#!/usr/bin/env ruby
# encoding: ascii-8bit

require 'tins/go'
include Tins::GO

def usage
  puts <<EOT
Usage: #{File.basename($0)} list|create|truncate|insert|replace [OPTION] [TABLES]

  Commands are
    - list:     display all tables in the backup

    - create:   display all create table statements in the backup. If TABLES
                are given, display only those statements.
      -d        if this OPTION is given, first drop the table (if it exists)
                before creation.

    - truncate: all tables or the given TABLES, if they exist.

    - insert:   extract insert statemnts from the backup. If TABLES are given,
                extract only those statements for these TABLES.
      -t        if this OPTION is given, truncate the table, before starting
                to insert.

    - replace:  extract insert statemnts from the backup, and convert them
                into replace statements. If TABLES are given, extract only
                those statements for these TABLES.
EOT
  exit 1
end

def bell(n = 1, s = 1)
  n.times do
    STDERR.print "\a\b"
    sleep s
  end
end

cmd = ARGV.shift or usage
opts = go('dtDi')

STDOUT.sync = true
STDIN.set_encoding 'ascii-8bit'
case cmd
when 'list'
  STDIN.grep(/^CREATE TABLE `([^`]+)` \(/) { puts $1 }
when 'create'
  STDIN.grep(/^CREATE TABLE `([^`]+)` \(/) do |stmt|
    table = $1
    next unless ARGV.empty? or ARGV.member?(table)
    if opts['d']
      puts "DROP TABLE IF EXISTS `#{table}`;"
      warn "Dropped table #{table}."
    end
    line = stmt
    puts line
    until line =~ /;$/
      line = STDIN.readline
      puts line
    end
    warn "Created table #{table}."
  end
when 'truncate'
  STDIN.grep(/^CREATE TABLE `([^`]+)` \(/) do |stmt|
    table = $1
    next unless ARGV.empty? or ARGV.member?(table)
    puts "TRUNCATE TABLE `#{table}`;"
    warn "Truncated table #{table}."
  end
when 'insert'
  truncated = {}
  STDIN.grep(/^INSERT (?:IGNORE )?INTO `(#{ARGV.empty? ? '[^`]+' : ARGV * '|'})`/) do |stmt|
    table = $1
    stmt.sub!(/(^INSERT) (INTO)/, '\1 IGNORE \2') if opts['i']
    if opts['t'] and not truncated.key?(table)
      puts "TRUNCATE TABLE `#{table}`;"
      truncated[table] = true
      warn "Truncated table #{table}."
    end
    puts stmt
    warn "Inserted into table #{table}."
  end
when 'replace'
  STDIN.grep(/^INSERT INTO `(#{ARGV.empty? ? '[^`]+' : ARGV * '|'})`/) do |stmt|
    table = $1
    puts stmt.sub(/^INSERT INTO `(?:[^`]+)`/, "REPLACE INTO `#{table}`")
    warn "Replaced into table #{table}."
  end
else
  usage
end
bell 3