#!/usr/bin/env ruby

require 'yaml'
require 'erb'

# load template data
DATA = YAML.load_file(File.join(__dir__, 'ops.yaml'))

switches = Hash.new { |h, k| h[k] = [] }
DATA['ops'].each do |set_id, ops|
  switches[set_id] = ops.select { |op|
    op['op'] != 'PREFIX'
  }.map { |op|
    # op hex string
    hex = op['hex'].to_s(16).upcase.rjust(2, '0')

    case op['op']
    when 'XX'
      [
        "case 0x%s: /* op: %s, cat: %s */",
        "  cpu_set_state(ctx, old_pc, GB_CPU_STATE_INVALID);",
        "  break;",
      ].join("\n") % [
        hex,
        op['id'],
        op['cat'],
      ]
    else
      # pc_expr
      pc_expr = if op['pc']
        'cpu_ww(ctx, RW_PC, old_pc + %d);' % [op['len']]
      else
        ''
      end

      # time expr
      time_expr = case op['time']
      when Numeric
        'clock = %d;' % [op['time']]
      when Hash
        'clock = %d; // t: %d, f: %d' % %w{f t f}.map { |k|
          op['time'][k]
        }
      else
        raise "unknown op time: #{hex}: #{op['time']}"
      end

      [
        "case 0x%s: /* op: \"%s\", cat: \"%s\" */",
        "  %s", # action_expr
        "  %s", # pc_expr
        "  %s", # time_expr
        "  break;"
      ].join("\n") % [
        hex,
        op['id'],
        op['cat'],
        op['code'] || 'cpu_set_state(ctx, old_pc, GB_CPU_STATE_NOT_IMPLEMENTED);',
        pc_expr,
        time_expr,
      ]
    end
  }.join("\n")
end

t = ERB.new(DATA['templates']['main'])
puts t.run(binding)