(import (chibi)
        (chibi json)
        (chibi filesystem)
        (chibi process)
        (chibi pathname)
        (chibi app)
        (chibi string)
        (chibi io)
        (srfi 1)
        (srfi 16)
        (srfi 95))

(define debug #t)
;(define output-dir "output")
;(define target "GET_FROM_INPUT")
;(define sources  (sort (directory-files (make-path target lang)) string<?))
;(define metadata (make-path target lang "Metadata.yaml"))
;(define output   (make-path output-dir target))

(define (directory-files-not-hidden dir)
  (filter
    (lambda (x) (and (not (string-prefix? "." x))
                     (string=? "md" (path-extension x))))
    (directory-files dir)))

(define (directory-sources lang dir)
  (map (lambda (x) (make-path dir lang x))
       (sort (directory-files-not-hidden (make-path dir lang)) string<?)))

(define (directory-meta lang dir)
  (make-path dir lang "Metadata.yaml"))

(define (process->string-or-fail call errmsg)
  (let* ((res (process->output+error+status call))
         (out (first res))
         (err (second res))
         (strcall (string-join call " "))
         (status (third res)))
    (if (= status 0)
        (begin
          (if debug
            (display
              (string-append "\nDEBUG: In call: " strcall "\n" err)
              (current-error-port)))
          out)
        (error (string-append
                 "\n"
                 errmsg
                 "\nIn call: " strcall
                 "\n" err)))))

(define (read-meta file)
  (parse-json
    (process->string-or-fail
      `("./utils/yaml2json.py" ,file)
      "Error parsing Metadata file")))

;TODO
(define (pandoc-web-simple lang out folder)
  "Receives a list of files and an optional metadata file:
  (pandoc-web '(file1 file2 ...) metafile)"
  (define pandoc-call
    (case-lambda
      (() `("pandoc"
            "--to=html"
            "-o" ,out
            "--standalone"
            "--no-highlight"
            "--data-dir=."
            ,(string-append "--resource-path=templates/web:" folder)
            "--base-header-level=2" ;"--shift-heading-level-by=-1" is the new way
            "--template=web-simple.html"
            "--lua-filter=toc.lua"
            "--lua-filter=anchored-h.lua"
            "--lua-filter=appendixes.lua"))
      ((files)
       (append (pandoc-call) files))
      ((files metafile)
       (append (pandoc-call files) `("--metadata-file" ,metafile)))))
  (process->string-or-fail
    (pandoc-call
      (directory-sources lang folder)
      (directory-meta lang folder))
    "Error in web-page creation"))


; TODO
(define (pandoc-web lang out folder)
  "Receives a list of files and an optional metadata file:
  (pandoc-web '(file1 file2 ...) metafile)"
  (define pandoc-call
    (case-lambda
      (() `("pandoc"
            "--to=html"
            "-o" ,out
            "--standalone"
            "--self-contained"
            "--base-header-level=2" ;"--shift-heading-level-by=-1" is the new way
            "--data-dir=."
            ,(string-append "--resource-path=./templates/web/:./templates:" folder)
            "--template=web.html"
            "--lua-filter=toc.lua"
            "--lua-filter=anchored-h.lua"
            "--lua-filter=appendixes.lua"))
      ((files)
       (append (pandoc-call) files))
      ((files metafile)
       (append (pandoc-call files) `("--metadata-file" ,metafile)))))
  (process->string-or-fail
    (pandoc-call
      (directory-sources lang folder)
      (directory-meta lang folder))
    "Error in web-page creation"))

(define (pandoc-book lang out folder)
  "Receives a list of files and an optional metadata file:
  (pandoc-web '(file1 file2 ...) metafile)"
  (define pandoc-call
    (case-lambda
      (() `("pandoc"
            "-o" ,out
            "--standalone"
            "--pdf-engine=xelatex"
            "--data-dir=."
            ,(string-append "--resource-path=" folder)
            "--template=book.latex"
            "--lua-filter=appendixes.lua"))
      ((files)
       (append (pandoc-call) files))
      ((files metafile)
       (append (pandoc-call files) `("--metadata-file" ,metafile)))))

  (process->string-or-fail
    (pandoc-call
      (directory-sources lang folder)
      (directory-meta lang folder))
    "Error in book creation"))

;; RUN THIS LIKE:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define args (cdr (command-line)))
(display (pandoc-web "es" "hola.html" (car args)))
;(display (pandoc-book "es" "hola.pdf" (car args)))

;(display (process->string-or-fail '("./utils/yaml2json.py"  "src/Programming_in_Python/es/Metadata.yaml")  ""))
;(display (cdr (assoc 'title (read-meta "src/Programming_in_Python/es/Metadata.yaml"))))