Changed filename, added some tech specs

Author: jmjatlanta

bsip-0040.md bsip-1041.mdbsip-0040.md renamed to bsip-1041.md

@@ -1,4 +1,4 @@
-    BSIP: 0040
+    BSIP: 1041
     Title: Escrow Feature
     Authors: taconator
     Status: Draft
@@ -235,8 +235,76 @@ This concept improves on Concept B yet has the following weaknesses:
 - If an escrow agent is invited, only a single report is required of the escrow agent by the blockchain for the agent receive the escrow fee.
 
 #### Technical Approach
+
 TBD
 
+# Technical Implementation
+
+Note: Any code below should be considered pseudo-code.
+
+The in-memory object for an escrow contract contains:
+```
+struct escrow_object {
+   uint32_t          escrow_id; // an ID suitable for sharing
+   account_id_type   from; // where the asset will be taken from
+   account_id_type   to; // where the asset will go
+   account_id_type   agent; // who is the escrow agent
+   asset             amount; // the asset and amount
+   fc::time_point_sec          ratification_deadline; // The contract should be agreed upon before this point in time.
+   fc::time_point_sec          escrow_expiration; // The movement of the asset should take place at this point in time.
+   asset             pending_fee; // the fee charged for the transaction
+   bool              to_approved = false; // if the contract was approved by the account ``to``
+   bool              agent_approved = false; // if the contract was approved by the escrow agent
+   bool              disputed = false; // if the contract is being disputed
+};
+```
+
+Create a new escrow contract
+```
+void_result escrow_transfer(const escrow_transfer_operation& o)
+{
+   Verify: ratification_deadline > head_block_time
+   Verify: escrow_expiration > head_block_time
+   Verify: ``from`` has enough BTS to cover fees
+}
+```
+
+Approve or reject an escrow contract
+```
+void_result escrow_approve(const escrow_approve_operation& o)
+{
+   Verify: Not attempting to change ``to``
+   Verify: Not attempting to change ``agent``
+   Verify: ratification_deadline > head_block_time
+}
+```
+
+Open a dispute on an escrow contract
+```
+void_result escrow_dispute(const escrow_dispute_operation& o)
+{
+   Verify: contract has been approved by ``to`` and ``agent``
+   Verify: contract is not already in dispute
+   Verify: Not attempting to change ``to``
+   Verify: Not attempting to change ``agent``
+}
+```
+
+Release an escrow contract
+```
+void_result escrow_release(const escrow_release_operation& o)
+{
+   Verify: Not attempting to change the asset nor the amount
+   Verify: Not attempting to change ``to``
+   Verify: Not attempting to change ``agent``
+   Verify: Funds must only be released to ``to`` or ``from``
+   Verify: Contract must have been approved
+   If ( contract is in dispute ) Then only ``agent`` can release funds
+   If ( contract is not in dispute ) Then only ``to`` or ``from`` can release funds
+   If ( contract is not in dispute ) Then the funds can be released to the opposite party (from->to) or (to->from)
+}
+```
+
 
 # Discussion
 ## <a name="responsible-escrow"></a>Responsible Escrow Behavior