#!/usr/bin/env ruby
# frozen_string_literal: true

require_relative '../lib/pzem016'
require 'optimist'
require 'ruby-progressbar'

progname = File.basename($PROGRAM_NAME)
commands = %w[read readconfig setconfig resetenergy scanbus]

global_opts = Optimist.options do
  banner "PZEM-016 power measurement module utility.\n\nSyntax: #{progname} [global options] <command> [options]\n\nCommands: #{commands}\n\nGlobal options:"
  opt :port, 'Serial port', type: :string, default: '/dev/ttyUSB0'
  opt :speed, 'Port speed', type: :integer, default: 9600
  opt :timeout, 'Retry timeout', type: :integer, default: 1
  opt :retries, 'Number of times to retry ModBus command', default: 1
  opt :name, 'Device name', type: :string, default: 'PZEM-016 Device'
  opt :debug, 'Extra noise', type: :boolean
  stop_on commands
end

cmd = ARGV.empty? ? '(not given)' : ARGV.shift.downcase.to_sym

cmd_opts = case cmd
   when :read, :readconfig # parse delete options
     Optimist.options do
       banner "Read #{cmd == :read ? "power" : "config"} values from specified device"
       opt :sladdr, 'Slave address', type: :integer, default: 1
       opt :json, 'Output JSON', type: :boolean, default: false
     end
   when :setconfig
     opts = Optimist.options do
       banner "Set device address and/or alarm threshold: #{progname} setconfig <addr|alarm> <value>"
       opt :sladdr, 'Slave address', type: :integer, default: 1
     end
     if ARGV.size == 2
       setting = ARGV.shift.downcase.to_sym
       Optimist.die "Specify one of 'addr' or 'alarm'; you gave '#{setting}'" unless %i[addr alarm].include?(setting)
       value = ARGV.shift.to_i
     else
       Optimist.die "syntax #{progname} setconfig <addr|alarm> <value>"
     end
     opts
   when :resetenergy
     Optimist.options do
       banner 'Reset (clear) the energy counter (KWH) on the specified device'
       opt :sladdr, 'Slave address', type: :integer, default: 1
     end
   when :scanbus
     Optimist.options do
       banner 'Scan ModBus for nodes/addrs'
       opt :read, 'Try to read values when node is found', type: :boolean
     end
   else
     puts "Valid commands: #{commands}"
     Optimist.die "unknown command: #{cmd}"
end

if global_opts[:debug]
  puts "Global options: #{global_opts.inspect}"
  puts "Subcommand: #{cmd.inspect}"
  puts "Subcommand options: #{cmd_opts.inspect}"
  puts "Remaining arguments: #{ARGV.inspect}"
end

bus = ModBus::RTUClient.connect(global_opts[:port], global_opts[:speed])

begin
  case cmd
  when :read
    bus.with_slave(cmd_opts[:sladdr]).tap do |slave|
      slave.read_retry_timeout = global_opts[:timeout]
      slave.read_retries = global_opts[:retries]
      input = Pzem016::InputRegisters.new(global_opts[:name], slave)
      input.read
      if cmd_opts[:json]
        puts input.to_json
      else
        input.report
      end
    end
  when :readconfig
    bus.with_slave(cmd_opts[:sladdr]).tap do |slave|
      slave.read_retry_timeout = global_opts[:timeout]
      slave.read_retries = global_opts[:retries]
      holding = Pzem016::HoldingRegisters.new(global_opts[:name], slave)
      holding.read
      if cmd_opts[:json]
        puts holding.to_json
      else
        holding.report
      end
    end
  when :setconfig
    slave = bus.with_slave(cmd_opts[:sladdr])
    slave.read_retry_timeout = global_opts[:timeout]
    slave.read_retries = global_opts[:retries]
    device = Pzem016::HoldingRegisters.new(global_opts[:name], slave)
    case setting
    when :addr
      device.set_address(value)
      puts "Address of slave at '#{cmd_opts[:sladdr]}' has been changed to '#{value}'"
    when :alarm
      device.set_alarm(value)
      puts "Alarm threshold value for slave at #{cmd_opts[:sladdr]} has been set to #{value} watts"
    end
  when :resetenergy
    puts "Slave at addr #{cmd_opts[:sladdr]} energy counter reset: #{Pzem016::HoldingRegisters.new(global_opts[:name],
                                                                                                   bus.with_slave(cmd_opts[:sladdr])).reset_energy}"
  when :scanbus
    begin
      (1..247).each do |address|
        bus.with_slave(address) do |slave|
          slave.read_retry_timeout = global_opts[:timeout]
          slave.read_retries = global_opts[:retries]
          begin
            value = slave.read_holding_registers(0, 3)
            puts "\nDevice found at address #{value[2]}\n"
            if cmd_opts[:read]
              input = Pzem016::InputRegisters.new(global_opts[:name], slave)
              input.read
              input.report
              puts
            end
          rescue StandardError
            print '.'
          end
        end
      end
      puts "\n"
    rescue Interrupt
      puts "\nscan interrupted\n"
    end
  else
    puts "Command required, one of #{commands}"
  end
rescue ModBus::Errors::ModBusTimeout
  puts 'ModBus timed out - are you sure you specified the correct --sladdr?'
end