/// Typst handout library, used for all documents in this repository.


/// If false, hide instructor info.
///
/// Compile with the following command to hide solutions:
/// `typst compile main.typ --input show_solutions=false`
///
/// Solutions are shown by default. This behavior
/// is less surprising than hiding content by default.
#let show_solutions = {
  if "show_solutions" in sys.inputs {
    // Show solutions unless they're explicitly disabled
    not (
      sys.inputs.show_solutions == "false" or sys.inputs.show_solutions == "no"
    )
  } else {
    // Show solutions by default
    true
  }
}

// Colors
#let ored = rgb("D62121")
#let ogrape = rgb("9C36B5")
#let ocyan = rgb("2288BF")
#let oteal = rgb("12B886")
#let ogreen = rgb("37B26D")
#let oblue = rgb("1C7ED6")



//
// MARK: header
//

#let make_title(
  group,
  quarter,
  title,
  subtitle,
) = {
  align(
    center,
    block(
      width: 60%,
      height: auto,
      breakable: false,
      align(
        center,
        stack(
          spacing: 7pt,
          (
            text(size: 10pt, group) + h(1fr) + text(size: 10pt, quarter)
          ),
          line(length: 100%, stroke: 0.2mm),
          (
            text(size: 20pt, title) + linebreak() + text(size: 10pt, subtitle)
          ),
          line(length: 100%, stroke: 0.2mm),
        ),
      ),
    ),
  )
}

#let warn = {
  set text(ored)
  align(
    center,
    block(
      width: 60%,
      height: auto,
      breakable: false,
      fill: rgb(255, 255, 255),
      stroke: ored + 2pt,
      inset: 3mm,
      (
        align(center, text(weight: "bold", size: 12pt, [Instructor's Handout]))
          + parbreak()
          + align(
            left,
            text(
              size: 10pt,
              [This handout contains solutions and notes.]
                + linebreak()
                + [Recompile without solutions before distributing.],
            ),
          )
      ),
    ),
  )
}

#let preparedby(name) = (
  text(
    size: 10pt,
    [Prepared by ]
      + name
      + [ on ]
      + datetime
        .today()
        .display("[month repr:long] [day padding:none], [year]"),
  )
)

//
// MARK: Solutions
//

#let solution(content) = {
  if show_solutions {
    align(
      center,
      stack(
        block(
          width: 100%,
          breakable: false,
          fill: ored,
          stroke: ored + 2pt,
          inset: 1.5mm,
          (
            align(left, text(fill: white, weight: "bold", [Solution:]))
          ),
        ),
        block(
          width: 100%,
          height: auto,
          breakable: false,
          fill: ored.lighten(80%).desaturate(10%),
          stroke: ored + 2pt,
          inset: 3mm,
          align(left, content),
        ),
      ),
    )
  }
}

#let notsolution(content) = {
  if not show_solutions { content }
}


//
// MARK: Sections
//

#let generic(t) = block(
  above: 8mm,
  below: 2mm,
  text(weight: "bold", t),
)

#let _generic_base(kind, ..args) = {
  counter("obj").step()
  if args.pos().len() == 0 {
    generic([
      #kind
      #context counter("obj").display():
    ])
  } else {
    generic(
      [
        #kind
        #context counter("obj").display():
      ]
        + " "
        + args.pos().at(0),
    )
  }
}

#let problem(..args) = _generic_base("Problem", ..args)
#let definition(..args) = _generic_base("Definition", ..args)
#let theorem(..args) = _generic_base("Theorem", ..args)


//
// MARK: Misc
//


#let hint(content) = {
  text(fill: rgb(100, 100, 100), style: "oblique", "Hint: ")
  text(fill: rgb(100, 100, 100), content)
}

#let note(content) = {
  text(fill: rgb(100, 100, 100), content)
}

#let examplesolution(content) = {
  let c = oblue

  align(
    center,
    stack(
      block(
        width: 100%,
        breakable: false,
        fill: c,
        stroke: c + 2pt,
        inset: 1.5mm,
        (
          align(left, text(fill: white, weight: "bold", [Example solution:]))
        ),
      ),
      block(
        width: 100%,
        height: auto,
        breakable: false,
        fill: c.lighten(80%).desaturate(10%),
        stroke: c + 2pt,
        inset: 3mm,
        align(left, content),
      ),
    ),
  )
}


//
// MARK: wrapper
//

#let handout(
  doc,
  group: none,
  quarter: none,
  title: none,
  by: none,
  subtitle: none,
) = {
  set par(leading: 0.55em, first-line-indent: 0mm, justify: true)
  set text(font: "New Computer Modern")
  set par(spacing: 0.5em)
  show list: set block(spacing: 0.5em, below: 1em)
  set heading(numbering: (..nums) => nums.pos().at(0))

  set page(
    margin: 20mm,
    width: 8in,
    height: 11.5in,
    footer: align(
      center,
      context counter(page).display(),
    ),
    footer-descent: 5mm,
  )


  set list(
    tight: false,
    indent: 5mm,
    spacing: 3mm,
  )

  show heading.where(level: 1): it => {
    set align(center)
    set text(weight: "bold")
    block[
      Section #counter(heading).display(): #text(it.body)
    ]
  }

  make_title(
    group,
    quarter,
    title,
    {
      if by == none { none } else { [#preparedby(by)\ ] }
      if subtitle == none { none } else { subtitle }
    },
  )

  if show_solutions {
    warn
  }
  doc
}