#!/usr/bin/env ruby

# Build yaml files which provide arguments passed to {lv,pv,vg}s and subsequent
# type conversions.
#
# ./generate_field_data ~/LVM2.2.02.38

require "fileutils"
require "yaml"

VERSION_FILE = "/VERSION".freeze
COLUMNS_FILE = "/lib/report/columns.h".freeze

debug = false

TYPE_CONVERSION_MAP = {
  # Only types we can really trust
  "uint32" => "Integer",
  "int32" => "Integer",
  # These were determined by reading the code, they invoke _(u)int32_disp right away
  "pvmdas" => "Integer",
  "vgmdas" => "Integer",
  "lvcount" => "Integer",
  "lvsegcount" => "Integer",
  "segstartpe" => "Integer",
  # listed to return STR?
  "lvkmaj" => "Integer",
  "lvkmin" => "Integer",
  "snpercent" => "Float",
  "copypercent" => "Float",
  # size32/64, these do unit formatting unless overridden on command line. We
  # typically want them in bytes so we can convert them to Integers safely
  "size32" => "Integer",
  "size64" => "Integer",
  # These types return size32/size64 as well
  "lvkreadahead" => "Integer",
  "pvsize" => "Integer",
  "devsize" => "Integer",
  "originsize" => "Integer",
  "pvfree" => "Integer",
  "pvused" => "Integer",
  "pvmdafree" => "Integer",
  "pvmdasize" => "Integer",
  "vgsize" => "Integer",
  "vgfree" => "Integer",
  "vgmda_free" => "Integer",
  "chunksize" => "Integer",
  "segstart" => "Integer",
  "segsize" => "Integer",
  "snapcount" => "Integer",
  "vgmdafree" => "Integer",
  "vgmdasize" => "Integer",
  "pvextvsn" => "Integer",
  "vgmissingpvcount" => "Integer",
  # Weird one, can be "auto" or size32
  "lvreadahead" => "String",
  "lvmetadatasize" => "Integer",
  "datapercent" => "Float",
  "metadatapercent" => "Float",
  "pvmdasused" => "Integer",
  "vgmdasused" => "Integer",
  "vgmdacopies" => "Integer",
  "thincount" => "Integer",
  "thinid" => "Integer",
  "discards" => "Integer",
  "thinzero" => "Integer",
  "transactionid" => "Integer",
  "raidmismatchcount" => "Integer",
  "raidwritebehind" => "Integer",
  "raidminrecoveryrate" => "Integer",
  "raidmaxrecoveryrate" => "Integer",
  "segsizepe" => "Integer",
  # New fields for caching
  "cache_total_blocks" => "Integer",
  "cache_used_blocks" => "Integer",
  "cache_dirty_blocks" => "Integer",
  "cache_read_hits" => "Integer",
  "cache_read_misses" => "Integer",
  "cache_write_hits" => "Integer",
  "cache_write_misses" => "Integer",

  # 2.02.169+
  "lv_size" => "Integer",
  "kernelmetadataformat" => "Integer",
  "seg_stripes" => "Integer",
  "seg_data_stripes" => "Integer",
  "seg_reshape_len" => "Integer",
  "seg_reshape_len_le" => "Integer",
  "seg_data_copies" => "Integer",
  "seg_data_offset" => "Integer",
  "seg_new_data_offset" => "Integer",
  "seg_parity_chunks" => "Integer",
  "cachemetadataformat" => "Integer",
}.freeze

lvm_source = ARGV[0]

version = File.readlines(lvm_source + VERSION_FILE)[0].split(/-git|\s+/)[0]

lvs     = []
lvssegs = []
pvs     = []
pvssegs = []
vgs     = []
File.readlines(lvm_source + COLUMNS_FILE).each do |line|
  # eg: FIELD(LVS, lv, STR, "LV UUID", lvid.id[1], 38, uuid, "lv_uuid", "Unique identifier")
  next unless line =~ /^FIELD\((.*)\)$/

  fields = $1.split(", ")
  fields.each { |f| f.gsub!(/^"/, ""); f.gsub!(/"$/, "") }
  p fields if debug
  app           = fields[0]
  general_type  = fields[2]
  specific_type = fields[6]
  column        = fields[7]
  method        = fields[7].dup
  description   = fields[8]
  p app, general_type, specific_type, column, method, description if debug

  if %w{NUM SIZ}.include?(general_type)
    attribute_type = TYPE_CONVERSION_MAP[specific_type]
    if attribute_type.nil?
      puts "Oops, missing type conversion data of column '#{specific_type}' use by '#{app}' which says its going to return a '#{specific_type}'"
      puts "Figure out the missing type and rerun."
      exit 1
    end
  else
    attribute_type = "String"
  end

  # our shorter nicer method names, according to the man page these can be
  # dropped when passing column names as arguments as well, but i found a few
  # with issues (seg_start).
  case app
  when "LVS", "LVSINFOSTATUS", "LVSSTATUS"
    method.sub!(/^lv_/, "")
  when "SEGS"
    method.sub!(/^seg_/, "")
  when "LABEL"
    method.sub!(/^pv_/, "")
  when "PVS"
    method.sub!(/^pv_/, "")
  when "PVSEGS"
    method.sub!(/^pvseg_/, "")
  when "VGS"
    method.sub!(/^vg_/, "")
  end

  attribute = {
    method: method,
    column: column,
    type_hint: attribute_type,
    description: description,
  }

  case app
  when "LVS", "LVSINFOSTATUS", "LVSSTATUS"
    lvs << attribute
  when "SEGS"
    lvssegs << attribute
  when "LABEL"
    pvs << attribute
  when "PVS"
    pvs << attribute
  when "PVSEGS"
    pvssegs << attribute
  when "VGS"
    vgs << attribute
  end
end

# we use vg_uuid as our crossover attribute that links vg->lv and vg->pv
attribute = { method: "vg_uuid",
              column: "vg_uuid",
              type_hint: "String",
              description: "For VolumeGroup to LogicalVolume relationship." }
lvs << attribute
attribute = { method: "vg_uuid",
              column: "vg_uuid",
              type_hint: "String",
              description: "For VolumeGroup to PhysicalVolume relationship." }
pvs << attribute

# and we link lv->lvsegment, pv->pvsegment
attribute = { method: "lv_uuid",
              column: "lv_uuid",
              type_hint: "String",
              description: "For LogicalVolume to LogicalVolumeSegment relationship." }
lvssegs << attribute
attribute = { method: "pv_uuid",
              column: "pv_uuid",
              type_hint: "String",
              description: "For PhysicalVolume to PhysicalVolumeSegment relationship." }
pvssegs << attribute

lvs.sort!     { |x, y| x[:column] <=> y[:column] }
lvssegs.sort! { |x, y| x[:column] <=> y[:column] }
pvs.sort!     { |x, y| x[:column] <=> y[:column] }
pvssegs.sort! { |x, y| x[:column] <=> y[:column] }
vgs.sort!     { |x, y| x[:column] <=> y[:column] }

attributes_dir = "lib/lvm/attributes/#{version}"
FileUtils.mkdir(attributes_dir)

disclaimer = <<~GO
  # These are column to object attribute mappings
  # generated by #{$0} based on
  # #{lvm_source}/lib/report/columns.h
GO

File.open("#{attributes_dir}/lvs.yaml", "w")    { |f| f.write(disclaimer); f.write(lvs.to_yaml) }
File.open("#{attributes_dir}/lvsseg.yaml", "w") { |f| f.write(disclaimer); f.write(lvssegs.to_yaml) }
File.open("#{attributes_dir}/pvs.yaml", "w")    { |f| f.write(disclaimer); f.write(pvs.to_yaml) }
File.open("#{attributes_dir}/pvsseg.yaml", "w") { |f| f.write(disclaimer); f.write(pvssegs.to_yaml) }
File.open("#{attributes_dir}/vgs.yaml", "w")    { |f| f.write(disclaimer); f.write(vgs.to_yaml) }

puts "Done."