#!/usr/bin/env ruby
# encoding: utf-8
# ruby: 3.0.2
=begin
server to query part database

to install sinatra
sudo pacman -S ruby-sinatra ruby-webrick
pikaur -S ruby-mysql2
=end
require 'set'
require 'mysql2'
require 'json'
require 'sinatra'

# allow dumping crashes in browser
DEBUG = true
# maximum number of parts returned
PARTS_LIMIT = 100
# credentials for database
CREDENTIALS = "credentials.json"
# folder name for served pages
PUBLIC = "public"
# folder name for part attachments (in PUBLIC)
ATTACHMENTS = "attachments"

raise "database information #{CREDENTIALS} do not exist" unless File.file? CREDENTIALS

# open server
configure do
  if DEBUG then
    set :show_exceptions, true
    set :logging, true
  else
    set :show_exceptions, false
    set :environment, :production
    set :logging, false
  end
  set :protection, :except => :json_csrf

  set :bind, 'localhost'
  set :port, 4244
  set :public_folder, "public"
  set :static, true
end

before do
  response.headers["Access-Control-Allow-Origin"] = "*"
  response.headers["Access-Control-Allow-Headers"] = "Content-Type"
  if request.request_method == 'OPTIONS'
    response.headers["Access-Control-Allow-Methods"] = "GET,POST"
    halt 200
  end
  
  # all replies are only JSON
  content_type 'application/json'
  # open database
  credentials = {}
  JSON.parse(IO.read(CREDENTIALS)).each {|key,value| credentials[key.to_sym] = value}
  Mysql2::Client.default_query_options.merge!(:as => :hash)
  @db = Mysql2::Client.new(credentials)
end

after do
  response.headers["Access-Control-Allow-Origin"] = "*"
  response.headers["Access-Control-Allow-Headers"] = "Content-Type"
end

get '/' do
  redirect to('/index.html')
end

def get_part_by_id(id)
  return nil unless id
  statement = @db.prepare("SELECT part.id, part.name, part.description, part.datasheet, manufacturer.name AS manufacturer, package.name AS package, part.pincount AS pincount, part.page AS page, part.family AS parent FROM part LEFT JOIN package ON package.id = part.package LEFT JOIN manufacturer ON manufacturer.id = part.manufacturer WHERE part.id = ?")
  part = statement.execute(id).to_a[0]
  return nil unless part
  parent = get_part_by_id(part["parent"])
  # merge parent info
  if parent then
    part.each do |k,v|
      part[k] ||= parent[k]
    end
  end
  # add all distributors
  distributors = @db.query("SELECT * FROM distributor").to_a
  statement = @db.prepare("SELECT * FROM distribution WHERE part = ?")
  distributions = statement.execute(id).to_a
  distributors.each do |distributor|
    distributions.each do |distribution|
      if distribution["distributor"] == distributor["id"] then
       distributor["sku"] = distribution["sku"]
       distributor["url"] = distributor["product_page"].gsub("%s", distribution["sku"])
      end
    end
    distributor.delete("id")
    distributor.delete("homepage")
    distributor.delete("product_page")
  end
  part["distributors"] = distributors
  # add inventory
  statement = @db.prepare("SELECT location.name AS location, inventory.quantity AS stock FROM inventory LEFT JOIN location ON location.id = inventory.location WHERE inventory.part = ? ORDER BY inventory.quantity DESC LIMIT 1")
  inventory = statement.execute(id).to_a[0]
  if inventory then
    part["location"] = inventory["location"]
    part["stock"] = inventory["stock"]
  end
  # add properties
  part["properties"] = {}
  statement = @db.prepare("SELECT property.name AS name, property_value.value AS value FROM property_value JOIN property ON property.id = property_value.property WHERE property_value.part = ?")
  statement.execute(id).each do |row|
    part["properties"][row["name"]] ||= []
    part["properties"][row["name"]] << row["value"]
  end
  if parent then
    parent["properties"].each do |k,v|
      part["properties"][k] ||= v
    end
  end
  # add attachments
  part["attachments"] = []
  dir = PUBLIC + "/" + ATTACHMENTS + "/" + part["name"]
  Dir.entries(dir).each do |file|
    path = dir + "/" + file
    next unless File.file? path
    part["attachments"] << ATTACHMENTS + "/" + part["name"] + "/" + file
  end
  if parent then
    part["attachments"] += parent["attachments"]
  end
  # clean up
  delete = ["parent"]
  delete.each do |k|
    part.delete k
  end
  return part
end

def get_part_by_name(name)
  statement = @db.prepare("SELECT id FROM part WHERE part.name = ?")
  id = statement.execute(name).to_a[0]
  if id then
    return get_part_by_id(id["id"])
  else
    return nil
  end
end

get '/part/:name' do
  part = get_part_by_name(params['name'])
  halt 404 unless part
  part.to_json
end

get '/search/:terms' do
  terms = params['terms'].split(" ")
  terms.keep_if {|term| term.length >= 3}
  halt 400 if terms.empty?
  # search in names, description, and category
  statements = []
  statements << @db.prepare("SELECT id FROM part WHERE name LIKE ?")
  statements << @db.prepare("SELECT id FROM part WHERE description LIKE ?")
  statements << @db.prepare("SELECT property_value.part AS id FROM property_value JOIN property ON property.id = property_value.property WHERE property.name = 'category' AND property_value.value LIKE ?")
  term_ids = []
  terms.each do |term|
    ids = Set.new
    # OR term location
    statements.each do |statement|
      statement.execute("%#{term}%").each do |row|
        ids << row["id"]
      end
    end
    term_ids << ids
  end
  # get all children
  statement = @db.prepare("SELECT id FROM part WHERE family IN (?)")
  term_ids.each do |term_id|
    statement.execute(term_id.to_a * ",").each do |row|
      term_id << row["id"]
    end
  end
  # AND terms
  ids = term_ids.shift
  term_ids.each do |term_id|
    ids &= term_id
  end
  parts = ids.collect {|id| get_part_by_id(id)}
  parts.compact!
  parts = parts[0, PARTS_LIMIT]
  parts.sort! {|x,y| x["name"] <=> y["name"]}
  parts.to_json
end

def delete_part(id)
  # first delete all children
  statement = @db.prepare("SELECT id FROM part WHERE family = ?")
  statement.execute(id).each do |row|
    puts "child: #{row['id']}"
    delete_part(row['id'])
    puts "deleted"
  end
  # delete all fields
  statements = []
  statements << @db.prepare("DELETE FROM property_value WHERE part = ?")
  statements << @db.prepare("DELETE FROM assembly WHERE assembled = ?")
  statements << @db.prepare("DELETE FROM assembly WHERE component = ?")
  statements << @db.prepare("DELETE FROM drawing WHERE part = ?")
  statements << @db.prepare("DELETE FROM attachment WHERE part = ?")
  statements << @db.prepare("DELETE FROM distribution WHERE part = ?")
  statements << @db.prepare("DELETE FROM property_value WHERE part = ?")
  statements << @db.prepare("DELETE FROM inventory WHERE part = ?")
  statements << @db.prepare("DELETE FROM part WHERE id = ?")
  statements.each do |statement|
    statement.execute(id)
  end
end

get '/delete/:id' do
  statement = @db.prepare("SELECT id FROM part WHERE id = ?")
  result = statement.execute(params['id'])
  halt 400 if result.to_a.empty?
  delete_part(params['id'])
  return 200
end