use math
use path
use re
use str

var cmd      = $e:qpdf~

fn -is-pdf {|f|
  str:has-suffix $f .pdf
}

fn -is-number {|arg|
  re:match '^\d+$' $arg
}

fn -is-rotate {|arg|
  re:match '^(\+|-)(\d+):.*' $arg
}

fn -is-seq {|arg|
  re:match '^\d+(,\d+)*$' $arg
}

fn -must-pdf {|f|
  if (not (-is-pdf $f)) {
    fail $f' n’est pas un fichier PDF'
  }
}

fn -must-not-exist {|f|
  var exist = ?(stat $f 2>&- > /dev/null)
  if (bool $exist) {
    fail $f' existe déjà'
  }
}

fn -must-exist {|f|
  var exist = ?(stat $f 2>&- > /dev/null)
  if (not (bool $exist)) {
    fail $f' n’existe pas'
  }
}

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

fn -make-seq {|seq|
  if (not (-is-seq $seq)) {
    fail $seq': pas une séquence'
  }
  set @seq = (order (str:split , $seq))
  var b = 1
  each {|ei|
    var e = (- $ei 1)
    if (== $b $e) {
      put $b
      set b = $ei
    } elif (< $b $e) {
      put $b'-'$e
      set b = $ei
    }
  } $seq
  put $b'-z'
}

fn -out {|in suffix|
  var out = (str:trim-suffix $in .pdf)
  str:join '' [ $out .pdf ]
}

fn -parse-selection {|in selection|
  if (-is-rotate $selection) {
    var out   = (-make-tmp)
    var i     = (str:index $selection :)
    var r sel = $selection[..$i] $selection[(+ $i 1)..]
    if (eq sel '') {
      set @sel = $in
    } else {
      set @sel = $in $sel
    }
    $cmd --empty --pages $@sel -- $out
    $cmd $out --replace-input --rotate=$r
    put $out
  } else {
    put $in $selection
  }
}

fn -parse-all {|args|
  var tmpfiles  = []
  var selection = []
  var in        = $nil
  var miss      = $nil
  try {
    each {|e|
      if (-is-pdf $e) {
        -must-exist $e
        if (not-eq $miss $nil) {
          set @selection = $@selection $miss
          set miss = $e
        }
        set in = $e
      } else {
        if (eq $in $nil) {
          fail 'Le pagerange doit être déclaré après un fichier d’entrée'
        }
        var @s = (-parse-selection $in $e)
        if (== (count $s) 1) {
          set @tmpfiles = $@tmpfiles $@s
        }
        set @selection = $@selection $@s
      }
    } $args
  } finally {
    put $selection $tmpfiles
  }
}

fn -merge {|&collate=$nil selection out|
  if (< (count $selection) 1) {
    fail 'Aucune sélection'
  }
  var @args = --empty --pages $@selection -- $out
  if (not-eq $collate $nil) {
    if (-is-number $collate) {
      set @args = $collate $@args
    }
    set @args = --collate $@args
  }
  $cmd $@args
}

fn merge {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail "la commande doit contenir au moins 2 paramètres"
  }
  var out = $args[$l]
  -must-pdf $out
  -must-not-exist $out

  var sel tmp = [] []
  try {
    set sel tmp = (-parse-all $args[..$l])
    -merge $sel $out
  } finally {
    if (> (count $tmp) 0) {
      rm -f $@tmp
    }
  }
}

fn split {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail "la commande doit contenir au moins 2 paramètres"
  }
  var out = $args[$l]
  -must-pdf $out
  -must-not-exist $out
  set args = $args[..$l]

  var size = $nil
  if (-is-number $args[0]) {
    set size @args = @args
  }

  var sel tmp = [] []
  try {
    set sel tmp = (-parse-all $args[..$l])
    var t = (-make-tmp)
    -merge $sel $t
    set @tmp = $@tmp $t
    var @ac = --split-pages
    if (not-eq $size $nil) {
      set @ac = $@ac $size
    }
    set @ac = $@ac $t $out/%d.pdf
    mkdir $out
    $cmd $@ac
  } finally {
    if (> (count $tmp) 0) {
      rm -f $@tmp
    }
  }
}

fn split-at {|@args|
  var l = (- (count $args) 1)
  if (< $l 2) {
    fail "la commande doit contenir au moins 3 paramètres"
  }
  var out = $args[$l]
  -must-pdf $out
  -must-not-exist $out
  var @seq = (-make-seq $args[0])
  set args = $args[1..$l]

  var sel tmp = [] []
  try {
    set sel tmp = (-parse-all $args[..$l])
    var t = (-make-tmp)
    -merge $sel $t
    set @tmp = $@tmp $t
    var i = 1
    each {|s|
      $cmd --empty --pages $t $s -- $out/$i.pdf
      set i = (+ $i 1)
    } $seq
  } finally {
    if (> (count $tmp) 0) {
      rm -f $@tmp
    }
  }
}

fn zip {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail "la commande doit contenir au moins 2 paramètres"
  }
  var out = $args[$l]
  var col = $true
  -must-pdf $out
  -must-not-exist $out
  set args = $args[..$l]

  if (-is-number $args[0]) {
    set col @args = $@args
  }

  var sel tmp = [] []
  try {
    set sel tmp = (-parse-all $args)
    -merge &collate=$col $sel $out
  } finally {
    if (> (count $tmp) 0) {
      rm -f $@tmp
    }
  }
}

fn unzip {|@args|
  var l = (- (count $args) 1)
  if (< $l 2) {
    fail 'unzip doit contenir au moins 3 paramètres'
  }
  var mod = $args[0]
  var out = $args[$l]
  -must-not-exist $out

  var sel tmp = [] []
  try {
    set sel tmp = (-parse-all $args[1..$l])
    var t       = (-make-tmp)
    -merge $sel $t
    set @tmp    = $@tmp $t
    var @sels   = (range $mod | put [])
    var end     = ($cmd --show-npages $t)
    range $end | each {|i|
      var m = (% $i $mod)
      set sel[$m] = (+ $i 1)
    }
    mkdir $out
    range $mod | each {|i|
      var @pr = (str:join ',' $@sels[$i])
      $cmd --empty --pages $t $@pr -- $out'/'(+ $i 1)'.pdf'
    }
  } finally {
    if (> (count $tmp) 0) {
      rm -f $@tmp
    }
  }
}

fn decrypt {|@args|
  var l = (count $args)
  if (or (< $l 1) (> $l 3)) {
    fail "decrypt doit contenir entre 1 et 3 paramètres"
  }
  var in  = $args[0]
  -must-pdf $in
  -must-exist $in
  var out = (-out $in _decrypted.pdf)
  var p   = $nil
  if (> $l 1) {
    set p = $args[1]
    if (== $l 3) {
      set out = $args[2]
      -must-pdf $out
    }
  }
  -must-not-exist $out
  if (eq $p $nil) {
    $cmd $in $out --decrypt
  } else {
    $cmd $in $out --decrypt $p
  }
}

fn help {|@args|
  cat $E:HOME/.config/elvish/aliases/qpdf.help
}

fn -date {|raw|
  var y m d = $raw[2..6] $raw[6..8] $raw[8..10]
  var h n s = $raw[10..12] $raw[12..14] $raw[14..16]
  var tz @_ = (str:split "'" $raw[16..])
  var date = (printf ^
    '%s-%s-%sT%s:%s:%s%s' ^
    $y $m $d ^
    $h $n $s ^
    $tz)
  date --date $date
}

fn -pts2cm {|v|
  / (math:round (* $v 3.52778)) 100
}

fn -size {|size|
  var u = 0
  var m = [
    &10=Kio
    &20=Mio
    &30=Gio
  ]
  while (< $u 30) {
    var p = (math:pow 2 (+ $u 10))
    if (< $size $p) {
      break
    }
    set u = (to-string (+ $u 10))
  }
  if (== $u 0) {
    put $size
  } else {
    var p = (math:pow 2 (+ $u 10))
    var e = (/ $size $p)
    printf '%.1f%s' $e $m[$u]
  }
}

fn -b2str {|b|
  if $b {
    put 'Oui'
  } else {
    put 'Non'
  }
}

fn -props {|input json|
  var objects   = $json[objects]
  var trailer   = $objects[trailer]
  var iid       = $trailer[/Info]
  var rid       = $trailer[/Root]
  var info      = $objects[$iid]
  var root      = $objects[$rid]
  var pages     = $objects[$root[/Pages]]
  var p1        = $objects[$pages[/Kids][0]][/MediaBox]

  var w         = (-pts2cm $p1[2])
  var h         = (-pts2cm $p1[3])
  var layout    = 'Portrait'
  if (> $w $h) {
    set layout = 'Paysage'
  }

  var props = [
    &path=(path:abs $input)
    &fsize=(-size (stat -c '%s' $input))
    &version=''
    &psize=(printf '%sx%s cm (%s)' $w $h $layout)
    &pages=$pages[/Count]
    &title=''
    &subject=''
    &author=''
    &producer=$info[/Producer]
    &creator=$info[/Creator]
    &cdate=(-date $info[/CreationDate])
    &mdate=''
    &acroform=(-b2str $json[acroform][hasacroform])
    &encrypted=(-b2str $json[encrypt][encrypted])
  ]
  
  #@TODO: version pdf
  if (has-key $info '/Title') {
    set props[title] = $info[/Title]
  }
  if (has-key $info '/Subject') {
    set props[subject] = $info[/Subject]
  }
  if (has-key $info '/Author') {
    set props[author] = $info[/Author]
  }
  if (has-key $info '/ModDate') {
    set props[mdate] = (-date $info[/ModDate])
  }

  put $props
}

fn info {|@args|
  var input = $args[0]
  var json  = ($cmd --json $input | from-json)
  var props = (-props $input $json)

  echo '               Chemin: '$props[path]
  echo '               Taille: '$props[fsize]
  echo '          Version PDF: '$props[version]
  echo '     Taille des pages: '$props[psize]
  echo '      Nombre de pages: '$props[pages]
  echo '............................................'
  echo '                Titre: '$props[title]
  echo '                Sujet: '$props[subject]
  echo '               Auteur: '$props[author]
  echo '             Créateur: '$props[creator]
  echo '           Producteur: '$props[producer]
  echo '     Date de création: '$props[cdate]
  echo ' Date de modification: '$props[mdate]
  echo '............................................'
  echo '              Chiffré: '$props[encrypted]
  echo '             Acroform: '$props[acroform]
}

edit:add-var epdf~ {|action @args|
  var actions = [
    &merge=$merge~
    &split=$split~
    &split-at=$split-at~
    &zip=$zip~
    &unzip=$unzip~
    &decrypt=$decrypt~
    &help=$help~
    &info=$info~
  ]
  if (not (has-key $actions $action)) {
    fail $action': action inconnue'
  }
  $actions[$action] $@args
}