// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: MIT

// Package scriptorium renders scientific documents server-side. It renders
// Markdown to HTML, TeX mathematics to MathML Core, and Mermaid flowchart
// and sequence diagrams to SVG. The output is deterministic, so the same
// input always produces byte-identical output.
//
// The library is built on the Go standard library alone: it carries no
// dependency of its own. It renders trusted input and applies no
// sanitisation; whether the produced HTML may reach a given audience is
// the consumer's policy, not the renderer's.
//
// A construct the renderer refuses to guess at is never dropped or
// mistranslated: it stays visible as its verbatim source in a marked
// element, so the author sees exactly what was not understood.
package scriptorium

import (
	"sourcedock.dev/petrbalvin/scriptorium/internal/diagram"
	"sourcedock.dev/petrbalvin/scriptorium/internal/markdown"
	"sourcedock.dev/petrbalvin/scriptorium/internal/mathml"
)

// Render renders the Markdown source to HTML. The grammar is the full
// CommonMark specification with the GitHub Flavored Markdown extensions,
// footnotes and definition lists. Rendering never fails and never
// sanitises: the input is trusted, and whether the output may reach an
// audience is the consumer's policy.
func Render(source []byte) []byte {
	return markdown.RenderHTML(source)
}

// RenderMath renders the TeX mathematics source to a MathML Core math
// element, in the inline form. A construct outside the mappable surface
// stays in the output as its verbatim source inside an merror element.
func RenderMath(source []byte) []byte {
	return mathml.Render(source, false)
}

// RenderMathDisplay renders the TeX mathematics source to a MathML Core
// math element in the display form, with display="block".
func RenderMathDisplay(source []byte) []byte {
	return mathml.Render(source, true)
}

// RenderDiagram renders the Mermaid diagram source to SVG. The diagram
// type must be one SupportedDiagram reports; every other type is refused
// with an error naming it.
func RenderDiagram(source []byte) ([]byte, error) {
	return diagram.Render(source)
}

// The Mermaid scope: every diagram type the library accepts. The choice
// is measured, not aesthetic: across the documentation of this forge the
// diagrams are 44 flowcharts (including the historical "graph" spelling)
// and 22 sequence diagrams, with a single outlying state diagram. Every
// other type is refused with a clear error rather than a guess.
var supportedDiagrams = map[string]bool{
	"flowchart":       true,
	"graph":           true, // the historical alias of flowchart
	"sequenceDiagram": true,
}

// SupportedDiagram reports whether the library renders the named
// Mermaid diagram type.
func SupportedDiagram(kind string) bool {
	return supportedDiagrams[kind]
}