require 'json'
require 'sinatra/base'

require_relative 'init'
require_relative 'authenticator'
require_relative 'models/user'
require_relative 'query_parser'

class Server < Sinatra::Application
  register Sinatra::ActiveRecordExtension
  set :port, 3000

  PAGE_LIMIT = 25
  HOSTNAME = ENV['SERVER_HOSTNAME'] || 'lycan.feeds.blue'

  helpers do
    def json_response(data)
      content_type :json
      JSON.generate(data)
    end

    def json_error(name, message, status: 400)
      content_type :json
      [status, JSON.generate({ error: name, message: message })]
    end

    def get_user_did
      if settings.development?
        did = if request.post?
          json = JSON.parse(request.body.read)
          request.body.rewind
          json['user']
        else
          params[:user]
        end

        if did
          return did
        else
          halt json_error('AuthMissing', 'Missing "user" parameter', status: 401)
        end
      else
        auth_header = env['HTTP_AUTHORIZATION']
        if auth_header.to_s.strip.empty?
          halt json_error('AuthMissing', 'Missing authentication header', status: 401)
        end

        begin
          method = request.path.split('/')[2]
          did = @authenticator.decode_user_from_jwt(auth_header, method)
        rescue StandardError => e
          halt json_error('InvalidToken', e.message, status: 401)
        end

        if did
          return did
        else
          halt json_error('InvalidToken', "Invalid JWT token", status: 401)
        end
      end
    end

    def load_user
      did = get_user_did

      if user = User.find_by(did: did)
        return user
      else
        halt json_error('AccountNotFound', 'Account not found', status: 401)
      end
    end
  end

  before do
    @authenticator = Authenticator.new(hostname: HOSTNAME)

    if settings.development?
      headers['Access-Control-Allow-Origin'] = '*'
    end
  end

  get '/' do
    "Awoo 🐺"
  end

  get '/xrpc/blue.feeds.lycan.searchPosts' do
    @user = load_user

    if params[:query].to_s.strip.empty?
      return json_error('MissingParameter', 'Missing "query" parameter')
    end

    if params[:collection].to_s.strip.empty?
      return json_error('MissingParameter', 'Missing "collection" parameter')
    end

    query = QueryParser.new(params[:query])

    collection = case params[:collection]
    when 'likes'   then @user.likes
    when 'pins'    then @user.pins
    when 'quotes'  then @user.quotes
    when 'reposts' then @user.reposts
    else return json_error('InvalidParameter', 'Invalid search collection')
    end

    if query.terms.empty?
      return json_response(terms: [], posts: [], cursor: nil)
    end

    items = collection
      .joins(:post)
      .includes(:post => :user)
      .matching_terms(query.terms)
      .excluding_terms(query.exclusions)
      .reverse_chronologically
      .after_cursor(params[:cursor])
      .limit(PAGE_LIMIT)

    post_uris = case params[:collection]
    when 'quotes'
      items.map { |x| "at://#{@user.did}/app.bsky.feed.post/#{x.rkey}" }
    else
      items.map(&:post).map(&:at_uri)
    end

    json_response(terms: query.terms, posts: post_uris, cursor: items.last&.cursor)
  end

  if settings.development?
    options '/xrpc/blue.feeds.lycan.startImport' do
      headers['Access-Control-Allow-Origin'] = '*'
      headers['Access-Control-Allow-Headers'] = 'content-type'
    end
  end

  post '/xrpc/blue.feeds.lycan.startImport' do
    did = get_user_did
    user = User.find_or_create_by(did: did)

    if !user.valid?
      json_error('InvalidRequest', 'Invalid DID')
    elsif user.import_job || user.active?
      json_response(message: "Import has already started")
    else
      user.create_import_job!

      status 202
      json_response(message: "Import has been scheduled")
    end
  end

  get '/xrpc/blue.feeds.lycan.getImportStatus' do
    did = get_user_did
    user = User.find_by(did: did)
    until_date = user&.imported_until

    case until_date
    when nil
      json_response(status: 'not_started')
    when :end
      json_response(status: 'finished')
    else
      progress = 1 - (until_date - user.registered_at) / (Time.now - user.registered_at)
      json_response(status: 'in_progress', position: until_date.iso8601, progress: progress)
    end
  end

  get '/.well-known/did.json' do
    json_response({
      '@context': ['https://www.w3.org/ns/did/v1'],
      id: "did:web:#{HOSTNAME}",
      service: [
        {
          id: '#lycan',
          type: 'LycanServer',
          serviceEndpoint: "https://#{HOSTNAME}"
        }
      ]
    })
  end
end