#! /usr/bin/perl
use warnings;
use strict;
use 5.010;
use WWW::Mechanize::GZip;
use HTML::TableExtract qw(tree);
use open ':std', OUT => ':utf8';
use Prompt::Timeout;
use constant TIMEOUT  => 3;
use constant MAXTRIES => 30;

my $site = 'http://www.fourmilab.ch/yoursky/cities.html';
my $mech = 'WWW::Mechanize::GZip'->new;
$mech->get($site);
$mech->follow_link( text => 'Portland OR' );
my $before_bound = 2457496.65;    #before conjunction
my $after_bound  = 2457496.75;    #after conjunction
$mech->set_fields(qw'date 2');
my $moonstring = 5;
my $jstr       = 3;
my $upper      = $before_bound;
my $lower      = $after_bound;
my $equal;
my $equal_sec;
my $now_string = localtime;
my $filename   = 'planet7.txt';
open( my $jh, '>>', $filename ) or die "Could not open file '$filename' $!";
say $jh "Script executed at $now_string";
my $attempts = 1;

while ( ( $jstr != $moonstring ) ) {

   my $default = ( ( $attempts >= MAXTRIES ) ) ? 'N' : 'Y';
   my $answer = prompt( "Make query number $attempts?", $default, TIMEOUT );
   exit if $answer =~ /^N/i;
   say "upper is $upper";
   say "lower is $lower";
   my $guess = closetohalf( $upper, $lower );
   say "guess is $guess";
   $mech->set_fields( jd => $guess );
   $mech->click_button( value => "Update" );
   my $te = 'HTML::TableExtract'->new;
   $te->parse( $mech->content );
   my $table      = ( $te->tables )[3];
   my $table_tree = $table->tree;
   my $venus      = $table_tree->cell( 5, 1 )->as_text;
   my $jupiter    = $table_tree->cell( 7, 1 )->as_text;
   $moonstring = string_to_second($venus);
   say "moon seconds is $moonstring";
   $jstr = string_to_second($jupiter);
   say "jupiter seconds is $jstr";

   if ( $jstr > $moonstring ) {
      $upper = $guess;
   }
   elsif ( $moonstring > $jstr ) {
      $lower = $guess;
   }
   else {
      $equal = $guess;
      say "equal, while condition should fail $equal";
      $equal_sec = $moonstring;
   }
   $te->delete;
   $attempts++;
}

say $jh "equal seconds is $equal_sec";

###redesign 4/20/16
## determining beginning
my $outer = $before_bound;
my $inner = $equal;
say $jh join "\t", 'moonstring', 'jstr', 'outer', 'inner', 'guess';
$attempts = 1;
while ( ( abs( $outer - $inner ) > .00001 ) ) {

   my $default = ( ( $attempts >= MAXTRIES ) ) ? 'N' : 'Y';
   my $answer = prompt( "Make query number $attempts?", $default, TIMEOUT );
   exit if $answer =~ /^N/i;
   say "outer is $outer";
   say "inner is $inner";
   my $guess = closetohalf( $outer, $inner );
   say "guess is $guess";
   $mech->set_fields( jd => $guess );
   $mech->click_button( value => "Update" );
   my $te = 'HTML::TableExtract'->new;
   $te->parse( $mech->content );
   my $table      = ( $te->tables )[3];
   my $table_tree = $table->tree;
   my $venus      = $table_tree->cell( 5, 1 )->as_text;
   my $jupiter    = $table_tree->cell( 7, 1 )->as_text;
   $moonstring = string_to_second($venus);
   $jstr       = string_to_second($jupiter);
   say $jh join "\t", $moonstring, $jstr, $outer, $inner, $guess;

   if ( $moonstring < $jstr ) {
      $outer = $guess;
   }
   elsif ( $moonstring == $jstr ) {
      $inner = $guess;
   }
   else {
      die "retrograde motion or bad data";
   }
   $te->delete;
   $attempts++;
}
say $jh "after beginning contraction, upper is $outer";
say $jh "after beginning contraction, lower is $inner";
my $begin_time = $inner;

## determine end time
$outer = $after_bound;
$inner = $equal;
say $jh join "\t", 'moonstring', 'jstr', 'outer', 'inner', 'guess';
$attempts = 1;
while ( ( abs( $outer - $inner ) > .00001 ) ) {

   my $default = ( ( $attempts >= MAXTRIES ) ) ? 'N' : 'Y';
   my $answer = prompt( "Make query number $attempts?", $default, TIMEOUT );
   exit if $answer =~ /^N/i;
   say "outer is $outer";
   say "inner is $inner";
   my $guess = closetohalf( $outer, $inner );
   say "guess is $guess";
   $mech->set_fields( jd => $guess );
   $mech->click_button( value => "Update" );
   my $te = 'HTML::TableExtract'->new;
   $te->parse( $mech->content );
   my $table      = ( $te->tables )[3];
   my $table_tree = $table->tree;
   my $venus      = $table_tree->cell( 5, 1 )->as_text;
   my $jupiter    = $table_tree->cell( 7, 1 )->as_text;
   $moonstring = string_to_second($venus);
   $jstr       = string_to_second($jupiter);
   say $jh join "\t", $moonstring, $jstr, $outer, $inner, $guess;
   if ( $moonstring > $jstr ) {
      $outer = $guess;
   }
   elsif ( $moonstring == $jstr ) {
      $inner = $guess;
   }
   else {
      die "retrograde motion or bad data";
   }
   $te->delete;
   $attempts++;
}

say $jh "after ending contraction, outer is $outer";
say $jh "after ending contraction, inner is $inner";
my $end_time      = $inner;
my $jul_length    = $end_time - $begin_time;
my $second_length = $jul_length * 86400;
say "duration in seconds is $second_length";
say $jh "duration in seconds is $second_length";

sub string_to_second {
   my $string = shift;
   my $return = 9000;
   if ( my $success = $string =~ /^(\d*)h\s+(\d*)m\s+(\d*)s$/ ) {
      $return = 3600 * $1 + 60 * $2 + $3;
   }
   else {
      say "string was misformed";
   }
   return $return;
}

sub closetohalf {
   my ( $up, $low ) = @_;
   $low + ( $up - $low ) * ( 0.4 + rand 0.2 );
}