# frozen_string_literal: true

# A Ruby re-creation of /rdb, the relational database tools Mark Williams
# Company sold for COHERENT (~1991).

require 'open3'
require 'date'
require 'tmpdir'
require 'fileutils'
require_relative 'rdb/version'

module Rdb
  ROOT = File.expand_path('..', __dir__)
  NUM = /\A\s*[+-]?(\d+\.?\d*|\.\d+)\s*\z/

  Command = Struct.new(:name, :desc, :syntax, :block)
  COMMANDS = {}

  class << self
    # RDB_ICASE=1 makes column names match without regard to case.  An exact
    # match always wins; several case-insensitive matches are an error.
    def icase?
      !%w[0 no false].include?(ENV['RDB_ICASE'].to_s.downcase) && !ENV['RDB_ICASE'].to_s.empty?
    end

    def column_index(head, name)
      exact = head.index(name)
      return exact if exact || !icase?

      hits = head.each_index.select { |i| head[i].casecmp?(name) }
      die "column name '#{name}' is ambiguous: #{hits.map { |i| head[i] }.join(', ')}" if hits.size > 1
      hits.first
    end

    def die(msg)
      abort "#{File.basename($PROGRAM_NAME)}: #{msg}"
    end

    # register 'name', 'description', 'syntax' do |args| ... end
    def register(name, desc, syntax = nil, &block)
      COMMANDS[name] = Command.new(name, desc, syntax || name, block)
    end

    def alias_for(name, target)
      cmd = COMMANDS.fetch(target)
      COMMANDS[name] = Command.new(name, cmd.desc, cmd.syntax.sub(target, name), cmd.block)
    end

    def run(name, args)
      cmd = COMMANDS[name] or die("unknown command '#{name}'")
      Env.new(name).instance_exec(args.dup, &cmd.block)
    end
  end
end

require_relative 'rdb/table'
require_relative 'rdb/env'
Dir[File.join(__dir__, 'rdb/cmd/*.rb')].sort.each { |f| require f }