use path
use re
use str

fn is-pdf {|file|
  eq (path:ext $file) '.pdf'
}

fn exist {|file|
  or (path:is-dir &follow-symlink=$true $file) (path:is-regular &follow-symlink=$true $file)
}

fn not-exist {|file|
  not (exist $file)
}

fn is-pdf-exist {|file|
  and (is-pdf $file) (exist $file)
}

fn is-number {|v|
  re:match '^\d+$' (to-string $v)
}

fn is-page-selection {|v|
  re:match '^(r?\d+|z)(-(r?\d+|z))?(,(r?\d+|z)(-(r?\d+|z))?)*(:(even|odd))?$' (to-string $v)
}

fn is-rotate-selection {|v|
  re:match '^(\+|-)?\d+(:(r?\d+|z)(-(r?\d+|z))?(,(r?\d+|z)(-(r?\d+|z))?)*(:(even|odd))?)?$' (to-string $v)
}

fn is-selection {|v|
  or (is-page-selection $v) (is-rotate-selection $v)
}

fn version {|in|
  var version    = (head -n 1 $in)
  set version @_ = (str:split "\r" $version)
  str:trim-prefix $version '%PDF-'
}

fn json {|in|
  qpdf $in --json | from-json
}

fn form {|in|
  var json = (json $in)
  put $json[acroform]
}

fn objects {|in|
  var json = (json $in)
  put $json[objects]
}

fn -object {|extend objects key|
  if (not (has-key $objects $key)) {
    put $nil
    return
  }
  var o = $objects[$key]
  if (and $extend (eq (kind-of $o) 'map')) {
    keys $o | each {|k|
      var v = $o[$k]
      if (has-key $objects $v) {
        set o[$k] = (-object $extend $objects $v)
      }
    }
  }
  put $o
}

fn object {|&extend=$false in key|
  -object $extend (objects $in) $key
}

fn filter {|&extend=$false in cond|
  var objects = (objects $in)
  keys $objects | each {|k|
    var o = (-object $extend $objects $k)
    if ($cond $o) {
      put [&id=$k &object=$o]
    }
  }
}

fn trailer {|in|
  object &extend=$true $in 'trailer'
}

fn pages {|in|
  var json = (json $in)
  put $json[pages]
}

fn nb-pages {|in|
  qpdf --show-npages $in
}

fn parse-selection {|@selection|
  var out = []
  var in  = $nil
  each {|e|
    if (is-pdf $e) {
      if (not-exist $e) {
        fail (printf '%s: le fichier n’existe pas' $e)
      }
      if (not-eq $in $nil) {
        set @out = $@out $in
      }
      set in = [
        &file=$e
        &rotate=$nil
        &selections=[]
      ]
      continue
    }
    if (eq $in $nil) {
      fail (printf '%s: pas de fichier avant la sélection' $e)
    }
    var r rc = $in[rotate] $nil
    if (is-page-selection $e) {
      set rc = $false
    } elif (is-rotate-selection $e) {
      set rc = $true
    } else {
      fail (printf '%s: paramètre invalide' $e)
    }
    if (not-eq $r $rc) {
      if (not-eq $r $nil) {
        set @out           = $@out $in
        set in[selections] = []
      }
      set in[rotate] = $rc
    }
    set in[selections] = [ (all $in[selections]) $e ]
  } $selection
  if (not-eq $in $nil) {
    set @out = $@out $in
  }
  put $out
}

fn -t {
  mktemp -q /tmp/qpdf_XXXXXXXXXX.pdf
}

fn rotate {|&empty=$false &out=$nil &keep=$false in @rotate|
  var @args = $in
  if (eq $out $nil) {
    set @args = $@args --replace-input
  } else {
    set @args = $@args $out
  }
  if $empty {
    set @args = $@args --empty
  }
  if $keep {
    set @rotate = (each {|r| put --rotate=$r } $rotate)
    qpdf $@args $@rotate
    return
  }
  var tmp = []
  try {
    var @tmp = (each {|r|
      var t r @s = (-t) (str:split ':' $r)
      set s = (str:join ':' $s)
      if (eq $s '') {
        qpdf $in $t --rotate=$r
      } else {
        qpdf $in $t --pages $in $s --
        qpdf $t --replace-input --rotate=$r
      }
      put $t
    } $rotate)
    qpdf $@args --pages $@tmp --
  } finally {
    rm -f $@tmp
  }
}

fn -catarg {|selection|
  var f r s   = $selection[file] $selection[rotate] $selection[selections]
  var out tmp = [] []
  if $r {
    var t    = (-t)
    set @tmp = $t
    set @out = $@out $t
    rotate &out=$t $f $@s
  } else {
    set @out = $@out $f
    if (> (count $s) 0) {
      set @out = $@out (str:join ',' $s)
    }
  }
  put $out $tmp
}

fn cat {|&empty=$false &collate=$nil &out=$nil @selection|
  var inputs    = (parse-selection $@selection)
  var pages tmp = [] []
  each {|in|
    var a t    = (-catarg $in)
    set @pages = $@pages $@a
    set @tmp   = $@tmp $@t
  } $inputs
  try {
    var in    = $pages[0]
    var @args = $in
    if (eq $out $nil) {
      set @args = $@args --replace-input
    } else {
      set @args = $@args $out
    }
    if $empty {
      set @args = $@args --empty
    }
    if (bool $collate) {
      var c = --collate
      if (is-number $collate) {
        set c = (str:join '=' [ $c $collate ])
      }
      set @args = $@args $c
    }
    qpdf $@args --pages $@pages --
  } finally {
    each {|t|
      rm -f $t
    } $tmp
  }
}

fn decrypt {|&out=$nil in @passwd|
  var @args = $in
  if (eq $out $nil) {
    set @args = $@args --replace-input
  } else {
    set @args = $@args $out
  }
  set @args = $@args --decrypt
  if (> (count $passwd) 0) {
    set @args = $@args $passwd[0]
  }
  qpdf $@args
}

fn -l0 {|n size|
  set n = (to-string $n)
  var l = (- $size (count $n))
  str:join '' [ (repeat $l 0) $n ]
}

fn split {|&empty=$false &size=1 in out|
  if (not-exist $out) {
    mkdir $out
  }
  var args = []
  if $empty {
    set @args = --empty
  }
  qpdf $@args --split-pages=$size $in $out'/%d.pdf'
}

fn uncat {|&empty=$false in out @selection|
  if (not-exist $out) {
    mkdir $out
  }
  var i = 1
  var n = (count $selection)
  set n = (count (to-string $n))
  each {|s|
    cat &empty=$empty &out=$out'/'(-l0 $i $n)'.pdf' $in $s
    set i = (+ $i 1)
  } $selection
}

fn raw-stream {|in out id|
  qpdf $in --show-object=$id --raw-stream-data > $out
}

fn filtered-stream {|in out id|
  qpdf $in --show-object=$id --filtered-stream-data --normalize-content=n --stream-data=uncompress --decode-level=all > $out
}