{{ define "main" }}

{{ $subjectCode := .Title }}

{{/* Find which semester this subject belongs to */}}
{{ $semester := "" }}
{{ range .Pages }}
  {{ if eq $semester "" }}
    {{ $raw := .Params.semester }}
    {{ if reflect.IsSlice $raw }}
      {{ $semester = index $raw 0 }}
    {{ else }}
      {{ $semester = $raw }}
    {{ end }}
  {{ end }}
{{ end }}

{{/* Breadcrumbs */}}
<nav class="uninotes-breadcrumbs breadcrumbs">
  <a href="/uninotes/">UniNotes</a>
  {{ if $semester }}
    {{ $semPage := site.GetPage (printf "/semester/%s" ($semester | urlize)) }}
    {{ if $semPage }}
      › <a href="{{ $semPage.RelPermalink }}">{{ $semester }}</a>
    {{ end }}
  {{ end }}
  › <span>{{ $subjectCode }}</span>
</nav>

<h1>{{ $subjectCode }}</h1>

{{/* List units sorted by date */}}
<ul class="uninotes-list uninotes-list--units">
  {{ range .Pages.ByDate }}
    <li class="uninotes-list__item">
      <a class="uninotes-list__link" href="{{ .RelPermalink }}">
        {{ with .Params.unit }}{{ . }}{{ else }}{{ .Title }}{{ end }}
      </a>
    </li>
  {{ end }}
</ul>

{{/* Subject prev/next — siblings are other subjectcodes in the same semester */}}
{{ if $semester }}
  {{ $semPage := site.GetPage (printf "/semester/%s" ($semester | urlize)) }}
  {{ if $semPage }}
    {{ $siblingCodes := slice }}
    {{ range $semPage.Pages }}
      {{ $raw := .Params.subjectcode }}
      {{ $code := "" }}
      {{ if reflect.IsSlice $raw }}
        {{ $code = index $raw 0 }}
      {{ else }}
        {{ $code = $raw }}
      {{ end }}
      {{ if and $code (not (in $siblingCodes $code)) }}
        {{ $siblingCodes = $siblingCodes | append $code }}
      {{ end }}
    {{ end }}
    {{ $siblingCodes = sort $siblingCodes }}

    {{ if gt (len $siblingCodes) 1 }}
      {{ $currentIdx := 0 }}
      {{ range $i, $c := $siblingCodes }}
        {{ if eq $c $subjectCode }}{{ $currentIdx = $i }}{{ end }}
      {{ end }}
      <nav class="page-nav">
        {{ if gt $currentIdx 0 }}
          {{ $prevCode := index $siblingCodes (sub $currentIdx 1) }}
          {{ $prevPage := site.GetPage (printf "/subjectcode/%s" ($prevCode | urlize)) }}
          {{ if $prevPage }}
            <a class="page-nav__previous-link" href="{{ $prevPage.RelPermalink }}">← {{ $prevCode }}</a>
          {{ end }}
        {{ end }}
        {{ if lt $currentIdx (sub (len $siblingCodes) 1) }}
          {{ $nextCode := index $siblingCodes (add $currentIdx 1) }}
          {{ $nextPage := site.GetPage (printf "/subjectcode/%s" ($nextCode | urlize)) }}
          {{ if $nextPage }}
            <a class="page-nav__next-link" href="{{ $nextPage.RelPermalink }}">{{ $nextCode }} →</a>
          {{ end }}
        {{ end }}
      </nav>
    {{ end }}
  {{ end }}
{{ end }}

{{ end }}