require 'bundler'
Bundler.require(:default)

require 'pg'
require 'net/smtp'
require 'httparty'
require 'json'
require 'dotenv'
require 'erb'
require 'date'
require 'tempfile'


# Load environment variables from.env file
Dotenv.load

DB_URL = ENV.fetch('DATABASE_URL', nil)

DB_USER = ENV.fetch('DB_USER', nil)
DB_PASSWORD = ENV.fetch('DB_PASSWORD', nil)
DB_HOST = ENV.fetch('DB_HOST', nil)
DB_PORT = ENV.fetch('DB_PORT', nil)
DB_NAME = ENV.fetch('DB_NAME', nil)

SMTP_SERVER = ENV.fetch('SMTP_SERVER')
SMTP_PORT = ENV.fetch('SMTP_PORT').to_i
SMTP_USERNAME = ENV.fetch('SMTP_USERNAME')
SMTP_PASSWORD = ENV.fetch('SMTP_PASSWORD')

HUGGINGFACE_API_URL = 'https://router.huggingface.co/hf-inference/models/mistralai/Mixtral-8x7B-Instruct-v0.1/v1/chat/completions'
HUGGINGFACE_API_TOKEN = ENV.fetch('HUGGINGFACE_API_TOKEN')

MAIL_BODY_PROMPT = <<-END
Analyze my recent weeks listening history and suggest a movie/comic character or celebrity that embodies the mood and spirit of my diverse music choices. Please keep the response concise and engaging, suitable for a marketing email.
Here are the titles that were listened to this week

END

def fetch_titles_from_db()
  raise "Please set either DATABASE_URL or DB_USER..." if DB_USER.nil? && DB_URL.nil?
  one_week_ago = Date.today - 7
  connection = !DB_URL.nil? ? PG.connect(DB_URL) : PG.connect(:dbname => DB_NAME, :host => DB_HOST, :user => DB_USER, :password => DB_PASSWORD)

  result = connection.exec_params("SELECT item_title FROM activities WHERE created_at >= $1 ORDER BY created_at DESC", [one_week_ago])
  connection.close
  results = []
  results = result.map { |row| row['item_title']} if result.any?
  return results
end

def generate_email_body(titles)
  return "You didnt listen to any music this week :`(" unless titles

  puts "Calling HF"
  body = mistral_request_body(titles)
  response = HTTParty.post(HUGGINGFACE_API_URL, headers: { 'Content-Type':'application/json','Authorization' => "Bearer #{HUGGINGFACE_API_TOKEN}" }, body: body)
  JSON.parse(response.body)['choices'][0]['message']['content']
end

def mistral_request_body(titles)
  formated_titles = titles.join(", ")
  {
    model: "mistralai/Mixtral-8x7B-Instruct-v0.1",
    messages: [
      {
        role: "user",
        content: "#{MAIL_BODY_PROMPT} #{formated_titles}"
      }
    ],
    max_tokens: 1000,
    stream: false
  }.to_json
end

def send_email(to, subject, body)
  current_time = Time.now.utc
  formatted_time = current_time.strftime("%a, %-d %b %Y %H:%M:%S %z")

  msg = <<-END
Subject: #{subject}
From: Weekly 1activity <#{SMTP_USERNAME}>
To: #{to}
Date: #{formatted_time}
MIME-Version: 1.0
Content-Type: text/html; charset=utf-8

#{body}
END

  smtp = Net::SMTP.new(SMTP_SERVER, SMTP_PORT)
  smtp.enable_starttls_auto
  smtp.start do |server|
    a = server.authenticate(SMTP_USERNAME, SMTP_PASSWORD)
    puts a.string
    begin
    a= server.send_message(msg, SMTP_USERNAME, to)
    puts a.string
    rescue Net::SMTPFatalError => e
      puts e.message
    end
  end
end

def main
  titles = fetch_titles_from_db
  total_plays = titles.length
  body = generate_email_body(titles)
  puts "HF done"
  template = ERB.new File.read('./template/mail.html.erb')
  html_body = template.result_with_hash({body: body, total_plays: total_plays})
  title = "Weekly listening report #{Date.today}"
  send_email("listening@sgui.de", title, html_body)
  puts "Email sent with subject: #{title}"

end

main