◊(Local Yarn Code "Check-in [e493f1c6]")

“Crystalizing” is an extra layer in between docs and templates that destructures the doc and stores
it in various pieces in a SQLite cache. Individual articles save chunks of rendered HTML to the
cache when their individual pages are rendered. The SQLite cache is then referenced by any page that
collects multiple articles and notes together. This is much faster than fetching docs and metas
through Pollen’s cache and re-converting them to HTML.

This module only provides three functions; almost all its code is private.

@defproc[(spell-of-summoning!) void?]

Initializes the SQLite database cache file. This involves creating the file
(@filepath{vitreous.sqlite}) if it does not exist, and running queries to create tables in the
database if they do not exist.

This function should be called near the beginning of any HTML template used to render an individual
article.

I could have made it so the function is called automatically every time Pollen is run. But that
This function is called automatically in @filepath{pollen.rkt} whenever HTML is the target output.
would mean it gets run even when the target is not HTML, which is unnecessary.

@defproc[(crystalize-article! [pagenode pagenode?] [doc txexpr?]) non-empty-string?]

Returns a string containing the HTML of @racket[_doc]. @margin-note{This is one function that breaks
my convention of using a prefix of @tt{html$-} for functions that return strings of HTML.}
Privately, it does a lot of other work. The article is saved to the SQLite cache. If the article
specifies a @racket['series] meta, information about that series is fetched and used in the
rendering of the article. If there are @racket[note]s in the doc, they are parsed and saved
individually to the SQLite cache. If any of the notes use the @code{#:disposition} attribute,
information about the disposition is parsed out and used in the rendering of the article.

@deftogether[(@defproc[(list-short/articles [#:series series (or/c string? boolean?) #t]
                                            [#:limit limit stringish? -1]
                                            [order string? "DESC"]) txexpr?]
              @defproc[(list-full/articles  [#:series series (or/c string? boolean?) #t]
                                            [#:limit limit stringish? -1]
                                            [order string? "DESC"]) txexpr?])]

Fetches the HTML for all articles from the SQLite cache and returns the HTML strings inside
a @racket['style] tagged X-expression. The articles will be ordered by publish date according to
@racket[_order] and optionally limited to the series specified in @racket[_series].

If @racket[_series] expression evaluates to @racket[#f], articles will not be filtered by series. If
it evaluates to @racket[#t] (the default), articles will be filtered by those that specify the
current output of @racket[here-output-path] in their @tt{series_pagenode} column in the SQLite
cache. If a string is supplied, articles will be filtered by those containing that exact value in
their @tt{series_pagenode} column in the SQLite cache.

The @racket[_order] expression must evaluate to either @racket["ASC"] or @racket["DESC"] and the
@racket[_limit] expressions must evaluate to a value suitable for use in the @tt{LIMIT} clause of
@ext-link["https://sqlite.org/lang_select.html"]{a SQLite @tt{SELECT} statement}. An expression that
evaluates to a negative integer (the default) is the same as having no limit.

The reason for enclosing the results in a @racket['style] txexpr is to prevent the HTML from being
escaped by @racket[->html] in the template. This tag was picked for the job because there will
generally never be a need to include any actual CSS information inside a @tt{<style>} tag in any
page, so it can be safely filtered out later. To remove the enclosing @tt{<style>} tag, see
@racket[unfence].

@defproc[(list-full/articles+notes [#:series series (or/c string? #f) #f]
                                   [#:limit limit exact-integer? -1]
                                   [order string? "DESC"]) txexpr?]

Like @racket[list-full/articles] except that notes and articles are combined side by side in the results.

@defproc[(unfence [html string?]) string?]

Returns @racket[_html] with all occurrences of @racket["<style>"] and @racket["</style>"] removed.
The contents of the style tags are left intact.

Use this with strings returned from @racket[->html] when called on docs containing
@racket[list-full/articles] or its siblings.

@defproc[(article-plain-title [pagenode pagenode?]) non-empty-string?]

Fetches the “plain” title (i.e., with no HTML markup) for the given article from the SQLite cache.
If the article did not specify a title, a default title is supplied. If the article contained
a @racket[note] that used the @code{#:disposition} attribute, the disposition-mark may be included
in the title.

Note that this needs to be called @emph{after} @racket[crystalize-article!] in order to get an
up-to-date value.

              @defproc[(series-pagetree) pagetree?])]

These are project-wide pagetrees: @racket[articles-pagetree] contains a pagenode for every Pollen
document contained in @racket[articles-path], and @racket[series-pagetree] contains a pagenode for
every Pollen document in @racket[series-path]. The pagenodes themselves point to the rendered
@tt{.html} targets of the source documents.

@defproc[(here-output-path) path?]

Returns the path to the current output file, relative to @racket[current-project-root]. If no metas
are available, raises an error. This is like what you can get from the @tt{here} variable that Pollen
provides, except it is available outside templates.

@section{Metas and @code{txexpr}s}

@defproc[(maybe-attr [key symbol?] [attrs txexpr-attrs?] [missing-expr any/c ""]) any/c]

Find the value of @racket[_key] in the supplied list of attributes, returning the value of
@racket[_missing-expr] if it’s not there.

                     "../dust.rkt"
                     "../snippets-html.rkt"
                     racket/base
                     racket/contract
                     racket/string
                     pollen/template
                     pollen/pagetree
                     txexpr
                     sugar/coerce))

@title{@filepath{snippets-html.rkt}}

@defmodule["snippets-html.rkt" #:packages ()]

Each “snippet” module provides all the document- and article-level blocks of structural markup

The @racket[_title-specified-in-doc?] form changes the HTML markup structure used.

@defproc[(html$-article-close [footertext string?]) non-empty-string?]

Returns a string containing a closing @tt{<section>} tag, a @tt{<footer>} element containing
@racket[_footertext], and a closing @tt{<article>} tag. If @racket[_footertext] is empty, the
@tt{<footer>} element will be omitted.

@defproc[(html$-article-listing-short [web-path string?] [pubdate string?] [title string?])
non-empty-string?]

Returns a string of HTML for an article as it would appear in a listing context in “short” form
(date and title only).

@defproc[(html$-page-body-close) non-empty-string?]

Returns a string containing the page’s @tt{<footer>} and closing tags.

@defproc[(html$-note-title [author string?] [pagenode pagenode?] [parent-title string?])
non-empty-string?]

;; since the database is merely a disposable cache, and since all the input
;; will be coming from me.

(require pollen/setup
         pollen/core
         pollen/template
         racket/string
         racket/function
         txexpr
         db/base
         "sqlite-tools.rkt"
         "snippets-html.rkt"
         "dust.rkt")

;; ~~~ Provides ~~~

(provide spell-of-summoning!
         crystalize-article!
         article-plain-title
         list-short/articles
         list-full/articles
         list-full/articles+notes
         unfence
         preheat-series!)

;; ~~~ Private use ~~~

(define DBFILE (build-path (current-project-root) "vitreous.sqlite"))

;; Since the DB exists to serve as a high-speed cache, the tables are constructed so that

    note_id
    title_html_flow
    author
    author_url
    date
    disposition
    content_html
    series_pagenode
    listing_full_html
    listing_excerpt_html  ; Not used for now
    listing_short_html))

(define table_series-fields
  '(pagenode
    title

    (notes->last-disposition-values note-txprs))
  
  (let* ([pubdate (select-from-metas 'published (current-metas))]
         [doc-html    (->html (cdr body-txpr))]
         [title-specified? (not (equal? '() maybe-title))]
         [title-val   (if (not (null? maybe-title)) (car maybe-title) maybe-title)]
         [title-tx    (make-article-title title-val body-txpr disposition disp-note-id)]
         [title-html  (->html title-tx)]
         [title-html  (apply string-append (map ->html (get-elements title-tx)))]
         [title-plain (tx-strs title-tx)]
         [series-node (series-pagenode)]
         [header      (html$-article-open title-specified? title-tx pubdate)]
         [footertext (make-article-footertext pagenode series-node disposition disp-note-id (length note-txprs))]
         [footer (html$-article-close footertext)]
         [notes-section-html (crystalize-notes! pagenode title-plain note-txprs)])

            (maybe-meta 'noun (series-noun))
            (length note-txprs)
            doc-html
            disposition
            disp-note-id
            (string-append header doc-html footer)
            "" ; listing_excerpt_html: Not yet used
            "")) ; listing_short_html: Not yet used
            (html$-article-listing-short (symbol->string pagenode) pubdate title-plain))) ; listing_short_html: Not yet used

    (apply query! (make-insert/replace-query 'articles table_articles-fields) article-record)
          
    (string-append header doc-html notes-section-html footer)))

;; ~~~ Retrieve listings of articles and notes ~~~
;; ~~~ (Mainly for use on Series pages         ~~~

;; (private) Create a WHERE clause matching a single series or list of series
(define (where/series s)
  (cond [(list? s)
         (let ([series (map (curry (format "~a/~a.html" series-path)) s)])
           (format "WHERE `series_pagenode` IN ~a" (list->sql-values series)))]
        [(string? s)
         (format "WHERE `series_pagenode` IS \"~a/~a.html\"" series-path s)]
        [(equal? s #t)
         (format "WHERE `series_pagenode` IS \"~a\"" (here-output-path))]
        [else ""]))

;; (private) Return a combined list of articles and notes sorted by date
(define (list/articles+notes type #:series [s #t] #:limit [limit -1] [order "DESC"])
  (define select #<<@@@@@
     SELECT `~a` FROM
       (SELECT `~a`, `published` FROM `articles`
        UNION SELECT
        `~a`,`date` AS `published` FROM `notes`
        ~a ORDER BY `published` ~a LIMIT ~a)
@@@@@
    )
  (query-list (sqltools:dbc) (format select type type type (where/series s) order limit)))

;; (private) Return a list of articles only, sorted by date
(define (list/articles type #:series [s #t] #:limit [limit -1] [order "DESC"])
  (define select "SELECT `~a` FROM `articles` ~a ORDER BY `published` ~a LIMIT ~a")
  (query-list (sqltools:dbc) (format select type (where/series s) order limit)))

;; ~~~~
;; Return cached HTML of articles and/or notes, fenced within a style txexpr to prevent it being
;; escaped by ->html. See also: definition of `unfence`

(define (list-short/articles #:series [s #t] #:limit [limit -1] [order "DESC"])
  `(style "<ul class=\"article-list\">"
          ,@(list/articles "listing_short_html" #:series s #:limit limit order)
          "</ul>"))

(define (list-full/articles #:series [s #t] #:limit [limit -1] [order "DESC"])
  `(style ,@(list/articles "listing_full_html" #:series s #:limit limit order)))

;; Return a combined list of articles and notes (“full content” version) sorted by date
(define (list-full/articles+notes #:series [s #t] #:limit [limit -1] [order "DESC"])
  `(style ,@(list/articles+notes "listing_full_html" #:series s #:limit limit order)))

;; Remove "<style>" and "</style>" introduced by using ->html on docs containing output from
;; listing functions
(define (unfence html-str)
  (regexp-replace* #px"<[\\/]{0,1}style>" html-str ""))

;; ~~~ Article-related helper functions ~~~
;;

;; Return a title txexpr for the current article, constructing a default if no title text was specified.
(define (make-article-title supplied-title body-tx disposition disp-note-id)
  (define title-elems
    (cond [(null? supplied-title) (list (default-title (get-elements body-tx)))]

          note-id
          title-html-flow
          author
          author-url
          note-date
          disposition-attr
          content-html
          (symbol->string (series-pagenode))
          listing-full-html
          "" ; listing_excerpt_html: Not used for now
          "")) ; listing_short_html: Not used for now
  
  ;; save to db
  (define save-note-query
    (format (string-append "INSERT OR REPLACE INTO `notes` (`rowid`, ~a) "

;;   joel@jdueck.net
;;   https://joeldueck.com
;; -------------------------------------------------------------------------

(require pollen/core
         pollen/pagetree
         pollen/setup
         pollen/file
         net/uri-codec
         gregor
         txexpr
         racket/list
         racket/string)

;; Provides common helper functions used throughout the project

(provide maybe-meta     ; Select from (current-metas) or default value ("") if not available
         maybe-attr     ; Return an attribute’s value or a default ("") if not available
         here-output-path
         series-noun    ; Retrieve noun-singular from current 'series meta, or ""
         series-title   ; Retrieve title of series in current 'series meta, or ""
         series-pagenode
         make-tag-predicate
         tx-strs
         ymd->english
         ymd->dateformat

(define articles-path "articles")

(define (default-title body-txprs)
  (format "“~a…”" (first-words body-txprs 5)))

(define (maybe-meta m [missing ""])
  (or (select-from-metas m (current-metas)) missing))

;; Return the current output path, relative to (current-project-root)
;; Similar to the variable 'here' which is only accessible in Pollen templates,
;; except this is an actual path, not a string.
(define (here-output-path)
  (cond [(current-metas)
         (define-values (_ rel-path-parts)
           (drop-common-prefix (explode-path (current-project-root))
                               (explode-path (string->path (select-from-metas 'here-path (current-metas))))))
         (->output-path (apply build-path rel-path-parts))]
        [else (error "No metas are available")]))

;; Checks current-metas for a 'series meta and returns the pagenode of that series,
;; or '|| if no series is specified.
(define (series-pagenode)
  (define maybe-series (or (select-from-metas 'series (current-metas)) ""))
  (cond
    [(non-empty-string? maybe-series)

(provide (all-defined-out)
         (all-from-out "crystalize.rkt" "snippets-html.rkt"))

(module setup racket/base
  (require syntax/modresolve pollen/setup)
  (provide (all-defined-out))
  (define poly-targets '(html))
  (define block-tags (cons 'title default-block-tags))
  (define block-tags (append '(title style) default-block-tags))
  (define cache-watchlist
    (map resolve-module-path '("tags-html.rkt"
                               "snippets-html.rkt"
                               "dust.rkt"
                               "crystalize.rkt"))))

(case (current-poly-target)
  [(html) (spell-of-summoning!)])

;; Macro for defining tag functions that automatically branch based on the 
;; current output format and the list of poly-targets in the setup module.
;; Use this macro when you know you will need keyword arguments.
;;
(define-syntax (poly-branch-kwargs-tag stx)
  (syntax-parse stx
    [(_ TAG:id)

<!DOCTYPE html>
<html lang="en">

◊html$-page-head[(select-from-metas 'title metas)]

◊html$-page-body-open[]

<section class="article-listing">

<h2>◊(select-from-metas 'title metas)</h2>

◊(unfence (->html doc #:splice? #t))

</section>

◊html$-page-body-close[]

</html>

         openssl/sha1
         "dust.rkt")

(provide html$-page-head
         html$-page-body-open
         html$-article-open
         html$-article-close
         html$-article-listing-short
         html$-page-body-close
         html$-note-title
         html$-note-contents
         html$-note-listing-full
         html$-note-in-article
         html$-notes-section)

(define (html$-article-close footertext)
  (cond [(non-empty-string? footertext)
         ◊string-append{</section>
          <footer class="article-info"><span class="x">(</span>◊|footertext|<span class="x">)</span></footer>
          </article>}]
        [else "</section></article>"]))
 

(define (html$-article-listing-short web-path pubdate title)
  ◊string-append{
  <li><a href="◊web-path">
    <div class="article-list-date caps">◊(ymd->english pubdate)</div>
    <div class="article-list-title">◊|title|</div>
  </a></li>})

(define (html$-page-body-close)
  ◊string-append{<footer>By Joel Dueck</footer>
 </main></body>})

;; Notes
;;
(define (html$-note-title author pagenode parent-title)

<!DOCTYPE html>
<html lang="en">
◊spell-of-summoning![]

◊(define article-html (crystalize-article! here doc))
◊(define page-title (article-plain-title here))
◊html$-page-head[page-title]

◊html$-page-body-open[]

◊article-html

◊html$-page-body-close[]

</html>