// Base document styling: CJK fonts, headings, math, paragraph layout, page.
//
// Zero external dependencies. Heading numbering uses builtin `numbering`
// strings (no @preview/numbly) so the package compiles with no network.

#import "fonts.typ"

/// Apply the base style to a document body. Used as `show: base-style`.
#let base-style(doc) = {
  // Language / region drive CJK line-breaking and punctuation.
  set text(lang: "zh", region: "cn", size: 12pt, font: fonts.serif)
  set text(cjk-latin-spacing: auto)

  // Heading numbering: 一、 / 1.1 / 1.1.1 — builtin numbering, no deps.
  set heading(numbering: "一、")
  show heading: set text(font: fonts.sans)

  // Number display equations.
  set math.equation(numbering: "(1)")

  set par(
    first-line-indent: (amount: 2em, all: true),
    leading: 0.8em,
    spacing: 1.5em,
    justify: true,
  )

  set page(
    margin: (x: 2.2cm, y: 2.4cm),
    footer: context align(center)[
      #counter(page).get().at(0) / #counter(page).final().at(0)
    ],
  )

  set table(inset: 5pt, stroke: 0.75pt)

  // Inline quotes -> subtle highlight (matches prototype feel).
  show quote.where(block: false): it => highlight(
    it.body,
    fill: gray.transparentize(60%),
    top-edge: 1em,
    bottom-edge: -0.2em,
    extent: 0.35em,
    radius: 0.25em,
  )

  show link: set text(fill: eastern)
  show link: underline

  doc
}

/// Cancel the active paragraph first-line indent (for tag lines that should
/// start flush-left). Defensive against both `length` and `dict` indent forms.
#let no-indent = context {
  let fli = par.first-line-indent
  if type(fli) == length {
    h(-fli)
  } else {
    h(-fli.amount)
  }
}

/// Document title block.
#let title-block() = {
  set align(center)
  set text(font: fonts.sans, size: 22pt, weight: "bold")
  context document.title
}

/// Subtitle + authors block under the title.
#let subtitle-block(subtitle) = {
  set align(center)
  set text(size: 14pt)
  v(1.2em, weak: true)
  subtitle
  context {
    let authors = document.author
    if authors != () {
      v(0.8em, weak: true)
      authors.join(h(1.5em))
    }
  }
  v(1.2em, weak: true)
}