#!/usr/bin/env tclkit8.5

package require Tk

set ::cursor(x) 1 

set ::rsspeak 0
set ::rsspeaktext ""

set ::vszpeak 0
set ::vszpeaktext ""

set ::follow_graph 1

proc draw.value {win value height id peak_ptr peaktext_ptr} {
 global cursor
 global scale

 upvar $peak_ptr peak
 upvar $peaktext_ptr peaktext

 set lasty [lindex [$win coords $id] end]
 # 800 is a good height for the graph offset
 set y [expr {800 - ($value / double($scale))}]

 $win coords $id [concat [$win coords $id] [list $cursor(x) $y]]

 #
 # Test if this value is greater than the previous peak.
 #

 if {$value > $peak} {
  set peak $value
  #
  # Change the previous peak's color
  #    
  if {"" ne $peaktext} {
   $win itemconfigure $peaktext -fill white -font {fixed 10}
  }
  set peaktext [$win create text $cursor(x) $y -text $value \
    -fill orange -font {fixed 14}]
 } else {
  $win create text $cursor(x) $y -text $value -fill white -font {fixed 10}
 }
}

proc update.stats {win pid} {
 global cursor

 if {[catch {exec ps -p $pid -o vsz=,rss=} res]} {
  return -code error $res
 }

 foreach {vsz rss} [split [string trim $res]] break

 global rsspeak
 global rsspeaktext

 set height [winfo height $win]
 draw.value $win $rss $height $::rssid rsspeak rsspeaktext
 incr cursor(x) 50 

 global vszpeak
 global vszpeaktext

 draw.value $win $vsz $height $::vszid vszpeak vszpeaktext
 incr cursor(x) 50

 $win config -scrollregion [$win bbox all]

 if {$::follow_graph} {
  $win xview moveto 1.0
 }

 after 1000 [list update.stats $win $pid]
}

proc view.tag {win tag} {
 foreach {x1 y1 x2 y2} [$win bbox all] break
 
 foreach {tx1 ty1 _ _} [$win bbox $tag] break

 $win xview moveto [expr {$tx1 / double($x2)}]
 $win yview moveto [expr {$ty1 / double($y2)}]
}

proc main {argc argv} {
 if {2 != $argc} {
  puts stderr "syntax is: [info script] pid scale"
  return 1
 }

 frame .controls
 pack [checkbutton .controls.follow -text "Follow Graph" -variable ::follow_graph] -side left

 pack [button .controls.rssPeak -text "Jump to RSS Peak" -command {
  set ::follow_graph 0
  view.tag .graph.c $::rsspeaktext
 }] -side left

 pack [button .controls.vsz -text "Jump to VSZ Peak" -command {
  set ::follow_graph 0
  view.tag .graph.c $::vszpeaktext
 }] -side left

 pack .controls -fill x


 frame .graph
 canvas .graph.c \
   -xscrollcommand {.graph.xscroll set} \
   -yscrollcommand {.graph.yscroll set} \
   -bg black
 scrollbar .graph.xscroll -command {.graph.c xview} -orient horizontal
 scrollbar .graph.yscroll -command {.graph.c yview}

 pack .graph -fill both -expand 1

 grid .graph.c -row 0 -column 0 -sticky nesw
 grid .graph.xscroll -row 1 -column 0 -sticky we
 grid .graph.yscroll -row 0 -column 1 -sticky ns

 grid columnconfigure .graph 0 -weight 100
 grid rowconfigure .graph 0 -weight 100 

 set ::vszid [.graph.c create line 0 0 1 1 -fill red]
 set ::rssid [.graph.c create line 0 0 1 1 -fill green]

 set ::scale [lindex $argv 1]

 update idletasks
 after idle [list update.stats .graph.c [lindex $argv 0]]
}

main $::argc $::argv