []byte, prim bool)
	Citation(out *bytes.Buffer, link, title []byte)
	Abbreviation(out *bytes.Buffer, abbr, title []byte)
	Example(out *bytes.Buffer, index int)
	Math(out *bytes.Buffer, text []byte, display bool)

	// Low-level callbacks
	Entity(out *bytes.Buffer, entity []byte)
	NormalText(out *bytes.Buffer, text []byte)

	// Header and footer
	DocumentHeader(out *bytes.Buffer, start bool)
	DocumentFooter(out *bytes.Buffer, start bool)

	// Frontmatter, mainmatter or backmatter
	DocumentMatter(out *bytes.Buffer, matter int)
	References(out *bytes.Buffer, citations map[string]*citation)

	// Helper functions
	Flags() int

	// Attr returns the inline attribute.
	Attr() *inlineAttr
	// SetAttr set the inline attribute.
	SetAttr(*inlineAttr)
	// AttrString return the string representation of this inline attribute.
	AttrString(*inlineAttr) string
}