use moi/util/format
use moi/util/pdf
use re
use str

fn -must-pdf {|file|
  if (not (pdf:is-pdf $file)) {
    fail (printf '%s n’est pas un fichier pdf' $file)
  }
}

fn -must-exist {|file|
  if (pdf:not-exist $file) {
    fail (printf '%s n’existe pas' $file)
  }
}

fn -must-not-exist {|file|
  if (pdf:exist $file) {
    fail (printf '%s existe déjà' $file)
  }
}

fn -must-pdf-exist {|file|
  -must-pdf $file
  -must-exist $file
}

fn -must-pdf-not-exist {|file|
  -must-pdf $file
  -must-not-exist $file
}

fn -must-valid {|v cond|
  if (not ($cond $v)) {
    fail (printf '%s: paramètre invalide' $v)
  }
}

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

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

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]
  var out    = (-out $in _decrypted.pdf)
  var passwd = []
  -must-pdf-exist $in
  if (> $l 1) {
    set @passwd = $args[1]
    if (> $l 2) {
      set out = $args[2]
    }
  }
  -must-pdf-not-exist $out
  pdf:decrypt &out=$out $in $@passwd
}

fn rotate {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail 'rotate doit contenir au moins 1 paramètres'
  }
  var in  = $args[0]
  var out = (-out $in _rotated.pdf)
  if (pdf:is-pdf $args[$l]) {
    set @args out = (all $args[1..])
  }
  -must-pdf-exist $in
  -must-pdf-not-exist $out
  each {|e|
    -must-valid $e $pdf:is-rotate-selection~
  } $args
  pdf:rotate &keep=$true &out=$out $in $@args
}

fn merge {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail 'merge doit contenir au moins 2 paramètres'
  }
  var @selection out = $@args
  -must-pdf-not-exist $out
  var has-in = $false
  each {|e|
    if (pdf:is-pdf $e) {
      -must-exist $e
      set has-in = $true
    } else {
      if (not $has-in) {
        fail 'Une sélection doit être précédée d’un fichier d’entrée'
      }
      -must-valid $e $pdf:is-selection~
    }
  } $selection
  pdf:cat &out=$out $@selection
}

fn unmerge {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail 'unmerge doit contenir au moins 2 paramètres'
  }
  var in  = $args[0]
  var out = (-out $in _unmerged)
  if (not (pdf:is-selection $args[$l])) {
    set @args out = (all $args[1..])
  }
  -must-pdf-exist $in
  -must-not-exist $out
  each {|e|
    -must-valid $e $pdf:is-selection~
  } $args
  pdf:uncat $in $out $@args
}

fn split {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail 'split doit contenir au moins 2 paramètres'
  }
  var out  = $args[$l]
  set args = $args[..$l]
  -must-not-exist $out
  var s = 1
  if (pdf:is-number $args[0]) {
    set s @args = $@args
  }
  var t = (pdf:-t)
  try {
    pdf:cat &out=$t $@args
    pdf:split &size=$s $t $out
  } finally {
    rm -f $t
  }
}

fn split-at {|@args|
  var l = (count $args)
  if (!= $l 3) {
    fail 'split-at doit contenir 3 paramètres'
  }
  var rg in out = $@args
  -must-pdf-exist $in
  -must-not-exist $out
  -must-valid $rg {|e| re:match '^\d+(,\d+)*$' $e }

  var b sel = 1 []
  str:split ',' $rg | order | each {|s|
    var e = (- $s 1)
    if (== $b $e) {
      set @sel = $@sel $b
      set b    = $s
    } elif (< $b $e) {
      set @sel = $@sel (printf '%d-%d' $b $e)
      set b    = $s
    }
  }
  set @sel = $@sel (printf '%d-z' $b)
  unmerge $in $@sel $out
}

fn zip {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail 'zip doit contenir au moins 2 paramètres'
  }
  var @selection out = $@args
  -must-pdf-not-exist $out
  var has-in = $false
  each {|e|
    if (pdf:is-pdf $e) {
      -must-exist $e
      set has-in = $true
    } else {
      if (not $has-in) {
        fail 'Une sélection doit être précédée d’un fichier d’entrée'
      }
      -must-valid $e $pdf:is-selection~
    }
  } $selection
  pdf:cat &collate=$true &out=$out $@selection
}

fn unzip {|@args|
  var l = (- (count $args) 1)
  if (< $l 1) {
    fail 'unzip doit contenir au moins 2 paramètres'
  }
  var in @sel out = $@args
  var mod         = 2
  if (pdf:is-number $in) {
    set mod = $in
    if (eq (count $sel) 0) {
      fail 'unzip doit contenir au moins 3 paramètres'
    }
    set in @sel = $@sel
  }
  -must-not-exist $out
  var t    = (pdf:-t)
  try {
    pdf:cat &out=$t $in $@sel
    var n = (pdf:nb-pages $t)
    mkdir $out
    range 1 (+ 1 $mod) | each {|m|
      var sel = (range 1 (+ $n 1) | each {|i|
        var s = (% $i $mod)
        if (== $s 0) {
          set s = $mod
        }
        if (== $s $m) {
          put $i
        }
      } | each $to-string~ | str:join ',')
      pdf:cat &out=(printf '%s/%d.pdf' $out $m) $t $sel
    }
  } finally {
    rm -f $t
  }
}

edit:add-var pdf~ {|action @args|
  var actions = [
    &help=$help~
    &decrypt=$decrypt~
    &rotate=$rotate~
    &merge=$merge~
    &cat=$merge~
    &unmerge=$unmerge~
    &uncat=$unmerge~
    &split=$split~
    &split-at=$split-at~
    &cut=$split-at~
    &zip=$zip~
    &unzip=$unzip~
    #&info=$info~
    #&list=$list~
    #&extract=$extract~
  ]
  if (not (has-key $actions $action)) {
    fail (printf '%s: action inconnue' $action)
  }
  $actions[$action] $@args
}