#!/usr/bin/env nu

# Register a new Slidev deck as a site page.
#
# The projection REPLACES a page's body and PRESERVES its frontmatter — so the page has to exist
# first, and it must carry title, slug, thumbnail and og_image. That is the one thing the
# projection cannot invent, and the one step nobody remembers: without it, `just decks` fails with
# "la página de destino no tiene frontmatter; no la sobrescribo a ciegas".
#
# This scaffolds those pages and prints the decks.ncl entry to add. It deliberately does NOT edit
# decks.ncl: that file is the manifest a human curates (which deck, which slugs, which language),
# and a script that rewrites a manifest is a script that decides what should be published.
#
# Usage (from outreach/):
#   nu scripts/decks/new-deck.nu rustikon.md rustikon-why-i-needed-rust \
#       --title-es "Rustikon: por qué necesité Rust" --slug-es rustikon-por-que-necesite-rust \
#       --title-en "Rustikon: Why I Needed Rust"     --slug-en rustikon-why-i-needed-rust

def outreach [] { $env.FILE_PWD | path dirname | path dirname }

def main [
  source: string                      # the Slidev md, relative to outreach/presentation/
  id: string                          # the deck id: file name of the pages, and the asset dir
  --title-es: string = ""     # omite el par title/slug de un idioma y ese idioma NO tendrá página
  --slug-es: string = ""
  --title-en: string = ""
  --slug-en: string = ""
  --source-en: string = ""    # fuente PROPIA de la página EN cuando el deck es bilingüe nativo
                              # (dos charlas reales, no una traducción): p. ej. rustikon.md (EN)
                              # + rustikon_es.md (ES). Omítelo si una sola fuente sirve ambos idiomas.
  --date: string = ""                 # ISO; defaults to today
  --author: string = "Jesús Pérez"
] {
  let src = [(outreach) "presentation" $source] | path join
  if not ($src | path exists) { error make { msg: $"no existe el deck: ($src)" } }

  # A separate EN source must exist and must actually differ — a page's `source` equal to the
  # deck's is just noise in the manifest, and a non-existent one fails the projection later, so
  # catch both here where the message can name the file.
  if (not ($source_en | is-empty)) {
    let esrc = [(outreach) "presentation" $source_en] | path join
    if not ($esrc | path exists) { error make { msg: $"no existe la fuente EN: ($esrc)" } }
    if ($source_en == $source) { error make { msg: "--source-en es igual a la fuente del deck; omítelo" } }
  }

  let when = if ($date | is-empty) { (date now | format date "%Y-%m-%d") } else { $date }

  # `source` per page: EN uses --source-en when given, otherwise the deck's own. Only a source
  # that DIFFERS from the deck default is emitted in the manifest below.
  let pages = [
    { lang: "es", title: $title_es, slug: $slug_es, source: $source }
    { lang: "en", title: $title_en, slug: $slug_en, source: (if ($source_en | is-empty) { $source } else { $source_en }) }
  ]

  # A language with no title/slug gets NO page. A deck that exists only in Spanish must not have
  # an English URL serving Spanish slides: a page that lies about its language is worse than a
  # page that does not exist.
  let wanted = ($pages | where {|p| not (($p.title | is-empty) or ($p.slug | is-empty)) })
  if ($wanted | is-empty) { error make { msg: "necesitas al menos --title-es/--slug-es o --title-en/--slug-en" } }

  # The URL category is localized (decks.ncl `category`): ES → presentaciones, EN → decks. The
  # loader resolves the body by {lang}/{category}/{id}.md, so BOTH the directory and the
  # frontmatter category must be the localized value, or the ES page 404s.
  let cat = (^nickel export --format json ([(outreach) "scripts" "decks" "decks.ncl"] | path join)
    | from json | get category)

  for p in $wanted {
    let category = ($cat | get $p.lang)
    let dir = [(outreach) "site" "site" "content" "resources" $p.lang $category] | path join
    let file = [$dir $"($id).md"] | path join
    if ($file | path exists) {
      print $"(ansi yellow)ya existe, no lo toco: ($file)(ansi reset)"
      continue
    }
    mkdir $dir
    # Only the frontmatter. The body is the projection's, and it is fenced by its own markers —
    # anything written here below the frontmatter would be overwritten on the first `just decks`.
    $"---
id: \"($id)\"
title: \"($p.title)\"
slug: \"($p.slug)\"
subtitle: \"\"
excerpt: \"\"

author: \"($author)\"
date: \"($when)\"
published: true
featured: false

category: \"($category)\"
tags: [\"ontoref\", \"slides\"]

# Card + share image. The webp carousel is no longer the CONTENT — the slides carry real text
# now — but slide 0 still makes the best thumbnail.
thumbnail: \"/images/decks/($id)/0.webp\"
image_url: \"/images/decks/($id)/0.webp\"
og_image: \"/images/og/decks-($id)-0.png\"

sort_order: 1
---
" | save --force $file
    print $"(ansi green)creada:(ansi reset) ($file)"
  }

  # Emit `source = …` per page ONLY where it differs from the deck default — that is exactly the
  # bilingual-native case (rustikon.md + rustikon_es.md), and it is the line deck-new used to make
  # you add by hand.
  let entries = ($wanted | each {|p|
    if ($p.source == $source) {
      $"        { lang = \"($p.lang)\", slug = \"($p.slug)\" },"
    } else {
      $"        { lang = \"($p.lang)\", slug = \"($p.slug)\", source = \"($p.source)\" },"
    }
  } | str join "\n")
  print $"
(ansi cyan)Añade esta entrada a scripts/decks/decks.ncl(ansi reset) — el manifiesto lo curas tú,
no un script: qué deck se publica, con qué slug y en qué idioma es una decisión, no un derivado.

    {
      source = \"($source)\",
      id = \"($id)\",
      pages = [
($entries)
      ],
    },

(ansi cyan)Y luego:(ansi reset)
    just decks                       # build + captura + proyección + puertas de artefacto
    just decks-served                # las puertas sobre la PÁGINA servida
"
}