/*
* Customisation
*/

#let lightgray = rgb("#eeeeee")

// Default font (embedded in Typst)
#let font-text = "libertinus serif"

#let mtext = text.with(font: font-text)

/*
* Macros
*/

// Frame for table, no vertical lines, top and bottom are bold
// s: stroke, to specify e.g. the width and color of strokes
#let frame(s) = (x, y) => (
  left: none,
  right: none,
  top: if y > 0 { s } else { 2*s },
  bottom: 2*s,
)

#let capitalize(string) = {
  return string.replace(
    regex("[A-Za-z]+('[A-Za-z]+)?"),
    word => upper(word.text.first()) + lower(word.text.slice(1)),
  )
}

#let get_L(k, cap:false) = context {
  let translations = state("translations").get()
  let term = translations.at(k, default:k)
  if cap {
    return capitalize(term)
  } else {
    return term
  }
}

// Formats number of points, "1 Punkt", "2 Punkte", etc.
// p: int
#let format_points = (p) => (
  context {
    if p <= 1 {
      [#p #get_L("point")]
    } else {
      [#p #get_L("points")]
    }
  }
)

// Displays a list of sub-questions and the associated points
// items: array of (int, expression), where
//   - int is the number of points this item is worth,
//   - expression is the item to typeset.
// example:
// #exercise_items((
//  (1, [Untersuchen Sie, ob $f$ injektiv ist.]),
//  (1, [Untersuchen Sie, ob $f$ surjektiv ist.]),
//  (1, [Geben Sie im Falle ihrer Existenz die Umkehrfunktion $f^(−1)$ an.])
//))
#let exercise_items(items) = block[
  #let c = counter("exercise_items")
  #c.update(0)
  #table(
    columns: (1fr, auto),
    stroke: none,
    ..for (points, statement) in items {
      let pt
      if points <= 1 {
        pt = get_L("point_short")
      } else {
        pt = get_L("points_short")
      }
      (
        [#c.step()#v(4pt) *#context c.display("a)")* #statement],
        rect(radius:1cm, inset: (x:5pt, y:3pt), stroke: gray+0.5pt)[#points #pt],
      )
    }
  )]

// Displays a header for the exercise, ex. number is incremented automatically
// Used to compute the overview table (see below)
// title: string, title of the exercise
// points: int, the number of points the exercise is worth
#let exercise_header(title, points) = {
  let exercise_counter = counter("exercise")
  context {
    let exercise_registry = state("exercise-registry").get()
    exercise_counter.step()
    let exercise_label = exercise_counter.display()
    // exercise_registry.update(entries => entries + ((exercise_label, title, points),))
  }
  block(radius: 1cm, stroke: none, fill: lightgray, inset: 1pt,
  table(
    columns: (auto, 1fr, auto),
    align: (left, center, right),
    stroke: none,
    [#rect(radius:1cm, outset: 4pt, inset: (x:2pt, y:0pt), fill: white)[*#get_L("exercise") #context{exercise_counter.display()}*]], [#title], [#rect(radius:1cm, outset: 4pt, inset: (x:2pt, y:0pt), fill: white)[*#format_points(points)*]],
  )
)}

#let exam(
  title: "%KLAUSUR or EXAM%",

  subtitle: [%COURSE_TITLE_FIRST_LINE% \ %COURSE_TITLE_SECOND_LINE%],
  header_left: "%COURSE_SHORT_TITLE%",
  header_right: "%DATE%",

  course_number: "%COURSE_NUMBER%",
  duration_minutes: "%DURATION%",

  instructions: none,

  language: "de", // or "en"
  font-size: 12pt,
  paper-size: "a4",

  body
) = {

/*
* Setup
*/

// Paper and text size
set page(paper: paper-size)
set text(size: font-size, lang: language, hyphenate: true)

/*
* Localization
*/

let translations = none
if language == "en" {
  translations = (
    course_number: "Course number",
    exam_duration: "Exam duration",
    student_name: "Name",
    student_number: "Student number",
    trainer_name: "Trainer",
    exercise: "Exercise",
    point: "point",
    points: "points",
    point_short: "pt",
    points_short: "pts",
    total_points: "Total",
    minutes: "minutes",
  )
} else if language == "de" {
  translations = (
    course_number: "LV-Nummer",
    exam_duration: "Arbeitszeit",
    student_name: "Name",
    student_number: "Matrikelnr.",
    trainer_name: "Übungsleiter",
    exercise: "Beispiel",
    point: "Punkt",
    points: "Punkte",
    point_short: "P.",
    points_short: "P.",
    total_points: "Gesamt",
    minutes: "Minuten",
  )
}

state("translations").update(translations)

// State and counter for exercises
context { let exercise_registry = state("exercise-registry", ()) }

// Displays an overview of the exam as a table, with
// a row per exercise, the corresponding points and space to write the mark.
// The 
let exercise_overview_table() = context {
  let entries = state("exercise-registry").final()
  let total_points = entries.fold(0, (sum, entry) => sum + entry.at(2))
  align(center)[
    #set text(size: 14pt)
    #table(
      columns: (auto, auto),
      stroke: frame(0.5pt),
      fill: none,
      inset: 10pt,
      align: horizon,
      table.header[#get_L("exercise")][#get_L("points", cap: true)],
      table.hline(stroke: 1pt),
      ..for entry in entries {
        (
          [#entry.at(0)],
          [#h(2cm) / #entry.at(2)],
        )
      },
      table.hline(stroke: 1pt),
      [*#get_L("total_points")*], [#h(2.2cm) / *#total_points*]
    )
  ]
}

// Header and footer
set page(
  header: [
    #header_left
    #h(1fr)
    _#(header_right)_
  ],
  footer: [#align(right)[#context(counter(page).display("1 / 1", both:true))]],
)

// Title page

v(1fr)
align(center)[= #title]
v(0.5cm)
align(center)[== #subtitle]
v(1fr)

[*#get_L("course_number")*: #course_number* \ #get_L("exam_duration"): #duration_minutes #get_L("minutes")*]

v(0.5cm)

table(
  fill: (lightgray, none),
  stroke: frame(0.5pt),
  columns: (auto, 1fr),
  inset: 10pt,
  align: horizon,
  [#get_L("student_name")], [],
  [#get_L("student_number")], [],
  [#get_L("trainer_name")], [],        // comment this line if unneeded
)

v(0.5cm)

if (instructions != none) {
  [ #instructions ]
} else {
  if language == "de" [
- Es sind keine Unterlagen und auch keine Taschenrechner erlaubt.
- Alle Rechenschritte (inklusive Zwischenresultate und Lösungswege) sind anzugeben und alle Antworten genau zu begründen bzw. zu beweisen!
- Schreiben Sie auf jedes _lose_ Blatt Ihren Namen und Ihre Matrikelnummer!
- Nicht mit roter Farbe schreiben.
  ]
  if language == "en" [
- Course material and calculators are not allowed.
- Write down all the steps, including intermediate results. All answers must be substantiated!
- Do not write in red.
  ]
}

v(1fr)

// exercise_overview_table()

v(1fr)

pagebreak()

body
}