module Vmpooler
  class API
  class V1 < Sinatra::Base
    api_version = '1'
    api_prefix  = "/api/v#{api_version}"

    helpers do
      include Vmpooler::API::Helpers
    end

    def backend
      Vmpooler::API.settings.redis
    end

    def metrics
      Vmpooler::API.settings.metrics
    end

    def config
      Vmpooler::API.settings.config[:config]
    end

    def pools
      Vmpooler::API.settings.config[:pools]
    end

    def pool_exists?(template)
      Vmpooler::API.settings.config[:pool_names].include?(template)
    end

    def need_auth!
      validate_auth(backend)
    end

    def need_token!
      validate_token(backend)
    end

    def fetch_single_vm(template)
      vm = backend.spop('vmpooler__ready__' + template)
      return [vm, template] if vm

      aliases = Vmpooler::API.settings.config[:alias]
      if aliases && aliased_template = aliases[template]
        vm = backend.spop('vmpooler__ready__' + aliased_template)
        return [vm, aliased_template] if vm
      end

      [nil, nil]
    end

    def return_vm_to_ready_state(template, vm)
      backend.sadd('vmpooler__ready__' + template, vm)
    end

    def account_for_starting_vm(template, vm)
      backend.sadd('vmpooler__running__' + template, vm)
      backend.sadd('vmpooler__migrating__' + template, vm)
      backend.hset('vmpooler__active__' + template, vm, Time.now)
      backend.hset('vmpooler__vm__' + vm, 'checkout', Time.now)

      if Vmpooler::API.settings.config[:auth] and has_token?
        validate_token(backend)

        backend.hset('vmpooler__vm__' + vm, 'token:token', request.env['HTTP_X_AUTH_TOKEN'])
        backend.hset('vmpooler__vm__' + vm, 'token:user',
          backend.hget('vmpooler__token__' + request.env['HTTP_X_AUTH_TOKEN'], 'user')
        )

        if config['vm_lifetime_auth'].to_i > 0
          backend.hset('vmpooler__vm__' + vm, 'lifetime', config['vm_lifetime_auth'].to_i)
        end
      end
    end

    def update_result_hosts(result, template, vm)
      result[template] ||= {}
      if result[template]['hostname']
        result[template]['hostname'] = Array(result[template]['hostname'])
        result[template]['hostname'].push(vm)
      else
        result[template]['hostname'] = vm
      end
    end

    def atomically_allocate_vms(payload)
      result = { 'ok' => false }
      failed = false
      vms = []

      payload.each do |requested, count|
        count.to_i.times do |_i|
          vm, name = fetch_single_vm(requested)
          if !vm
            failed = true
            metrics.increment('checkout.empty.' + requested)
            break
          else
            vms << [ name, vm ]
            metrics.increment('checkout.success.' + name)
          end
        end
      end

      if failed
        vms.each do |(name, vm)|
          return_vm_to_ready_state(name, vm)
        end
        status 503
      else
        vms.each do |(name, vm)|
          account_for_starting_vm(name, vm)
          update_result_hosts(result, name, vm)
        end

        result['ok'] = true
        result['domain'] = config['domain'] if config['domain']
      end

      result
    end

    # Provide run-time statistics
    #
    # Example:
    #
    # {
    #   "boot": {
    #     "duration": {
    #       "average": 163.6,
    #       "min": 65.49,
    #       "max": 830.07,
    #       "total": 247744.71000000002
    #     },
    #     "count": {
    #       "total": 1514
    #     }
    #   },
    #   "capacity": {
    #     "current": 968,
    #     "total": 975,
    #     "percent": 99.3
    #   },
    #   "clone": {
    #     "duration": {
    #       "average": 17.0,
    #       "min": 4.66,
    #       "max": 637.96,
    #       "total": 25634.15
    #     },
    #     "count": {
    #       "total": 1507
    #     }
    #   },
    #   "queue": {
    #     "pending": 12,
    #     "cloning": 0,
    #     "booting": 12,
    #     "ready": 968,
    #     "running": 367,
    #     "completed": 0,
    #     "total": 1347
    #   },
    #   "pools": {
    #     "ready": 100,
    #     "running": 120,
    #     "pending": 5,
    #     "max": 250,
    #   }
    #   "status": {
    #     "ok": true,
    #     "message": "Battle station fully armed and operational.",
    #     "empty": [ # NOTE: would not have 'ok: true' w/ "empty" pools
    #       "redhat-7-x86_64",
    #       "ubuntu-1404-i386"
    #     ],
    #     "uptime": 179585.9
    # }
    #
    # If the query parameter 'view' is provided, it will be used to select which top level
    # element to compute and return. Select them by specifying them in a comma separated list.
    # For example /status?view=capacity,boot
    # would return only the "capacity" and "boot" statistics. "status" is always returned

    get "#{api_prefix}/status/?" do
      content_type :json

      if params[:view]
        views = params[:view].split(",")
      end

      result = {
        status: {
          ok: true,
          message: 'Battle station fully armed and operational.'
        }
      }

      result[:capacity] = get_capacity_metrics(pools, backend) unless views and not views.include?("capacity")
      result[:queue] = get_queue_metrics(pools, backend) unless views and not views.include?("queue")
      result[:clone] = get_task_metrics(backend, 'clone', Date.today.to_s) unless views and not views.include?("clone")
      result[:boot] = get_task_metrics(backend, 'boot', Date.today.to_s) unless views and not views.include?("boot")

      # Check for empty pools
      result[:pools] = {} unless views and not views.include?("pools")
      pools.each do |pool|
        # REMIND: move this out of the API and into the back-end
        ready    = backend.scard('vmpooler__ready__' + pool['name']).to_i
        running  = backend.scard('vmpooler__running__' + pool['name']).to_i
        pending  = backend.scard('vmpooler__pending__' + pool['name']).to_i
        max      = pool['size']
        lastBoot = backend.hget('vmpooler__lastboot',pool['name']).to_s
        aka      = pool['alias']

        result[:pools][pool['name']] = {
          ready:    ready,
          running:  running,
          pending:  pending,
          max:      max,
          lastBoot: lastBoot
        }

        if aka
          result[:pools][pool['name']][:alias] = aka
        end

        # for backwards compatibility, include separate "empty" stats in "status" block
        if ready == 0
          result[:status][:empty] ||= []
          result[:status][:empty].push(pool['name'])

          result[:status][:ok] = false
          result[:status][:message] = "Found #{result[:status][:empty].length} empty pools."
        end
      end unless views and not views.include?("pools")

      result[:status][:uptime] = (Time.now - Vmpooler::API.settings.config[:uptime]).round(1) if Vmpooler::API.settings.config[:uptime]

      JSON.pretty_generate(Hash[result.sort_by { |k, _v| k }])
    end

    get "#{api_prefix}/summary/?" do
      content_type :json

      result = {
        daily: []
      }

      from_param = params[:from] || Date.today.to_s
      to_param   = params[:to]   || Date.today.to_s

      # Validate date formats
      [from_param, to_param].each do |param|
        if !validate_date_str(param.to_s)
          halt 400, "Invalid date format '#{param}', must match YYYY-MM-DD."
        end
      end

      from_date, to_date = Date.parse(from_param), Date.parse(to_param)

      if to_date < from_date
        halt 400, 'Date range is invalid, \'to\' cannot come before \'from\'.'
      elsif from_date > Date.today
        halt 400, 'Date range is invalid, \'from\' must be in the past.'
      end

      boot = get_task_summary(backend, 'boot', from_date, to_date, :bypool => true)
      clone = get_task_summary(backend, 'clone', from_date, to_date, :bypool => true)
      tag = get_tag_summary(backend, from_date, to_date)

      result[:boot] = boot[:boot]
      result[:clone] = clone[:clone]
      result[:tag] = tag[:tag]

      daily = {}

      boot[:daily].each do |day|
        daily[day[:date]] ||= {}
        daily[day[:date]][:boot] = day[:boot]
      end

      clone[:daily].each do |day|
        daily[day[:date]] ||= {}
        daily[day[:date]][:clone] = day[:clone]
      end

      tag[:daily].each do |day|
        daily[day[:date]] ||= {}
        daily[day[:date]][:tag] = day[:tag]
      end

      daily.each_key do |day|
        result[:daily].push({
          date: day,
          boot: daily[day][:boot],
          clone: daily[day][:clone],
          tag: daily[day][:tag]
        })
      end

      JSON.pretty_generate(result)
    end

    get "#{api_prefix}/summary/:route/?:key?/?" do
      content_type :json

      result = {}

      from_param = params[:from] || Date.today.to_s
      to_param   = params[:to]   || Date.today.to_s

      # Validate date formats
      [from_param, to_param].each do |param|
        if !validate_date_str(param.to_s)
          halt 400, "Invalid date format '#{param}', must match YYYY-MM-DD."
        end
      end

      from_date, to_date = Date.parse(from_param), Date.parse(to_param)

      if to_date < from_date
        halt 400, 'Date range is invalid, \'to\' cannot come before \'from\'.'
      elsif from_date > Date.today
        halt 400, 'Date range is invalid, \'from\' must be in the past.'
      end

      case params[:route]
        when 'boot'
          result = get_task_summary(backend, 'boot', from_date, to_date, :bypool => true, :only => params[:key])
        when 'clone'
          result = get_task_summary(backend, 'clone', from_date, to_date, :bypool => true, :only => params[:key])
        when 'tag'
          result = get_tag_summary(backend, from_date, to_date, :only => params[:key])
        else
          halt 404, JSON.pretty_generate({ 'ok' => false })
      end

      JSON.pretty_generate(result)
    end

    get "#{api_prefix}/token/?" do
      content_type :json

      status 404
      result = { 'ok' => false }

      if Vmpooler::API.settings.config[:auth]
        status 401

        need_auth!

        backend.keys('vmpooler__token__*').each do |key|
          data = backend.hgetall(key)

          if data['user'] == Rack::Auth::Basic::Request.new(request.env).username
            token = key.split('__').last

            result[token] ||= {}

            result[token]['created'] = data['created']
            result[token]['last'] = data['last'] || 'never'

            result['ok'] = true
          end
        end

        if result['ok']
          status 200
        else
          status 404
        end
      end

      JSON.pretty_generate(result)
    end

    get "#{api_prefix}/token/:token/?" do
      content_type :json

      status 404
      result = { 'ok' => false }

      if Vmpooler::API.settings.config[:auth]
        token = backend.hgetall('vmpooler__token__' + params[:token])

        if not token.nil? and not token.empty?
          status 200

          pools.each do |pool|
            backend.smembers('vmpooler__running__' + pool['name']).each do |vm|
              if backend.hget('vmpooler__vm__' + vm, 'token:token') == params[:token]
                token['vms'] ||= {}
                token['vms']['running'] ||= []
                token['vms']['running'].push(vm)
              end
            end
          end

          result = { 'ok' => true, params[:token] => token }
        end
      end

      JSON.pretty_generate(result)
    end

    delete "#{api_prefix}/token/:token/?" do
      content_type :json

      status 404
      result = { 'ok' => false }

      if Vmpooler::API.settings.config[:auth]
        status 401

        need_auth!

        if backend.del('vmpooler__token__' + params[:token]).to_i > 0
          status 200
          result['ok'] = true
        end
      end

      JSON.pretty_generate(result)
    end

    post "#{api_prefix}/token" do
      content_type :json

      status 404
      result = { 'ok' => false }

      if Vmpooler::API.settings.config[:auth]
        status 401

        need_auth!

        o = [('a'..'z'), ('0'..'9')].map(&:to_a).flatten
        result['token'] = o[rand(25)] + (0...31).map { o[rand(o.length)] }.join

        backend.hset('vmpooler__token__' + result['token'], 'user', @auth.username)
        backend.hset('vmpooler__token__' + result['token'], 'created', Time.now)

        status 200
        result['ok'] = true
      end

      JSON.pretty_generate(result)
    end

    get "#{api_prefix}/vm/?" do
      content_type :json

      result = []

      pools.each do |pool|
        result.push(pool['name'])
      end

      JSON.pretty_generate(result)
    end

    post "#{api_prefix}/vm/?" do
      content_type :json
      result = { 'ok' => false }

      payload = JSON.parse(request.body.read)

      if payload
        invalid = invalid_templates(payload)
        if invalid.empty?
          result = atomically_allocate_vms(payload)
        else
          invalid.each do |bad_template|
            metrics.increment('checkout.invalid.' + bad_template)
          end
          status 404
        end
      else
        metrics.increment('checkout.invalid.unknown')
        status 404
      end

      JSON.pretty_generate(result)
    end

    def extract_templates_from_query_params(params)
      payload = {}

      params.split('+').each do |template|
        payload[template] ||= 0
        payload[template] += 1
      end

      payload
    end

    def invalid_templates(payload)
      invalid = []
      payload.keys.each do |template|
        invalid << template unless pool_exists?(template)
      end
      invalid
    end

    post "#{api_prefix}/vm/:template/?" do
      content_type :json
      result = { 'ok' => false }

      payload = extract_templates_from_query_params(params[:template])

      if payload
        invalid = invalid_templates(payload)
        if invalid.empty?
          result = atomically_allocate_vms(payload)
        else
          invalid.each do |bad_template|
            metrics.increment('checkout.invalid.' + bad_template)
          end
          status 404
        end
      else
        metrics.increment('checkout.invalid.unknown')
        status 404
      end

      JSON.pretty_generate(result)
    end

    get "#{api_prefix}/vm/:hostname/?" do
      content_type :json

      result = {}

      status 404
      result['ok'] = false

      params[:hostname] = hostname_shorten(params[:hostname], config['domain'])

      rdata = backend.hgetall('vmpooler__vm__' + params[:hostname])
      unless rdata.empty?
        status 200
        result['ok'] = true

        result[params[:hostname]] = {}

        result[params[:hostname]]['template'] = rdata['template']
        result[params[:hostname]]['lifetime'] = (rdata['lifetime'] || config['vm_lifetime']).to_i

        if rdata['destroy']
          result[params[:hostname]]['running'] = ((Time.parse(rdata['destroy']) - Time.parse(rdata['checkout'])) / 60 / 60).round(2)
          result[params[:hostname]]['state'] = 'destroyed'
        elsif rdata['checkout']
          result[params[:hostname]]['running'] = ((Time.now - Time.parse(rdata['checkout'])) / 60 / 60).round(2)
          result[params[:hostname]]['state'] = 'running'
        elsif rdata['check']
          result[params[:hostname]]['state'] = 'ready'
        else
          result[params[:hostname]]['state'] = 'pending'
        end

        rdata.keys.each do |key|
          if key.match('^tag\:(.+?)$')
            result[params[:hostname]]['tags'] ||= {}
            result[params[:hostname]]['tags'][$1] = rdata[key]
          end

          if key.match('^snapshot\:(.+?)$')
            result[params[:hostname]]['snapshots'] ||= []
            result[params[:hostname]]['snapshots'].push($1)
          end
        end

        if rdata['disk']
          result[params[:hostname]]['disk'] = rdata['disk'].split(':')
        end

        # Look up IP address of the hostname
        begin
          ipAddress = TCPSocket.gethostbyname(params[:hostname])[3]
        rescue
          ipAddress = ""
        end

        result[params[:hostname]]['ip'] = ipAddress

        if config['domain']
          result[params[:hostname]]['domain'] = config['domain']
        end
      end

      JSON.pretty_generate(result)
    end

    delete "#{api_prefix}/vm/:hostname/?" do
      content_type :json

      result = {}

      status 404
      result['ok'] = false

      params[:hostname] = hostname_shorten(params[:hostname], config['domain'])

      rdata = backend.hgetall('vmpooler__vm__' + params[:hostname])
      unless rdata.empty?
        need_token! if rdata['token:token']

        if backend.srem('vmpooler__running__' + rdata['template'], params[:hostname])
          backend.sadd('vmpooler__completed__' + rdata['template'], params[:hostname])

          status 200
          result['ok'] = true
        end
      end

      JSON.pretty_generate(result)
    end

    put "#{api_prefix}/vm/:hostname/?" do
      content_type :json

      status 404
      result = { 'ok' => false }

      failure = false

      params[:hostname] = hostname_shorten(params[:hostname], config['domain'])

      if backend.exists('vmpooler__vm__' + params[:hostname])
        begin
          jdata = JSON.parse(request.body.read)
        rescue
          halt 400, JSON.pretty_generate(result)
        end

        # Validate data payload
        jdata.each do |param, arg|
          case param
            when 'lifetime'
              need_token! if Vmpooler::API.settings.config[:auth]

              unless arg.to_i > 0
                failure = true
              end
            when 'tags'
              unless arg.is_a?(Hash)
                failure = true
              end

              if config['allowed_tags']
                failure = true if not (arg.keys - config['allowed_tags']).empty?
              end
            else
              failure = true
          end
        end

        if failure
          status 400
        else
          jdata.each do |param, arg|
            case param
              when 'lifetime'
                need_token! if Vmpooler::API.settings.config[:auth]

                arg = arg.to_i

                backend.hset('vmpooler__vm__' + params[:hostname], param, arg)
              when 'tags'
                filter_tags(arg)
                export_tags(backend, params[:hostname], arg)
            end
          end

          status 200
          result['ok'] = true
        end
      end

      JSON.pretty_generate(result)
    end

    post "#{api_prefix}/vm/:hostname/disk/:size/?" do
      content_type :json

      need_token! if Vmpooler::API.settings.config[:auth]

      status 404
      result = { 'ok' => false }

      params[:hostname] = hostname_shorten(params[:hostname], config['domain'])

      if ((params[:size].to_i > 0 )and (backend.exists('vmpooler__vm__' + params[:hostname])))
        result[params[:hostname]] = {}
        result[params[:hostname]]['disk'] = "+#{params[:size]}gb"

        backend.sadd('vmpooler__tasks__disk', params[:hostname] + ':' + params[:size])

        status 202
        result['ok'] = true
      end

      JSON.pretty_generate(result)
    end

    post "#{api_prefix}/vm/:hostname/snapshot/?" do
      content_type :json

      need_token! if Vmpooler::API.settings.config[:auth]

      status 404
      result = { 'ok' => false }

      params[:hostname] = hostname_shorten(params[:hostname], config['domain'])

      if backend.exists('vmpooler__vm__' + params[:hostname])
        result[params[:hostname]] = {}

        o = [('a'..'z'), ('0'..'9')].map(&:to_a).flatten
        result[params[:hostname]]['snapshot'] = o[rand(25)] + (0...31).map { o[rand(o.length)] }.join

        backend.sadd('vmpooler__tasks__snapshot', params[:hostname] + ':' + result[params[:hostname]]['snapshot'])

        status 202
        result['ok'] = true
      end

      JSON.pretty_generate(result)
    end

    post "#{api_prefix}/vm/:hostname/snapshot/:snapshot/?" do
      content_type :json

      need_token! if Vmpooler::API.settings.config[:auth]

      status 404
      result = { 'ok' => false }

      params[:hostname] = hostname_shorten(params[:hostname], config['domain'])

      unless backend.hget('vmpooler__vm__' + params[:hostname], 'snapshot:' + params[:snapshot]).to_i.zero?
        backend.sadd('vmpooler__tasks__snapshot-revert', params[:hostname] + ':' + params[:snapshot])

        status 202
        result['ok'] = true
      end

      JSON.pretty_generate(result)
    end
  end
  end
end