markdown

type Frontmatter struct {
	Title     string         `yaml:"title"`
	Author    string         `yaml:"author"`
	CSS       string         `yaml:"css"`
	Papersize string         `yaml:"papersize"`
	Format    string         `yaml:"format"`
	Lang      string         `yaml:"lang"`
	Extra     map[string]any `yaml:"-"` // all key-value pairs (including the known ones)
}

type Options struct {
	Template      bool   // apply Go template expansion before processing
	CSSFile       string // additional CSS file to load
	DebugMarkdown bool   // print expanded Markdown to stdout instead of generating PDF
	DebugHTML     bool   // print generated HTML to stdout instead of generating PDF
	// Format selects a PDF conformance level. "PDF/UA" enables the
	// accessibility tagging pipeline (StructTreeRoot, MarkInfo, role-mapped
	// element tree, XMP pdfuaid:part 1). Empty means a plain PDF.
	Format string
	// Lang is the BCP47 language tag written to the PDF catalog (/Lang) and
	// used as the document-wide hyphenation default. Required for PDF/UA.
	Lang string
	// Title becomes the document /Title (catalog + XMP dc:title). PDF/UA
	// also auto-enables /DisplayDocTitle so PDF readers show the title in
	// the window chrome instead of the filename.
	Title string
	// OutputPath is the resolved PDF output path. If empty, falls back
	// to <input>.pdf alongside the input file.
	OutputPath string
	// MaxPasses caps the auto-rerun loop used to converge the aux file
	// (forward references like total page count). Values <1 are treated
	// as 1 (single pass, no rerun).
	MaxPasses int
	// SetupLua is called once per pass on a fresh lua.State to register
	// modules. May be nil for callers that have already initialised the
	// state (e.g. ProcessHTMLString from the htmlbag bridge — that path
	// reuses the caller's state and ignores SetupLua entirely).
	SetupLua func(l *lua.State)
	// ScriptArgs becomes arg[1..n] in the Lua state. arg[0] is the
	// input filename, arg[-1] is the interpreter (os.Args[0]).
	ScriptArgs []string
	// Result, if non-nil, is populated with end-of-pass statistics.
	// The final pass's data wins. Nil disables collection.
	Result *Result
	// SourceDateEpoch, when non-zero, overrides the PDF CreationDate.
	// Combined with baseline-pdf's already-deterministic /ID (MD5 of
	// xref content) this yields byte-stable PDFs across runs with the
	// same input — the SOURCE_DATE_EPOCH reproducible-builds protocol.
	SourceDateEpoch time.Time
}

type Result struct {
	Pages    int                    `json:"pages"`
	Passes   int                    `json:"passes"`
	Headings []htmlbag.HeadingEntry `json:"headings"`
}