(defcontract property_transaction_main_contract ()
  (fields
      (buyer_0 :type pubkey :init nil)
      (buyer_1 :type pubkey :init nil)
      (seller_0 :type pubkey)
      (seller_1 :type pubkey :init nil)
      (real_estate_agent :type pubkey :init nil)
      (sellers_bank :type pubkey :init nil)
      (buyers_bank :type pubkey :init nil)
      (land_registry :type pubkey :init nil)
      (telia :type pubkey :init nil)

      (property_ID :type string :init nil)
      (price :type integer :init nil)
      (access_date :type integer :init nil)
      (access_place :type string :init nil)
      (contract_date :type integer :init nil)
      (deposit_amount :type integer :init nil)
      (escrow_account :type string :init nil)
      (seller_account :type string :init nil)
      (buyer_ID :type integer :init nil) ; Field for Personal number used by telia, format: YYYYMMDDXXXX
      (seller_ID :type integer :init nil) ; Field for Personal number used by telia, format: YYYYMMDDXXXX
      (buyer_1_ID :type integer :init nil) ; Field for Personal number used by telia, format: YYYYMMDDXXXX
      (seller_1_ID :type integer :init nil) ; Field for Personal number used by telia, format: YYYYMMDDXXXX
      (purchase_contract :type string :init nil)
      (bill_of_sale :type string :init nil)
      (hash_of_credit_document :type string :init nil)
      (hash_of_mortgage_loan_document :type string :init nil)
      (mortgage_deed_sub_contract_ID :type string :init nil)
      (state :type string :init nil))
  (actions

    (intiate ((agent-pk pubkey))
        "Invite Real Estate Agent"
     (guard
        (signatures seller_0)
        (eql state nil))

    (locally
        (invite agent-pk))
    (update real_estate_agent agent-pk
       state :set_property_information))

    (set-property-information
        ((property-id string) (price-local integer) (contract-date integer) (deposit-amount integer) (escrow-account string) (seller-account string))
            "Input price,contract date, deposit amount, escrow account, seller account"
      (guard
          (signatures real_estate_agent)
          (eql state :set_property_information)
          (eql property_ID nil)
          (eql price  nil)
          (eql contract_date nil)
          (eql deposit_amount nil)
          (eql escrow_account nil)
          (eql seller_account nil)
        )
      (update property_ID property-id
          price price-local 
          contract_date contract-date
          deposit_amount deposit-amount
          escrow_account escrow-account
          seller_account seller-account
          state :invite-parties)
    )

    (invite-parties ((buyer-0-pk pubkey) (buyer-1-pk pubkey) (seller-1-pk pubkey) (buyers-bank-pk pubkey) (sellers-bank-pk pubkey) (sellers-bank-pk pubkey) (land-registry-pk pubkey) (telia-pk pubkey))
        "Invite buyer(s), buyers bank, sellers bank and land registry to the contract"
      (guard 
          (signatures real_estate_agent)
          (eql state :invite-parties)
      )
       (locally
        (invite buyer-0-pk buyer-1-pk buyers-bank-pk sellers-bank-pk land-registry-pk telia-pk seller-1-pk ))
      (update buyer_0 buyer-0-pk
       buyer_1 buyer-0-pk
       buyers_bank buyers-bank-pk
       sellers_bank sellers-bank-pk
       land_registry land-registry-pk
       telia telia-pk
       seller_1 seller-1-pk 
       state :verify-seller-0)
    )
    
    (verify-seller ((seller-id integer))
        "Verify Seller"
      (guard
        (signatures telia)
        (eql state :verify-seller-0)
        (eql seller_1 "")
        )
        
      (locally
        (verify seller-id)
      )
      (update seller_ID seller-id
       state :verify-buyer-0)
    )
    
    (verify-sellers-0 ((seller-id integer))
        "Verify Seller"
      (guard
        (signatures telia)
        (eql state :verify-seller-0)
        (not (eql seller_1 ""))
        )
        
      (locally
        (verify seller-id)
      )
      (update seller_ID seller-id
       state :verify-seller-1)
     )
    
    (verify-sellers-1 ((seller-1-id integer))
        "Verify Seller"
      (guard
        (signatures telia)
        (eql state :verify-seller-1)
        (not (eql seller_1 ""))
        )
        
      (locally
        (verify seller-1-id)
      )
      (update seller_1_ID seller-1-id
       state :verify-buyer-0)
    )


    (verify-buyer ((buyer-id integer))
      (guard
          (signatures telia)
          (eql state :verify-buyer-0)
          (eql buyer_1 "")
          
      )
      (update buyer_ID buyer-id
       state :verify-buyer-1)
    )
    
    (verify-buyers-0 ((buyer-0-id integer))
      (guard
          (signatures telia)
          (eql state :verify-buyer-0)
          (not (eql buyer_1 ""))
      )
      (update buyer_ID buyer-0-id
       state :verify-buyer-1)
    )
    
    (verify-buyers-1 ((buyer-1-id integer))
      (guard
          (signatures telia)
          (eql state :verify-buyer-1)
          (not (eql buyer_1 ""))
      )
      (update buyer_1_ID buyer-1-id
       state :upload-purchase-contract)
    )
    
    (upload-purchase-contract ((purchase-contract string))
       "Upload purchase contract"
      (guard
          (signatures real_estate_agent)
          (eql state :upload-purchase-contract)
      )
      (update purchase_contract purchase-contract
       state :buyer-sign-purchase-contract)
    )
    
    (buyer-sign-purchase-contract ()
        "Buyer signs purchase contract"
      (guard
          (signatures buyer_0)
          (eql state :buyer-sign-purchase-contract)
      )
      (update state :seller-sign-purchase-contract)
    )
    
    (seller-sign-purchase-contract ()
        "Seller signs purchase contract"
      (guard
          (signatures seller_0)
          (eql state :seller-sign-purchase-contract)
      )
      (update state :buyers-bank-offers-credit-loan)
     )
     
    (buyers-bank-offers-credit-loan ((hash-of-credit-document string))
       "Buyers bank offers credit loan"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-offers-credit-loan)
      )
      (update hash_of_credit_document hash-of-credit-document
       state :buyer-accepts-credit-loan)
    )
    
    (buyer-accepts-credit-loan ()
        "Buyer accepts credit loan"
      (guard
          (signatures buyer_0)
          (eql state :buyer-accepts-credit-loan)
      )
      (update state :buyer-authorizes-deposit-payment)
     )
     
    (buyer-authorizes-deposit-payment ()
        "Buyer authorizes deposit payment"
      (guard
          (signatures buyer_0)
          (eql state :buyer-authorizes-deposit-payment)
      )
      (update state :buyers-bank-confirms-payment)
     )
     
    (buyers-bank-confirms-payment ()
        "Buyers bank confirms sent payment"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-confirms-payment)
      )
      (update state :real-estate-agent-confirms-payment)
     )
     
    (real-estate-agent-confirms-payment ()
        "Real estate agent confirms received payment"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-confirms-payment)
      )
      (update state :land-registry-issues-preliminary-title-deed)
     )
     
    (real-estate-agent-cancels-contract ()
        "Real estate agent received no payment and cancels contract"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-confirms-payment)
      )
      (update state :real-estate-agent-received-no-payment-and-cancels-contract)
     )
     
    (land-registry-issues-preliminary-title-deed ()
        "Land registry issues preliminary title deed"
      (guard
          (signatures land_registry)
          (eql state :land-registry-issues-preliminary-title-deed)
      )
      (update state :real-estate-agent-payout-deposit)
     )
     
    (real-estate-agent-payout-deposit ()
       "Real estate agent pays out deposit"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-payout-deposit)
      )
      (update state :seller-confirms-received-payment)
     )
     
    (seller-confirms-received-payment ()
       "Seller has received the payment"
      (guard
          (signatures seller_0)
          (eql state :seller-confirms-received-payment)
      )
      (update state :buyers-bank-offers-mortgage-loan)
     )
     
    (buyers-bank-offers-mortgage-loan ((hash-of-mortgage-loan-document string))
        "Buyers bank offers mortgage loan"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-offers-mortgage-loan)
      )
      (update state :buyer-signs-mortgage-loan-document
              hash_of_mortgage_loan_document hash-of-mortgage-loan-document)
     )
     
    (buyer-signs-mortgage-loan-document ()
        "Buyer signs mortgage loan document"
      (guard
          (signatures buyer_0)
          (eql state :buyer-signs-mortgage-loan-document)
      )
      (update state :real-estate-agent-confirms-settlement-documents)
     )
     
    (real-estate-agent-confirms-settlement ()
        "Real estate agents confirms settlement"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-confirms-settlement-documents)
          )

      (update state :real-estate-agent-confirms-access-date)
      )
      
    (real-estate-agent-confirms-access-date ((access-date integer) (access-place string))
          "Real estate agent confirms access date and place"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-confirms-access-date)
      )
      (update state :real-estate-agent-confirms-final-settlement-upload-bill-of-sale
              access_date access-date
              access_place access-place)
     )
     
    (real-estate-agent-confirms-final-settlement-upload-bill-of-sale ((bill-of-sale string))
        "Real estate agents confirms final settlement and uploads bills of sale"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-confirms-final-settlement-upload-bill-of-sale)
          )
      (update state :buyer-signs-bill-of-sale
              bill_of_sale bill-of-sale)
     )
     
    (buyer-signs-bill-of-sale ()
        "Buyer signs bill of sale"
      (guard
          (signatures buyer_0)
          (eql state :buyer-signs-bill-of-sale)
          )
      (update state :seller-signs-bill-of-sale)
     )
     
    (seller-signs-bill-of-sale ()
        "Seller signs bill of sale"
      (guard
          (signatures seller_0)
          (eql state :seller-signs-bill-of-sale)
          )
      (update state :buyer-authorizes-full-payment)
     )
     
    (buyer-authorizes-full-payment ()
        "Buyer authorizes full payment"
      (guard
          (signatures buyer_0)
          (eql state :buyer-authorizes-full-payment)
          )
      (update state :buyers-bank-sends-full-payment)
     )
     
    (buyers-bank-sends-full-payment ()
        "Buyers bank sends full payment"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-sends-full-payment)
          )
      (update state :seller-confirms-full-payment)
     )
     
    (seller-confirms-full-payment ()
        "Seller confirms full payment has been received"
      (guard
          (signatures seller_0)
          (eql state :seller-confirms-full-payment)
          )
         
      (update state :real-estate-agent-confirms-keys-transfered)
     )
     
    (real-estate-agent-confirms-keys-transfered ()
        "Real estate agent confirms keys transfered"
      (guard
          (signatures real_estate_agent)
          (eql state :real-estate-agent-confirms-keys-transfered)
          )
      (update state :buyers-bank-creates-mortgage-deed-contract)
     )
     
    (buyers-bank-creates-mortgage-deed-contract ((mortgage-deed-sub-contract-id string))
        "Buyers bank creates mortgage deed contract"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-creates-mortgage-deed-contract)
          )
      (update state :buyers-bank-confirms-pending-state-of-mortgage-deed-contract
            mortgage_deed_sub_contract_ID mortgage-deed-sub-contract-id)
     )
    
    (buyers-bank-confirms-pending-state-of-mortgage-deed-contract ()
        "buyers-bank-confirms-pending-state-of-mortgage-deed-contract"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-confirms-pending-state-of-mortgage-deed-contract)
          )
      (update state :land-registry-approves-title-deed)
     )
     
    (land-registry-approves-title-deed ()
        "Land registry approves title deed"
      (guard
          (signatures land_registry)
          (eql state :land-registry-approves-title-deed)
          )
      (update state :buyers-bank-confirms-completed-mortgage-deed-contract)
      )
     
    (land-registry-denies-title-deed ()
        "Land registry denies title deed"
      (guard
          (signatures land_registry)
          (eql state :land-registry-approves-title-deed)
          )
      (update state :Land-registry-denied-title-deed)
     )
        
    (buyers-bank-confirms-completed-mortgage-deed-contract ()
        "Buyers bank confirms completed mortgage deed contract"
      (guard
          (signatures buyers_bank)
          (eql state :buyers-bank-confirms-completed-mortgage-deed-contract)
          )
      (update state :Title-deed-and-mortgage-deed-finalized)
)))