expect script to munge Zyxel poe status from telnet into a json blob

pull_zyx_poe.expect

#!/usr/bin/env expect

#exp_internal 1
#log_user 1
# hi! we're hand-crafting JSON, fuckit
puts "{"

log_user 0
set timeout 5
set host [lindex $argv 0]
set port [lindex $argv 1]
set user [lindex $argv 2]
set pass [lindex $argv 3]

spawn telnet $host $port

expect "Username:"
send "$user\r"

expect "Password:"
send "$pass\r"

expect "#"
send "show power inline consumption\r"

## UNITS(?) ##
# example output for this section:
#Unit Power Status Nominal  Allocated       Consumed Available
#                  Power    Power           Power    Power
#---- ----- ------ -------- --------------- -------- ---------                            
#1    On    Normal 170Watts   6Watts (  3%)   6Watts 163Watts
# handle switch units
expect "Unit*"
# grab the labels for our objects
set header [concat {*}[split $expect_out(0,string) " "]]
#puts $header
# match the separator line
#              "Unit..er"
expect -re {\r\n----.*--\r\n}
# match integers...
puts "\"Units\": \["
set unit 0
expect -re {(\d+)} {
  if {$unit > 0} {
    puts ",\n"
  }
  set unit [expr $unit + 1]
  # grab the index...
  set instance [lindex $expect_out(buffer) end]
  #puts $instance
  # now find the *end* of that line and break it up
  expect -re {\r\n}
  # we cheat here and remove the "percent power used" by dropping the element (it didn't really get a header either)
  set attrs [lreplace [concat {*}[split [string map { ( {} ) {} "\r\n" {} } $expect_out(buffer)] \S+]] 4 4]
  set object [lmap k $header v [linsert $attrs 0 $instance] {list $k $v}]
  #puts $object
  # now print that
  puts -nonewline "\{"
  set attrct 0
  foreach attr $object {
    if {$attrct > 0} {
      puts -nonewline ", "
    }
    set key [lindex $attr 0]
    set value [lindex $attr 1]
    set attrct [expr $attrct + 1]

    # print key
    puts -nonewline "\""
    puts -nonewline $key
    puts -nonewline "\": "

    # print/modify value
    # we cheated on unit and "Watts" values
    if {$key == "Unit"} {
      set matchWatts 0
    } else {
      set matchWatts [string first "Watts" $value]
    }
    if {$matchWatts >= 0} {
      set value [string map { Watts {} } $value]
    } else {
      puts -nonewline "\""
    }
    puts -nonewline $value
    if {$matchWatts < 0} {
      puts -nonewline "\""
    }
  }
  puts -nonewline "\}"
}
puts "\n\],"

## PORTS ##
# example output for this section:
#Port Power Limit (Admin) (mW) Power (mW) Voltage (mV) Current (mA)
#---- ------------------------ ---------- ------------ ------------
#1    0     (0    )            0          0            0
#2    0     (0    )            0          0            0
#3    0     (0    )            0          0            0
#4    0     (0    )            0          0            0
#5    0     (0    )            0          0            0
#6    31200 (31200)            1800       53686        34
expect "\r\n" # advance the line
expect "Port*\r\n----*--\r\n" # match header and next line
# grab the labels for our objects
set header [lreplace [concat {*}[split [string map { "Limit" {} ( {} ) {} "mW" {} "mV" {} "mA" {} } [lindex [split $expect_out(0,string) "\r\n"] 0]]]] 1 1 "Limit"]
#puts $header
puts "\"Ports\": \["

# we get to handle pagination *and* output, gaaah
set port 0
expect {
  # port statistic
  -re {(\d)+} {
    if {$port > 0} {
      puts ","
    }
    set instance [lindex $expect_out(buffer) end]
    expect -re {\r\n}
    # puts $expect_out(buffer)
    set attrs [concat {*}[split [string map { ( {} ) {} "\r\n" {} } $expect_out(buffer)] " "]]
    set object [lmap k $header v [linsert $attrs 0 $instance] {list $k $v}]
    #puts $object
    set attrct 0
    puts -nonewline "\{"
    foreach attr $object {
      # handle multiple attributes
      if {$attrct > 0} {
        puts -nonewline ", "
      }
      # key
      puts -nonewline "\""
      puts -nonewline [lindex $attr 0]
      puts -nonewline "\": "
      puts -nonewline [lindex $attr 1]
      set attrct [expr $attrct + 1]
    }
    puts -nonewline "\}"
    set port [expr $port + 1]
    exp_continue
  }
  # handle paging
  -- "--More--" {
    send " "
    expect "2K" # "\r\n\u001b\[A\u001b\[2K" seems to be the sequence used to rewrite lines after prompt
    exp_continue
  }
  # handle prompt (we're done)
  -- "#" {
    set success 1
  }
}
puts "]"
puts "}"

#interact