/*
* 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.
// Updates the exercise's points automatically.
// 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(override-points: true, numbering: "a)", items) = block[
  #let c = counter("exercise-items")
  #let exercise_points = 0
  #c.update(0)
  #table(
    columns: (1fr, auto),
    stroke: none,
    ..for (points, statement) in items {
      exercise_points += points
      let pt
      if points <= 1 {
        pt = get_L("point_short")
      } else {
        pt = get_L("points_short")
      }
      (
        [#c.step()#v(4pt) *#context c.display(numbering)* #statement],
        rect(radius:1cm, inset: (x:5pt, y:3pt), stroke: gray+0.5pt)[#points #pt],
      )
    }
  )

  #if override-points {
    context {
      state("exercise-registry").update( arr => {
        if (arr.len() == 0) {
          arr
        } else {
          let new_arr = arr.slice(0, arr.len()-1)
          new_arr.push((arr.last().at(0), arr.last().at(1), exercise_points))
          new_arr
        }
      })
    }
  }
]

// 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(title, points) = {
  // state("exercise_points").update(points)
  let exercise_counter = counter("exercise")
  exercise_counter.step()
  context {
    let current_exercise = exercise_counter.get().at(0)
    let exercise-numbering = state("exercise-numbering").get()
    let exercise_registry = state("exercise-registry")
    let final_points = 0
    if (exercise_registry.final().len() >= current_exercise) {
      final_points = exercise_registry.final().at(exercise_counter.get().at(0)-1).at(2)
    }
    let exercise_label = exercise_counter.display(exercise-numbering)
    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(exercise-numbering)}*]], [#title], [#rect(radius:1cm, outset: 4pt, inset: (x:2pt, y:0pt), fill: white)[*#format_points(final_points)*]],
  )
)}}

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

  course-title: [%COURSE_TITLE_FIRST_LINE% \ %COURSE_TITLE_SECOND_LINE%],
  course-short-title: "%course-short-title%",
  course-code: "%course-code%",

  date: "%DATE%",

  institution: smallcaps("NAWI Graz"),

  duration-minutes: "%DURATION%",

  ask-student-number: false,
  ask-trainer-name: false,
  ask-group: true,

  instructions: none,

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

  exercise-numbering: "1",

  body
) = {

/*
* Setup
*/

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

state("exercise-numbering").update(exercise-numbering)

/*
* Localization
*/

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

state("translations").update(translations)

// State and counter for exercises
state("exercise-registry").update(())

// Displays an overview of the exam as a table, with
// a row per exercise, the corresponding points and space to write the mark.

let exercise_overview_table() = context {
  let exercise_registry = state("exercise-registry")
  let entries = exercise_registry.final()
  let total_points = entries.fold(0, (sum, entry) => sum + entry.at(2))

  let columns = entries.map((i) => 1fr)
  columns.push(1fr)
  [== #get_L("points_obtained")]
  set text(size: 14pt)
  block(radius: 0.3cm, stroke: none, fill: lightgray, inset: (x:0pt, y:4pt),
  table(
    columns: columns,
    stroke: none,
    fill: none,
    gutter: 0pt,
    inset: (x, y) => {
      let top = 8pt
      if y == 0 { top = 2pt }
      if x == 0 {
        (left:4pt, right:2pt, top: top, bottom: 0pt)
      } else if x == entries.len() {
        (left:2pt, right:4pt, top: top, bottom: 0pt)
      } else {
        (left:2pt, right:2pt, top: top, bottom: 0pt)
      }
    },
    align: (x, y) => { if (y == 1) { right+horizon } else { center+horizon }},
    ..for entry in entries {
      (
        [#get_L("exercise_short", cap: true) #entry.at(0)],
      )
    },
    [*#get_L("total_points")*],
    ..for entry in entries {
      (
        rect(radius:0.2cm, fill: white, width: 100%, inset: 8pt, outset: 0pt, stroke:none)[/#entry.at(2)],
      )
    },
    rect(radius:0.2cm, fill: white, width: 100%, inset: 8pt, outset: 0pt, stroke:black)[#strong([/#total_points])],
  )
)
}

// Header and footer
set page(
  header-ascent: 20%,
  header: [
    #set text(size: 8pt)
    #table(
      stroke: none,
      gutter: 4pt,
      inset: 0pt,
      align: (x, y) => { if x < 2 { left+bottom } else { right }},
      columns: (auto, 1fr, auto),
    [#institution], [], [#course-short-title \ _#(date)_],
    )
  ],
  footer: [#align(right)[#context(counter(page).display("1 / 1", both:true))]],
)

// Title page

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

[*#get_L("course-code")*: #course-code \ *#get_L("exam_duration"): #duration-minutes #get_L("minutes")*]

v(0.5cm)

block(radius: 0.2cm, fill: lightgray, inset: 3pt, clip: true, table(
  fill: lightgray,
  stroke: none,
  columns: (auto, 1fr),
  gutter: 3pt,
  inset: (left:7pt, right:0pt, y:0pt),
  align: horizon,
  [#get_L("student_name")], rect(fill: white, width: 100%, radius: 0.2cm),
  .. if ask-student-number {
    ([#get_L("student_number")], rect(fill: white, width: 100%, radius: 0.2cm))
  },
  ..if ask-trainer-name {
    ([#get_L("trainer_name")], rect(fill: white, width: 100%, radius: 0.2cm))
  },
  ..if ask-group {
    ([#get_L("group")], rect(fill: white, width: 100%, radius: 0.2cm))
  }
))

v(0.5cm)

if (instructions != none) {
  [ #instructions ]
} else {
  if language == "de" [
- _Lesen Sie die ganze Prüfungsaufgabe durch_.
- 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.
- Viel Erfolg!
  ]
  if language == "en" [
- _Before starting, read the whole exam._
- 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.
- Good luck!
  ]
}

v(1fr)

exercise_overview_table()

v(1fr)

pagebreak()

body
}