// 教材模板 —— 定理/代码/目录 + 封面页 + 三线表

#import "@preview/bookly:3.1.0": *
#import "@preview/great-theorems:0.1.2": *
#import "@preview/codly:1.3.0": *
#import "@preview/showybox:2.0.4": showybox

// ── helpers ──────────────────────────────────────────────────────────────

#let content-to-string(content) = {
  if content.has("text") {
    content.text
  } else if content.has("children") {
    content.children.map(content-to-string).join("")
  } else if content.has("body") {
    content-to-string(content.body)
  } else if content == [ ] {
    " "
  } else {
    ""
  }
}

// ── blockquote themes ────────────────────────────────────────────────────

#let blockquote-themes = (
  ("课堂小实验", rgb("#F0FDF4"), rgb("#16A34A")),
  ("关键洞察",    rgb("#FFFBEB"), rgb("#D97706")),
  ("工程警示",    rgb("#FEF2F2"), rgb("#DC2626")),
  ("前沿瞭望",    rgb("#F3E8FF"), rgb("#9333EA")),
  ("历史视角",    rgb("#FEF3C7"), rgb("#B45309")),
  ("你知道吗",    rgb("#ECFEFF"), rgb("#0891B2")),
)

#let themed-blockquote(body) = {
  let body-str = content-to-string(body)
  let theme = blockquote-themes.find(t => body-str.contains(t.at(0)))
  let (fill-color, stroke-color) = if theme != none {
    (theme.at(1), theme.at(2))
  } else {
    (rgb("#F1F5F9"), rgb("#64748B"))
  }
  block(
    fill: fill-color,
    stroke: (left: 4pt + stroke-color),
    inset: (x: 14pt, y: 10pt),
    radius: (right: 4pt),
    spacing: 1.2em,
    body,
  )
}

#let primary   = rgb("#1F4E79")
#let secondary = rgb("#2C3E50")
#let accent    = rgb("#3467A8")
#let light     = rgb("#96A0AA")
#let rule-blue = accent.lighten(46%)

// Filled mathblocks: inset so fill does not hug text; radius slightly larger than codly (4pt)
#let _mathblock-inset = (x: 14pt, y: 12pt)
#let _mathblock-radius = 5pt

// Theorem-like environments (great-theorems)
#let theorem = mathblock(
  blocktitle: "Theorem",
  fill: rgb("#E8F0FE"),
  inset: _mathblock-inset,
  radius: _mathblock-radius,
)
#let lemma = mathblock(
  blocktitle: "Lemma",
  fill: rgb("#F3E8FF"),
  inset: _mathblock-inset,
  radius: _mathblock-radius,
)
#let proof = proofblock(
  inset: _mathblock-inset,
  radius: _mathblock-radius,
)
#let example = mathblock(
  blocktitle: "Example",
  fill: rgb("#F0FDF4"),
  inset: _mathblock-inset,
  radius: _mathblock-radius,
)
// Uncounted block: titles must use `title: ...`, not a positional string (see great-theorems README).
#let exercise = mathblock(
  blocktitle: "Exercise",
  prefix: [],
  titlix: title => [*习题*~#title~。#h(0.25em)],
  fill: rgb("#FEF3C7"),
  inset: (x: 14pt, y: 13pt),
  radius: _mathblock-radius,
)

#let cover-page(title, subtitle, date) = {
  page(margin: (top: 3cm, bottom: 3cm, left: 3cm, right: 3cm))[
    #align(center + horizon)[
      #v(2cm)
      #text(size: 28pt, weight: "bold", fill: primary, title)
      #if subtitle != none {
        v(0.8cm)
        text(size: 16pt, fill: accent, subtitle)
      }
      #if date != none {
        v(2cm)
        text(size: 12pt, fill: light, date)
      }
    ]
  ]
}

#let three-line-table(..args) = {
  let kwargs = args.named()
  let children = args.pos()

  let new_children = ()
  let header_seen = false

  for child in children {
    if child.func() == table.header {
      new_children.push(table.hline(stroke: 1.25pt + rule-blue))
      new_children.push(child)
      header_seen = true
    } else if header_seen and child.func() == table.hline {
      new_children.push(table.hline(stroke: 0.75pt + rule-blue))
      header_seen = false
    } else {
      new_children.push(child)
    }
  }
  new_children.push(table.hline(stroke: 1.25pt + rule-blue))

  kwargs.stroke = none
  kwargs.inset = (x: 8pt, y: 5pt)

  table(..new_children, ..kwargs)
}

// Reference-list block: smaller text, hanging indent, tighter rhythm.
// Wrap a 参考文献 / References section's body via `#references[ ... ]`.
#let references(body) = block({
  set text(size: 9.5pt)
  set par(
    justify: true,
    leading: 0.7em,
    spacing: 0.6em,
    first-line-indent: 0pt,
    hanging-indent: 1.5em,
  )
  body
})

#let textbook(
  title: none,
  subtitle: none,
  date: none,
  body,
) = {
  if title != none {
    cover-page(title, subtitle, date)
    pagebreak()
  }

  set text(
    font: (
      "Cambria",
      "PingFang SC",
    ),
    size: 11pt,
    lang: "zh",
  )

  show raw: set text(font: (
    "Courier New",
    "Menlo",
    "Monaco",
    "SimSun",
  ))

  // Long-form reading: most generous body rhythm in this family
  set par(
    justify: true,
    leading: 0.86em,
    spacing: 1.2em,
    first-line-indent: (amount: 2em, all: true),
  )

  show: codly-init
  codly(
    stroke: 0.5pt + rule-blue,
    fill: rgb("#F8F9FA"),
    zebra-fill: none,
    lang-stroke: none,
    lang-fill: light.lighten(60%),
    radius: 4pt,
  )

  show: great-theorems-init
  set heading(numbering: "1.1")

  // 按章编号：每章开始时重置图片/表格计数器
  set figure(numbering: (..nums) => {
    let h = counter(heading).get()
    let ch = if h.len() > 0 { h.first() } else { 1 }
    numbering("1-1", ch, nums.pos().first())
  })

  // List rhythm: spacing ≥ leading (0.86em), slightly looser than body for long-form reading
  set list(indent: 1.2em, body-indent: 0.45em, spacing: 0.98em)
  set enum(indent: 1.2em, body-indent: 0.45em, spacing: 0.98em)

  // 每章从新页开始（第一章除外，因为前面已有 pagebreak）
  let first-chapter = state("first-chapter", true)

  show heading.where(level: 1): it => {
    counter(figure.where(kind: image)).update(0)
    counter(figure.where(kind: table)).update(0)

    context if not first-chapter.get() {
      pagebreak()
    }
    first-chapter.update(false)

    v(1.45em)
    text(size: 18pt, weight: "bold", fill: primary, it)
    v(0.55em)
  }

  show heading.where(level: 2): it => {
    v(1.1em)
    text(size: 14pt, weight: "bold", fill: accent, it)
    v(0.5em)
  }

  show heading.where(level: 3): it => {
    v(0.8em)
    text(size: 12pt, weight: "bold", fill: secondary, it)
    v(0.4em)
  }

  // Blockquote → themed block
  show quote.where(block: true): it => themed-blockquote(it.body)

  set page(
    paper: "a4",
    margin: (top: 2.5cm, bottom: 2.5cm, left: 2.5cm, right: 2.5cm),
    header: context {
      let h = query(selector(heading.where(level: 1))).find(it => it.location().page() == here().page())
      if h != none {
        align(right)[
          #text(size: 9pt, fill: light)[
            #h.body
          ]
        ]
      }
    },
    footer: context {
      align(center)[
        #text(size: 9pt, fill: light)[
          — #counter(page).display("1") —
        ]
      ]
    },
  )

  show link: it => text(fill: accent, it)

  outline(title: "目录", depth: 2)
  pagebreak()

  body
}