\version "2.20"

#(define part-first-pages '(0))

#(define (part-first-page? layout props)
  (= (chain-assoc-get 'page:page-number props -1)
     (ly:output-def-lookup layout 'first-page-number)))

#(define (reset-part-first-page layout props arg)
"Returns page-number-string, starting every bookpart with page-number 0.
Relying on the extern defined `part-first-pages'.
"
  (set! props (prepend-alist-chain 'part-first-page '(0) props))

  (let* ((real-page-number (chain-assoc-get 'page:page-number props -1))
         (parts-page-number (- real-page-number (car part-first-pages))))

    (if (part-first-page? layout props)
        (set! part-first-pages (cons (1- real-page-number) part-first-pages)))

    (set! props
      (cons
        (list
          (cons 'page:page-number-string (number->string parts-page-number))
          (cons 'page:page-number parts-page-number))
        props))
    (interpret-markup layout props arg)))

#(define ((print-part-first-page-as-one number-type) layout props arg)

  (set! props
    (cons
      (list
        (cons 'page:page-number-string
              (let ((page-number
                     (chain-assoc-get 'page:page-number props -1)))
                (cond ((eq? number-type 'roman-lower)
                       (fancy-format #f "~(~@r~)" page-number))
                      ((eq? number-type 'roman-upper)
                       (fancy-format #f "~@r" page-number))
                      ((eq? number-type 'arabic)
                       (number->string page-number))
                      (else (number->string page-number)))))
        (cons 'page:page-number
              (chain-assoc-get 'page:page-number props -1)))
      props))
  (interpret-markup layout props arg))

\paper {
  %first-page-number = #-3
  print-first-page-number = ##t
  oddMarkup =
  #(define-scheme-function (number-type)(symbol?)
    #{
      \markup
        \column {
          \fill-line {
            " "
            \on-the-fly #not-part-first-page \fromproperty #'header:instrument
            \on-the-fly #print-page-number-check-first
              %% use in this order:
              \on-the-fly #reset-part-first-page
              \on-the-fly #(print-part-first-page-as-one number-type)
              \fromproperty #'page:page-number-string
          }
          \vspace #5
        }
    #})

  evenMarkup =
  #(define-scheme-function (number-type)(symbol?)
    #{
      \markup
        \column {
          \fill-line {
            \on-the-fly #print-page-number-check-first
              %% use in this order:
              \on-the-fly #reset-part-first-page
              \on-the-fly #(print-part-first-page-as-one number-type)
              \fromproperty #'page:page-number-string
            \on-the-fly #not-part-first-page \fromproperty #'header:instrument
            " "
          }
          \vspace #5
        }
    #})

  oddFooterMarkup = \markup {
    \column {
      \fill-line {
            \concat {
              "real book number: "
            \on-the-fly #print-page-number-check-first
              \fromproperty #'page:page-number-string
          }
      }
      \fill-line {
        %% Copyright header field only on first page in each boob.
        \on-the-fly #part-first-page \fromproperty #'header:copyright
      }
      \fill-line {
        %% Tagline header field only on last page in the book.
        \on-the-fly #last-page \fromproperty #'header:tagline
      }
    }
  }
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXAMPLES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

#(set-default-paper-size "a7")


\book {
  \bookpart {
        \markup
          \column {
            \vspace #5
            \fill-line {
              \override #'(box-padding . 10)
            \rounded-box "MY BOOK 2"
            }
          }
  }
  \bookpart {
    \paper {
      %page-number-type = #'roman-lower
      oddHeaderMarkup = \oddMarkup #'roman-lower
      evenHeaderMarkup = \evenMarkup #'roman-lower
      %oddFooterMarkup = ##f
    }
    \markuplist \table-of-contents

  }

  \bookpart {
    \paper {
      oddHeaderMarkup = \oddMarkup #'arabic
      evenHeaderMarkup = \evenMarkup #'arabic
    }
    \tocItem "one1"
    \tocItem "one2"
    \tocItem "one3"
    \tocItem "one4"
    \tocItem "one1"
    \tocItem "one2"
    \tocItem "one3"
    \tocItem "one4"
    \repeat unfold 2 { c''1 \pageBreak }
  }

  \bookpart {
    \paper {
      oddHeaderMarkup = \oddMarkup #'arabic
      evenHeaderMarkup = \evenMarkup #'arabic
    }
    \tocItem "two1"
    \tocItem "two2"
    \tocItem "two3"
    \tocItem "two4"
    \tocItem "two1"
    \tocItem "two2"
    \tocItem "two3"
    \tocItem "two4"
    \repeat unfold 2 { d''1 \pageBreak }
  }

  \bookpart {
    \paper {
      oddHeaderMarkup = \oddMarkup #'arabic
      evenHeaderMarkup = \evenMarkup #'arabic
    }
    \tocItem "three1"
    \tocItem "three2"
    \tocItem "three3"
    \tocItem "three4"
    \tocItem "three1"
    \tocItem "three2"
    \tocItem "three3"
    \tocItem "three4"
    { e''1 \pageBreak }

    \tocItem "four1"
    \tocItem "four2"
    \tocItem "four3"
    \tocItem "four4"
    \tocItem "four1"
    \tocItem "four2"
    \tocItem "four3"
    \tocItem "four4"
    { f''1 \pageBreak }
  }
}