#!/usr/bin/en perl
# The MIT License (MIT)
# 
# Copyright (c) 2011-2015 Ismaël Bouya http://www.normalesup.org/~bouya/
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

use Switch;
use strict;

my $file = "comptes.data";

my @actions=('Ajouter un participant');
my %participants = ();
my @transactions = ();
my @descriptions = ();
my $evenement_def;
my $remboursements = "";

if($#ARGV==0) {
    open FILE, $ARGV[0] || die "Impossible de lire le fichier";
    $evenement_def = <FILE>;
    chomp($evenement_def);
    while(my $noms = <FILE>) {
	if($noms eq "\n") { last; }
	my ($numero,$nom) = split(/ /,$noms,2);
	chomp($nom);
	$participants{$nom} = $numero;
    }
    while(my $transaction = <FILE>) {
	if($transaction eq "\n") { last; }
	chomp($transaction);
	push(@transactions,$transaction);
	my $description = <FILE>;
	chomp($description);
	push(@descriptions,$description);
    }
    $file = $ARGV[0];
}

GLOBALE: while(1) {
    if(keys(%participants)>0) {
	$actions[1]="Ajouter une dépense";
	$actions[2]="Enregistrer";
    }
    if(scalar(@transactions)>0) {
	$actions[3]="Voir les dépenses de quelqu'un";
	$actions[2]="Enregistrer";
	$actions[4]="Equilibrage";
	$actions[5]="Voir une transaction";
    }

    my $action;
    while(1) {
	my $i = 1;
	my $var;
	my @vart = ( @actions, 'Sortir' );
	my $message = '';
	foreach $var ( @vart ) {
	    $message .= $i++.') '.$var."\n";
	}
	print $message;
	$var = <STDIN>;
	chop($var);
	if(/\D/ || $var < 1 || $var > $i) {
	    print "Mauvaise entrée\n";
	    next;
	}
	$action = $vart[$var-1];
	last;
    }
    switch ($action) {
	case "Ajouter un participant" {
	    print "Nom du participant\n";
	    my $participant = <STDIN>;
	    chomp($participant);
	    $participants{$participant} = keys(%participants)+1;
	}
	case "Ajouter une dépense" {
	    print "Qui a payé ?\n";
	    my $paye;
	    while(1) {
		my $i = 1;
		my $var;
		my @vart = ( keys(%participants), "Annuler" );
		foreach $var ( @vart ) {
		    print $i++.') '.$var."\n";
		}
		$var = <STDIN>;
		chop($var);
		if(/\D/ || $var < 1 || $var > $i) {
		    print "Mauvaise entrée\n";
		    next;
		}
		$paye = $vart[$var-1];
		last;
	    }
	    if($paye eq "Annuler") {
		next GLOBALE;
	    }
	    print "Quoi ?\n";
	    my $description = <STDIN>;
	    chomp($description);
	    print "Combien ?\n";
	    my $prix = <STDIN>;
	    chomp($prix);
	    print "Pour qui ?\n";
	    my $repartition = "";
	    my $total_parts = 0;
	  DESTS: while(1) {
	      my $dest;
	      while(1) {
		  my $i = 1;
		  my $var;
		  my @vart = ( keys(%participants), "Ajouter à tous", "Fini" );
		  foreach $var ( @vart ) {
		      print $i++.') '.$var."\n";
		  }
		  $var = <STDIN>;
		  chop($var);
		  if(/\D/ || $var < 1 || $var > $i) {
		      print "Mauvaise entrée\n";
		      next;
		  }
		  $dest = $vart[$var-1];
		  last;
	      }
	      switch($dest) {
		  case "Fini" {
		      if($repartition eq "") { print "Annulé\n"; }
		      elsif($total_parts == 0) {
			  print "Le nombre total de parts est nul, il faut en ajouter !\n";
			  next DESTS;
		      }
		      else {
			  push(@transactions, $participants{$paye}.' '.$prix.$repartition);
			  push(@descriptions, $description);
		      }
		      last DESTS;
		  }
		  case "Ajouter à tous" {
		      print "Nombre de parts ?\n";
		      my $parts = <STDIN>;
		      chomp($parts);
		      if(!($parts == 0)) {
			  foreach my $participant (keys(%participants)) {
			      $repartition .= ' '.$participants{$participant}.':'.scalar($parts);
			      $total_parts += scalar($parts);
			  }
		      }
		  }
		  else {
		      print "Nombre de parts ?\n";
		      my $parts = <STDIN>;
		      chomp($parts);
		      if(!($parts == 0)) {
			  $repartition .= ' '.$participants{$dest}.':'.scalar($parts);
			  $total_parts += scalar($parts);
		      }
		  }
	      }
	  }
	}
	case "Voir les dépenses de quelqu'un" {
	    my $personne;
	    while(1) {
		my $i = 1;
		my $var;
		my @vart = ( keys(%participants), "Annuler" );
		foreach $var ( @vart ) {
		    print $i++.') '.$var."\n";
		}
		$var = <STDIN>;
		chop($var);
		if(/\D/ || $var < 1 || $var > $i) {
		    print "Mauvaise entrée\n";
		    next;
		}
		$personne = $vart[$var-1];
		last;
	    }
	    if($personne eq "Annuler") {
		next GLOBALE;
	    }
	    my $depenses = 0;
	    my $frais = 0;
	    foreach my $transaction (@transactions) {
		my @table_trans = split(/ /,$transaction);
		my $payeur = shift(@table_trans);
		my $prix = shift(@table_trans);
		if($payeur == $participants{$personne}) {
		    $depenses += $prix;
		}
		my $parts = 0;
		my $frac = 0;
		my $repartition;
		foreach $repartition (@table_trans) {
		    my ($pers,$part) = split(/:/,$repartition);
		    if($pers == $participants{$personne}) {
			$frac += $part;
		    }
		    $parts += $part;
		}
		$frais += $prix*$frac/$parts;
	    }
	    print $personne." a payé ".$depenses." EUR\n";
	    print "et a pour ".sprintf("%.2f",$frais)." EUR de frais au total.\n";
	    print "Il a donc un solde de ".sprintf("%.2f",$depenses-$frais)." EUR\n";
	    my $pause = <STDIN>;
	}
	case "Voir une transaction" {
	    my $transaction;
	    while(1) {
		my $i = 1;
		my $var;
		my @vart = ( @descriptions, "Annuler" );
		foreach $var ( @vart ) {
		    print $i++.') '.$var."\n";
		}
		$var = <STDIN>;
		chop($var);
		if(/\D/ || $var < 1 || $var > $i) {
		    print "Mauvaise entrée\n";
		    next;
		}
		$transaction = $var-1;
		last;
	    }
	    my @table_trans = split(/ /,$transactions[$transaction]);
	    my $payeur = shift(@table_trans);
	    my $prix = shift(@table_trans);
	    my $Tparts = 0;
	    my $repartition;
	    my %parts;
	    foreach my $pers (keys(%participants)) {
		if($payeur == $participants{$pers}) {
		    print $descriptions[$transaction]." (payé par ".$pers."), ".$prix." EUR\n";
		    last
		}
	    }
	    foreach $repartition (@table_trans) {
		my ($pers,$part) = split(/:/,$repartition);
		$Tparts += $part;
		$parts{$pers} += $part;
	    }
	    foreach my $pers (keys(%participants)) {
		if(!exists $parts{$participants{$pers}}) {
		    next;
		}
		print $pers.", ".$parts{$participants{$pers}}." part(s), soit ". $prix*$parts{$participants{$pers}}/$Tparts." EUR\n";
	    }
	    my $pause = <STDIN>;
	}
	case "Enregistrer" {
	    print "Nom de l'événement ?";
	    if(!($evenement_def eq "")) {
		print " [".$evenement_def."]";
	    }
	    print "\n";
	    my $evenement = <STDIN>;
	    chomp($evenement);
	    if($evenement eq "") {
		$evenement = $evenement_def;
	    }
	    open FILE, ">".$file;
	    print FILE $evenement."\n";
	    my $key;
	    foreach $key (keys(%participants)) {
		print FILE $participants{$key}." ".$key."\n";
	    }
	    print FILE "\n";
	    for(my $i=0;$i<scalar(@transactions);$i++) {
		print FILE $transactions[$i]."\n";
		print FILE $descriptions[$i]."\n";
	    }
	    print FILE "\n";
	    print FILE $remboursements;
	    close FILE;
	}
	case "Equilibrage" {
	    my %Tdepenses = ();
	    my %Tfrais = ();
	    my %Tsolde = ();
	    $remboursements = "";
	    foreach my $Ttransaction (@transactions) {
		my @Ttable_trans = split(/ /,$Ttransaction);
		my $Tpayeur = shift(@Ttable_trans);
		my $Tprix = shift(@Ttable_trans);
		$Tdepenses{$Tpayeur} = $Tdepenses{$Tpayeur} + $Tprix;
		my $Tparts = 0;
		my $Tfrac = 0;
		my $Trepartition;
		foreach $Trepartition (@Ttable_trans) {
		    my ($Tpers,$Tpart) = split(/:/,$Trepartition);
		    $Tparts += $Tpart;
		}
		foreach $Trepartition (@Ttable_trans) {
		    my ($Tpers,$Tpart) = split(/:/,$Trepartition);
		    $Tfrais{$Tpers} = $Tfrais{$Tpers} + $Tprix*$Tpart/$Tparts;
		}
	    }
	    foreach my $Tpersonne (keys(%participants)) {
		my $numero = $participants{$Tpersonne};
		$Tsolde{$Tpersonne} = sprintf("%.2f",$Tdepenses{$numero}-$Tfrais{$numero});
		print $Tpersonne." a un solde de ".$Tsolde{$Tpersonne}." EUR\n";
	    }
	    my $pause = <STDIN>;
	    print "Y-a-t-il des remboursements plus aisés ?\n";
	    my $ouinon;
	    while(1) {
		my $i = 1;
		my $var;
		my @vart = ( "Oui", "Non" );
		foreach $var ( @vart ) {
		    print $i++.') '.$var."\n";
		}
		$var = <STDIN>;
		chop($var);
		if(/\D/ || $var < 1 || $var > $i) {
		    print "Mauvaise entrée\n";
		    next;
		}
		$ouinon = $vart[$var-1];
		last;
	    }
	  AISE: while($ouinon eq "Oui") {
	      print "Qui ?\n";
	      my $personne;
	      while(1) {
		  my $i = 1;
		  my $var;
		  my @vart = ( keys(%participants), "Fini" );
		  foreach $var ( @vart ) {
		      print $i++.') '.$var."\n";
		  }
		  $var = <STDIN>;
		  chop($var);
		  if(/\D/ || $var < 1 || $var > $i) {
		      print "Mauvaise entrée\n";
		      next;
		  }
		  $personne = $vart[$var-1];
		  last;
	      }
	      if($personne eq "Fini") { last AISE; }
	      print "Avec qui ?\n";
	      my $personneb;
	      while(1) {
		  my $i = 1;
		  my $var;
		  my @vart = ( keys(%participants), "Annuler" );
		  foreach $var ( @vart ) {
		      print $i++.') '.$var."\n";
		  }
		  $var = <STDIN>;
		  chop($var);
		  if(/\D/ || $var < 1 || $var > $i) {
		      print "Mauvaise entrée\n";
		      next;
		  }
		  $personneb = $vart[$var-1];
		  last;
	      }
	      if($personneb eq "Annuler") { next AISE; }
	      if($Tsolde{$personne}*$Tsolde{$personneb}<0) {
		  my $pers_inf = ($Tsolde{$personne}<0)?$personne:$personneb;
		  my $pers_sup = ($Tsolde{$personne}>0)?$personne:$personneb;
		  my $inf = (abs($Tsolde{$personne})<abs($Tsolde{$personneb}))?abs($Tsolde{$personne}):abs($Tsolde{$personneb});
		  $remboursements .= $pers_inf." doit ".$inf." EUR à ".$pers_sup."\n";
		  $Tsolde{$pers_inf} += $inf;
		  $Tsolde{$pers_sup} -= $inf;
	      }
	  }
	    # Une boucle pour détecter si on a des couples qui s'annulent mutuellement
	  COUPLE: foreach my $personne (keys(%participants)) {
	      if($Tsolde{$personne} == 0) { next; }
	      foreach my $personneb (keys(%participants)) {
		  if($Tsolde{$personneb} + $Tsolde{$personne} != 0) { next; }
		  my $pers_inf = ($Tsolde{$personne}<0)?$personne:$personneb;
		  my $pers_sup = ($Tsolde{$personne}>0)?$personne:$personneb;
		  my $val = abs($Tsolde{$personne});
		  $remboursements .= $pers_inf." doit ".$val." EUR à ".$pers_sup."\n";
		  $Tsolde{$pers_inf} += $val;
		  $Tsolde{$pers_sup} -= $val;
		  next COUPLE;
	      }
	  }
	  REMB: while(1) {
	      # On supprime les 0, et on fait deux hashs
	      my %Tneg = ();
	      my %Tpos = ();
	      foreach my $personne (keys(%Tsolde)) {
		  if($Tsolde{$personne} == 0) { delete $Tsolde{$personne}; }
		  elsif($Tsolde{$personne} < 0) { $Tneg{$personne} = $Tsolde{$personne}; }
		  elsif($Tsolde{$personne} > 0) { $Tpos{$personne} = $Tsolde{$personne}; }
	      }
	      if(keys(%Tneg) == 0) {
		  last REMB;
	      }
	      foreach my $neg (sort { $Tneg{$a} cmp $Tneg{$b} } keys %Tneg) {
		  my $max = 0;
		  my $positif = 0;
		  foreach my $pos (sort { $Tpos{$a} cmp $Tpos{$b} } keys %Tpos) {
		      if($Tpos{$pos} + $Tneg{$neg}>0) {
			  $positif = $pos;
			  last;
		      }
		      $max = $pos;
		  }
		  if(!($max eq 0)) {
		      $remboursements .= $neg." doit ".$Tsolde{$max}." EUR à ".$max."\n";
		      $Tsolde{$neg} += $Tsolde{$max};
		      delete $Tsolde{$max};
		  }
		  else {
		      $remboursements .= $neg." doit ".-$Tsolde{$neg}." EUR à ".$positif."\n";
		      $Tsolde{$positif} += $Tsolde{$neg};
		      delete $Tsolde{$neg};
		  }
		  next REMB;
	      }
	  }
	    print $remboursements;
	    my $pause = <STDIN>;
	}
	case "Sortir" {
	    last GLOBALE;
	}
    }
}