require 'rest_client'
require 'json'
require 'socialcast'

module Socialcast
  module Gitx
    module Github
      private
      # request github authorization token
      # User-Agent is required
      # store the token in ~/.socialcast/credentials.yml for future reuse
      # @see http://developer.github.com/v3/oauth/#scopes
      # @see http://developer.github.com/v3/#user-agent-required
      def authorization_token
        credentials = Socialcast::CommandLine.credentials
        return credentials[:scgitx_token] if credentials[:scgitx_token]

        username = current_user
        raise "Github user not configured.  Run: `git config --global github.user 'me@email.com'`" if username.empty?
        password = ask("Github password for #{username}: ") { |q| q.echo = false }

        payload = {:scopes => ['repo'], :note => 'Socialcast Git eXtension', :note_url => 'https://github.com/socialcast/socialcast-git-extensions'}.to_json
        response = RestClient::Request.new(:url => "https://api.github.com/authorizations", :method => "POST", :user => username, :password => password, :payload => payload, :headers => {:accept => :json, :content_type => :json, :user_agent => 'socialcast-git-extensions'}).execute
        data = JSON.parse response.body
        token = data['token']
        Socialcast::CommandLine.credentials = credentials.merge(:scgitx_token => token)
        token
      rescue RestClient::Exception => e
        process_error e
        throw e
      end

      # returns the url of the created pull request
      # @see http://developer.github.com/v3/pulls/
      def create_pull_request(token, branch, repo, body, assignee)
        payload = {:title => branch, :base => base_branch, :head => branch, :body => body}.to_json
        say "Creating pull request for "
        say "#{branch} ", :green
        say "against "
        say "#{base_branch} ", :green
        say "in "
        say repo, :green
        response = RestClient::Request.new(:url => "https://api.github.com/repos/#{repo}/pulls", :method => "POST", :payload => payload, :headers => {:accept => :json, :content_type => :json, 'Authorization' => "token #{token}"}).execute
        data = JSON.parse response.body

        assign_pull_request(token, branch, assignee, data) if assignee ## Unfortunately this needs to be done in a seperate request.

        url = data['html_url']
        url
      rescue RestClient::Exception => e
        process_error e
        throw e
      end

      # find the PRs matching the given commit hash
      # https://developer.github.com/v3/search/#search-issues
      def pull_requests_for_commit(token, repo, commit_hash)
        query = "#{commit_hash}+type:pr+repo:#{repo}"
        say "Searching github pull requests for #{commit_hash}"
        response = RestClient::Request.new(:url => "https://api.github.com/search/issues?q=#{query}", :method => "GET", :headers => {:accept => :json, :content_type => :json, 'Authorization' => "token #{token}"}).execute
        JSON.parse response.body
      rescue RestClient::Exception => e
        process_error e
        throw e
      end

      def assign_pull_request(token, branch, assignee, data)
        issue_payload = { :title => branch, :assignee => assignee }.to_json
        RestClient::Request.new(:url => data['issue_url'], :method => "PATCH", :payload => issue_payload, :headers => {:accept => :json, :content_type => :json, 'Authorization' => "token #{token}"}).execute
      rescue RestClient::Exception => e
        data = JSON.parse e.http_body
        say "Failed to assign pull request: #{data['message']}", :red
      end

      def process_error(e)
        data = JSON.parse e.http_body
        say "Failed to create pull request: #{data['message']}", :red
      end

      # @returns [String] socialcast username to assign the review to
      # @returns [nil] when no buddy system configured or user not found
      def socialcast_review_buddy(current_user)
        review_requestor = review_buddies[current_user]

        if review_requestor && review_buddies[review_requestor['buddy']]
          review_buddies[review_requestor['buddy']]['socialcast_username']
        end
      end

      def github_review_buddy(current_user)
        review_requestor = review_buddies[current_user]
        if review_requestor
          review_requestor['buddy']
        end
      end

    end
  end
end