Add RejectedTransfer model, simplify auto matching (#1690)

* Allow transfers to match when inflow is after outflow

* Simplify transfer auto matching with RejectedTransfer model

* Validations

* Reset migrations

app/models/account.rb

@@ -159,4 +159,62 @@ class Account < ApplicationRecord
         entryable: Account::Valuation.new
     end
   end
+
+  def transfer_match_candidates
+    Account::Entry.select([
+      "inflow_candidates.entryable_id as inflow_transaction_id",
+      "outflow_candidates.entryable_id as outflow_transaction_id",
+      "ABS(inflow_candidates.date - outflow_candidates.date) as date_diff"
+    ]).from("account_entries inflow_candidates")
+      .joins("
+        JOIN account_entries outflow_candidates ON (
+          inflow_candidates.amount < 0 AND
+          outflow_candidates.amount > 0 AND
+          inflow_candidates.amount = -outflow_candidates.amount AND
+          inflow_candidates.currency = outflow_candidates.currency AND
+          inflow_candidates.account_id <> outflow_candidates.account_id AND
+          inflow_candidates.date BETWEEN outflow_candidates.date - 4 AND outflow_candidates.date + 4
+        )
+      ").joins("
+        LEFT JOIN transfers existing_transfers ON (
+          existing_transfers.inflow_transaction_id = inflow_candidates.entryable_id OR
+          existing_transfers.outflow_transaction_id = outflow_candidates.entryable_id
+        )
+      ")
+      .joins("LEFT JOIN rejected_transfers ON (
+        rejected_transfers.inflow_transaction_id = inflow_candidates.entryable_id AND
+        rejected_transfers.outflow_transaction_id = outflow_candidates.entryable_id
+      )")
+      .joins("JOIN accounts inflow_accounts ON inflow_accounts.id = inflow_candidates.account_id")
+      .joins("JOIN accounts outflow_accounts ON outflow_accounts.id = outflow_candidates.account_id")
+      .where("inflow_accounts.family_id = ? AND outflow_accounts.family_id = ?", self.family_id, self.family_id)
+      .where("inflow_candidates.entryable_type = 'Account::Transaction' AND outflow_candidates.entryable_type = 'Account::Transaction'")
+      .where(existing_transfers: { id: nil })
+      .order("date_diff ASC") # Closest matches first
+  end
+
+  def auto_match_transfers!
+    # Exclude already matched transfers
+    candidates_scope = transfer_match_candidates.where(rejected_transfers: { id: nil })
+
+    # Track which transactions we've already matched to avoid duplicates
+    used_transaction_ids = Set.new
+
+    candidates = []
+
+    Transfer.transaction do
+      candidates_scope.each do |match|
+        next if used_transaction_ids.include?(match.inflow_transaction_id) ||
+               used_transaction_ids.include?(match.outflow_transaction_id)
+
+        Transfer.create!(
+          inflow_transaction_id: match.inflow_transaction_id,
+          outflow_transaction_id: match.outflow_transaction_id,
+        )
+
+        used_transaction_ids << match.inflow_transaction_id
+        used_transaction_ids << match.outflow_transaction_id
+      end
+    end
+  end
 end